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Anaesthesia 2003 Feb;58(2):170-6
Department of Anaesthetics, Royal Infirmary of Edinburgh, UK.
Forty anxious day case patients undergoing extraction of third molar teeth under local anaesthesia with sedation, were studied in a randomised double-blind controlled trial. A target-controlled infusion of propofol was compared with patient-controlled propofol for sedation, combined with a small dose of midazolam to improve amnesia. The objectives of the study were to measure the total dose of propofol used by the two groups and assess recovery and patient satisfaction. The mean dose of propofol used in the patient-controlled sedation group was significantly less than the target-controlled group (p < 0.00007). Five patients became over-sedated in the target-controlled group compared with none in the patient-controlled group. Only one of the three tests of performance showed that the target-controlled patients were more sedated. Patient satisfaction was high in both groups despite a greater recollection of events in the patient-controlled group.
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PMID: 12622106, UI: 22509032
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Anaesthesia 2003 Feb;58(2):201-2
PMID: 12562438, UI: 22450062
Anaesthesia 2003 Feb;58(2):186; discussion 186
PMID: 12562419, UI: 22450043
Anaesthesia 2003 Feb;58(2):136-42
Department of Anaesthetics, Guy's, King's and St. Thomas' School of Medicine, King's College London, 2nd Floor NGH, Guy's Hospital, London SE1 9RT, UK.
The Streamlined Liner of the Pharynx Airway (SLIPA) is a new inexpensive disposable supraglottic airway designed to seal without the use of an inflatable cuff. It comprises a hollow blow-moulded soft plastic airway shaped to form a seal in the pharynx. Being hollow, liquid entrapment is possible and this may provide effective protection against aspiration. A model silicone rubber pharynx with an 'oesophageal' tube for injecting volumes of regurgitant liquid was designed to evaluate the SLIPA and the standard and ProSeal laryngeal mask airways during positive-pressure ventilation. A linear relationship between the volume 'regurgitated' and the volume 'aspirated' was found with the laryngeal mask airway and the ProSeal laryngeal mask airway with the drainage tube clamped. Both the ProSeal laryngeal mask airway with an open drainage tube and the SLIPA, but not the standard laryngeal mask airway, provided effective protection against 'aspiration' during positive-pressure ventilation using the model. In a clinical study, 120 patients were randomly allocated to receive controlled ventilation of the lungs via the standard laryngeal mask airway or the SLIPA. Both devices were equally easy to insert and satisfactory for airway management.
PMID: 12562409, UI: 22450033
Anaesthesia 2003 Feb;58(2):131-5
University Department of Anaesthesia and Intensive Care Medicine, CHR de la Citadelle, Boulevard du 12eme de Ligne 1, 4000 Liege, Belgium.
The effects of intra-operative magnesium sulphate on pain relief after major lumbar surgery were investigated in 24 patients. Patients were randomly allocated to receive either an infusion of 50 mg x kg(-1) magnesium sulphate or an equivalent volume of saline at induction of anaesthesia. Anaesthesia was induced with propofol and remifentanil. Tracheal intubation was facilitated using rocuronium. Maintenance was achieved with remifentanil and sevoflurane in nitrous oxide/ oxygen. Intra-operative monitoring included standard equipment and neuromuscular transmission. During surgery, neuromuscular block recovery was longer in the magnesium group. Postoperative opioid consumption and pain scores were lower in the magnesium group. The first night's sleep and the global satisfaction scores were better in the magnesium group. The results of the study support magnesium sulphate as a useful adjuvant for postoperative analgesia after major lumbar surgery.
PMID: 12562408, UI: 22450032
Anaesthesia 2003 Feb;58(2):111-6
Department of Anaesthesia, St James's University Hospital, Beckett Street, Leeds, LS9 7TF, UK.
Atelectasis occurs during general anaesthesia. This is partly responsible for the impairment of gas exchange that occurs peri-operatively. During cardiopulmonary bypass, this atelectasis is exacerbated by the physical collapse of the lungs. As a result, poor arterial oxygenation is often seen postoperatively. We tested the effect of an 'alveolar recruitment strategy' on arterial oxygenation in a prospective randomised study of 78 patients undergoing cardiopulmonary bypass. Patients were divided equally into three groups of 26. Group 'no PEEP' received a standard post bypass manual lung inflation, and no positive end-expiratory pressure was applied until arrival at intensive care unit. Group '5 PEEP' received a standard post bypass manual inflation, and then 5 cmH2O of positive end-expiratory pressure was applied and maintained until extubation on intensive care. The third group, 'recruitment group', received a pressure-controlled stepwise increase in positive end-expiratory pressure up to 15 cmH2O and tidal volumes of up to 18 ml x kg(-1) until a peak inspiratory pressure of 40 cmH2O was reached. This was maintained for 10 cycles; the positive end-expiratory pressure of 5 cmH2O was maintained until extubation on intensive care. There was a significantly better oxygenation in the recruitment group at 30 min and 1 h post bypass when compared with the no PEEP and 5 PEEP groups. There was no significant difference in any of the groups beyond 1 h. Application of 5 cmH2O positive end-expiratory pressure alone had no significant effect on oxygenation. No complications due to the alveolar recruitment manoeuvre occurred. We conclude that the application of an alveolar recruitment strategy improves arterial oxygenation after cardiopulmonary bypass surgery.
