Anesthesiology
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Multicenter Study Comparative Study Clinical Trial
Multisite evaluation of a continuous intraarterial blood gas monitoring system.
We compared the performance of a new, continuous intraarterial blood gas (CIABG) monitor with arterial values obtained periodically and analyzed by conventional equipment. ⋯ Over the range of values and under the clinical conditions studied, CIABG monitoring provides immediate blood gas results and trend information with sufficient agreement with in vitro results to be reliable for decision making in most clinical circumstances. Generally, the differences in the values between the two methods of analysis were the result of the combination of the inherent errors of each method. Additional studies need to be undertaken to evaluate the performance of the CIABG monitor across wider ranges of blood gas values, especially for arterial PO2 values less than 60 mmHg and arterial PCO2 values greater than 50 mmHg.
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Randomized Controlled Trial Clinical Trial
Hemodynamic and analgesic profile after intrathecal clonidine in humans. A dose-response study.
Epidural clonidine produces effective postoperative analgesia in humans. Observed side effects include hypotension, bradycardia, sedation, and dryness of the mouth. A recent clinical study demonstrated that 150 micrograms intrathecal clonidine administered postoperatively as the sole analgesic agent was effective but produced hypotension and sedation. Animal studies have provided evidence of a biphasic effect on blood pressure after intrathecal clonidine administration, but no data concerning this effect in humans currently exist. This study was performed to evaluate the dose-response hemodynamic and analgesic profiles of intrathecal clonidine administered after a standard surgical intervention, without perioperative administration of additional analgesics, local anesthetics, or tranquilizers. ⋯ These results demonstrate dose-dependent analgesia after intrathecal clonidine at doses as great as 450 micrograms. The nearly immediate analgesic effect observed after intrathecal injection of 300 and 450 micrograms clonidine strongly argues for a spinal rather than a systemic site of action of this alpha 2-adrenergic agonist. After 300 and 450 micrograms intrathecal clonidine a relative hemodynamic stability is observed, suggesting a pressor effect at peripheral sites.
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Comparative Study
Neuromuscular effects of rocuronium on the diaphragm and adductor pollicis muscles in anesthetized patients.
Rocuronium has properties that may make it suitable for rapid-sequence intubation. However, its neuromuscular effects have been studied only on the adductor pollicis. This study compares the neuromuscular effect of rocuronium on the diaphragm and adductor pollicis in humans. ⋯ The diaphragm is more resistant than the adductor pollicis to rocuronium, as shown by greater ED50 and ED95 and faster recovery of the twitch height. The intubating dose of 0.60 mg.kg-1 is close to the ED95 of 0.50 mg.kg-1 for the diaphragm.