Anesthesia and analgesia
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Anesthesia and analgesia · Jun 1995
Randomized Controlled Trial Comparative Study Clinical TrialNitrous oxide decreases the threshold for vasoconstriction less than sevoflurane or isoflurane.
The core temperature triggering thermoregulatory arteriovenous shunt constriction is designated the threshold for vasoconstriction. High thresholds are generally desirable because vasoconstriction helps prevent further core hypothermia by decreasing cutaneous heat loss and constraining metabolic heat to the core thermal compartment. Previous studies suggest that nitrous oxide (N2O) may inhibit thermoregulatory vasoconstriction less than comparable doses of volatile anesthetics. ⋯ The threshold for vasoconstriction was 35.8 +/- 0.3 degrees C in the patients given 50% N2O combined with 0.5 MAC sevoflurane, which was significantly greater than that in those given 1.0 MAC sevoflurane: 35.1 +/- 0.4 degrees C. Similarly, the threshold for vasoconstriction was 35.9 +/- 0.3 degrees C in the patients given 60% N2O combined with 0.5 MAC isoflurane, which was significantly greater than that in those given 1.0 MAC isoflurane: 35.0 +/- 0.5 degrees C. We thus conclude that N2O impairs thermoregulation less than sevoflurane or isoflurane.
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Anesthesia and analgesia · Jun 1995
Randomized Controlled Trial Comparative Study Clinical TrialPostoperative analgesia for outpatient arthroscopic knee sugery with intraarticular bupivacaine and ketorolac.
Intraarticular (IA) local anesthetics are often used for the management and prevention of pain after arthroscopic knee surgery. Systemic ketorolac is also useful in the management of these patients. Ketorolac, a nonsteroidal antiinflammatory drug (NSAID), alters the sensitivity of peripheral nociceptors by reducing the local concentration of allogenic chemicals which are activated by peripheral tissue injury. ⋯ The results of this study revealed a significant difference in analgesia from the IA administration of ketorolac. The group who received a combination of IA bupivacaine and IA ketorolac had decreased postoperative pain, a decreased need for postoperative analgesics, and an increased analgesic duration. We conclude that the use of IA ketorolac improved comfort in patients undergoing knee arthroscopy.
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Anesthesia and analgesia · Jun 1995
Randomized Controlled Trial Clinical TrialPeroperative adenosine infusion reduces the requirements for isoflurane and postoperative analgesics.
The aims of this study were to investigate the influence of adenosine infusion, firstly, on postoperative analgesic requirements, and secondly, on peroperative isoflurane requirements. Seventy-five women, aged 18-70 yrs, ASA grades I and II, scheduled for breast surgery, were randomly assigned to peroperatively receive a double-blind intravenous infusion of either adenosine, 80 micrograms.kg-1.min-1, or placebo, during surgery under isoflurane/N2O/O2 anesthesia. ⋯ Further, the postoperative 24-h opioid requirements were reduced by 27% in the adenosine group (P < 0.03). In conclusion, we found that a peroperative infusion of a small dose of adenosine during breast surgery, reduces the peroperative anesthetic requirements, and the demand for post-operative analgesics.
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Anesthesia and analgesia · Jun 1995
Randomized Controlled Trial Comparative Study Clinical TrialObjective and subjective impairment from often-used sedative/analgesic combinations in ambulatory surgery, using alcohol as a benchmark.
Impairment caused by different sedative/analgesic combinations commonly used in ambulatory settings was compared to that of alcohol at blood alcohol concentrations (BACs) higher than or equal to 0.10%. Impairment was measured via subjective (mood) and objective (psychomotor performance) assays. Twelve healthy human volunteers (10 males and 2 females; age range 21-34 yr) participated in this prospective, double-blind, randomized, cross-over study. ⋯ Psychomotor impairment caused by alcohol at 15 min postingestion (at a BAC of 0.11% +/- 0.03% [mean +/- SE]) was used as a benchmark with which impairment caused by other sedative/analgesic combinations was compared. All the study drug combinations produced impairment (i.e., impairment greater than that seen with PLC), similar to that observed with alcohol at a BAC of 0.11%. We have demonstrated that some sedative/analgesic drug combinations used in anesthesia for ambulatory procedures produce impairment similar to or greater than that observed with a large dose of alcohol.
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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.