Anesthesia and analgesia
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Anesthesia and analgesia · Aug 1992
Modification of a new catheter for air retrieval and resuscitation from lethal venous air embolism: effect of nitrous oxide on air retrieval.
A modification of a new Arrow prototype catheter was evaluated for its ability to retrieve venous air emboli and for its effect on the success rate of resuscitation from venous air emboli in dogs anesthetized with isoflurane and nitrous oxide (66%) in oxygen. In an additional group of dogs, nitrogen was substituted for nitrous oxide in the inspired gases to determine whether the presence of nitrous oxide (as traditionally used in this model of lethal venous air emboli) increased the apparent amount of gas retrieval or altered the success rate of resuscitation. Dogs were placed in the seated position with the head 90 degrees to the horizontal. ⋯ Attempts to aspirate venous air emboli were begun with the first decrease in expired CO2. The amounts of gas retrieved, expressed as a percent of the injected air, and the incidence of successful resuscitation were compared between groups. In both treatment groups (nitrous oxide and nitrogen), the percent of injected venous air retrieved (73% +/- 13% and 65% +/- 21%, mean value +/- SD, respectively) and success rate of resuscitation (four of six dogs in each group) were significantly increased compared with the control group in which no attempt was made to retrieve injected venous air, and none of the six dogs survived.(ABSTRACT TRUNCATED AT 250 WORDS)
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Anesthesia and analgesia · Aug 1992
Randomized Controlled Trial Clinical TrialEffects of ketorolac and bupivacaine on recovery after outpatient arthroscopy.
The effects of intraarticular bupivacaine, systemic ketorolac, and a combination of both treatments on postoperative pain and mobilization were evaluated in 60 healthy outpatients undergoing arthroscopic knee surgery under general anesthesia. After induction of anesthesia, patients received 2 mL of either ketorolac (60 mg) or saline solution (1 mL IV and 1 mL IM). On completion of surgery, the patient's knee joint was injected with 30 mL of either 0.5% bupivacaine or saline solution, according to a randomized, double-blind protocol. ⋯ Similarly, there were no differences in the times to ambulation or discharge or in analgesic requirements at home. In conclusion, a combination of systemic ketorolac and intraarticular bupivacaine decreased analgesic requirements and pain on awakening after arthroscopic surgery. However, the use of ketorolac alone or in combination with bupivacaine offered no advantage over bupivacaine alone with respect to recovery times after outpatient arthroscopy.
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Anesthesia and analgesia · Aug 1992
Randomized Controlled Trial Comparative Study Clinical TrialContinuous interpleural infusion of bupivacaine for postoperative analgesia after surgery with flank incisions: a double-blind comparison of 0.25% and 0.5% solutions.
Postoperative analgesia, as assessed by visual analogue scale scores (0-10) and patient-controlled analgesia morphine requirements, pulmonary function (forced vital capacity and forced expiratory volume in 1 s), and plasma bupivacaine concentrations were studied in patients receiving interpleural blockade with bupivacaine after surgery with a flank incision. Two groups of 10 patients received either 0.5% or 0.25% bupivacaine, both with epinephrine (5 micrograms/mL). Pain relief was initiated when patients had visual analogue scale scores greater than or equal to 4. ⋯ Patient-controlled analgesia morphine use was also similar in the 0.25% (21.3 +/- 14.6 mg) and 0.5% (21.0 +/- 16.0 mg) groups (mean +/- SD). In both groups, forced vital capacity and forced expiratory volume in 1 s improved significantly within 60 min (P less than 0.05). Peak plasma concentrations (Cmax) and the area under the plasma concentration-time curve (AUC) over 24 h were higher (P less than 0.001) in the 0.5% group (Cmax, 1.47 +/- 0.37 micrograms/mL; AUC, 1511 +/- 323 micrograms.mL-1.min) than those in the 0.25% group (Cmax, 0.55 +/- 0.22 micrograms/mL; AUC, 680 +/- 118 micrograms.mL-1.min) (mean +/- SD).(ABSTRACT TRUNCATED AT 250 WORDS)
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Anesthesia and analgesia · Aug 1992
Randomized Controlled Trial Clinical TrialContinuous low-dose 3-in-1 nerve blockade for postoperative pain relief after total knee replacement.
We have investigated the value of a 3-in-1 nerve block, followed by a continuous low-dose infusion of bupivacaine into the femoral nerve sheath for postoperative analgesia after total knee replacement. Thirty-seven patients were randomly allocated to either a control group or a study group. The study group had a catheter placed in the ipsilateral femoral nerve sheath. ⋯ This was followed by a continuous infusion of 0.125% bupivacaine at 6 mL/h. The study group had significantly lower pain scores 4 and 24 h postoperatively (P less than 0.01) and required less postoperative opioid analgesic medication (P less than 0.01) than the control group. The authors conclude that a continuous low-dose infusion into the femoral nerve sheath results in better pain relief than conventional intramuscularly administered narcotics after total knee arthroplasty.