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Anesthesiology 2002 Sep;97(3):762-3
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PMID: 12218562, UI: 22205792
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Anesthesiology 2002 Sep;97(3):755; discussion 756
PMID: 12218554, UI: 22205784
Anesthesiology 2002 Sep;97(3):745-9
Department of Anesthesiology, The University of Texas Medical Branch, Galveston 77555, USA. ramuelle@utmb.edu
PMID: 12218547, UI: 22205777
Anesthesiology 2002 Sep;97(3):735-7
Department of Anesthesiology and Resuscitology, Okayama University Medical School, Okayama City, Japan.
PMID: 12218543, UI: 22205773
Anesthesiology 2002 Sep;97(3):622-9
Faculte de Pharmacie, Universite de Montreal, Quebec, Canada.
BACKGROUND: Mivacurium and isomers undergo rapid hydrolysis by plasma cholinesterase. As this enzyme is largely distributed, it cannot be excluded that these isomers might undergo peripheral elimination. This hypothesis was investigated in patients by measuring the difference between arterial and venous concentrations under a constant-rate continuous infusion of mivacurium. METHODS: During propofol-remifentanil anesthesia, eight adult consenting patients received an intravenous bolus dose of 0.2 mg/kg mivacurium, followed by a constant infusion (3, 5, or 7 microg. kg. min ) into the brachial vein. One hour after starting the infusion, arterial (radial artery) and venous (contralateral brachial vein) blood samples were drawn simultaneously at 15-min intervals for 45 min. Mivacurium isomers and metabolite plasma concentrations were determined by stereospecific high-performance liquid chromatography. Using the corresponding arterial and venous concentrations, the tissue extraction coefficient as well as total body clearance were calculated. RESULTS: During steady state conditions, the venous concentrations of the and isomers were 34 +/- 13% and 42 +/- 11% (mean +/- SD) lower than the corresponding arterial concentrations (P < 0.05), respectively. For the isomer, the difference between venous and arterial concentrations was 3 +/- 4% (P = 0.063). Total body clearances of the and isomers were greater when based on venous sampling (P < 0.05). CONCLUSION: Pharmacokinetic parameters derived from a constant infusion of mivacurium depend heavily on the sampling site (arterial or venous) for the rapidly hydrolyzed isomers. These results strongly suggest a significant metabolism of mivacurium within muscle tissue that may account for the large interpatient variability in response to mivacurium.
PMID: 12218529, UI: 22205759
Anesthesiology 2002 Sep;97(3):616-21
Department of Anesthesiology, Hotel-Dieu du Centre-Hospitalier de l' Universite de Montreal (CHUM) and University of Montreal, Quebec, Canada.
BACKGROUND: Dosage guidelines for muscle relaxants are based on dose-response studies, normally performed after several minutes of stable nitrous oxide (N O)-opioid anesthesia. However, relaxants are used immediately after induction of anesthesia. The study was designed to determine the influence of the duration of anesthesia and N O on the onset time at the adductor pollicis (AP) and the corrugator supercilii (CS) muscles of maximum neuromuscular blockade after mivacurium. METHODS: After institutional approval and informed consent, patients were randomly allocated into three groups. Anesthesia was induced with alfentanil and propofol. Group A (n = 10) received mivacurium (0.1 mg/kg) immediately after loss of consciousness. Groups B (n = 10) and C (n = 10) received mivacurium after 15 min of anesthesia with propofol alone (B) or propofol with N O (C). The evoked response to train-of-four stimulation was measured by acceleromyography at the AP and the CS. RESULTS: Maximum neuromuscular blockade (%T1, median [range]) was significantly less in group A than in groups B and C ( < 0.001) at both the AP (81 [47-90]; 90 [35-100]; 100 [93-100], respectively) and the CS (19 [5-63]; 68 [61-100]; 89 [72-100], respectively). Maximum neuromuscular blockade was less in group B than in group C ( < 0.001) at the AP. Onset time of maximum neuromuscular blockade was not different between groups but was shorter at the CS than at the AP. CONCLUSIONS: Duration of anesthesia and N O before mivacurium injection affect intensity of neuromuscular blockade but not onset time. Neuromuscular blockade obtained at the AP after several minutes of stable anesthesia with N O is greater than immediately after induction. This explains in part the discrepancy between the measured ED and the intubating dose.
