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Items 1 - 57 of 57 |
One page. |
Proper consent for clinical anesthesia research may be difficult to obtain on the day of surgery.
Sosis MB.
Publication Types:
PMID: 15385406 [PubMed - in process]
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Intrathecal meperidine and shivering in obstetric anesthesia.
Yu SC, Ngan Kee WD, Kwan AS.
Publication Types:
PMID: 15385404 [PubMed - in process]
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Laryngotracheal topicalization with lidocaine before intubation decreases the incidence of coughing on emergence from general anesthesia.
Minogue SC, Ralph J, Lampa MJ.
Department of Anesthesia, Vancouver General Hospital and the University of British Columbia, Vancouver, BC, Canada. minogues@indigo.ie
Coughing on emergence can result in a number of undesirable side effects, including hypertension, tachycardia, tachyarrhythmias, increased intracranial pressure, and increased intraocular pressure. The efficacy of endotracheal spraying with lidocaine at the time of intubation in preventing coughing on emergence is unknown. In a double-blind placebo-controlled study, we randomized 50 ASA physical status I and II patients presenting for elective gynecological surgery <2 h duration to receive either endotracheal lidocaine 160 mg or placebo before intubation. Both groups were comparable in terms of demographics and intraoperative conditions. The incidence of coughing before tracheal extubation was less frequent in the lidocaine group (26%) than in the placebo group (66%, P < 0.01), as was the incidence after tracheal extubation (4% versus 30%, P = 0.022). This study supports the use of endotracheal lidocaine before intubation in patients undergoing general anesthesia for surgery <2 h duration where coughing on emergence is undesirable.
PMID: 15385385 [PubMed - in process]
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A comparison of single versus multiple injections on the extent of anesthesia with coracoid infraclavicular brachial plexus block.
Rodriguez J, Barcena M, Taboada-Muniz M, Lagunilla J, Alvarez J.
Department of Anesthesiology, Complexo Hospitalario Universitario de Santiago, Santiago de Compostela, Spain. jaimerodriguezgarcia@nacom.es
Single-injection coracoid infraclavicular brachial plexus block produces inconsistent anesthesia of the upper limb. In this study, we sought to determine the number of injections needed to provide a reasonably complete anesthesia of the upper limb with this approach. Seventy-five patients were randomly assigned to receive a coracoid block guided by nerve stimulator with 42 mL of 1.5% mepivacaine with a single-injection (Group 1), dual-injection (Group 2), or triple-injection (Group 3) technique. No search for a specific motor response was performed in any group. Sensory and motor block was assessed 5 and 20 min after the end of the injection of local anesthetic. Significantly less complete anesthesia to pinprick in the distributions of the axillary, musculocutaneous, radial, ulnar, and medial cutaneous forearm nerves was found in Group 1 at 20 min. Significantly less complete paralysis for arm, wrist, and hand movements was found in Group 1 at 20 min. No significant difference was found between Groups 2 and 3. We conclude that dual and triple injection of local anesthetic guided by nerve stimulator increases the efficacy of coracoid block when compared with a single-injection technique.
PMID: 15385381 [PubMed - in process]
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Faculty and finances of United States anesthesiology training programs: 2002-2003.
Tremper KK, Shanks A, Sliwinski M, Barker SJ, Hines R, Tait AR.
University of Michigan, Department of Anesthesiology, Ann Arbor, MI 48109, USA. ktremper@umich.edu
Between February, 2000 and August, 2002 three surveys have been submitted to the program directors of the anesthesiology training programs in the United States (U.S.) to assess the departments' needs for faculty and financial support from their institutions. In this article we present the results of a fourth follow-up survey. This survey also asked questions regarding the need for additional support to meet the new 80-h workweek resident requirement and asked the average academic time offered to faculty. The average department has 40 faculty members with 3.7 open faculty positions in the 78% of departments with open positions. Only 25% of the departments planned to add personnel to comply with the 80-h resident workweek. Fifty-one percent of the departments had a positive financial margin of 15,908 dollars/full-time equivalent (FTE) faculty anesthesiologist (faculty FTE), whereas 34% had a negative margin of 42,603 dollars/faculty FTE. The overall institutional support was 85,607 dollars/faculty FTE, which is a 43% increase over the previous year. The average academic time provided to faculty was 13.8%, a decline from 20% in 2000. Twenty-five percent of departments have closed an anesthetizing location as a result of a lack of faculty in 2003. Open faculty positions in U.S. training programs have remained fairly constant at 8% to 10% from 2000 to 2003. Institutional support for training departments has more than doubled since 2000, reaching approximately 85,000 dollars/faculty in 2003.
PMID: 15385373 [PubMed - in process]
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Postoperative pain after abdominal hysterectomy: a double-blind comparison between placebo and local anesthetic infused intraperitoneally.
Gupta A, Perniola A, Axelsson K, Thorn SE, Crafoord K, Rawal N.
Department of Clinical Medicine, Division of Anesthesiology, University Hospital, Orebro, Sweden. anil.gupta@orebroll.se
Abdominal hysterectomy is associated with moderate to severe postoperative pain. We randomly divided 40 patients (ASA status I-II) undergoing elective abdominal hysterectomy into 2 groups: group P received an infusion of normal saline 5 mL/h via a catheter placed intraperitoneally at the end of surgery, and group L received 0.25% levobupivacaine 12.5 mg/h (5 mL/h). Ketobemidone was administered IV via a patient-controlled analgesia pump as a rescue analgesic in all patients. The catheter was removed after 24 h. Incisional pain, deep pain, and pain on coughing were assessed 1, 2, 3, 4, 8, 16, and 24 h after surgery by using a visual analog scale. Ketobemidone consumption during 0-72 h was recorded. Time to sit, walk, eat, and drink; home discharge; and plasma concentrations of levobupivacaine were also determined. Pain at the incision site, deep pain, and pain on coughing were all significantly less in group L compared with group P at 1-2 h after surgery. After 4 h, the mean visual analog scale pain scores at rest and during coughing remained <3 cm during most time periods. Total ketobemidone consumption during 4-24 h was significantly less in group L compared with group P (mean, 19 versus 31 mg, respectively). A less frequent incidence of postoperative nausea, but not vomiting, was also found during 4-24 h in group L compared with group P (P < 0.025). Total and free plasma concentrations of levobupivacaine were small. We conclude that levobupivacaine used as an infusion intraperitoneally after elective abdominal hysterectomy has significant opioid-sparing effects.
PMID: 15385371 [PubMed - in process]
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The effect of a model-based predictive display on the control of end-tidal sevoflurane concentrations during low-flow anesthesia.
Kennedy RR, French RA, Gilles S.
Department of Anaesthesia, Christchurch Hospital and Christchurch School of Medicine and Health Sciences, Christchurch, New Zealand. ross.kennedy@chmeds.ac.nz
We have shown that a multicompartment model accurately predicts end-tidal (ET) sevoflurane (sevo) and isoflurane concentrations. The model has been adapted to use real-time fresh gas flow and vaporizer settings to display a 10-min prediction of ET sevo concentrations. In this study, we evaluated the effect of the predictive display on the speed and accuracy of changes in ET sevo by the anesthesiologist. Fifteen patients were studied in whom sevo-based anesthesia was expected to last more than 2 h. Four step changes of target ET concentration (+0.5, +1.0, -1.0, and -0.5 vol%) were made either unaided or with the prediction display. Fresh gas flow was 1 L/min. Response time, maximum overshoot, and stability in the 5 min after the target was achieved were compared by using two-tailed paired Student's t-tests. Changes were made on average 1.5-2.3 times faster with the predictive display than without it. These differences were statistically significant (P < 0.05) for the +0.5, +1.0, and -0.5 vol% step changes but not for the -1.0 vol% change. There were no differences in the degree of overshoot or stability. These differences are comparable to those seen with an automatic feedback control system. This system may simplify the administration of volatile anesthesia and the use of low-flow anesthesia.
PMID: 15385368 [PubMed - in process]
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A comparison of bispectral index and rapidly extracted auditory evoked potentials index responses to noxious stimulation during sevoflurane anesthesia.
Ekman A, Brudin L, Sandin R.
