Anesthesia and analgesia
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Anesthesia and analgesia · Jan 1989
Randomized Controlled Trial Clinical TrialFailure of proglumide, a cholecystokinin antagonist, to potentiate clinical morphine analgesia. A randomized double-blind postoperative study using patient-controlled analgesia (PCA).
The potential clinical utility of drug interactions between morphine and the cholecystokinin antagonist proglumide was examined in 80 postoperative patients suffering from moderate to severe pain. Four groups of ASA I-III patients (mean age 51 years, mean weight 72 kg) recovering from major abdominal or gynecological surgery (mean duration of surgery 141 minutes) performed under balanced anesthesia (midazolam, droperidol, fentanyl, N2O, enflurane) were randomly assigned to self-administer morphine-proglumide mixtures on the first postoperative day (ODAC; morphine demand dose 3 mg; infusion rate 0.36 mg/hr; lockout time 2 minutes; hourly maximum dose 15 mg/hr; proglumide doses per demand 0, 50 micrograms, 100 micrograms, or 50 mg). ⋯ There were no statistically significant differences between the groups either for drug consumption, pain scores, or side effects. It is therefore concluded that proglumide does not potentiate morphine analgesia in a clinical (postoperative) setting.
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Anesthesia and analgesia · Jan 1989
Paravertebral somatic nerve block: a clinical, radiographic, and computed tomographic study in chronic pain patients.
The spread of solution after a standardized paravertebral injection was studied to determine the precision and predictability of paravertebral spread. The spread of 5 ml of a solution of radiological contrast medium (sodium iothalamate) and local anesthetic mixture after 45 (34 thoracic, 11 lumbar) paravertebral injections was studied in 31 patients by radiography and computed tomography and correlated with the clinical effects. Spread confined to the paravertebral area occurred after only eight (18%) injections. ⋯ The distance from bony landmarks to pleura frequently fell outside the limits recommended by many standard texts. We conclude that the spread of a small volume of solution after paravertebral injection is imprecise and unpredictable. Neurolytic and diagnostic paravertebral injections performed without the aid of radiological imaging and contrast media should be regarded as hazardous and interpreted with extreme caution.
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Anesthesia and analgesia · Jan 1989
Dose-response relationships for edrophonium and neostigmine as antagonists of moderate and profound atracurium blockade.
To measure the ability of neostigmine and edrophonium to reverse moderate and profound atracurium blockade, dose-response relationships were established for these reversal agents given at 1% and 10% twitch height recovery. Eighty-five ASA I and II adult patients received atracurium, 0.4 mg/kg, during a thiopental-nitrous oxide-enflurane anesthetic. Train-of-four stimulation was applied every 12 seconds, and the force of contraction of the adductor pollicis muscle was recorded. ⋯ The ED80 for edrophonium was 0.22 +/- 0.04 mg/kg and 1.14 +/- 0.33 mg/kg, respectively. These values corresponded to neostigmine:edrophonium potency ratios of 16.6 +/- 3.5 and 35.3 +/- 8.9 at 90% and 99% blockade respectively (P less than 0.006). We conclude that the relative potency of neostigmine is greater than that of edrophonium for antagonism of profound atracurium blockade.
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Anesthesia and analgesia · Jan 1989
Ketamine potentiates nondepolarizing neuromuscular relaxants in a primate.
Ketamine has many neuromuscular effects in vitro. Its neuromuscular effects in vivo have been controversial and inconsistent. To systematically examine its neuromuscular effects over a wide dose range and its interaction with all popular nondepolarizing neuromuscular relaxants, the effects of ketamine 2, 5, and 10 mg/kg IV were studied on a continuous but incomplete (50%) neuromuscular block preestablished by an IV infusion of d-tubocurarine, atracurium, vecuronium, and pancuronium. ⋯ Ketamine 2 mg/kg potentiated the neuromuscular relaxants in the following order of magnitude: vecuronium greater than atracurium greater than d-tubocurarine greater than pancuronium. However, with a 10 mg/kg dose of ketamine, pancuronium became as potentiated as was vecuronium, i.e., pancuronium = vecuronium greater than atracurium greater than d-tubocurarine. It is concluded that in the primate, ketamine potentiates all nondepolarizing muscle relaxants in a dose-dependent manner.