Anesthesia and analgesia
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Anesthesia and analgesia · Oct 1998
Randomized Controlled Trial Multicenter Study Clinical TrialPostoperative analgesic effects of three demand-dose sizes of fentanyl administered by patient-controlled analgesia.
Many studies have demonstrated the postoperative analgesic efficacy of fentanyl delivered i.v. by patient-controlled analgesia (PCA) devices at demand doses ranging from 10 to 50 microg, but none has sought to define the optimal fentanyl PCA dose. In this randomized, double-blind, multicenter study, we compared the safety and efficacy of three administered demand-dose sizes of fentanyl (20, 40, and 60 microg) in 150 patients after major surgery. Efficacy was dose-dependent; positive response rates (i.e., a global assessment score of "very good" or "excellent" and the absence of severe opioid adverse effects) were 42%, 52%, and 68% for the 20, 40, and 60 microg demand-dose groups, respectively, and were significantly higher in the 60 microg demand-dose group. The number of doses administered and missed attempts were significantly smaller in the 40 and 60 microg demand-dose groups compared with the 20 microg demand-dose group. This suggests that the 20 microg demand dose provided inadequate pain relief. Adverse respiratory events were more frequent and mean respiratory rates were significantly slower with the 60 microg demand dose, compared with the 20 or 40 microg demand doses. These results indicate that, of these three doses, the 40 microg demand dose was optimal for fentanyl PCA management of moderate to severe pain after major surgery. ⋯ The postoperative analgesic efficacy of fentanyl delivered i.v. by patient-controlled analgesia devices has been demonstrated for demand doses ranging from 10 to 50 microg, but the optimal fentanyl dose remains unknown. In this randomized, double-blind study, we compared three demand dose sizes of fentanyl (20, 40, and 60 microg) and found that the 40 microg demand dose was the most appropriate for fentanyl patient-controlled analgesia management of postoperative pain.
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Anesthesia and analgesia · Oct 1998
Randomized Controlled Trial Comparative Study Clinical TrialA granisetron-droperidol combination prevents postoperative vomiting in children.
This study was performed to compare the efficacy of a granisetron-droperidol combination with each antiemetic alone to prevent postoperative vomiting after tonsillectomy with or without adenoidectomy in children. One hundred eighty pediatric patients, ASA physical status I, aged 4-10 yr, were enrolled in a prospective, randomized, double-blind investigation and assigned to one of three treatment regimens: granisetron 40 microg/kg (Group G), droperidol 50 microg/kg (Group D), or granisetron 40 microg/kg plus droperidol 50 microg/kg (Group GD) (n = 60 in each group). These drugs were administered i.v. after an inhaled induction. The same standard general anesthetic technique and postoperative analgesia were used throughout. The rate of complete response, defined as no emesis and no need for rescue antiemetic, 0-3 h after anesthesia was 83% in Group G, 60% in Group D, and 97% in Group GD (P = 0.029 versus Group G, P = 0.001 versus Group D). The corresponding rates 3-24 h after anesthesia were 83%, 55%, and 97% (P = 0.029 versus Group G, P = 0.001 versus Group D). No clinically important adverse events were observed in any of the groups. In conclusion, a granisetron-droperidol combination is superior to each antiemetic alone in complete response in children undergoing general anesthesia for tonsillectomy. ⋯ We compared the efficacy of granisetron plus droperidol with each antiemetic alone for the prevention of postoperative vomiting in children. The granisetron-droperidol combination was highly effective against postoperative emesis.
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Anesthesia and analgesia · Oct 1998
Randomized Controlled Trial Clinical TrialCryoanalgesia: effect on postherniorrhaphy pain.