Department of Anesthesiology and Intensive Care, Regional Hospital, Kalmar, Sweden. andrease@ltkalmar.se
In 21 patients given sevoflurane anesthesia, we simultaneously compared the abilities of Bispectral Index (BIS) and rapidly extracted auditory evoked potentials index (AAI) to display the effect of an increasing cerebral concentration of sevoflurane, with and without noxious stimulation. In addition to BIS/AAI, hemodynamic variables were monitored. After titrating sevoflurane to BIS = 50-55 during 15 min, the end-tidal concentration of sevoflurane (1.46% +/- 0.20%) was doubled followed by a noxious stimulus, laryngoscopy, applied at random time points within the following 15 min. After the end-tidal concentration of sevoflurane was doubled, a substantial reduction in BIS was observed, whereas only a slight reduction in AAI was seen (P < 0.0001). BIS/AAI responses to laryngoscopy were not attenuated with increasing wash-in of sevoflurane. After noxious stimulation, AAI exceeded the highest recommended value, 25, in 3 cases, whereas BIS did not exceed the recommended threshold, 60, in any of the patients. Response times for BIS and AAI were 44.5 +/- 26 and 47 +/- 31 s, respectively. These results suggest that, at a hypnotic level associated with surgical sevoflurane anesthesia, BIS better displays drug-related alterations in the level of hypnosis than AAI or hemodynamic variables but there is no difference between BIS and AAI in the time to response to a noxious stimulus.
PMID: 15385365 [PubMed - in process]
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Propofol does not inhibit lidocaine metabolism during epidural anesthesia.
Nakayama S, Miyabe M, Kakiuchi Y, Inomata S, Osaka Y, Fukuda T, Kohda Y, Toyooka H.
Department of Anesthesiology, Institute of Clinical Medicine, University of Tsukuba, Tsukuba 305-8575, Japan.
Propofol is sometimes used in combination with epidural anesthesia with lidocaine. In this study, we investigated the effect of propofol on the plasma concentration of lidocaine and its principal metabolites during epidural anesthesia with lidocaine. Thirty-two patients were randomly allocated to receive either propofol or sevoflurane anesthesia (n = 16 each). In the propofol group, anesthesia was maintained with a target concentration of propofol of 4 microg/mL. In the sevoflurane group, anesthesia was maintained with 1.5% sevoflurane. Lidocaine was administered epidurally in an initial dose of 5 mg/kg, followed by a continuous infusion at 2.5 mg x kg(-1) x h(-1). Free components of plasma lidocaine and its metabolites-monoethylglycinexylidide (MEGX) and glycinexylidide (GX)-were measured 30, 60, 120, and 180 min after the initiation of continuous epidural injection by using high-performance liquid chromatography. Free lidocaine, MEGX, and GX were separated from 2 mL of plasma by ultrafiltration filter units. Hemodynamic data were similar between groups. The plasma concentrations of free lidocaine were not significantly different between groups. The ratios of free MEGX to free lidocaine and free GX to free MEGX were not different between groups. In conclusion, propofol does not alter the metabolism of epidural lidocaine compared with sevoflurane.
PMID: 15385363 [PubMed - in process]
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Sevoflurane anesthesia attenuates adenosine diphosphate-induced P-selectin expression and platelet-leukocyte conjugate formation.
Huang GS, Li CY, Hsu PC, Tsai CS, Lin TC, Wong CS.
Department of Anesthesiology, Tri-Service General Hospital, National Defense Medical Center, National Defense University, Taipei, Taiwan, Republic of China.
The expression of P-selectin on the surface of platelets and platelet-leukocyte conjugate formation are considered to be an indicator of platelet activation and are important in thrombotic and inflammatory disease. Previous studies have reported the inhibitory effects of sevoflurane on platelet aggregation. We investigated whether sevoflurane alters the expression of P-selectin on platelets and the formation of platelet-leukocyte conjugates. Twenty-five patients undergoing minor extremity surgery received sevoflurane-based general anesthesia, with mask induction and laryngeal mask airway anesthesia maintenance. Whole blood was obtained before and 40 min after sevoflurane anesthesia. Unstimulated and adenosine diphosphate-stimulated samples of whole blood and platelet rich plasma were stained with fluorochrome-conjugated antibodies. The expression of P-selectin on platelets and the formation of platelet-leukocyte conjugates were measured using flow cytometry. Sevoflurane inhibited platelet P-selectin expression. It also reduced the formation of platelet-leukocyte conjugates, both in unstimulated and adenosine diphosphate-stimulated blood samples at 3%-4% end-expiratory sevoflurane concentrations used to maintain anesthesia.
PMID: 15385361 [PubMed - in process]
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Tactile assessment for the reversibility of rocuronium-induced neuromuscular blockade during propofol or sevoflurane anesthesia.
Kim KS, Cheong MA, Lee HJ, Lee JM.
Department of Anesthesiology, Hanyang University Hospital, Seoul, Sungdong gu, Korea. kimks@hanyang.ac.kr
We sought to determine whether tactile train-of-four (TOF) count can predict the efficacy of neostigmine administration for rocuronium-induced blockade during propofol or sevoflurane anesthesia, and to follow subsequent recovery until the TOF ratio reached 0.9. One-hundred-sixty patients, divided into eight equal groups, were randomly allocated to maintenance of anesthesia with propofol or sevoflurane. The tactile response of the adductor pollicis to TOF stimulation was evaluated on one arm, and the mechanomyographic response was recorded on the other. Neuromuscular block was induced with rocuronium 0.6 mg/kg and maintained with rocuronium to 15% of the control first twitch in TOF. Neostigmine 0.07 mg/kg was administered on reappearance of the first (Group I), second (Group II), third (Group III), or fourth (Group IV) tactile TOF response in each anesthesia. At this time, sevoflurane or the propofol dosage was reduced in each group (n = 20 in each group). The times from administration of neostigmine until the TOF ratio recovered to 0.7, 0.8, and 0.9 were recorded. The times [median (range)] to TOF ratio = 0.9 were 8.6 (4.7-18.9), 7.5 (3.4-9.8), 5.4 (1.6-8.6), and 4.7 (1.3-7.2) min in Groups I-IV during propofol anesthesia, respectively, and 28.6 (8.8-75.8), 22.6 (8.3-57.4), 15.6 (7.3-43.9), and 9.7 (5.1-26.4) min in corresponding groups during sevoflurane anesthesia, respectively (P < 0.0001). We recommend more than 2 TOF responses with propofol anesthesia and 4 TOF responses with sevoflurane anesthesia for adequate reversal within 10 and 15 min, respectively. The more tactile TOF responses present at the time of reversal achieved greater adequate recovery; however, tactile TOF responses are not a completely reliable predictor within a reasonable time period.
PMID: 15385354 [PubMed - in process]
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Blood glucose control during selective arterial stimulation and venous sampling for localization of focal hyperinsulinism lesions in anesthetized children.
Cucchiaro G, Markowitz SD, Kaye R, Adzick NS, Litman RS, Stanley CA, Watcha MF.
Children's Hospital of Philadelphia, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA. cucchiaro@email.chop.edu
Surgical management of congenital hyperinsulinism is improved by accurate localization of small, focal dysregulated pancreatic lesions using the arterial stimulation and venous sampling (ASVS) test, which can demonstrate increased hepatic venous insulin concentrations after selective arterial injections of calcium. However, anesthesia-related increases in blood glucose can induce insulin secretion, making it difficult to interpret ASVS test data. In this retrospective study, we examined the effect of anesthetic interventions on blood glucose concentrations in 68 children undergoing ASVS testing. We considered only the glucose concentrations observed before calcium stimulation in the final analysis. The choice of drugs for induction (sevoflurane, propofol, or thiopentone), maintenance inhaled anesthetics (sevoflurane, desflurane, or isoflurane), and the use of caudal epidural bupivacaine were not associated with significant differences in the mean blood glucose concentration before ASVS. However, patients receiving remifentanil infusions had smaller mean glucose concentrations (80 +/- 18 versus 100 +/- 44 mg x dl(-1), P = 0.01). These concentrations were also significantly smaller if tracheal intubation was delayed for at least 10 min after induction while patients received inhaled anesthetics via a face mask along with remifentanil infusions (79 +/- 14 for delayed intubation versus 95 +/- 39 mg x dl(-1) for early intubation, respectively, P = 0.03). The percentage increase in glucose concentrations from preintubation values was significantly smaller in these subjects (3.7% +/- 21.9% for delayed intubation versus 31.7% +/- 60.4% for early intubation, P = 0.02). We conclude that the anesthetic management protocol for these patients should include the use of remifentanil infusions and the administration of inhaled anesthetics and remifentanil infusions for a minimum of 10 min to establish a deep plane of anesthesia before tracheal intubation.
PMID: 15385347 [PubMed - in process]
Comment on:
Interpretation of PO2 via FIO2.
Stemp L.
Publication Types:
PMID: 15333448 [PubMed - indexed for MEDLINE]
Comment on:
Postoperative analgesia following total knee arthroplasty.
Lang SA, Rooney ME.
Publication Types:
PMID: 15333447 [PubMed - indexed for MEDLINE]
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A novel approach to infraclavicular brachial plexus block: the ultrasound experience.