PMID: 12218528, UI: 22205758
Anesthesiology 2002 Sep;97(3):608-15
Department of Anesthesiology, The University of Texas Medical Branch, Galveston 77555, USA. aaboulei@utmb.edu
BACKGROUND: Intergroup comparisons of clinical productivity are important for strategic planning and evaluation of clinical and business operations. However, in a preliminary study, comparisons of two anesthesiology groups using "per full-time equivalent" measurements were confounded by different concurrencies or staffing ratios, whereas measurements based on "per operating room (OR) site," "per case," and "billed American Society of Anesthesiologists (ASA) units per hour of care" permitted meaningful comparisons despite differing concurrencies. The purpose of this study was to determine whether these measurements would allow for meaningful comparisons when applied to multiple groups. METHODS: Annual totals of total ASA units (tASA), 15-min time units, and the number of cases billed, as well as the average number of daily anesthetizing sites (OR sites) staffed and the average number of anesthesiologists required to the staff sites, were collected from each group that participated. All anesthesia care billed with ASA units was included, except for obstetric care. Any clinical service not billed using ASA units was excluded. Productivity measurements (concurrency, tASA/OR site, hours billed per OR site per day, hours billed per case, tASA billed per hour of anesthesia care, and base units per case) were calculated. Median and range for all groups and for private-practice and academic groups were determined. RESULTS: Eleven private-practice and nine academic groups from 12 states participated in the study. Productivity measurements that are influenced by duration of surgery (hours billed per case, tASA billed per hour of anesthesia care) differed significantly between groups, with private-practice groups having shorter duration than academic groups (median hours billed per case, 1.5 2.6, respectively). Although tASA/OR site measurements were similar in private-practice and academic groups, academic groups worked significantly longer hours billed per OR site per day (median, 6.0 h 7.8, respectively) to achieve the same level of tASA/OR site. Hourly billing productivity (tASA billed per hour of anesthesia care) correlated highly with surgical duration (hours billed per case). CONCLUSION: This study demonstrates a method of comparing departmental clinical productivity between anesthesiology groups. Private-practice groups provided care for cases of shorter duration than academic groups. This difference was evident in several productivity measurements.
PMID: 12218527, UI: 22205757
Anesthesiology 2002 Sep;97(3):578-84
Department of Anesthesiology, Ludwig-Maximilians-University, Munich, Germany. peter.conzen@ana.med.uni-muenchen.de
BACKGROUND: Sevoflurane is degraded to compound A (CpA) by carbon dioxide absorbents containing strong base. CpA is nephrotoxic in rats. Patient exposure to CpA is increased with low fresh gas flow rates, use of Baralyme, and high sevoflurane concentrations. CpA formation during low-flow and closed circuit sevoflurane anesthesia had no significant renal effects in surgical patients with normal renal function. Preexisting renal insufficiency is a risk factor for postoperative renal dysfunction. Although preexisting renal insufficiency is not affected by high-flow sevoflurane, the effect of low-flow sevoflurane in patients with renal insufficiency is unknown. METHODS: After obtaining institutional review board approval, 116 patients with a stable preoperative serum creatinine concentration 1.5 mg/dl or greater were assessable. Patients were randomized to receive either sevoflurane (n = 59, 0.8-2.5 vol%) or isoflurane (n = 57, 0.5-1.4 vol%) at a fresh gas flow rate of 1 l/min or less. Use of opioids was restricted to a minimum, and Baralyme was used to increase CpA exposure. Inspiratory and expiratory CpA concentrations were measured during anesthesia. Renal function (serum creatinine and blood urea nitrogen, urine protein and glucose, creatinine clearance) was measured preoperatively and 24 and 72 h after induction. RESULTS: Demographic patient data did not differ between groups. Patients received 3.1 +/- 2.4 minimum alveolar concentration-hours sevoflurane or 3.8 +/- 2.6 minimum alveolar concentration-hours isoflurane (mean +/- SD). Durations of low flow were 201.3 +/- 98.0 and 213.6 +/- 83.4 min, respectively. Maximum inspiratory CpA with sevoflurane was 18.9 +/- 7.6 ppm (mean +/- SD), resulting in an average total CpA exposure of 44.0 +/- 30.6 ppm/h. There were no statistically significant changes from baseline to 24- and 72-h values for serum creatinine or blood urea nitrogen, creatinine clearance, urine protein, and glucose, nor were there significant differences between both anesthetics. CONCLUSION: There were no statistically significant differences in measured parameters of renal function after low-flow sevoflurane anesthesia compared with isoflurane. These results suggest that low-flow sevoflurane anesthesia is as safe as low-flow isoflurane and does not alter kidney function in patients with preexisting renal disease.
