Anesthesia and analgesia
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This study quantitated the force applied during tracheal intubation to determine (a) whether the force differed among novice and experienced intubators, and (b) whether the force required differed when intubating patients' tracheas versus intubating the trachea of a commonly used training mannequin. We studied 27 tracheal intubations performed by 17 experienced (greater than 100 prior intubations) and 10 novice (less than 10 prior intubations) intubators. Each intubation was performed with a No. 3 Macintosh blade instrumented with strain gauges to determine force applied in the sagittal plane. ⋯ The only difference was in the impulse (force x duration), which was more for the novice group largely because of the longer average duration of intubation (40 +/- 12 s vs 19 +/- 4 s, P = 0.06). Among experienced intubators, we found that applied force correlated with patient weight and Mallampati class. Intubation of the Laerdal Airway Management Trainer required mean forces comparable to those required in patients (26.6 +/- 2.5 N vs 22.3 +/- 2.9 N), although the maximum force applied during the intubation effort was greater (58.3 +/- 4.7 N vs 43.2 +/- 4.7 N, P less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)
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Anesthesia and analgesia · Mar 1992
Randomized Controlled Trial Comparative Study Clinical TrialMivacurium: dose-response relationship and administration by repeated injection or infusion.
The dose-response relationship and neuromuscular blockade after infusion or repeated injection of mivacurium were studied in 65 patients in nitrous oxide-narcotic anesthesia. The ED95 (twitch tension) was determined in 45 patients by intravenous injection of a single bolus of 30, 39, 47, 54, or 60 micrograms/kg (9 patients per dose). Another 20 patients received an initial bolus of 2 x ED95 followed either by an infusion started at 5% twitch recovery (i.e., 95% depression) and adjusted to sustain 95% twitch depression (n = 10) or by repeated injection of 0.6 x ED95 whenever twitch tension had recovered to 25% of control (n = 10). ⋯ A 6 +/- 2 min recovery index was found after up to 10 repeat injections given every 9 +/- 3 min. There was no significant effect of neostigmine in both groups. In conclusion, the recovery indices after the infusion or repeat injection of near-equal doses of mivacurium were identical.
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Anesthesia and analgesia · Mar 1992
Comparative StudyHemidiaphragmatic paresis during interscalene brachial plexus block: effects on pulmonary function and chest wall mechanics.
We studied the effects of unilateral hemidiaphragmatic paresis caused by interscalene brachial plexus block on routine pulmonary function in eight patients. In an additional four patients, we studied changes in chest wall motion during interscalene block anesthesia by chest wall magnetometry. Ipsilateral hemidiaphragmatic paresis, as diagnosed by ultrasonography, developed in all patients within 5 min of interscalene injection of 45 mL of 1.5% mepivacaine with added epinephrine and bicarbonate. ⋯ Peak expiratory and maximum midexpiratory flow rates were also significantly reduced. Interscalene block caused changes in pulmonary function and chest wall mechanical motion that were similar to those published in previous studies on patients with hemidiaphragmatic paresis of pathological or surgical etiology. Interscalene block probably should not be performed in patients who are dependent on intact diaphragmatic function and in those patients unable to tolerate a 25% reduction in pulmonary function.
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Anesthesia and analgesia · Mar 1992
Randomized Controlled Trial Comparative Study Clinical TrialDifferential analgesic effects of low-dose epidural morphine and morphine-bupivacaine at rest and during mobilization after major abdominal surgery.
In a double-blind, randomized study, epidural infusions of low-dose morphine (0.2 mg/h) combined with low-dose bupivacaine (10 mg/h) were compared with epidural infusions of low-dose morphine (0.2 mg/h) alone for postoperative analgesia at rest and during mobilization and cough in 24 patients after elective major abdominal surgery. All patients in addition received systemic piroxicam (20 mg daily). ⋯ We conclude, that low-dose epidural bupivacaine potentiates postoperative low-dose epidural morphine analgesia during mobilization and cough. Evaluation of postoperative analgesic regimens should include assessment of pain during various activities as different analgesics may have differential effects on pain at rest and during mobilization.