Brull R, McCartney CJ, Chan VW.
Publication Types:
PMID: 15333441 [PubMed - indexed for MEDLINE]
Comment on:
AEP "Click Detection" failure: may be, may be not!
Chan MT, Ho SS, Gin T.
Publication Types:
PMID: 15333439 [PubMed - indexed for MEDLINE]
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Levobupivacaine 0.2% or 0.125% for continuous sciatic nerve block: a prospective, randomized, double-blind comparison with 0.2% ropivacaine.
Casati A, Vinciguerra F, Cappelleri G, Aldegheri G, Grispigni C, Putzu M, Rivoltini P.
Department of Anesthesiology, Vita-Salute University, IRCCS H San Raffaele, Via Olgettina 60, 20132 Milan, Italy. casati.andrea@hsr.it
In 60 patients receiving elective hallux valgus repair, we compared the efficacy of continuous popliteal sciatic nerve block produced with 0.2% ropivacaine (n = 20), 0.2% levobupivacaine (n = 20), or 0.125% levobupivacaine (n = 20) infused with a patient-controlled system starting 3 h after a 30-mL bolus of the 0.5% concentration of the study drug and for 48 h (baseline infusion rate, 6 mL/h; incremental dose, 2 mL; lockout time, 15 min; maximum incremental doses per hour, 3). No differences were reported in the intraoperative efficacy of the nerve block. The degree of pain was similar in the three groups throughout the study period, both at rest and during motion. Total consumption of local anesthetic solution during the first 24 h was 148 mL (range, 144-228 mL) with 0.2% ropivacaine, 150 mL (range, 144-200 mL) with 0.2% levobupivacaine, and 148 mL (range, 144-164 mL) with 0.125% levobupivacaine (P = 0.59). The volume of local anesthetic consumed during the second postoperative day was 150 mL (range, 144-164 mL) with 0.2% ropivacaine, 154 mL (range, 144-176 mL) with 0.2% levobupivacaine, and 151 mL (range, 144-216 mL) with 0.125% levobupivacaine (P = 0.14). A smaller proportion of patients receiving 0.2% levobupivacaine showed complete recovery of foot motor function as compared with 0.2% ropivacaine and 0.125% levobupivacaine, both at 24 h (35% vs 85% and 95%; P = 0.0005) and at 48 h (60% vs 100% and 100%; P = 0.001). We conclude that sciatic infusion with both 0.125% and 0.2% levobupivacaine provides adequate postoperative analgesia after hallux valgus repair, clinically similar to that provided by 0.2% ropivacaine; however, the 0.125% concentration is preferred if early mobilization of the operated foot is required.
Publication Types:
- Clinical Trial
- Randomized Controlled Trial
PMID: 15333432 [PubMed - indexed for MEDLINE]
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A comparison of intrathecal plain solutions containing ropivacaine 20 or 15 mg versus bupivacaine 10 mg.
Kallio H, Snall EV, Kero MP, Rosenberg PH.
Department of Anesthesia, Forssa District Hospital, PO Box 42, FIN-30101 Forssa, Finland. helena.kallio@fstky.fi
Ropivacaine, which blocks sensory nerve fibers more readily than motor fibers, is considered to be less potent than bupivacaine. Our hypothesis was that, when used in spinal anesthesia for day surgery, ropivacaine 15 and 20 mg would provide faster motor recovery than bupivacaine 10 mg. This prospective, randomized, double-blinded study included 90 ambulatory lower-extremity surgery patients who received 2 mL of ropivacaine 1%, ropivacaine 0.75%, or bupivacaine 0.5%. Motor block was tested with the Bromage scale, and sensory block was tested with pinprick. Ropivacaine 15 mg provided faster recovery of motor block (150 min) than did bupivacaine 10 mg (210 min; P = 0.005), but the median duration of sensory block at T10 (140 min) did not differ significantly from that with bupivacaine 10 mg (140 min). The median duration of sensory block at T10 was significantly longer with ropivacaine 20 mg (170 min) than with bupivacaine 10 mg (140 min; P = 0.005), but the median recovery from motor block (210 min) did not differ significantly. We conclude that the duration of sensory block of ropivacaine was two thirds and the duration of motor block was half when compared with bupivacaine, with calculations based on the duration-per-milligram of the local anesthetic.
Publication Types:
- Clinical Trial
- Randomized Controlled Trial
PMID: 15333400 [PubMed - indexed for MEDLINE]
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Threshold current for an insulated epidural needle in pediatric patients.
Tsui BC, Wagner A, Cave D, Seal R.
Department of Anesthesiology and Pain Medicine, University of Alberta Hospitals, 3B2.32 Walter Mackenzie Health Science Centre, 8440-112 St., Edmonton, Alberta, Canada T6G 2B7. btsui@ualberta.ca
We designed this study to determine the threshold current for nerve stimulation of an insulated needle in the epidural space. The intended dermatome was identified using the bony landmarks of the spine. An 18-gauge insulated Tuohy needle was inserted perpendicularly to the skin and advanced until "loss of resistance" was felt. A nerve stimulator was then connected to the insulated needle. Twenty patients were studied using an insulated Tuohy needle and one patient was studied using a noninsulated Tuohy needle. Muscle twitch was elicited with a current of 11.1 +/- 3.1 mA (mean +/- sd) in all patients in which an insulated needle was used. Muscle twitches were within 2 myotomes of the intended level (based on bony landmarks). Muscle twitch was not elicited with a noninsulated needle. After catheter threading, positive stimulation tests were elicited via epidural catheters in all patients (4.9 +/- 2.3 mA). Postoperative radiograph confirmed all catheter placements within 2 myotomes of the muscle twitches. Electrical stimulation may be a useful adjuvant tool to loss of resistance for confirming proper thoracic epidural needle placement. The threshold current criteria for an insulated needle (6-17 mA) would be higher than the original Tsui test criteria described for an epidural catheter (1-10 mA) in the epidural space.
PMID: 15333396 [PubMed - indexed for MEDLINE]
One-millimeter thickness makes a great difference.
Voronov G, Alexander B, Krishnankutty S, Khorasani A.
Publication Types:
PMID: 15329622 [PubMed - indexed for MEDLINE]
Comment on:
Effects of long-term nerve blockade in the spared nerve injury model.
Kissin I, Lee SS.
Publication Types:
PMID: 15329619 [PubMed - indexed for MEDLINE]
Comment on:
Why should primary care physicians even wait for surgery in high risk patients?
Kempen PM.
Publication Types:
PMID: 15329612 [PubMed - indexed for MEDLINE]
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The spinal antinociceptive effect of nocistatin in neuropathic rats is blocked by D-serine.
Muth-Selbach U, Dybek E, Kollosche K, Stegmann JU, Holthusen H, Lipfert P, Ulrich Zeilhofer H.
Klinik fur Anaesthesiologie, Universitatsklinikum Dusseldorf, Dusseldorf, Germany. muthslb@uni-duesseldorf.de
BACKGROUND: The neuropeptide nocistatin (NST) has been implicated in the modulation of nociceptive responses in the spinal cord. Depending on the dose, both pronociceptive and antinociceptive effects have repeatedly been reported. The pronociceptive effect is most likely attributable to inhibition of synaptic glycine and gamma-aminobutyric acid release and a subsequent reduction in the activation of inhibitory glycine and gamma-aminobutyric acid receptors, but the mechanisms of its antinociceptive action have hitherto remained elusive. It has recently been demonstrated that synaptically released glycine contributes to N-methyl-D-aspartate receptor activation. The authors therefore investigated whether a reduction in glycine release might also account for the antinociceptive action of NST in neuropathic rats. METHODS: The authors analyzed the effects of spinally applied NST in the chronic constriction injury model of neuropathic pain. NST was injected intrathecally from nanomolar to picomolar doses and its effects on thermal paw withdrawal latencies were monitored. Furthermore, we tested whether D-serine (100 microg per rat), a full agonist at the glycine binding site of the N-methyl-D-aspartate receptor, would interfere with the effects of NST. RESULTS: At high doses (10 nmol/rat), intrathecally injected NST was pronociceptive, whereas lower doses (1 pmol/rat) elicited antinociception. The antinociceptive, but not the pronociceptive, action was occluded by intrathecal pretreatment with D-serine. L-serine, which does not bind to N-methyl-D-aspartate receptors, affected neither the pronociceptive nor the antinociceptive effect. CONCLUSIONS: These results demonstrate that NST produces a biphasic dose-dependent effect on neuropathic pain. The spinal antinociception by NST is most likely attributable to inhibition of glycine-dependent N-methyl-D-aspartate receptor activation.
PMID: 15329601 [PubMed - indexed for MEDLINE]
Comment in:
Influence of hemorrhagic shock followed by crystalloid resuscitation on propofol: a pharmacokinetic and pharmacodynamic analysis.