PMID: 12218523, UI: 22205753
Anesthesiology 2002 Sep;97(3):540-9
Department of Anesthesia, McGill University Health Centre, Royal Victoria Hospital, Montreal, Quebec, Canada HA1. franco.carli@muhc.mcgill.ca
BACKGROUND: Multimodal analgesia programs have been shown to decrease hospital stay, but it not clear which functions are restored after surgery. The objective of this study is to evaluate the impact of epidural anesthesia and analgesia on functional exercise capacity and health-related quality of life. METHODS: Sixty-four patients undergoing elective colonic resection were randomized to either patient-controlled analgesia with morphine or thoracic epidural analgesia with bupivacaine and fentanyl (epidural group). All patients in both groups received similar perioperative care and were offered the same amount of postoperative oral nutrition and assistance with mobilization. Primary outcome was functional exercise capacity as measured by the 6-min walking test, and secondary outcome was health-related quality of life, as measured by the SF-36 health survey. These were assessed before surgery and at 3 and 6 weeks after hospital discharge. Other variables measured in hospital included pain and fatigue visual analogue scale, bowel function, time out of bed, nutritional intake, complication rate, readiness for discharge, and length of hospital stay. RESULTS: Although the 6-min walking test and the SF-36 physical health component decreased in both groups at 3 and 6 weeks after surgery, the patient-controlled analgesia group experienced a significantly greater decrease at both times (P < 0.01). Patients in the epidural group had lower postoperative pain and fatigue scores, which allowed them to mobilize to a greater extent (P < 0.05) and eat more (P < 0.05). Length of hospital stay and incidence of complications were similar in both groups, although patients in the epidural group were ready to be discharged earlier. CONCLUSIONS: The superior quality of pain relief provided by epidural analgesia had a positive impact on out-of-bed mobilization, bowel function, and intake of food, with long-lasting effects on exercise capacity and health-related quality of life.
PMID: 12218518, UI: 22205748
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Anesthesiology 2002 Aug;97(2):525; discussion 526
PMID: 12151954, UI: 22145676
Anesthesiology 2002 Aug;97(2):524-5; discussion 525
PMID: 12151953, UI: 22145675
Anesthesiology 2002 Aug;97(2):521; discussion 521-2
PMID: 12151950, UI: 22145672
Anesthesiology 2002 Aug;97(2):488-96
Department of Anesthesiology, Allegheny General Hospital, Pittsburgh Pennsylvania 15212-4772, USA. sjones@wpahs.org
BACKGROUND: The maintenance of constant cerebral blood flow (CBF) as mean cerebral perfusion pressure (CPP) varies is commonly referred to as CBF-pressure autoregulation. The lower limit of autoregulation is the CPP at which the vasodilatory capacity is exhausted and flow falls with pressure. We evaluated variability in the magnitude of percent change in CBF during the hypotensive portion of the autoregulatory curve. We hypothesize that this variability, in normal animals, obeys a Gaussian distribution and characterizes a vasodilatory mechanism that is inherently different from that described by the lower limit. METHODS: Sixty-five male Sprague-Dawley rats were anesthetized with 0.5-1% halothane and 70% nitrous oxide in oxygen. Body temperature was maintained at 37 degrees C. Using a closed, superfused cranial window, CBF (as % of control) was determined using laser Doppler flowmetry (LDF) through the window with the intracranial pressure set at 10 mmHg. Animals with low vascular reactivity to inhaled carbon dioxide and superfused adenosine diphosphate (ADP) or acetylcholine were excluded. MABP was sequentially