PMID: 12562405, UI: 22450029
Anaesthesia 2003 Feb;58(2):107-10
PMID: 12562404, UI: 22450028
Anesth Analg 2003 Apr;96(4):1239-40
Department of Anesthesiology, University Hospital Hamburg-Eppendorf, Hamburg, Germany. University of Virginia Health System, Charlottesville, VA.
[Medline record in process]
PMID: 12651706, UI: 22537641
Anesth Analg 2003 Apr;96(4):1237-8
Professor of Anesthesiology, Boston University School of Medicine, Anesthesia Associates of Massachusetts, Department of Anesthesia, Boston University Medical Center, Boston, MA. Department of Anesthesiology, Virginia Mason Medical Center, Seattle, WA.
PMID: 12651701, UI: 22537636
Anesth Analg 2003 Apr;96(4):1234-5
Department of Anesthesiology and Intensive Care Medicine, University of Cologne, Cologne, Germany. Dept of Anesthesia, Royal Free Hospital, Hampstead, London.
PMID: 12651696, UI: 22537631
Anesth Analg 2003 Apr;96(4):1233
Yale University School of Medicine, Department of Anesthesiology, New Haven, CT.
PMID: 12651695, UI: 22537630
Anesth Analg 2003 Apr;96(4):1193-200
Department of Anesthesiology, Mayo Clinic Foundation, Rochester, Minnesota.
PMID: 12651684, UI: 22537619
Anesth Analg 2003 Apr;96(4):1178-82
Department of Anesthesia, Citta di Roma Hospital, Rome, Italy. Department of Anaesthesia and Intensive Care, South Manchester University Hospital, Wythenshawe, Manchester, United Kingdom.
In this study, we sought to determine the minimum analgesic doses and relative potencies of fentanyl and sufentanil when they are used as the sole epidural analgesic during the first stage of labor. Nulliparous parturients (n = 66) in spontaneous labor at term gestation and requesting epidural analgesia were enrolled into this prospective, double-blinded, randomized, sequential-allocation study. Each woman received fentanyl or sufentanil diluted with 0.9% wt/vol saline to a volume of 10 mL. The initial dose was arbitrarily chosen to be 125 micro g for fentanyl and 25 micro g for sufentanil, with subsequent doses being determined by the response of the previous patient (testing interval, 5 micro g for fentanyl and 1 micro g for sufentanil). Efficacy was accepted if the visual analog score decreased to </=10 mm on a 100-mm scale within 30 min. The minimum analgesic dose or median effective dose was 21.1 micro g (95% confidence interval [CI], 20.2-21.9 micro g) for sufentanil and 124.2 micro g (95% CI, 118.1-130.6 micro g) for fentanyl (P < 0.0001). The sufentanil/fentanyl potency ratio was 5.9 (95% CI, 5.6-6.3). In conclusion, we have established the equivalent doses and relative potencies of fentanyl and sufentanil for epidural analgesia in the first stage of labor. IMPLICATIONS: This study determined the minimum analgesic doses of fentanyl and sufentanil for epidural anesthesia in the first stage of labor. The sufentanil/fentanyl potency ratio was 5.9. This ratio may be used to establish the equivalent doses for fentanyl and sufentanil for epidural analgesia in labor.
PMID: 12651680, UI: 22537615
Anesth Analg 2003 Apr;96(4):1173-7
Service d'Anesthesie-Reanimation, Hotel-Dieu, Lyon, France.
We compared the administration of 0.15% ropivacaine plus 0.5 micro g/mL of sufentanil with that of 0.10% ropivacaine plus 0.5 micro g/mL of sufentanil for labor analgesia with patient-controlled epidural analgesia (PCEA) to determine whether a decreased concentration of ropivacaine could produce equally effective analgesia. One-hundred-thirty healthy pregnant women at term were randomized in a double-blinded fashion. The PCEA settings were as follows: 12-mL initial bolus, 5-mL bolus dose, 5-min lockout interval, and 10 mL/h basal infusion. Patient demographics and labor characteristics were comparable in both groups. No differences were observed for pain scores, maternal satisfaction, volume of anesthetic solution administered, number of boluses requested and delivered, need for supplemental boluses, mode of delivery, motor block, side effects, or Apgar scores. Patients in the 0.10% ropivacaine group used significantly less drug than those in the 0.15% group (mean, 57 mg; 95% confidence interval, 50.5-63.5 mg; versus mean, 88.0 mg; 95% confidence interval, 74.4-93.3 mg, respectively; P < 0.0001). Ropivacaine 0.10% plus 0.5 micro g/mL of sufentanil administered via PCEA for labor analgesia is equally effective as ropivacaine 0.15% plus 0.5 micro g/mL of sufentanil, with a 30% local anesthetic-sparing effect and a 40% reduction in cost. However, this reduction in local anesthetic is not associated with a decrease in the incidence of motor block, side effects, or instrumental deliveries. IMPLICATIONS: Ropivacaine 0.10% plus 0.5 micro g/mL of sufentanil given via patient-controlled epidural anesthesia for labor analgesia is equally as effective as ropivacaine 0.15% plus 0.5 micro g/mL of sufentanil, with a 30% local anesthetic-sparing effect and a 40% reduction in cost. This reduction in ropivacaine concentration is not associated with a decrease in the incidence of motor block, side effects, or instrumental deliveries.
PMID: 12651679, UI: 22537614
Anesth Analg 2003 Apr;96(4):1145-9
Departement d'Anesthesie-Reanimation and. Service de Sante Publique et de Biostatistiques, Marseille, France.