Johnson KB, Egan TD, Kern SE, McJames SW, Cluff ML, Pace NL.
Department of Anesthesiology, University of Utah School of Medicine, Salt Lake City, Utah 84132-2304, USA. ken.johnson@hsc.utah.edu
BACKGROUND: Previous work has demonstrated that ongoing hemorrhagic shock dramatically alters the distribution, clearance, and potency of propofol. Whether volume resuscitation after hemorrhagic shock restores drug behavior to baseline pharmacokinetics and pharmacodynamics remains unclear. This is particularly relevant because patients suffering from hemorrhagic shock are typically resuscitated before surgery. To investigate this, the authors studied the influence of an isobaric bleed followed by crystalloid resuscitation on the pharmacokinetics and pharmacodynamics of propofol in a swine model. The hypothesis was that hemorrhagic shock followed by resuscitation would not significantly alter the pharmacokinetics but would influence the pharmacodynamics of propofol. METHODS: After approval from the Animal Care Committee, 16 swine were randomly assigned to control and shock-resuscitation groups. Swine randomized to the shock-resuscitation group were bled to a mean arterial blood pressure of 40 mm Hg over a 20-min period and held there by further blood removal until 42 ml/kg of blood had been removed. Subsequently, animals were resuscitated with lactated Ringer's solution to maintain a mean arterial blood pressure of 70 mm Hg for 60 min. After resuscitation, propofol (750 microg x kg(-1) x min(-1)) was infused for 10 min. The control group underwent a sham hemorrhage and resuscitation and received propofol at the same dose and approximate time as the shock-resuscitation group. Arterial samples (20 from each animal) were collected at frequent intervals until 180 min after the infusion began and were analyzed to determine drug concentrations. Pharmacokinetic parameters for each group were estimated using a three-compartment model. The electroencephalogram Bispectral Index Scale was used as a measure of drug effect. Pharmacodynamics were characterized using a sigmoid inhibitory maximal effect model. RESULTS: The raw data demonstrated minimal differences in the mean plasma propofol concentrations between groups. The compartment analysis revealed some subtle differences between groups in the central and slow equilibrating volumes, but the differences were not significant. Hemorrhagic shock followed by resuscitation shifted the concentration effect relationship to the left, demonstrating a 1.5-fold decrease in the effect-site concentration required to achieve 50% of the maximal effect in the Bispectral Index Scale. CONCLUSIONS: Hemorrhagic shock followed by resuscitation with lactated Ringer's solution did not alter the pharmacokinetics but did increase the potency of propofol. These results demonstrate that alterations in propofol pharmacokinetics observed in moderate to severe blood loss can be reversed with resuscitation. These results suggest that a modest reduction in propofol is prudent to achieve a desired drug effect after resuscitation from severe hemorrhagic shock.
PMID: 15329589 [PubMed - indexed for MEDLINE]
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Accuracy of pharmacokinetic models for predicting plasma fentanyl concentrations in lean and obese surgical patients: derivation of dosing weight ("pharmacokinetic mass").
Shibutani K, Inchiosa MA Jr, Sawada K, Bairamian M.
New York Medical College, Valhalla, New York 10595, USA.
BACKGROUND: The currently available pharmacokinetic models for fentanyl were derived from normal weight patients and were not scaled to body weight. Their application to obese patients may cause overprediction of the plasma concentration of fentanyl. This study examined the influence of body weight on the predictive accuracy of two models (Anesthesiology 1990; 73:1091-102 and J Pharmacol Exp Ther 1987; 240:159-66). Further, we attempted to derive suggested dosing mass weights for fentanyl that improved predicted accuracy. METHOD: Seventy patients undergoing major elective surgery with total body weight (TBW) <85 kg and body mass index <30 (Group L) and 39 patients with TBW >/=85 kg and body mass index >30 (Group O) were studied. In Group L and Group O, the mean TBW was 69 kg, and 125 kg, respectively and the mean body mass index in Group L and Group O was 24 and 44, respectively. Fentanyl infusion was used during surgery and postoperatively for analgesia. Plasma fentanyl concentrations were measured and predicted concentrations were obtained by computer simulation; 465 pairs of measured and predicted values were obtained. RESULTS: The influence of TBW on the performance errors of the original two models was examined with nonlinear regression analysis. Shafer error versus TBW showed a highly significant negative relationship (R squared = 0.689, P < 0.001); i.e., the Shafer model systematically overestimated fentanyl concentration as weight increased. The Scott and Stanski model showed greater variation (R squared = 0.303). We used the exponential equation for Shafer performance error versus TBW to derive suggested dosing weights ("pharmacokinetic mass") for obese patients. The pharmacokinetic mass versus TBW curve was essentially linear below 100 kg (with slope of 0.65) and approached a plateau above 140 kg. For patients weighing 140 to 200 kg, dosing weights of 100-108 kg are projected. Total body clearance (ml/min) showed a strong linear correlation with pharmacokinetic mass (r = 0.793; P < 0.001), whereas the relationship with TBW was nonlinear. CONCLUSION: Actual body weight overestimates fentanyl dose requirements in obese patients. Dosing weight (pharmacokinetic mass) derived from the nonlinear relationship between prediction error and TBW proved to have a linear relationship with clearance.
Publication Types:
PMID: 15329584 [PubMed - indexed for MEDLINE]
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A new closed-loop control system for isoflurane using bispectral index outperforms manual control.
Locher S, Stadler KS, Boehlen T, Bouillon T, Leibundgut D, Schumacher PM, Wymann R, Zbinden AM.
Department of Anesthesiology, Research Section, University of Berne, Switzerland.
BACKGROUND: Automatic control of depth of hypnosis using the Bispectral Index (BIS) can help to reduce phases of inadequate control. Automated BIS control with propofol or isoflurane administration via an infusion system has recently been described, a comparable study with isoflurane administration via a vaporizer had not been conducted yet. Our hypothesis was that our new model based closed-loop control system can safely be applied clinically and maintains the BIS within a defined target range better than manual control. METHODS: Twenty-three patients, American Society of Anesthesiologists risk class I-III, scheduled for decompressive spinal surgery were randomized into groups with either closed-loop or manual control of BIS using isoflurane. An alfentanil target-controlled infusion was adjusted according to standard clinical practice. The BIS target was set to 50 during the operation. The necessity of human intervention in the control system and events of inadequate sedation (BIS <40 or BIS >60) were counted. The number of phases of inadequate control, defined as BIS >/=65 for more than 3 min, were recorded. The performance of the controller was assessed by several indicators (mean absolute deviation and median absolute performance error) and measured during the skin incision phase, the subsequent low flow phase, and the wound closure phase. Recovery profiles of both groups were compared. RESULTS: No human intervention was necessary in the closed-loop control group. The occurrence of inadequate BIS was quantified with the mean and median values of the area under the curve and amounted to 0.360 and 0.088 for the manual control group and 0.049 and 0.017 for the closed-loop control group, respectively. In the manual control group nine phases of inadequate control were recorded, compared with one in the closed-loop control group, 10.3% to 0.5% of all observed anesthesia time. During all phases the averages of the performance parameters (mean absolute deviation and median absolute performance error) were more than 30% smaller in closed-loop control than in manual control (P < 0.05 between groups). CONCLUSIONS: Closed-loop control with BIS using isoflurane can safely be applied clinically and performs significantly better than manual control, even in phases with abrupt changes of stimulation that cannot be foreseen by the control system.
Publication Types:
- Clinical Trial
- Randomized Controlled Trial
PMID: 15329583 [PubMed - indexed for MEDLINE]
Comment on:
Dexmedetomidine: another arrow for the clinician's quiver.
Ebert T, Maze M.
Publication Types:
PMID: 15329580 [PubMed - indexed for MEDLINE]
Anaesthesia for laparoscopic urological surgery.
Conacher ID, Soomro NA, Rix D.
Freeman Hospitals Trust, Newcastle upon Tyne, UK.
Laparoscopy for urological surgery is a relatively recent surgical innovation. Some centres have substantial experience of single operations, but very few have experience with a comprehensive range. Our programme began with nephrectomy and pyeloplasty, and has expanded to provide for a living related kidney donor programme and for other procedures usually conducted open. Recently, it has included prostate and bladder cancer surgery. The learning curve and implications for anaesthesia are described on the basis of the experience of one anaesthetist with 124 patients. Perioperative care issues, in common with other abdominal laparoscopic procedures, relate to operating positions, the consequences of carbon dioxide under pressure in the abdomen and postoperative analgesia. There is only a small requirement for regional anaesthesia supplementation and invasive analgesia. The corporate laparoscopic cholecystectomy experience was used as the foundation for anaesthesia and to delineate specific organ system issues and any interventions. Significant differences were found in the spectrum of the urological patient population and comorbidity, notably renal function or dysfunction, and complications.