lowered by exsanguination to 100, 85, 70, 55, and 40 mmHg. Using the %CBF versus CPP plots for each curve (1) the lower limit of autoregulation was identified; (2) the pattern of autoregulation was classified as "peak" (a rise in LDF flow of at least 15% as arterial pressure was dropped), "classic" (plateau with a fall), or "none" (a fall in LDF flow of greater than 15%); (3) the area under the autoregulatory curve between CPPs of 30 and 90 mmHg was calculated; and (4) the magnitude of the %CBF response to hypotension was assessed by determining the %CBF at a CPP of 60 mmHg (%CBFCPP60). RESULTS: Of the 65 curves, 21 had the peak pattern, 33 the classic pattern, and 11 the none pattern. The %CBFCPP60 and autoregulatory area displayed Gaussian distributions, consistent with normal variability. Although %CBFCPP60, autoregulatory area, and pattern were significantly correlated (r or rho > 0.84, P < 0.001), the lower limit correlated weakly with autoregulatory area (r = 0.34, P = 0.012), and not at all with autoregulatory pattern or %CBFCPP60. CONCLUSIONS: The %CBFCPP60 measures an aspect of the autoregulatory curve that is distinct from the lower limit. The peak autoregulatory pattern indicates that vessels are dilating more than is necessary to maintain a plateau in response to the pressure decrease, whereas the none pattern existed in spite of acceptable vascular responses to inhaled carbon dioxide and superfused ADP or ACh and the lack of surgical trauma. These results provide a different view of autoregulation during hypotension, are most likely dependent on the highly regional CBF method used, and could have implications concerning potential cerebral ischemia and hypotension during anesthesia.
PMID: 12151941, UI: 22145663
Anesthesiology 2002 Aug;97(2):374-81
Department of Anesthesia, McGill University, Montreal, Quebec, Canada.
BACKGROUND: Epidural blockade with local anesthetic has been shown to blunt the increase in plasma glucose concentration during and after abdominal surgery. The aim of the study was to test the hypothesis that epidural blockade inhibits this hyperglycemic response by attenuating endogenous glucose production. The authors further examined if the modification of glucose production by epidural blockade has an impact on perioperative protein catabolism. METHODS: Sixteen patients undergoing colorectal surgery received either general anesthesia and epidural blockade with local anesthetic (n = 8) or general anesthesia alone (control, n = 8). Glucose and protein kinetics were assessed by stable isotope tracer technique ([6,6-2H2]glucose, L-[1-13C]leucine) during and 2 h after surgery. Plasma concentrations of glucose, lactate, free fatty acids (FFA), cortisol, glucagon, and insulin were also determined. RESULTS: Epidural blockade blunted the perioperative increase in the plasma concentration of glucose, cortisol, and glucagon when compared with the control group (P < 0.05). Plasma concentrations of lactate, FFA, and insulin did not change. Intra- and postoperative glucose production was lower in patients with epidural blockade than in control subjects (intraoperative, epidural blockade 8.2 +/- 1.9 vs. control 10.7 +/- 1.4 micromol x kg(-1) x min(-1), P < 0.05; postoperative, epidural blockade 8.5 +/- 1.8 vs. control 10.5 +/- 1.2 micromol x kg(-1) x min(-1), P < 0.05), whereas glucose clearance decreased to a comparable extent in both groups (P < 0.05). Protein breakdown (P < 0.05), protein synthesis (P < 0.05), and amino acid oxidation (P > 0.05) decreased with both anesthetic techniques. CONCLUSIONS: Epidural blockade attenuates the hyperglycemic response to surgery through modification of glucose production. The perioperative suppression of protein metabolism was not influenced by epidural blockade.
