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
Potentiation of the analgesic properties of fentanyl-like opioids with alpha 2-adrenoceptor agonists in rats.
Data on the analgesic properties of alpha 2 agonists and their interactions with opioids are conflicting. Experiments were conducted in rats to evaluate whether various available alpha 2 agonists can potentiate the analgesic properties of opioids and to determine the route of administration needed for optimal interaction. ⋯ The tested alpha 2 agonists can potentiate the analgesic properties of opioids, but they have no intrinsic antinociceptive effects on spinal reflexes on their own. The potentiating activities of the alpha 2 agonists could be measured both in terms of a reduction of the amount of opioid needed to reach a particular level of analgesia and in terms of a longer duration of analgesia with a fixed dose of the opioid. The potentiations were observed with various alpha 2 agonists and opioids and appeared independent of the routes of administration.
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Randomized Controlled Trial Comparative Study Clinical Trial
A single dose of morphine sulfate increases the incidence of vomiting after outpatient inguinal surgery in children.
In children, opioids are valuable both for their analgesic properties and for their salutary effect on emergence delirium. Although intraoperative administration of opioids is often cited as the cause of postoperative emesis, few data quantitating the magnitude of this effect exist. ⋯ For children undergoing inguinal surgery, the administration of a single dose of intravenous morphine after the induction of anesthesia smooths emergence from anesthesia as assessed by improved cooperation and sedation in the PACU, decreases the need for postoperative analgesics, but increases the incidence of vomiting in the first 24 h after surgery.