PMID: 15377587 [PubMed - as supplied by publisher]
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Role of {beta}-blockade in anaesthesia and postoperative pain management after hysterectomy.
Chia YY, Chan MH, Ko NH, Liu K.
Department of Anaesthesiology, Kaohsiung Veterans General Hospital, and School of Medicine, National Yang-Ming University, 386, Ta-Chung First Road, Kaohsiung 813, Taiwan.
BACKGROUND: Perioperative use of beta-blockers has been advocated as a strategy to prevent cardiac sequelae. This study evaluated the influence of perioperative esmolol administration upon anaesthesia and postoperative pain management amongst patients undergoing hysterectomy. METHODS: Ninety-seven ASA I-II patients, undergoing abdominal total hysterectomy, were randomly divided into one of two groups. Patients in the Esmolol group received an i.v. loading dose of esmolol 0.5 mg kg(-1) followed by infusion of 0.05 mg kg(-1) min(-1) before anaesthesia induction. The infusion was documented at the completion of surgery. The Control group received a volume of normal saline. After surgery, all patients were treated with patient-controlled i.v. analgesia (PCA), which was programmed to deliver 1 mg of morphine on demand for 3 consecutive days. Pain intensity on movement and at rest, sedation score, and side effects were recorded. RESULTS: The two groups were comparable with respect to their characteristics. Patients in the esmolol group received significantly lower end-tidal isoflurane concentrations (1.0 (0.3) vs 1.4 (0.5)%, respectively; P<0.001) and fentanyl (0.9 (0.2) vs 1.2 (0.5) micro g kg(-1), respectively; P=0.006) during anaesthesia. They also showed a reduced heart rate and arterial pressure response to tracheal intubation, skin incision, and tracheal extubation. The Esmolol group consumed less PCA morphine in 3 days (37.3 (8.4) vs 54.7 (11.2) mg, respectively; P=0.005). Pain intensity and medication side effects were similar in the two groups. CONCLUSION: The results suggest that perioperative esmolol administration during anaesthesia reduces the intraoperative use of inhalation anaesthetic and fentanyl, decreases haemodynamic responses, and reduced morphine consumption for the first 3 postoperative days.
PMID: 15377583 [PubMed - as supplied by publisher]
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Small dose of clonidine mixed with low-dose ropivacaine and fentanyl for epidural analgesia after total knee arthroplasty{dagger}
Forster JG, Rosenberg PH.
Department of Anaesthesiology and Intensive Care Medicine, Helsinki University Central Hospital, PB 340, FIN-00029 Helsinki, Finland.
BACKGROUND: We studied whether a small dose of clonidine added to a ropivacaine-fentanyl mixture improves epidural analgesia without provoking side effects typically related to larger amounts of epidural clonidine. METHODS: In this randomized, double-blinded study, patients (</=85 yr, ASA I-III) underwent total knee arthroplasty (TKA) performed under spinal anaesthesia. After the operation, patients received an epidural infusion consisting of ropivacaine 2 mg ml(-1) and fentanyl 5 micro g ml(-1) either without (Group RF, n=33) or with clonidine 2 micro g ml(-1) (Group RFC, n=36). The infusion rate was adjusted within the range 3-7 ml h(-1). RESULTS: Average rate of infusion was slightly smaller in Group RFC than in Group RF (mean (SD) 4.7 (0.72) vs 5.2 (0.8) ml h(-1), P=0.004). Compared with the RF group, patients in the RFC group required significantly less rescue pain medication, that is i.m. oxycodone (median (25th, 75th percentile) 0 (0, 7) vs 7 (0, 12) mg, P=0.027). Arterial pressure and heart rate were slightly lower in Group RFC throughout the study period (mean difference between the groups 5 mm Hg (P<0.002) and 3 min(-1) (P=0.12), respectively). The groups did not differ statistically with respect to nausea, motor block, and sedation. CONCLUSIONS: The small amount of clonidine added to the low-dose ropivacaine-fentanyl mixture reduced the need for opioid rescue pain medication after TKA. Clonidine slightly decreased arterial pressure and heart rate without jeopardizing haemodynamics. Otherwise, the side effect profiles were comparable in both groups.
PMID: 15377579 [PubMed - as supplied by publisher]
Comment on:
Oxygen supplementation during Caesarean delivery.
Mandal NG, Gulati A.
Publication Types:
PMID: 15304413 [PubMed - indexed for MEDLINE]
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Editorial III: Remembering awareness.
Sneyd JR.
Publication Types:
PMID: 15304410 [PubMed - indexed for MEDLINE]
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Epidural infusion or combined femoral and sciatic nerve blocks as perioperative analgesia for knee arthroplasty.
Davies AF, Segar EP, Murdoch J, Wright DE, Wilson IH.
Department of Anaesthesia, R D and E Hospital, Exeter, UK. Anthony.Davies@phnt.swest.nhs.uk
BACKGROUND: Peripheral neural blockade appears to provide effective analgesia with potentially less morbidity than central neuraxial techniques. We compared the relative benefits of combined femoral (3-in-1) and sciatic nerve block with epidural blockade for postoperative knee arthroplasty analgesia. METHODS: Sixty patients, ASA I-III, undergoing unilateral knee replacement were prospectively randomized to receive either a lumbar epidural infusion or combined single-shot femoral (3-in-1) and sciatic blocks (combined blocks). All patients received standard general anaesthesia. Visual analogue pain scores and rescue opioid requirements were recorded at four time points postoperatively. Patient satisfaction, morbidity, block insertion time, perioperative blood loss and rehabilitation indices were also assessed. RESULTS: In both groups, pain on movement was well controlled at discharge from recovery and 6 h postoperatively but increased at 24 and 48 h. Median (95% CI) analogue scale scores were 0 (0-0), 15 (0-30), 55 (38-75) and 54 (30-67) mm for epidural block and 0.5 (0-22), 21.5 (10-28), 40 (20-50) and 34.5 (21-55) mm for combined block. VAS pain scores with the combined blocks were significantly lower at 24 h (P=0.004). Total morphine usage was low in both groups: median epidural group 17 mg (8-32) versus combined blocks 13 mg (7.8-27.5). Patient satisfaction was high in both groups with median (95% CI) scores of 100 (85-100), 83 (70-100) and 82 (57-90) mm for epidural and 90 (73-100), 100 (77-100) and 97 (80-100) mm for combined blocks (not significant). Perioperative blood loss and rehabilitation indices were also similar. CONCLUSIONS: Combined femoral (3-in-1) and sciatic blocks offer a practical alternative to epidural analgesia for unilateral knee replacements.
Publication Types:
- Clinical Trial
- Randomized Controlled Trial
PMID: 15247111 [PubMed - indexed for MEDLINE]
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Cardiovascular changes following insertion of oropharyngeal and nasopharyngeal airways.
Tong JL, Smith JE.
Department of Anaesthesia, University Hospital Birmingham, Selly Oak Hospital, Birmingham B29 6JD, UK.
BACKGROUND: The cardiovascular responses following the insertion of oropharyngeal airways in anaesthetized patients have been found to be of little consequence. However, those following the insertion of nasopharyngeal airways have not been studied. The aim of this investigation was to compare the cardiovascular responses to the insertion of oropharyngeal and nasopharyngeal airways in anaesthetized patients. METHODS: Twenty-four ASA I or II patients aged 16-65 yr, requiring nasotracheal intubation as part of their anaesthetic management, received a standardized general anaesthetic and were randomly allocated to receive either a nasopharyngeal or an oropharyngeal airway. RESULTS: The two groups were similar with respect to age, weight and gender. There was a significant decrease in systolic pressure following the induction of anaesthesia in both groups. Following nasopharyngeal airway insertion, there was a significant rise in systolic pressure above pre-insertion levels (P< or =0.001), though not above pre-induction levels (P=0.808). There was no significant change in the oropharyngeal airway insertion group (P=0.619). At 1 min post-insertion, the mean (sd) systolic pressure in the nasopharyngeal insertion group, 122 (21.6) mm Hg, was significantly greater than that in the oropharyngeal insertion group, 103 (15.3) mm Hg (P=0.017). Diastolic pressure followed a similar pattern. In both groups, heart rate fell after induction and fell further after insertion, and at 4 min post-insertion was significantly lower than pre-induction and pre-insertion levels. There was no significant difference in heart rates between the two groups (P=0.372). CONCLUSIONS: The pressor response following the insertion of nasopharyngeal airways in anaesthetized patients is significantly greater than that following the insertion of oropharyngeal airways. However, the mean rise in arterial pressure does not exceed pre-induction level, and thus the response is less severe than that likely to be associated with orotracheal or nasotracheal intubation.