Cryoanalgesia versus sham treatment was applied to the ilioinguinal and iliohypogastric nerves after mesh repair of an inguinal hernia under local anesthesia in 48 male patients in a prospective, randomized, and observer- and patient-blinded trial. Pain was scored daily during rest, while coughing, and during mobilization to the sitting position for 1 wk and weekly for 8 wk on a four-point verbal rank scale. Use of supplementary analgesics and sensory disturbances were recorded. Assessments were made for allodynia, hyperalgesia, and mechanical pain detection thresholds 8 wk postoperatively. Cumulative pain scores for the first postoperative week were equal in the two groups, as was the use of analgesics. Eight weeks postoperatively, three cases of hyperalgesia to pinprick were detected in the cryoanalgesia group, and 10 patients in the cryoanalgesia group versus 5 in the sham-treatment group reported disturbed sensibility. We conclude that cryoanalgesia of the iliohypogastrical and ilioinguinal nerve does not decrease postherniorrhaphy pain. ⋯ Does freezing of sensory nerves in the groin reduce pain after hernia repair? Extreme cold (-60 degrees C) was applied in a double-blind, randomized study. No difference in pain scores was found. Sensory disturbances were seen in treatment and control patients. Freezing cannot be recommended for pain relief after hernia repair.
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Anesthesia and analgesia · Oct 1998
Randomized Controlled Trial Comparative Study Clinical TrialSingle-dose tropisetron for preventing postoperative nausea and vomiting after breast surgery.
In this randomized, double-blind, placebo-controlled study, we compared the efficacy of tropisetron 5 mg with tropisetron 2 mg for the prevention of postoperative nausea and vomiting (PONV) after breast surgery. One hundred forty-eight female patients were randomized to receive either tropisetron 5 mg (n = 49), tropisetron 2 mg (n = 49), or saline (n = 50) before the induction of anesthesia with thiopental and morphine. Anesthesia was maintained with nitrous oxide and isoflurane. Postoperative analgesia was provided by patient-controlled analgesia with i.v. morphine. The incidence of PONV, the pain score, and the analgesic requirement were recorded for 48 h. There was no difference among groups in patient characteristics, risk factors for PONV, morphine consumption, or side effects. During the first 6 h postoperatively, the incidence of PONV after tropisetron 2 mg and 5 mg were similar and were superior to placebo (P < 0.001). After 6 h, the incidence of PONV increased significantly in patients who had received tropisetron 2 mg (P = 0.01) and was greater than that in patients who had received tropisetron 5 mg (P = 0.001). We conclude that single-dose tropisetron 5 mg is more effective than tropisetron 2 mg in the prevention of PONV after breast surgery. ⋯ Breast surgery is associated with a high incidence of postoperative nausea and vomiting. A single dose of i.v. tropisetron 5 mg is well tolerated and decreases the number of vomiting and nausea episodes after surgery.
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Anesthesia and analgesia · Oct 1998
Randomized Controlled Trial Clinical TrialThe effect of the interaction of propofol and alfentanil on recall, loss of consciousness, and the Bispectral Index.
The Bispectral Index (BIS) correlates well with the level of consciousness with single anesthetic drugs. We studied the effect of the interaction of propofol with alfentanil on propofol concentration and BIS associated with 50% probability of loss of consciousness and lack of recall (Cp50 and BIS50, respectively). We studied 40 consenting volunteers at two institutions who were randomly assigned to receive stepped increases of propofol (10 subjects at each site), propofol plus alfentanil 50 ng/mL (10 subjects at Emory site), or propofol plus alfentanil 100 ng/mL (10 subjects at Duke site) by using a target-controlled infusion device. Measures of sedation, BIS, deltaBIS (absolute change of BIS after a painful stimulus), memory, and drug concentration were obtained at each target drug concentration. The relation among BIS, measured drug concentration, sedation score, and presence or absence of recall was determined by linear and logistic regression for different drug regimens, and the prediction probability (Pk) was calculated. The addition of alfentanil in increasing doses did not significantly affect the BIS50 and propofol Cp50 values for loss of consciousness and lack of recall. DeltaBIS was significantly decreased by both an increase in the concentration of propofol and the presence of alfentanil. The Pk for BIS was >0.93 with all drug regimens, better than those of the target and measured propofol concentrations. We conclude that BIS correlated well with the hypnotic component of anesthesia independent of the presence of an opioid. Moreover, the level of consciousness, and, therefore, the BIS index, is affected by a painful stimulus, and this response is ablated either by opioids or increasing propofol concentration. ⋯ In volunteers, the sedation and changes in memory function produced by propofol correlated well with changes in the Bispectral Index. This relationship was not altered by the addition of an analgesic (alfentanil). However, in moderately sedated patients who received a painful stimulus, the Bispectral Index increased, but this response was blocked by the analgesic or increasing propofol concentrations.