Cerebral hyperemia has been demonstrated during emergence from anesthesia in neurosurgical patients, but its mechanism is speculative. We performed this study to test the hypothesis that this could be attributed to sympathetic overactivity. Thirty neurosurgical patients were included in a prospective, randomized, double-blinded study comparing esmolol, a short-acting beta-blocker, and a placebo. Esmolol (0.3 mg. kg(-1). min(-1)) was infused from the end of anesthesia to 15 min after extubation. Cerebral blood flow velocity (CBFV), mean arterial blood pressure, and heart rate were recorded before anesthesia, during anesthesia after surgery, at extubation, and 5-60 min after extubation. Cardiac output (COe) was estimated by using an esophageal Doppler from anesthesia to 60 min after extubation. CBFV, COe, and heart rate were significantly lower in the esmolol group. Mean arterial blood pressure was comparable between the groups. There was no correlation between CBFV and COe at any time point during the study. In conclusion, esmolol blunted the CBFV increase during emergence, confirming that sympathetic overactivity contributes to cerebral hyperemia during neurosurgical recovery. IMPLICATIONS: Esmolol blunted the postoperative increase in cerebral blood flow velocity in neurosurgical patients. The origin of sympathetic hyperactivity and its potential deleterious consequences require further study.
PMID: 12651674, UI: 22537609
Anesth Analg 2003 Apr;96(4):1109-1113
Department of Anesthesiology, The University of Texas Medical Branch, Galveston, Texas. Department of Anesthesia, University of Iowa, Iowa City, Iowa. Department of Anesthesiology, Jefferson Medical College, Philadelphia, Pennsylvania. Medical Data Applications, Ltd., Jenkintown, Pennsylvania. ||Department of Anesthesiology, Perioperative Medicine and Pain Management, University of Miami, Miami, Florida. Department of Anesthesiology and Pain Management, The University of Texas Southwestern Medical Center, Dallas, Texas.
[Record supplied by publisher]
Determination of operating room (OR) block allocation and case scheduling is often not based on maximizing OR efficiency, but rather on tradition and surgeon convenience. As a result, anesthesiology groups often incur additional labor costs. When negotiating financial support, heads of anesthesiology departments are often challenged to justify the subsidy necessary to offset these additional labor costs. In this study, we describe a method for calculating a statistically sound estimate of the excess labor costs incurred by an anesthesiology group because of inefficient OR allocation and case scheduling. OR information system and anesthesia staffing data for 1 yr were obtained from two university hospitals. Optimal OR allocation for each surgical service was determined by maximizing the efficiency of use of the OR staff. Hourly costs were converted to dollar amounts by using the nationwide median compensation for academic and private-practice anesthesia providers. Differences between actual costs and the optimal OR allocation were determined. For Hospital A, estimated annual excess labor costs were $1.6 million (95% confidence interval, $1.5-$1.7 million) and $2.0 million ($1.89-$2.05 million) when academic and private-practice compensation, respectively, was calculated. For Hospital B, excess labor costs were $1.0 million ($1.08-$1.17 million) and $1.4 million ($1.32-1.43 million) for academic and private-practice compensation, respectively. This study demonstrates a methodology for an anesthesiology group to estimate its excess labor costs. The group can then use these estimates when negotiating for subsidies with its hospital, medical school, or multispecialty medical group. IMPLICATIONS: We describe a new application for a previously reported statistical method to calculate operating room (OR) allocations to maximize OR efficiency. When optimal OR allocations and case scheduling are not implemented, the resulting increase in labor costs can be used in negotiations as a statistically sound estimate for the increased labor cost to the anesthesiology department.
PMID: 12651669
Anesth Analg 2003 Apr;96(4):1104-8
Departments of Anesthesiology and. Anthropology, University of Washington. Anesthesia Clinical Services, University of Washington Medical Center, Seattle, Washington.
Previously, the authors reported trends in anesthesia quality and productivity in a university-based anesthesia practice as it responded to increasing service demands with shortages of qualified staff and decreasing reimbursement. From 1992 to 1997, productivity increased, with a significant decrease in patient injury. In this study, we analyzed whether previous productivity and quality gains were sustained from 1998 to 2000 despite continued staff shortages. Productivity, caseload, and outcome data were abstracted from departmental administrative and quality-improvement reports. Retrospective cohort analysis compared trends during 3 yr of moderate productivity (1994-1996) with those during 3 yr of high productivity (1998-2000). The mean monthly productivity in 1998-2000 (15 +/- 0.6 billed hours per attending per clinical day) was larger than levels from 1994 to 1996 (mean, 14 +/- 0.7 h; P < 0.01). The overall continuous quality improvement report rate was slower at larger productivity levels, as were rates of patient injuries. When adjusted for declining report rates, patient injury rates showed no change between smaller- and larger-productivity years. Adjusted rates of operational inefficiencies and human errors were more frequent at larger productivity levels. Although the pressures of increased demands, shrinking resources, and shortages of qualified academic anesthesiologists have not abated, productivity and quality have been sustained. Future management must be directed toward reductions in operational inefficiencies and human error. IMPLICATIONS: Our academic anesthesia service sustained increases in productivity with maintenance of quality. During a 3-yr period of high productivity, patient injury rates did not increase compared with prior years with lower productivity.
PMID: 12651668, UI: 22537603
Anesth Analg 2003 Apr;96(4):1083-8
Departments of Anesthesiology, Dartmouth Medical School, Dartmouth-Hitchcock Medical Center, Lebanon, New Hampshire. Central Vermont Medical Center, Berlin, Vermont.