Publication Types:
- Clinical Trial
- Randomized Controlled Trial
PMID: 15220172 [PubMed - indexed for MEDLINE]
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Right thoracic paravertebral analgesia for hepatectomy.
Ho AM, Karmakar MK, Cheung M, Lam GC.
Department of Anaesthesia and Intensive Care, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, NT, Hong Kong SAR, People's Republic of China. hoamh@cuhk.edu.hk
Haemostatic deficiencies, common among cirrhotic patients, may deteriorate further after hepatectomy, increasing the bleeding risk associated with the use of thoracic epidural analgesia. We describe two patients who enjoyed immediate post-operative tracheal extubation and satisfactory analgesia using mainly right thoracic paravertebral analgesia after right lobe hepatectomy.
Publication Types:
PMID: 15220169 [PubMed - indexed for MEDLINE]
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Epidural oxycodone or morphine following gynaecological surgery.
Yanagidate F, Dohi S.
Department of Anesthesiology and Pain Medicine, Gifu University Graduate School of Medicine, 1-1 Yanagido, Gifu City, Gifu 501-1194, Japan.
BACKGROUND: The analgesic action of oxycodone is of rapid onset, in contrast to morphine, and is mediated by kappa-opioid receptors of the spinal cord. We compared analgesia and side-effects of epidural oxycodone with those of morphine after gynaecological surgery. METHODS: We studied prospectively in 75 women in a double-blind, randomized manner: epidural morphine 6 mg day(-1) (n=25), epidural oxycodone 6 mg day(-1) (n=25) and epidural oxycodone 12 mg day(-1) (n=25). All patients underwent gynaecological surgery under general (isoflurane and nitrous oxide) and epidural anaesthesia. Visual analogue scale (VAS) pain scores at rest and on coughing, verbal descriptive scale (VDS) satisfaction scores, sedation scores, pruritus scores and nausea/vomiting scores were recorded for 3 days after surgery. RESULTS: VAS pain scores at rest in patients who received oxycodone 6 mg day(-1) were higher than in patients who received morphine 6 mg day(-1) at 6 h and on the first postoperative day and were significantly higher than in patients who received oxycodone 12 mg day(-1) on the first postoperative day. Scores for nausea, vomiting and pruritus in patients who received oxycodone 6 mg day(-1) and 12 mg day(-1) were lower than those in patients who received morphine. No significant differences were seen in VAS at cough and VDS satisfaction scores between the three groups. CONCLUSION: Epidural oxycodone was as effective as morphine at the doses investigated, with fewer side-effects.
Publication Types:
- Clinical Trial
- Randomized Controlled Trial
PMID: 15220165 [PubMed - indexed for MEDLINE]
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Recognition and management of maternal cardiac disease in pregnancy.
Ray P, Murphy GJ, Shutt LE.
Department of Anaesthesia, St Michaels Hospital, Bristol and Department of Cardiac Surgery, Bristol Royal Infirmary, Bristol BS2 8HW, UK. paramray@hotmail.com
Heart disease is a leading cause of maternal death. The aim of this study is to review the most common causes of cardiac disease, highlight factors that should be recognized by the clinician, and address recent advances in the anaesthetic management of these patients. Incipient cardiac disease, including peripartum cardiomyopathy, myocardial infarction and aortic dissection, accounts for approximately one in six maternal deaths. The keys to successful diagnosis and management of incipient disease are: a high index of suspicion, particularly in women with known risk factors for cardiovascular disease; a low threshold for radiological investigations; early cardiology input; and invasive monitoring during labour and delivery. Echocardiography is a safe, non-invasive test, under-used in pregnancy. Management of pregnant women with pre-existing cardiac problems should be undertaken by multidisciplinary teams in tertiary centres. In women with pre-existing cardiac disease wishing to proceed to term, cardiac status must be optimized preoperatively and planned elective delivery is preferable. Vaginal delivery is preferable, and with careful incremental regional anaesthesia is safe in most women with cardiac disease. The presence of adequate systems for early detection, appropriate referral to specialist centres, and timely delivery with multidisciplinary support can minimize the serious consequences of poorly controlled heart disease in pregnancy.
Publication Types:
PMID: 15194627 [PubMed - indexed for MEDLINE]
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Ibuprofen vs. acetaminophen vs. ibuprofen and acetaminophen after arthroscopically assisted anterior cruciate ligament reconstruction.
Dahl V, Dybvik T, Steen T, Aune AK, Rosenlund EK, Raeder JC.
Volvat Medical Centre, Department of Anesthesia, Oslo, Norway. dr.dahl@online.no
BACKGROUND AND OBJECTIVE: The analgesic potency of non-steroidal anti-inflammatory drugs and acetaminophen are still being debated. We have assessed the relative analgesic effect of ibuprofen, acetaminophen or the combination of both after orthopaedic surgery. METHODS: Sixty-one ASA I patients, scheduled for an elective anterior cruciate ligament reconstruction under general anaesthesia were randomized, in a double blind fashion, into one of three groups. The ibuprofen group (n = 17) received ibuprofen 800 mg orally 1 h before operation and again at 6 and 12 h after the initial dose. The acetaminophen group (n = 20) received of acetaminophen 1 g orally at the same time intervals. The combination group (n = 24) received both ibuprofen 800 mg and acetaminophen 1 g. Surgery was performed under general anaesthesia with propofol and fentanyl for induction and maintenance with propofol and nitrous oxide in oxygen. The patients were monitored for 24 h thereafter, and the following variables were assessed: pain by visual analogue and verbal scales, need for rescue intravenous opioid analgesia (i.e. ketobemidone) and adverse events. RESULTS: The ibuprofen group and the combination group experienced significantly less pain during the first 6 h after surgery than the acetaminophen group using the visual analogue and the verbal scales. The acetaminophen group also had a significantly higher average consumption of opioids during the first 6 and 24 h. There were no significant differences between the ibuprofen group and the combination group in respect of experienced pain or consumption of rescue analgesia. The incidence of side-effects, postoperative haemoglobin concentration and renal function, judged by creatinine clearance, were identical between the groups. CONCLUSION: Ibuprofen 800 mg thrice daily reduced pain to a greater degree than acetaminophen 1 g thrice daily, after anterior cruciate ligament reconstruction under general anaesthesia. The combination of acetaminophen and ibuprofen did not provide any superior analgesic effect.
Publication Types:
- Clinical Trial
- Randomized Controlled Trial
PMID: 15248627 [PubMed - indexed for MEDLINE]
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The systemic absorption and disposition of levobupivacaine 0.5% after epidural administration in surgical patients: a stable-isotope study.
Simon MJ, Veering BT, Stienstra R, van Kleef JW, Williams SG, McGuire GM, Burm AG.
Leiden University Medical Centre, Department of Anaesthesiology, Leiden, The Netherlands. M.J.G.Simon@lumc.nl
BACKGROUND AND OBJECTIVE: Absorption and disposition kinetics can be studied with a stable-isotope method. The aim of this study was to validate a stable-isotope method for levobupivacaine and to derive the relevant pharmacokinetics after epidural administration. METHODS: Eight volunteers (18-32 yr) received approximately 23 mg of both levobupivacaine and deuterium-labelled levobupivacaine simultaneously by intravenous infusion. Venous blood samples were taken for 8 h. Fifteen patients (23-85 yr) received 19 mL levobupivacaine 0.5% (including a 3 mL test dose) epidurally and, 25 min later, approximately 25 mg deuterium-labelled levobupivacaine (D3-levobupivacaine) intravenously. Arterial blood samples were collected for 24 h. Plasma concentrations were determined using liquid chromatography-mass spectrometry. Plasma concentration-time data were analysed by compartmental and non-compartmental analysis. RESULTS: Based on the ratio of the normalized areas under the curve of unlabelled and deuterium-labelled levobupivacaine in volunteers, as determined by both compartmental (mean ratio: 1.02, 90% CI: 1.00-1.04) and non-compartmental analysis (mean ratio: 1.02, 90% CI: 1.00-1.03) the two formulations were considered equivalent. In surgical patients the elimination half-life (mean +/- SD: 196 +/- 65 min), total body clearanc (349 +/- 114 mL min(-1)) and volume of distribution at steady state (56 +/- 14 L), derived by compartmental analysis, were similar to those obtained by non-compartmental analysis. The absorption was bi-phasic. The fractio absorbed and half-life of the fast absorption process were 0.22 +/- 0.06 and 5.2 +/- 2.7 min, respectively. Th values for the slow absorption process were 0.84 +/- 0.14 and 386 +/- 91 min, respectively. CONCLUSIONS: D3-levobupivacaine is pharmacokinetically equivalent to unlabelled levobupivacaine and can be used to study the absorption and disposition kinetics after perineural administration of levobupivacaine in a single experiment.
