Anesthesia and analgesia
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Anesthesia and analgesia · Jun 1995
Randomized Controlled Trial Clinical TrialAttenuation of cardiovascular responses to tracheal extubation with diltiazem.
We conducted a randomized, double-blind study to examine the effects of intravenous (i.v.) diltiazem (0.1 or 0.2 mg/kg) on hemodynamic changes during tracheal extubation and emergence from anesthesia in 80 ASA physical status I patients undergoing elective gynecologic surgery. The effect of diltiazem was compared with that of lidocaine or saline. Anesthesia was maintained with 0.5%-1.5% isoflurane and 60% nitrous oxide (N2O) in oxygen. ⋯ The inhibitory effect on these cardiovascular responses was greatest with diltiazem 0.2 mg/kg, while the extent of attenuation by diltiazem 0.1 mg/kg was similar to that by lidocaine. We concluded that a bolus dose of i.v. diltiazem 0.1 or 0.2 mg/kg given 2 min before extubation was of value in attenuating the cardiovascular changes occurring in association with tracheal extubation and emergence from anesthesia. This alleviative effect of diltiazem was equal or superior to that of i.v. lidocaine 1 mg/kg.
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Anesthesia and analgesia · Jun 1995
Carbon monoxide production from degradation of desflurane, enflurane, isoflurane, halothane, and sevoflurane by soda lime and Baralyme.
Anecdotal reports suggest that soda lime and Baralyme brand absorbent can degrade inhaled anesthetics to carbon monoxide (CO). We examined the factors that govern CO production and found that these include: 1) The anesthetic used: for a given minimum alveolar anesthetic concentration (MAC)-multiple, the magnitude of CO production (greatest to least) is desflurane > or = enflurane > isoflurane > halothane = sevoflurane. 2) The absorbent dryness: completely dry soda lime produces much more CO than absorbent with just 1.4% water content, and soda lime containing 4.8% or more water (standard soda lime contains 15% water) generates no CO. ⋯ These results suggest that CO generation can be avoided for all anesthetics by using soda lime with 4.8% (or more) water or Baralyme with 9.7% (or more) water, and by using inflow rates of less than 2-3 L/min. Such inflow rates are low enough to ensure that the absorbent does not dry out.
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Anesthesia and analgesia · Jun 1995
Randomized Controlled Trial Comparative Study Clinical TrialThe effects of ketorolac and fentanyl on postoperative vomiting and analgesic requirements in children undergoing strabismus surgery.
Fifty-four ASA I and II children 1 to 10 yr of age undergoing strabismus surgery were randomized to receive in a double-blind fashion intravenous ketorolac (0.9 mg/kg), fentanyl (1 microgram/kg), or saline placebo (2 mL) during a standardized general anesthetic. Patients received no analgesic or antiemetics intraoperatively except for the study drug. Patients receiving ketorolac or placebo compared to fentanyl had a significantly lower incidence of postoperative vomiting in the day surgery unit (DSU) (P = 0.03) and overall (DSU plus home) (P = 0.005). ⋯ No patients required fentanyl postoperatively, indicating that rectal acetaminophen administered in the postanesthesia recovery room provides sufficient analgesia for pediatric strabismus surgery. In conclusion, neither ketorolac nor fentanyl was associated with less postoperative vomiting or analgesic requirements compared to saline placebo administered during pediatric strabismus surgery. Fentanyl should be avoided, as it was associated with a significantly greater incidence of postoperative vomiting compared to ketorolac or placebo.
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Anesthesia and analgesia · Jun 1995
Influence of isoflurane, fentanyl, thiopental, and alpha-chloralose on formation of brain edema resulting from a focal cryogenic lesion.
The objective of this study was to analyze the effects of various anesthetics on the formation of brain edema resulting from a focal cryogenic lesion. Thirty rabbits (six per group) were anesthetized with isoflurane (1 minimum alveolar anesthetic concentration [MAC] 2.1 vol%), fentanyl (bolus 5 micrograms/kg; infusion rate 1.0-0.5 micrograms.kg-1.min-1), thiopental (32.5 mg.kg-1.h-1), or alpha-chloralose (50 mg/kg). Control animals (sham operation, no lesion) received alpha-chloralose (50 mg/kg). ⋯ Brain tissue samples were collected at multiple sites close to and distant from the lesion. Mean arterial pressure, arterial PCO2 and PO2, hematocrit, body temperature, and blood glucose were not different between groups during the posttraumatic course (except for an increased arterial pressure with alpha-chloralose compared to thiopental 4-6 h after trauma). The specific gravity of cortical gray matter was significantly reduced up to a distance of 6 mm from the center of the lesion in animals anesthetized with isoflurane, thiopental, or alpha-chloralose and up to 9 mm in animals given fentanyl.(ABSTRACT TRUNCATED AT 250 WORDS)
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Spinal neostigmine produces analgesia in chronically prepared rats, but not in sheep. However, since pain itself activates bulbospinal inhibitory pathways, neostigmine may be more effective in the postoperative period. We examined in sheep the antinociceptive effect of intrathecal neostigmine in the acute postoperative period and determined the muscarinic receptor subtype activated by neostigmine. ⋯ In contrast, intrathecal neostigmine caused no antinociception in another similar study performed at least 5 days after surgery. Pirenzepine, but not AFDX-116, abolished antinociception from neostigmine, suggesting an action on M1 subtype muscarinic receptors. Intrathecal neostigmine is antinociceptive in sheep during the acute postoperative period, and these data suggest that spinal cholinergic tone, and hence intrathecal neostigmine's analgesic effect, may be enhanced during the acute postoperative period.