Postoperative pain after total knee arthroplasty (TKA) is severe and can complicate early physical therapy. We tested the hypothesis that intrathecal clonidine would improve postoperative analgesia for TKA using a hyperbaric bupivacaine spinal anesthetic. In a double-blinded, placebo-controlled protocol, 81 ASA physical status I-III patients undergoing either a single or bilateral TKA were randomized into 4 groups with the following 2-mL solutions added to 15 mg of hyperbaric bupivacaine: 1) sterile saline, 2) morphine (250 micro g), 3) morphine (250 micro g) with clonidine (25 micro g), and 4) morphine (250 micro g) with clonidine (75 micro g). At 1, 2, 4, 6, 12, and 24 h postoperatively, we measured visual analog scales (VAS), cumulative IV morphine consumption, hemodynamics, nausea, ancillary drugs, and side effects. Our primary comparison was between the clonidine with morphine groups versus the morphine group. We found that the combined administration of intrathecal clonidine and morphine decreased 24 h IV morphine consumption by 13 mg (P = 0.028) when compared with intrathecal morphine alone. This corresponded to a decrease in the VAS score of 1.3 cm at 24 h postoperatively (P = 0.047). Adverse side effects were similar among all groups with the exception of more relative hypotension in the clonidine groups through postoperative hour 6. We conclude that the coadministration of intrathecal clonidine and morphine decreases the 24-h IV morphine consumption and improves the 24-h VAS score when compared with intrathecal morphine alone. IMPLICATIONS: In this prospective, randomized, double-blinded, and placebo-controlled trial, we identify an effective postoperative analgesic approach in total knee replacement surgery. Intrathecal morphine (250 micro g) combined with clonidine (25 or 75 micro g) provided superior analgesia compared with intrathecal morphine alone.
PMID: 12651665, UI: 22537600
Anesth Analg 2003 Apr;96(4):1056-61
Istituto di Anestesia e Rianimazione Ospedale San Luigi, Orbassano, Italy. A e. B, Ospedale San Giovanni Bosco, Torino, Italy. Istituto di Anestesia e Rianimazione Ospedale San Giovanni Battista, Torino, Italy. ||Hudson RCI, Upplands Vasby, Sweden.
The Anesthetic Conserving Device (ACD) is a high-flow anesthesia system closed to volatile anesthetics only. We compared the ACD with a circle system under different fresh gas flow (FGF) conditions. Eighty-one patients undergoing major surgery were randomly allocated to receive sevoflurane from a circle circuit combined either with the ACD placed at the Y-piece (n = 41) or with a vaporizer (n = 40). The FGF was set to 8 L/min in the ACD system, where the circle circuit served as a nonrebreather. In the conventional circle system without ACD, the vaporizer was supplied with 1-, 1.5-, 3-, and 6-L/min FGFs. We compared the ACD with the circle system under the four FGFs in terms of sevoflurane dosing, sevoflurane consumption, humidification efficiency, and environmental pollution. The ACD and the low-flow circle system (1.5- and 1-L/min FGFs) resulted in the smallest sevoflurane consumption. The increase in inspired sevoflurane concentration was faster with the circle system than with the ACD only with FGFs >/=3 L/min. The removal of ACD from the circuit allowed the fastest washout of sevoflurane. Respiratory gas humidification was always adequate. Sevoflurane ambient concentration with the ACD was 1-70 ppb. The ACD is a valid and simple alternative to low-flow systems. IMPLICATIONS: The Anesthetic Conserving Device (ACD) is a new device for anesthetic vapor delivery. We demonstrated that the ACD reduces anesthetic consumption and environmental pollution similarly to a low-flow circle system, offering advantages such as simplicity, no toxicity from compounds produced in the absorber, and potential cost savings.
PMID: 12651660, UI: 22537595
Anesth Analg 2003 Apr;96(4):1004-9
Department of Anesthesia, Harvard Medical School, Brigham & Women's Hospital, Boston, Massachusetts. Department of Psychology, Harvard University, Cambridge, Massachusetts.
Studies demonstrate lasting cognitive impairment in elderly persons after anesthesia and surgery. We tested the hypothesis that general anesthesia contributes to this cognitive impairment. Six- and 18-mo-old Fischer 344 rats were trained in a 12-arm radial arm maze and were then randomized to anesthesia for 2 h with 1.2% isoflurane/70% nitrous oxide/30% oxygen or a control treatment consisting of 30% oxygen. Rats recovered for 24 h and then were tested daily on the radial arm maze for 8 wk. Performance of young control rats was stable throughout the experiment. In contrast, aged control rats improved their performance as measured by time to complete the maze but not by error rate. After anesthesia, time to complete the maze did not change in young rats, but error rate decreased (P < 0.05 at 1 and 3 wk), indicating improved performance. In contrast, previously anesthetized aged rats failed to improve with repeated testing and took longer to complete the maze than aged control rats (P < 0.05 at 1 and 3 wk). These data demonstrate that general anesthesia with isoflurane and nitrous oxide improves the memory performance on an established spatial memory task in young rats, but in aged rats it attenuates the improvement in performance that otherwise occurs with repeated testing. Therefore, isoflurane and nitrous oxide anesthesia produces a sustained learning impairment in aged rats. IMPLICATIONS: This study demonstrates that general anesthesia with isoflurane and nitrous oxide improves spatial memory in young rats but impairs it in aged rats for at least 3 wk, indicating that it can influence memory for much longer than previously recognized and may adversely affect memory processes in the aged.