PMID: 15248626 [PubMed - indexed for MEDLINE]
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Air leakage around endotracheal tube cuffs.
Dullenkopf A, Schmitz A, Frei M, Gerber AC, Weiss M.
University Children's Hospital, Department of Anaesthesia, Zurich, Switzerland. alex.dullenkopf@kispi.unizh.ch
BACKGROUND AND OBJECTIVE: To compare the recently introduced Microcuff endotracheal tube with conventional tubes in respect of the cuff pressures required to prevent air leakage. METHODS: The following tubes (ID 7.0mm) were compared: Microcuff HVLP ICU, Mallinckrodt HiLo, Portex Profile Soft Seal, Rüsch Super Safety Clear and Sheridan CF. Fifty patients undergoing endotracheal intubation with a cuffed tube of internal diameter 7.0 mm were studied. Tracheas were intubated using one of the endotracheal tubes in random order. Cuff pressure to prevent air leakage at standardized ventilator setting (peak inspiratory pressure 20 cmH2O/PEEP 5 cmH2O/respiratory rate 15 breaths min(-1)) was assessed by auscultation of audible sounds at the mouth. Patients characteristics and cuff pressures from each brand were compared to the Microcuff group using the Mann-Whitney U-test (P < 0.05 was chosen as the level of statistical significance). RESULTS: Patients' median age (range) was 14.2 (12.0-17.1) yr, body weight 57.5 (40.0-81.9) kg and length 164.9 (146.5-190.0) cm. No significant differences in patients' characteristics were found between groups. Mean cuff pressure (all tubes) required for air sealing was 19.1 (8-42) cmH2O. The Microcuff tube required significantly lower sealing pressures (9.5 (8-12) cmH2O) compared to the other brands of endotracheal tube (P < 0.05, Mann-Whitney U-test). CONCLUSION: The Microcuff endotracheal tube with its ultra-thin polyurethane cuff membrane required the lowest sealing pressure to prevent air leakage. These features are potentially of interest for long-term intubated patients and for cuffed endotracheal tubes in children, allowing tracheal sealing at lower cuff pressures implying less damage to the trachea.
PMID: 15248624 [PubMed - indexed for MEDLINE]
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Observations on intraoperative monitoring of visual pathways using steady-state visual evoked potentials.
Wiedemayer H, Fauser B, Sandalcioglu IE, Armbruster W, Stolke D.
University of Essen, Department of Neurosurgery, Essen, Germany. helmut.wiedemayer@uni-essen.de
BACKGROUND AND OBJECTIVE: Former studies revealed conflicting information on the usefulness of intraoperative monitoring of visual evoked potentials. This study was designed to evaluate the characteristics of visual evoked potential recording in surgically anaesthetized patients using the modality of steady-state visual evoked potentials. METHODS: In 30 cases with non-cranial surgery steady-state visual evoked potentials were recorded in the awake and surgically anaesthetized patient using total intravenous anaesthesia. For stimulation, goggles with red light-emitting diodes at a frequency of 8.5 Hz were used. A two-channel recording with silver cup electrodes at Oz to Fz and Oz to earlobe was used. All traces were analysed for the presence of the characteristically sinusoidal waveform and amplitudes and latencies of the main peaks were measured. RESULTS: Recordings during surgery demonstrated a minor latency prolongation of 16% and a more pronounced amplitude attenuation of 67% compared to the recordings in the awake patients. These differences were statistically significant (paired t-test, P < 0.001). In surgically anaesthetized patients steady-state visual evoked potentials showed a relatively high intra- and interindividual variability. In four of 30 patients completely stable recordings were obtained, whereas in 14 patients identifiable waves were recordable in only less than 50% of the intraoperative traces. Of the total 1360 traces recorded intraoperatively clearly identifiable steady-state visual evoked potentials patterns were present in 56% of the traces. There was no correlation between the magnitude of the evoked potential amplitude and its stability in intraoperative recordings. CONCLUSIONS: We conclude from this study, that steady-state visual evoked potential recordings in the surgically anaesthetized patient appeared to be more stable compared to our earlier findings using transient visual evoked potentials. However, further efforts are necessary to improve the stability of the recordings during surgery and thus allow for a more reliable intraoperative monitoring of visual pathways in routine clinical practice.
PMID: 15248621 [PubMed - indexed for MEDLINE]
Comment on:
B-Aware: recall of intraoperative events.
Pavlovic D, Usichenko T.
Publication Types:
PMID: 15351187 [PubMed - indexed for MEDLINE]
Comment on:
B-Aware: recall of intraoperative events.
Deem S, Souter MJ.
Publication Types:
PMID: 15351186 [PubMed - indexed for MEDLINE]
Abstracts of the joint meeting of the Association ofPaediatric Anaesthetists of Great Britain and Ireland (APA) and the Swiss Society of Paediatric Anaesthetists (SGKA), 17-18 September 2004, Zurich, Switzerland.
[No authors listed]
PMID: 15385026 [PubMed - as supplied by publisher]
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Halothane, isoflurane and sevoflurane in pediatric anesthesia: can we decrease costs without increasing adverse events?
Nava-Ocampo AA, Alarcon-Almanza JM, Moyao-Garcia D, Ramirez-Mora JC, Salmeron J.
Department of Anaesthesia and Respiratory Therapy, Hospital Infantil de Mexico Federico Gomez, Dr Marquez no. 162, Mexico DF 06720, Mexico (email: navaocampo_aa@yahoo.com)
PMID: 15385025 [PubMed - in process]
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Anesthesia in a child with Batten disease.
Gopalakrishnan S, Sidduiqui S, Mayhew JF.
Resident, Department of Anesthesiology, University of Arkansas Medical Center, Arkansas Children's Hospital, Little Rock, Arkansas, USA.
PMID: 15385024 [PubMed - in process]
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Bilateral pulmonary hydatid cysts in a child: anesthetic management.
Dave N, Halbe AR, Kadam PP, Oak SN, Parelkar SV.
Department of Anesthesiology, TN Medical College and BYL Nair Hospital, Mumbai, India.
PMID: 15385023 [PubMed - in process]
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Cardiac arrest in a patient with Larsen syndrome under sevoflurane anesthesia.
Saricaoglu F, Dal D.
Faculty of Medicine, Department of Anesthesiology and Reanimation, Hacettepe University School of Medicine, Ankara, Turkey (email: fatmasaricao@yahoo.com)
PMID: 15385022 [PubMed - in process]
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The anesthetic management of an intrabronchial escape of a hydatid's ruptured laminated membrane during rigid bronchoscopy.
Dabir S, Boloursaz MR, Javaherzadeh M, Radpay B, Parsa T.
Assistant Professor of Anesthesia, Department of Anesthesiology, National Research Institute of Tuberculosis and Lung Disease - Dr Masih Daneshvari Hospital, Niavaran, Darabad, Tehran 19556, Iran.
Summary We describe the anesthetic management of a case in whom a previously undiagnosed pulmonary hydatid cyst manifested as a large amount of intrabronchial fragmented pieces of laminated membrane suddenly and unexpectedly during diagnostic rigid bronchoscopy.
PMID: 15385021 [PubMed - in process]
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Anesthetic management of a patient with Freeman-Sheldon syndrome.
Agritmis A, Unlusoy O, Karaca S.
Specialist of Anaesthesia, Department of Anaesthesiology, Cerrahpasa Faculty of Medicine, Istanbul University, Istanbul, Turkey.
Summary The Freeman-Sheldon syndrome (FSS) is rare congenital myopathy and dysplasia. The musculoskeletal and soft-tissue manifestations of FSS often require orthopedic and plastic reconstructive surgery. We report a case of 19-month-old girl with FSS.
PMID: 15385019 [PubMed - in process]
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Anesthetic management in Joubert syndrome.
Vodopich DJ, Gordon GJ.
Department of Anesthesiology, MetroHealth Medical Center, Cleveland, OH, USA.
Summary We review the anesthetic implications of Joubert syndrome and report that spinal anesthesia under intravenous propofol sedation proved satisfactory for repair of an inguinal hernia in a spontaneously ventilating infant with this syndrome. We caution that anatomical peculiarities may complicate performance of a caudal epidural block and suggest consideration of the use of caffeine to ameliorate the apneic episodes seen in early infancy in this syndrome.
PMID: 15385018 [PubMed - in process]
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Postoperative behavioral changes following anesthesia with sevoflurane.
Keaney A, Diviney D, Harte S, Lyons B.