PMID: 12151927, UI: 22145649
Anesthesiology 2002 Aug;97(2):359-66
Department of Anesthesiology, Pediatrics, and Child and Adolescent Psychiatry, Yale University School of Medicine, New Haven, Connecticut 06520-8051, USA. shu-ming@yale.edu
BACKGROUND: P6 acupuncture in adults is reported to be an effective preventive treatment for postoperative nausea and vomiting (PONV). It is not clear, however, whether this technique is effective as a preventive treatment for PONV in children. METHODS: Children undergoing anesthesia and surgery were randomized to four groups: (a) intravenous saline + bilateral P6 acupoint injections (n = 50); (b) intravenous droperidol + bilateral P6 sham acupuncture (n = 49); (c) intravenous saline + bilateral sham point injections (n = 43); (d) intravenous saline +bilateral P6 sham acupuncture (n = 45). The perioperative anesthetic technique was standardized in all subjects. The incidence of postoperative nausea and vomiting (PONV) was evaluated in postanesthesia care unit (PACU) and 24 h after surgery. RESULTS: Incidence of nausea in the PACU was significantly lower in the acupoint group as compared with the sham point group (32% vs. 56%, P = 0.029) and P6 sham group (32% vs. 64%, P = 0.002) but not as compared with the droperidol group (32% vs. 46%, P = ns). Similarly, subjects in the acupoint group had a significantly lower incidence of vomiting in the PACU as compared with the sham point group (12% vs. 33%, P = 0.026) and P6 sham group (12% vs. 31%, P = 0.029) but not as compared with the droperidol group (12% vs. 18%, P = ns). The combined incidence of early PONV was also lower in the acupoint group as compared with the sham point group (P = 0.045) and P6 sham group (P = 0.004) but not as compared with the droperidol group (42% vs. 51%, P = ns). Finally, significantly fewer subjects in the acupoint group required intravenous ondansetron as an initial rescue therapy (P = 0.024). At 24 h after surgery, however, the incidence of late PONV was similar among the four study groups (P = ns). CONCLUSION: In children, P6 acupoint injections are as effective as droperidol in controlling early postoperative nausea and vomiting.
PMID: 12151925, UI: 22145647
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BMJ 2002 Sep 7;325(7363):532-3
Vitreoretinal Department, Moorfields Eye Hospital, London EC1V 2PD. yyfung@aol.com
PMID: 12217995, UI: 22205913
Br J Anaesth 2002 Jun;88(6):881; discussion 881-2
PMID: 12173218, UI: 22163554
Br J Anaesth 2002 Jun;88(6):879-80; discussion 880
PMID: 12173215, UI: 22163552
Br J Anaesth 2002 Jun;88(6):760-3
PMID: 12173190, UI: 22163526
Can J Anaesth 2002 Jun-Jul;49(6):642-3
PMID: 12067890, UI: 22062779
Can J Anaesth 2002 Jun-Jul;49(6):640-1
PMID: 12067887, UI: 22062776
Can J Anaesth 2002 Jun-Jul;49(6):635-6
PMID: 12067882, UI: 22062771
Can J Anaesth 2002 Jun-Jul;49(6):634
PMID: 12067881, UI: 22062770
Can J Anaesth 2002 Jun-Jul;49(6):614-9
Department of Anesthesiology, MetroHealth Medical Center, Case Western Reserve University, Cleveland, Ohio, USA.
PURPOSE: Cricoid pressure is commonly used during rapid sequence induction and intubation to minimize the risk of aspiration. The objective of the study was to evaluate the ease of fibreoptic (WuScope System(TM)) intubation in anesthetized adults receiving cricoid pressure. METHODS: The intubation difficulty scale (IDS) was used to measure tracheal intubation difficulties in 33 patients undergoing elective surgery with general anesthesia and complete neuromuscular blockade. Each patient had their trachea intubated under two conditions: with and without cricoid pressure. The order of conditions was determined randomly. Cricoid pressure was applied by an experienced anesthesia provider. MAIN RESULTS: An IDS value of 0 (ideal intubation, that is one performed by the first operator on the first attempt, using the first technique with full visualization of the glottis and no vocal cord compression) occurred in 30 of 33 patients (91%) without cricoid pressure and in 22 of 33 patients (67%) with cricoid pressure (P < 0.05). Cricoid pressure compressed the vocal cords in nine patients (27%) and impeded tracheal tube placement in five (15%). In three patients (9%), pressure had to be released in order to successfully intubate. CONCLUSION: Cricoid pressure may impede or even prevent fibreoptic laryngoscopic intubation with the WuScope System(TM).