PMID: 12651650, UI: 22537585
Anesthesiology 2003 Apr;98(4):1014-5
*Associate Director of Pediatric Anesthesia and Research Director. Current position: Assistant Professor, Department of Anesthesiology, University of Vermont, Burlington, Vermont.
PMID: 12657867, UI: 22543542
Anesthesiology 2003 Apr;98(4):1005-7
*Medical doctor, Department of Anesthesiology and Reanimation, dagger Medical doctor, Department of Radiology.
PMID: 12657864, UI: 22543539
Anesthesiology 2003 Apr;98(4):995-1003
*Associate in Anesthesia, Children Hospital, Assistant in Anaesthesia, Harvard Medical School.
PMID: 12657863, UI: 22543538
Anesthesiology 2003 Apr;98(4):964-8
* Specialist Anesthetist.
BACKGROUNDAn initial pilot study of 300 sub-Tenon local anesthetic blocks (STBs) for intraocular surgery established the effectiveness and patient acceptability of the technique. Following this, a decision was made in 1995 to change from sharp needle techniques to STB for all eye surgeries performed during local anesthesia at Auckland Hospital (Auckland, New Zealand) by reeducation of anesthetists and surgeons. At this point, sufficient data were not available to confirm that STB would avoid the complications associated with the passage of sharp needles into the orbit or would cause a different set of serious complications.METHODSA prospective study of the next 6,000 consecutive STBs performed at Auckland Hospital was carried out over a period of 6 yr (from 1995 to 2000).RESULTSSub-Tenon block is very effective, with a surgeon and patient acceptability rate of 98.8%. Insertion of the sub-Tenon cannula and administration of the anesthetic produces minimal discomfort, being completely painless in 68.8% of cases. There were no serious block-related complications in this series, supporting the safety of the sub-Tenon technique.CONCLUSIONThe experience at Auckland Hospital provides further support for the avoidance of passing sharp needles into the orbit.
PMID: 12657860, UI: 22543535
Anesthesiology 2003 Apr;98(4):957-63
* Assistant Professor, Department of Anesthesiology, Duke University Medical Center. dagger Associate Professor. Department of Anesthesiology, Perioperative and Pain Medicine, Brigham and Women's Hospital, Harvard Medical School.
BACKGROUNDDystocia is characterized by abnormal progress of labor and is a common contemporary indication for cesarean delivery in the United States. There has been considerable controversy as to whether epidural analgesia causes dysfunctional labor leading to cesarean delivery for dystocia. The minimum local analgesic concentration (MLAC) is a clinical model used to determine the relative potencies of local anesthetics in the first stage of labor. In this article, the authors report a prospective study determining the MLAC of bupivacaine in early labor of parturients who eventually delivered either vaginally or via cesarean section.METHODSAn up-down sequential allocation technique was used to determine the MLAC of bupivacaine in 57 nulliparous parturients assigned to either vaginal delivery or cesarean section arms. In addition, patients were assigned to groups receiving or not receiving intravenous oxytocin at the time of epidural placement. Only patients who delivered by the assigned delivery mode were included in the MLAC analyses.RESULTSParturients who later delivered vaginally had 25% and 31% lower MLAC values (0.078% and 0.085% wt/vol bupivacaine, receiving or not receiving intravenous oxytocin, respectively) than those who later delivered by cesarean section (0.102% and 0.106% wt/vol bupivacaine, receiving or not receiving intravenous oxytocin, respectively).CONCLUSIONSThese data suggest that an increased local anesthetic requirement for epidural labor analgesia is associated with more intense pain related to dystocia. Women in early, clinically normal labor but who later develop dystocia require more local anesthetic and, by inference, are experiencing more severe pain than women who deliver vaginally. This association should be considered when studying the relation between the method of labor analgesia and the course of labor.
PMID: 12657859, UI: 22543534
Anesthesiology 2003 Apr;98(4):912-920
*Ph.D. Candidate, Department of Anesthesiology, University of Michigan, and Department of Neuroscience and Anatomy, The Pennsylvania State University College of Medicine. dagger Professor, Department of Anesthesiology, University of Michigan.
BACKGROUNDAdenosine modulates cell excitability, acetylcholine release, nociception, and sleep. Pontine cholinergic neurotransmission contributes to the generation and maintenance of electroencephalographic and behavioral arousal. Adenosine A(1) receptors inhibit arousal-promoting, pontine cholinergic neurons, and adenosine enhances sleep. No previous studies have determined whether pontine adenosine also modulates recovery from anesthesia. Therefore, the current study tested the hypotheses that dialysis delivery of the adenosine A(1) receptor agonist N6-p-sulfophenyladenosine (SPA) into the pontine reticular formation would decrease acetylcholine release and increase the time needed for recovery from halothane anesthesia.METHODSA microdialysis probe was positioned in the pontine reticular formation of halothane-anesthetized cats. Probes were perfused with Ringer's solution (control) followed by the adenosine A(1) receptor agonist SPA (0.088 or 8.8 mm). Dependent measures included acetylcholine release and a numeric assessment of recovery from anesthesia. An intensive, within-subjects design and analysis of variance evaluated SPA's main effect on acetylcholine release and anesthetic recovery. The adenosine A(1) receptor antagonist 8-cyclopentyl-1,3-dipropylxanthine (DPCPX, 100 &mgr;m) was coadministered with SPA to test for antagonist blocking of SPA's effects.RESULTSSPA significantly (P < 0.0001) decreased acetylcholine release in the pontine reticular formation and significantly (P < 0.0001) delayed recovery from anesthesia. Coadministration of SPA and DPCPX caused no decrease in acetylcholine release or delay in postanesthetic recovery. Dialysis delivery of SPA into the cerebellar cortex confirmed that the SPA effects were site-specific to the pontine reticular formation.CONCLUSIONThe results provide a novel extension of the sleep-promoting effects of adenosine by showing that pontine delivery of an adenosine A(1) receptor agonist delays resumption of wakefulness following halothane anesthesia. This extension is consistent with a potentially larger relevance of the current findings for efforts to specify neurons and molecules causing physiologic and behavioral traits comprising anesthetic states. These data support the conclusion that adenosine A(1) receptors in medial regions of the pontine reticular formation, known to modulate sleep, also contribute to the generation and/or maintenance of halothane anesthesia.