Department of Anaesthesia & Critical Care Medicine, Our Lady's Hospital for Sick Children, Crumlin, Dublin, Ireland.
Summary Background : Behavioral disturbance following hospitalization is a relatively frequent event, some children still having negative behavioral changes (NBC) 1 month following their operation. Sevoflurane has a propensity to induce 'excitement' during induction of anaesthesia, and delirium in the immediate postoperative phase. The aim of this study was to evaluate whether this translates into prolonged behavioral change. Methods : A total of 120 children presenting for daycase surgical procedures under anesthesia were included in the study. Children were randomized to induction and maintenance of anesthesia with sevoflurane or halothane. No additional sedative drugs were administered. Postoperative behavioral change was assessed using the Post-Hospital Behavior Questionnaire (PHBQ) on postoperative days 1, 7 and 30. Results : The Sevoflurane group (n = 63) were more distressed on emergence of anesthesia than the Halothane group (n = 57) (P < 0.05). About 58.3, 46.8 and 38.3% of all children exhibited NBC on postoperative days 1, 7 and 30, respectively. There was no association between anesthetic agent and behavior. There was a significant relationship between decreasing age and NBC (P < 0.005). Conclusions : Children anesthetized with sevoflurane exhibit more immediate postoperative distress than those anesthetized with halothane. This difference is not carried over into the longer posthospital period. Negative behavioral changes occur more frequently with decreasing age.
PMID: 15385017 [PubMed - in process]
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The effect of remifentanil on cerebral blood flow velocity in children anesthetized with propofol.
Lagace A, Karsli C, Luginbuehl I, Bissonnette B.
Department of Anaesthesia, University of Toronto, Toronto, Ontario, Canada.
Summary Background : Cerebrovascular stability and rapid anesthetic emergence are desirable features of a neuroanesthetic regimen. In this randomized crossover study the effect of a low-dose remifentanil infusion on cerebral blood flow velocity (CBFV) in children anesthetized with propofol was evaluated. Methods : Twenty healthy children aged 1-6 years undergoing urological surgery were enrolled. Following face mask induction with sevoflurane, anesthesia was maintained with a standardized propofol infusion. Rocuronium was used to facilitate tracheal intubation and normothermia, and normocapnia were maintained. All children received a caudal epidural block, and a transcranial Doppler probe was placed to measure middle cerebral artery blood flow velocity (Vmca). Each patient received a remifentanil regimen of 0.5 microg.kg(-1) followed by 0.2 microg.kg(-1).min(-1) in a predetermined order of remifentanil + propofol or propofol alone. Vmca, mean arterial pressure (MAP) and heart rate (HR) were recorded simultaneously at equilibrium with and without remifentanil. Results : The combination of remifentanil and propofol caused an 8.1% decrease in MAP (P = 0.0005) and an 11.8% decrease in HR (P < 0.0001) compared with propofol alone. Vmca was not different between the two groups (P = 0.4041). Conclusion : The addition of remifentanil to propofol anesthesia in children causes a reduction in MAP and HR without affecting CBFV. This may imply that cerebral blood pressure autoregulation is preserved in children under propofol and remifentanil anesthesia.
PMID: 15385016 [PubMed - in process]
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Effects of low dose ketamine before induction on propofol anesthesia for pediatric magnetic resonance imaging.
Tomatir E, Atalay H, Gurses E, Erbay H, Bozkurt P.
Associate Professor of Anaesthesiology, Department of Anaesthesiology, Pamukkale University Medical Faculty, Denizli, Turkey.
Summary Background : We aimed to investigate effects of low dose ketamine before induction on propofol anesthesia for children undergoing magnetic resonance imaging (MRI). Methods : Forty-three children aged 9 days to 7 years, undergoing elective MRI were randomly assigned to receive intravenously either a 2.5 mg.kg(-1) bolus of propofol followed by an infusion of 100 microg.kg(-1).min(-1) or a 1.5 mg.kg(-1) bolus of propofol immediately after a 0.5 mg.kg(-1) bolus of ketamine followed by an infusion of 75 microg.kg(-1).min(-1). If a child moved during the imaging sequence, a 0.5-1 mg.kg(-1) bolus of propofol was given. Systolic and diastolic blood pressures, heart rate, peripheral oxygen saturation and respiratory rates were monitored. Apnea, the requirement for airway opening maneuvers, secretions, nausea, vomiting and movement during the imaging sequence were noted. Recovery times were also recorded. Results : Systolic blood pressure and heart rate decreased significantly in the propofol group, while blood pressure did not change and heart rate decreased less in the propofol-ketamine group. Apnea associated with desaturation was observed in three patients of the propofol group. The two groups were similar with respect to requirements for airway opening maneuvers, secretions, nausea-vomiting, movement during the imaging sequence and recovery time. Conclusions : Intravenous administration of low dose ketamine before induction and maintenance with propofol preserves hemodynamic stability without changing the duration and the quality of recovery compared with propofol alone.
PMID: 15385013 [PubMed - in process]
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Levobupivacaine spinal anesthesia in neonates: a dose range finding study.
Frawley GP, Farrell T, Smith S.
Department of Paediatric Anaesthesia and Pain Management, Royal Children's Hospital, Melbourne, Australia.
Summary Background : Our aim was to determine the clinical efficacy of levobupivacaine for awake spinal anesthesia in ex-premature infants having lower abdominal surgery. The secondary aim was to determine the minimum local analgesic dose (MLAD) defined as the median effective local anesthetic dose for spinal anesthesia in neonates. Methods : Fifty neonates <55 weeks postconceptional age having lower abdominal surgery were enrolled. The dose of levobupivacaine was determined by up-down sequential allocation. The first infant received 1.25 mg.kg(-1) 0.5% levobupivacaine with subsequent doses determined by the response of the previous patient. Dose interval was 0.25 mg.kg(-1). Results : There were no significant adverse effects attributable to levobupivacaine. Success rates for 1.25, 1, 0.75 and 0.5 mg.kg(-1) were 100, 83, 81 and 46%, respectively. Mean duration (95% confidence interval) of lower limb motor blockade was 81.7 min (75.8-87.6 min). Duration of anesthesia far exceeded surgical duration in all but one case. The up-down sequences were analyzed with the Dixon and Massey method. The motor block MLAD (95% confidence interval) was 0.48 mg.kg(-1) (0.42-0.54). Probit analysis was used to compare calculated ED(50) and to calculate an ED(95) by extrapolation of data into the clinical range. The ED(50) (95% C.I.) was 0.52 mg.kg(-1) (0.30-0.73). The calculated ED(95) was 1.14 mg.kg(-1) (0.78-1.50). These values were confirmed by logit analysis. Conclusions : Levobupivacaine is an effective agent for spinal anesthesia in neonates at a recommended dose of 1 mg.kg(-1). It appears to be of equivalent potency to racemic bupivacaine for motor blockade in ex-premature infants requiring lower abdominal surgery.
PMID: 15385012 [PubMed - in process]
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Droperidol for perioperative sedation causes a transient prolongation of the QTc time in children under volatile anesthesia.
Stuth EA, Stucke AG, Cava JR, Hoffman GM, Berens RJ.
Department of Anesthesiology, Medical College of Wisconsin, Milwaukee, WI, USA.
Summary Background : Droperidol is useful for postoperative sedation in infants and children after cardiac surgery because it provides sedation and akinesia with minimal respiratory depression. However, droperidol has been associated with QT prolongation and ventricular arrhythmias. We investigated, if neuroleptanalgesic doses of droperidol led to QT prolongation and cardiac arrhythmias in children undergoing cardiac surgery. Methods : We retrospectively analysed electrocardiogram rhythm strips that were obtained before and in time increments after a 100 microg.kg(-1) intravenous bolus of droperidol in 20 children undergoing cardiac surgery. The longest QT interval was determined in each ECG and corrected for heart rate (QTc). All arrhythmias were recorded. Results : Droperidol led to a significant increase in QTc time that was still present at 15 min but had resolved within 30 min after the bolus. No associated arrhythmias were observed. Conclusions : The statistically significant prolongation of QTc time after a sedative dose of droperidol is of concern because it may increase the risk for malignant cardiac arrhythmias. A large, prospective study is necessary to identify the true risk for arrhythmias after droperidol in this patient population, but our study suggests that any arrhythmogenic risk, if present, will be very transient, since the increase in QTc time was limited to a period of less than 30 min after the bolus.
PMID: 15385011 [PubMed - in process]
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Infectious diseases of childhood and their anesthetic implications.
Walt JH, Jacob R, Zoanetti DC.
Department of Paediatric Anaesthesia, Women's and Children's Hospital, Adelaide, South Australia, Australia.
PMID: 15385008 [PubMed - in process]
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