PMID: 12067876, UI: 22062765
Can J Anaesth 2002 Jun-Jul;49(6):610-3
Department of Anesthesiology and Reanimation, Ondokuz Mayis University, Faculty of Medicine, Samsun, Turkey. bengimd@hotmail.com
PURPOSE: To report a case of awake tracheal intubation through the intubating laryngeal mask airway (ILMA) in a patient with halo traction. Clinical features: A 16-yr-old, 40 kg, boy with atlanto-occipital instability and halo traction was scheduled for surgery under general anesthesia. The head of the patient was fixed in a position of flexion and extension was impossible. Cranial magnetic resonance imaging revealed that pharyngeal and laryngeal axes were aligned, but that the oral axis was in an extreme divergent plane. The tongue and oropharynx were anesthetized with 10% lidocaine spray and bilateral superior laryngeal nerve blockade was performed. Under sedation, awake orotracheal intubation via ILMA was successful. Fibreoptic bronchoscopy has been recommended for awake tracheal intubation in such patients. Other techniques, such as use of the Bullard laryngoscope have been described also but awake tracheal intubation through the ILMA in patients with a halo device in situ has seldom been reported in the medical literature. CONCLUSION: Airway management of patients with cervical spine instability includes adequate preoperative evaluation of the airway and choosing the appropriate intubation technique. We suggest that the ILMA may be an adequate alternative for awake tracheal intubation in patients with an unstable cervical spine and cervical immobilization with a halo device.
PMID: 12067875, UI: 22062764
Can J Anaesth 2002 Jun-Jul;49(6):600-4
Department of Anesthesiology, Baystate Medical Center, Springfield, Massachusetts, USA.
PURPOSE: Epidural fentanyl after a lidocaine and epinephrine test dose, provides adequate analgesia and allows for ambulation during early labour. The current study was designed to determine the influence of hydromorphone added to an epidural fentanyl bolus (e.g., whether there is an increase in duration of analgesia). METHODS: Forty-four labouring primigravid women, at less than 5 cm cervical dilation, who requested epidural analgesia were enrolled in this randomized, double-blind study. After a 3 mL test dose of lidocaine with epinephrine, patients received fentanyl 100 microgram (in 10 mL volume). They randomly received the fentanyl with either saline or hydromorphone (300 microgram). After administration of the initial analgesic, pain scores and side effects were recorded for each patient at ten, 20, and 30 min, and every 30 min thereafter, by an observer blinded to the technique used. RESULTS: The patients were taller in the hydromorphone group (P < 0.04). There were no other demographic differences between the two groups. The mean duration prior to re-dose was not significantly different in the group that received hydromorphone (135 +/- 52 min) compared to the control group (145 +/- 46 min). Side effects were similar between the two groups. No patient in either group experienced any detectable motor block. CONCLUSION: In early labouring patients, the addition of hydromorphone (300 microgram) to epidural fentanyl (100 microgram after a lidocaine and epinephrine test dose) neither prolongs the duration of analgesia nor affects the ability to ambulate, and cannot be recommended according to the current study.
PMID: 12067873, UI: 22062762
Can J Anaesth 2002 Jun-Jul;49(6):571-4
Department of Anesthesiology, Duke University Medical Center, Durham, North Carolina, USA. bucke001@mc.duke.edu
PURPOSE: Patients with hypertrophic obstructive cardiomyopathy (HOCM), a genetic disorder resulting in idiopathic myocardial thickening, can present the anesthesiologist with significant management difficulties. This report reviews the physiology of this important disease process and describes the use of paravertebral nerve blocks (PVB) in the management of a patient with HOCM who presented for partial mastectomy with axillary lymph node dissection. Clinical features: A 72-yr-old female presented for breast cancer surgery with a significant past medical history of HOCM diagnosed during hospitalization for non-small cell lung cancer. PVB were performed at thoracic levels 1-6 and 5 mL of 0.5% ropivacaine and epinephrine 1:400,000 was injected at each level. Intraoperatively the patient required no other medication for analgesia and was comfortable and conversant during the two-hour procedure. She remained pain free following the operation and did not require any opioid medication until the following day. CONCLUSIONS: PVB provide excellent analgesia and are a useful alternative anesthetic when faced with the HOCM patient requiring major breast surgery.