PMID: 12657853
Anesthesiology 2003 Apr;98(4):842-848
*Research Assistant, dagger Predoctoral Fellow, double dagger Professor and Chairman, section sign Assistant Professor.
BACKGROUNDWith invasion of bacteria, the host defense system is activated by a complex cascade of various mechanisms. Local anesthetics previously were shown to interact with diverse components of the immune response, such as leukocyte adherence on endothelial monolayers, oxidative burst, or crosstalk within lymphocyte subset populations. However, effects of newer local anesthetics like bupivacaine and ropivacaine on antibacterial host defense-primarily phagocytosis activity, oxidative burst, or CD11b expression-still remain unclear.METHODSWhole blood samples were preincubated with local anesthetics (lidocaine, 9.2, 92.2, and 1,846 &mgr;m; bupivacaine, 6.1, 61, and 770 &mgr;m; ropivacaine, 6.4, 64, and 801 &mgr;m). For the oxidative burst and CD11b assay, dihydroethidium was added to the probes. After viable Staphylococcus aureus was added in a 5 to 1 ratio following leukocyte count, phagocytosis was stopped at different times, and staining with monoclonal antibodies was performed for subsequent flow cytometric analysis of phagocytosis activity, oxidative burst, and CD11b expression.RESULTSGranulocyte phagocytosis activity, CD11b expression, and generation of reactive oxygen species were significantly reduced by lidocaine (P < 0.0002) and bupivacaine (P < 0.005) in the highest concentration (1,846 &mgr;m and 770 &mgr;m, respectively). The capability of granulocytes to ingest bacteria was significantly depressed only by lidocaine (P < 0.003). Ropivacaine had no significant effect on any parameter investigated.CONCLUSIONSLocal anesthetic dose and structure dependently inhibit inflammatory and immunologic parameters of granulocyte functions. Ropivacaine shows low interference with granulocyte immunologic and inflammatory functions.
PMID: 12657844
Anesthesiology 2003 Apr;98(4):5A-6A
PMID: 12657836, UI: 22543511
Anesthesiology 2003 Mar;98(3):798
PMID: 12606936, UI: 22494342
Anesthesiology 2003 Mar;98(3):784-5
Department of Anesthesia, CLINIC Hospital Universitari, Barcelona, Spain. jocon@clinic.ub.es
PMID: 12606927, UI: 22494333
Anesthesiology 2003 Mar;98(3):781-3
Department of Anesthesiology and Intensive Care, Hamamatsu University School of Medicine, Japan. igaiga@hama-med.ac.jp
PMID: 12606926, UI: 22494332
Anesthesiology 2003 Mar;98(3):723-8
Orthopedic Anesthesia, Cook County Hospital, Chicago, Illinois 60612, USA. Carlofra@aol.com
BACKGROUND: Every approach to the sciatic nerve in the buttocks currently requires the identification of pelvic bone structures. The large size of the nerve and its constant trajectory suggest that a simplified approach is possible. METHODS: During the first stage, 24 sciatic nerves in adult cadavers were dissected. The most significant findings were, (1) caudal to the piriformis muscle the sciatic nerve runs parallel to the midline (intergluteal sulcus); (2) the distance between the nerve and the intergluteal sulcus during this course is approximately 10 cm in adults, regardless of their gender, size, or body habits. In the clinical stage 20 blocks were performed at 10 cm from the midline of the buttocks using a nerve stimulator and insulated needles. RESULTS: All blocks were accomplished in less than 8.5 min. The technique proved easy to teach. Residents performed most of the blocks. Incision time, measured from the time of the injection, was less than 29 min in all cases. There were 18 successful blocks and 2 failures. CONCLUSIONS: Because of the intimate relationship of the sciatic nerve to the bony pelvis, the position of this nerve in the buttocks is constant. Caudal to the piriformis muscle the nerve runs vertically between the ischium and the greater trochanter. The location of this narrow passage, not the buttocks' size, determines the position of the nerve. While the size of the buttocks is variable among different individuals and in the same individual at different stages of adult life, the relationship of the sciatic nerve to the pelvis is constant throughout life. Using this relationship to our advantage, a sciatic block in adults can be accomplished at 10 cm lateral to the intergluteal sulcus without a need for identification of buried structures or line tracings.
