Anesthesia and analgesia
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Anesthesia and analgesia · Nov 1995
Randomized Controlled Trial Clinical TrialAntagonism of mivacurium neuromuscular block: neostigmine versus edrophonium.
This study was designed to compare the effectiveness of antagonism of mivacurium blockade with either neostigmine, edrophonium, or spontaneous recovery. Thirty ASA physical status I or II patients provided informed consent and were randomized to one of the following groups: Group 1, placebo saline; Group 2, edrophonium (1 mg/kg); and Group 3, neostigmine (70 micrograms/kg) (n = 10/group). All studied patients had anesthesia induced with propofol and maintained with propofol/N2O/fentanyl. ⋯ Clinically adequate spontaneous recovery (TOF% > or = 70%) of the mivacurium block with placebo required 15-18 min. On average, clinically adequate antagonism of mivacurium by edrophonium was 50% faster than placebo and 30%-40% faster than with neostigmine. In summary, the speed of antagonism with edrophonium is faster than with neostigmine when antagonizing deep mivacurium NM block.(ABSTRACT TRUNCATED AT 250 WORDS)
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Anesthesia and analgesia · Nov 1995
Clinical TrialLaryngeal mask airway positioning is related to Mallampati grading in adults.
The Mallampati classification is a commonly used means of preoperatively predicting a difficult endotracheal intubation. As the laryngeal portion of the laryngeal mask airway (LMA) must sit over the larynx, we wondered whether the Mallampati classification also predicts difficulty in achieving adequate seating of the LMA. LMA positioning was assessed prospectively in 100 adult patients by fiberoptic bronchoscopy to determine whether there was a relationship between the ease of seating of the LMA and the Mallampati classification. ⋯ In all 28 cases of difficulty with LMA insertion, the patients were Mallampati class 2 or 3. In two cases the LMA was abandoned, and in these cases both patients were Mallampati class 3, (P = 0.0001 by chi 2 analysis). We conclude that the Mallampati classification indicates difficulty not only in tracheal intubation but also in achieving an adequate airway with the LMA.
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Anesthesia and analgesia · Nov 1995
Cerebral metabolic consequences of hypotensive challenges in hemodiluted pigs with and without cardiopulmonary bypass.
We tested the hypothesis that progressive aortic hypotension with bicarotid occlusion produces greater reductions in cerebral blood flow (CBF) and more flow-metabolism mismatching with hemodilution during cardiopulmonary bypass (CPB) than with hemodilution alone. In Yorkshire pigs randomized to hemodilution with CPB (n = 10) or hemodilution without CPB (control; n = 9), the effects of bicarotid ligation and graded hypotension on CBF (microspheres), the electroencephalogram (EEG), and cortical energy metabolites were examined. After bicarotid ligation, systemic flow was reduced for 15-min intervals of 80, 60, and 40 mm Hg aortic pressure, followed by a cortical brain biopsy. ⋯ Although CBF remained 40% lower at each level of hypotension in CPB than control animals (P < 0.05), EEG scores showed no intergroup differences, indicating similar flow-metabolism matching. Brain metabolites were similar between CPB and control groups (adenosine triphosphate, 9.6 +/- 2.4 vs 12.4 +/- 1.9 mumol/g; adenosine diphosphate, 6.0 +/- 0.7 vs 6.3 +/- 0.4 mumol/g; adenosine monophosphate, 4.8 +/- 0.9 vs 3.8 +/- 0.8 mumol/g; creatine phosphate, 8.3 +/- 1.8 vs 7.9 +/- 1.0 mumol/g; and lactate, 178.4 +/- 20.2 vs 150.8 +/- 13.9 mumol/g). Thus, despite significantly lower CBF during hypotension with bicarotid occlusion in hemodiluted animals during normothermic CPB, cortical electrical activity and the balance between flow and metabolism did not differ from those in control animals without CPB.
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Anesthesia and analgesia · Nov 1995
Aprotinin prolongs whole blood activated partial thromboplastin time but not whole blood prothrombin time in patients undergoing cardiac surgery.
Aprotinin is being used increasingly to limit cardiopulmonary bypass (CPB)-induced coagulation derangements. Since whole blood prothrombin time (PT) and activated partial thromboplastin time (APTT) assays are beneficial in the treatment of bleeding after CPB, we studied the potential effect of aprotinin on these whole blood assays. Blood specimens from 151 cardiac surgical patients were obtained in two phases: prior to heparin administration, before CPB, and subsequent to heparin neutralization after CPB. ⋯ Whole blood PT results were similar between normal saline. (NS)- and aprotinin-spiked specimens before CPB (A, 12.9 +/- 1.5s; NS, 12.8 +/- 1.5s; P = 0.76) and after CPB (A, 17.5 +/- 2.4s; NS, 17.7 +/- 2.4s; P = 0.58). In contrast, whole blood APTT results were prolonged in aprotinin-spiked specimens prior to CPB (A, 63.3 +/- 32.2s; NS, 38.6 +/- 16.3s; P < 0.0001) and after CPB (A, 65.9 +/- 23.7s; NS, 45.7 +/- 14.4s; P < 0.0001). A dose-dependent prolongation of whole blood APTT by aprotinin was demonstrated by a greater mean difference in APTT (P = 0.0001) between specimens spiked with NS or 200 KIU (17.5 +/- 12.2s) vs 400 KIU (27.8 +/- 21.5s) of aprotinin.(ABSTRACT TRUNCATED AT 250 WORDS)