PMID: 12067868, UI: 22062757
Can J Anaesth 2002 Jun-Jul;49(6):566-70
Second Department of Anesthesiology, Toho University School of Medicine, Tokyo, Japan.
PURPOSE: It has been reported that the addition of epinephrine and/or bicarbonate to local anesthetic enhances the depth of epidural blockade and that initial partial bolus injection results in greater caudal spread. We evaluated the anesthetic effects of lidocaine with epinephrine and/or bicarbonate injected into the epidural space by bolus or catheter injection. METHODS: Forty-four patients undergoing epidural anesthesia with 17 mL of 2% lidocaine containing 1:200,000 epinephrine at L4-5 or L5-S1 were randomly divided into four groups. Lidocaine was administrated via epidural catheter [lidocaine catheter (LC) group] or Tuohy needle (lidocaine bolus group), lidocaine-bicarbonate was administrated via catheter (lidocaine-bicarbonate catheter group) or needle [lidocaine-bicarbonate bolus (LBB) group]. Pain threshold after repeated electrical stimulation was performed at L2 and S1 regions. Motor blockade was evaluated using the Bromage scale. Sympathetic blockade was assessed with plethysmographic waveforms from the toe. RESULTS: The pain threshold of the S1 dermatome in LBB group was significantly higher than in the lidocaine only groups, however, differences in the pain threshold at the L2 dermatome among the groups were insignificant. The onset of sensory blockade in the S1 dermatome in the LBB group was significantly shorter than in the LC group. Significantly greater motor blockade was achieved in the lidocaine-bicarbonate groups than in the lidocaine-only groups. The amplitude of plethysmographic waveforms significantly increased within each group. CONCLUSION: Epidural bolus injection of lidocaine-bicarbonate with epinephrine improves the pain threshold and speeds the onset of the blockade of the first sacral region.
PMID: 12067867, UI: 22062756
Eur J Pharmacol 2002 Sep 6;451(1):43
Department of Anaesthesiology, Technische Universitat Munchen, Ismaninger Str. 22, 81675, Munich, Germany
[Medline record in process]
The rapid application of solutions containing the volatile anaesthetics isoflurane or sevoflurane induced inward currents in human embryonic kidney (HEK293) cells carrying rat recombinant alpha(1)beta(2)gamma(2L) GABA(A) receptor assemblies. The responses evoked by the anaesthetics applied via a fast delivery system were recorded using the patch-clamp technique in the whole-cell mode. The anaesthetics induced a fast inward current which was followed by a prominent tail current upon the rapid withdrawal of the agent. These currents were simulated using a kinetic scheme embodying two agonist-like binding steps required for receptor activation, and one binding step by which the anaesthetic induces an open-channel block. According to this model of a biphasic receptor modulation, the open-channel block delays the ion flux through the ligand-gated receptors and, thus, prolongs the overall duration of the current response. Open-channel blocks might also be operative in other ligand-gated ion channels to modulate synaptic strength.
PMID: 12223227, UI: 22211583
Obstet Gynecol 2002 Apr;99(4):652-3
Department of Rehabilitation Medicine, Thomas Jefferson University Hospital, Philadelphia, Pennsylvania, USA. sarmisthar@yahoo.com
BACKGROUND: Sciatic nerve compression has been well documented as a cause of perioperative sciatic neuropathy but rarely during cesarean. CASE: A parturient complained of left foot drop after cesarean delivery for twins performed under spinal anesthesia. Intraoperatively, her right hip was raised with padding under the right buttock to tilt the pelvis approximately 30 degrees to the left. Postoperatively, the patient had weakness, sensory changes, and diminished reflexes in the left lower extremity. Electrodiagnostic studies supported a diagnosis of neurapraxia and partial denervation in the distribution of the sciatic nerve. By postpartum week 6, she had full recovery. CONCLUSION: Elevating the right buttock during cesarean can cause compression of the underlying structures of the left buttock and result in sciatic neuropathy. Decreasing the duration of time the patient is in the left lateral position may reduce the risk of this uncommon but debilitating complication.
PMID: 12039129, UI: 22035956
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