PMID: 12606918, UI: 22494324
Anesthesiology 2003 Mar;98(3):719-22
Department of Anesthesiology, Trakya University Medical Faculty, Edirne, Turkey. alparslanturan@yahoo.com
BACKGROUND: Neostigmine has been added to local anesthetics for different nerve blocks. This study was conducted to evaluate effects of neostigmine when added to ropivacaine for caudal anesthesia. METHODS: We studied children, aged 1-5 yr, undergoing inguinal hernia and hypospadias surgery. After standard induction of anesthesia, Group I received 0.2% ropivacaine 0.5 ml/kg and Group II received 0.2% ropivacaine 0.5 ml/kg with 2 microg/kg neostigmine via the caudal route. Heart rate, mean arterial pressure, and pulse oximetry were recorded before induction, after induction, and then every 10 min after caudal anesthesia. Hemodynamic, Toddler-Preschooler Postoperative Pain Scale pain score, and sedation score values were recorded 30 min after extubation and at hours 2, 4, 6, 12, and 24. A pain score greater than 3/10 resulted in administration of rectal paracetamol. RESULTS: There were no differences between the groups in demographic and hemodynamic data, duration of surgery and anesthesia, time to extubation, or sedation scores. The pain scores were significantly lower in Group II at 6 and 12 h (P < 0.05). Time to first analgesic requirement was statistically prolonged in Group II (19.2 +/- 5.5h) when compared with Group I (7.1 +/- 5.7 h) (P < 0.05). Total analgesic consumption was statistically larger in Group I (174 +/- 96 mg) when compared with Group II (80 +/- 85.5 mg) (P < 0.05). The incidence of vomiting (3 patients in Group II and 1 patient in Group I) was not statistically significantly different. CONCLUSIONS: The authors found that a single caudal injection of neostigmine when added to ropivacaine offers an advantage over ropivacaine alone for postoperative pain relief in children undergoing genitourinary surgery.
PMID: 12606917, UI: 22494323
Anesthesiology 2003 Mar;98(3):651-7
University of Toronto, Toronto, Ontario, Canada. davy.cheng@uwo.ca
BACKGROUND: The authors assessed the safety and resource use associated with fast-track cardiac anesthesia (FTCA) after coronary artery bypass graft surgery (CABG) over a 1-yr period. METHODS: One hundred twenty patients were initially randomized to FTCA (n = 60) or conventional anesthetic (n = 60) for primary elective CABG surgery. Patients were followed for 1-yr after index surgery through linkage to universal administrative databases. Acute care hospital readmission rates and length of stay (LOS) and the downstream use of health resources were compared. Resource use was analyzed as use of hospital and rehabilitation center bed-days, expenditures on physician services, and use of cardiac drugs. RESULTS: There were no deaths during the 1-yr follow-up after initial discharge; 15 (25%) patients from both groups were readmitted to acute care hospitals in the follow-up period. The mean LOS for acute care readmission was 0.3 (1.0) in the FTCA and 1.6 (6.3) days in the conventional group at 3 months; P= 0.01, 95% CI (0.1, 5.7) and 0.8 (1.8) and 2.9 (9.6) days at 12 months; P= 0.01, 95% CI (0.2, 7.5). Two (3.3%) patients in the FTCA group and 9 (15%) patients in the conventional group were transferred to rehabilitation facilities. The LOS was 0.3 (1.5) and 2.3 (5.7) days respectively; P= 0.001, 95% CI (0.6, 4.0). Specialist visits were more frequent in the FTCA group 6.2 (13.2) versus 1.9 (2.2) visits respectively; P= 0.002, 95% CI (-9.0, -1.3). Percentage reduction of FTCA cost was 68% at 3 months, P= 0.0002 and 49.5% at 1-yr, P= 0.004 after index hospital discharge. CONCLUSIONS: Fast-track cardiac anesthesia is a safe practice that decreases resource use for a 1-yr period after index hospitalization.
PMID: 12606909, UI: 22494315
Anesthesiology 2003 Mar;98(3):597-8
PMID: 12606898, UI: 22494304
Eur J Anaesthesiol 2003 Mar;20(3):257-8
PMID: 12650500, UI: 22537011
Eur J Anaesthesiol 2003 Mar;20(3):239-44
University of Wurzburg, Department of Anaesthesiology, Germany. peter.kranke@mail.uni-wuerzburg.de
BACKGROUND AND OBJECTIVE: Acute hiccup is a minor complication that can occur during sedation or general anaesthesia. The disorder can disturb the surgical field, might interfere with lung ventilation or could hamper diagnostic procedures. The objective was to perform a systematic search for interventions aimed at treating hiccup occurring during anaesthesia or sedation. METHODS: A systematic search for reports describing interventions to treat hiccup in conjunction with anaesthesia was carried out (MEDLINE, EMBASE, Cochrane-Library, manual screening of reference lists and review articles, up to December 2001). Search terms were 'hiccup', 'singultus' or 'hiccough'. RESULTS: Twenty-six reports involving approximately 581 patients focused on hiccup remedies in the anaesthesia setting. Only one report was substantiated by a randomized controlled trial. This investigated methylphenidate 10 mg intravenously in 51 patients, which did not show a beneficial effect compared with placebo. Hiccup was a self-limiting phenomenon. Case series and case reports focused on various systemically applied drugs in 12 reports, stimulating techniques (e.g. pharyngeal stimulation) in seven, topical applied remedies (e.g. intranasal ice-cold water) in four, and ventilation techniques (e.g. continuous positive pressure ventilation) in two. CONCLUSIONS: A large variety of interventions have been proposed for the treatment of hiccup during anaesthesia and sedation. However, perioperative treatment is still based on empirical findings and no treatment is 'evidence-based'. Thus, no valid recommendations for the treatment of hiccup can be derived. Uncontrolled observations are inadequate to establish treatment efficacy.
PMID: 12650496, UI: 22537007
Eur J Anaesthesiol 2003 Mar;20(3):212-9
Hamamatsu University School of Medicine, Department of Anesthesiology and Intensive Care, Hamamatsu, Japan. je2fbw@hama-med.ac.jp
BACKGROUND AND OBJECTIVE: The aim was to determine the effect of acute and chronic administration of 7-nitroindazole, a selective neuronal nitric oxide synthase inhibitor, on the righting reflex ED50 and the minimum alveolar concentration during sevoflurane anaesthesia in rats. METHODS: 7-Nitroindazole was acutely (0, 50 and 100 mg kg(-1)) and chronically (0 and 150 mg kg(-1) day(-1), 4 days) administered to rats. After the preparation, the minimum alveolar concentration and the righting reflex ED50 were measured. The concentration of cGMP in the brain, cerebellum and spinal cord was also measured. RESULTS: Acute administration reduced the minimum alveolar concentration (50 mg kg(-1), 58.8% (95% CI: 50.3-67.3%) of the baseline value, P < 0.01; 100 mg kg(-1), 55.8 (46.9-64.7), P < 0.01) and the righting reflex ED50 (50 mg kg(-1), 27.2 (17.2-37.2), P < 0.01; 100 mg kg(-1), 14.3 (6.6-22.0), P < 0.01). Chronic administration did not reduce the minimum alveolar concentration; however, it reduced the righting reflex ED50 (65.3 (52.9-77.7), P < 0.01). Overall, the reduction in minimum alveolar concentration in the acute and chronic protocol did not correlate with that of the righting reflex ED50. 7-Nitroindazole (100 mg kg(-1), acute) reduced the cGMP concentration within the cerebellum by 55.4%; however, it did not decrease concentrations in the brain or spinal cord. CONCLUSIONS: Different mechanisms are responsible for the observed alterations to the minimum alveolar concentration and the righting reflex ED50 following treatment with 7-nitroindazole. The nitric oxide-cGMP pathway might play a less important role in the determination of minimum alveolar concentration than the righting reflex ED50.
PMID: 12650492, UI: 22537003
Eur J Anaesthesiol 2003 Mar;20(3):205-11
University School of Medicine, Department of Anaesthesiology, CSV Arrixaca Hospital, Murcia, Spain.
BACKGROUND AND OBJECTIVE: This study was designed to compare the haemodynamic, electrophysiological and pharmacodynamic effects of three selective inhibitors of the different isoenzyme forms of phosphodiesterase (PDE) on ischaemia-induced dysrhythmias in the anaesthetized rat. The drugs used were pimobendan, a selective PDE III inhibitor, rolipram, a selective PDE IV inhibitor, and zaprinast, a selective PDE V inhibitor. METHODS: The coronary artery was occluded 15 min after commencing drug administration, and myocardial ischaemia was maintained for 30 min during which the heart rate and mean arterial pressure were recorded. cAMP and cGMP were determined by radioimmunoassay. RESULTS: Pretreatment with rolipram decreased the duration of ventricular tachycardia without any change in the incidences of dysrhythmias or the mortality rate. This drug did not modify ventricular content of adenosine 3',5'-cyclic monophosphate (cAMP) or guanosine 3',5'-cyclic monophosphate (cGMP). Pimobendan (1 mg kg(-1) + 0.1 mg kg(-1) min) decreased the duration of ventricular tachycardia. This dose of pimobendan and zaprinast (1 mg kg(-1) + 0.1 mg kg(-1) min(-1)) increased the incidence rate of ventricular fibrillation following coronary artery ligation and the mortality rate. Moreover, both drugs increased cGMP in the ventricle. CONCLUSIONS: The results demonstrated that pimobendan and zaprinast increased the incidence of dysrhythmias and the mortality rate, which was accompanied by an increase in the ventricular content of cGMP. Rolipram decreased the duration of ventricular tachycardia without a change in the cyclic nucleotide content or in the mortality rate.
PMID: 12650491, UI: 22537002
Eur J Anaesthesiol 2003 Mar;20(3):175-81
University Hospital, Department of Anaesthesiology and Intensive Care, Munster, Germany.
In adults, a number of measures to reduce perioperative blood loss have been established. These techniques serve to reduce patients' exposure to homologous blood. Most adults are concerned with this issue especially since many patients became infected with human immunodeficiency virus (HIV) during the 1980s through exposure to blood components. While blood-saving strategies are widely used in adults, they are mostly neglected in infants. However, it is these young patients with their whole life in front of them who, it could be argued, would benefit especially from any potentially avoidable infection (HIV, hepatitis, etc.) or immunological complications. In infants and small children, these blood-sparing techniques may not be as effective as in adults and technical limitations may prevent their application. However, some of these measures can be used and may serve to prevent or reduce exposure to homologous blood. In the following review, blood-saving techniques established in adults are described and their applicability for paediatric patients discussed.
PMID: 12650487, UI: 22536998
Eur J Anaesthesiol 2002 Jul;19(7):532-4
PMID: 12113620, UI: 22108337
JAMA 2003 Mar 12;289(10):1307-10
Department of Paediatric Surgery, Institute of Child Health and Great Ormond Street Hospital for Children, London, England. l.spitz@ich.ucl.ac.uk
PMID: 12633195, UI: 22521476
Lancet 2003 Mar 1;361(9359):783
PMID: 12620759, UI: 22508474