Anesthesia and analgesia
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Anesthesia and analgesia · Nov 2000
Randomized Controlled Trial Multicenter Study Comparative Study Clinical TrialPostoperative nausea and vomiting after sevoflurane with or without ondansetron compared with propofol in female patients undergoing breast surgery.
We studied 180 female patients undergoing breast surgery. The patients were randomly allocated to receive one of three anesthetic techniques. Compared with either propofol or sevoflurane alone, sevoflurane with ondansetron resulted in a decreased incidence of postoperative nausea and vomiting. Sevoflurane with ondansetron prophylaxis is a good alternative to propofol with respect to avoiding postoperative nausea and vomiting.
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Anesthesia and analgesia · Nov 2000
Randomized Controlled Trial Comparative Study Clinical TrialA comparison of the effects of propofol and midazolam on memory during two levels of sedation by using target-controlled infusion.
We examined memory during sedation with target-controlled infusions of propofol and midazolam in a double-blinded five-way, cross-over study in 10 volunteers. Each active drug infusion was targeted to sedation level 1 (asleep) and level 4 (lethargic) as determined with the Observer Assessment of Alertness/Sedation scale. At the target level of sedation, drug concentration was clamped for 30 min, during which time neutral words were presented. After 2 h, explicit memory was assessed by recall, and implicit memory by using a wordstem completion test. Venous drug concentrations (mean +/- SD) were 1350 ng/mL (+/-332 ng/mL) for propofol and 208 ng/mL (+/-112 ng/mL) for midazolam during Observer Assessment of Alertness/Sedation scale level 4; and 1620 ng/mL (+/-357 ng/mL) and 249 ng/mL (+/-82 ng/mL) respectively during level 1. The wordstem completion test frequencies at low level sedation were significantly higher than spontaneous frequencies (8.7% + 2.4%; P: < 0.05 in all cases), and lower than during placebo (33.6% + 23%) (P: < 0.05 in all cases, except P: = 0.076 for propofol at level 4). Clinically distinct levels of sedation were accompanied by small differences in venous propofol or midazolam concentrations. This indicates steep concentration-effect relationships. Neutral information is still memorized during low-level sedation with both drugs. The memory effect of propofol and midazolam did not differ significantly. ⋯ Implicit memory can occur during different states of consciousness and might lead to psychological damage. In 10 volunteers, implicit memory was investigated during sedation with propofol and midazolam in a double-blinded, placebo-controlled study. To compare the effects of both drugs, they were titrated using a computer-controlled infusion system to produce similar high and low levels of sedation.
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Anesthesia and analgesia · Nov 2000
Randomized Controlled Trial Comparative Study Clinical TrialSmall-dose droperidol effectively reduces nausea in a general surgical adult patient population.
In this prospective, randomized, placebo-controlled study, we (1) determined whether 0.625 mg of IV droperidol given 30 min before emergence from general anesthesia reduces the incidence of immediate and delayed postoperative nausea and vomiting (PONV) in a general surgical adult patient population, and (2) compared the efficacy of droperidol, ondansetron, and promethazine for the rescue treatment of PONV. One hundred fifty adult patients receiving general anesthesia for >2 h received either droperidol (0.625 mg IV) or a placebo before emergence. Patients requiring treatment for PONV in the postanesthesia care unit were randomized to receive either droperidol (0.625 mg IV), ondansetron (4 mg IV), or promethazine (12. 5 mg IV). Droperidol effectively prevented PONV (6.8% in droperidol-treated patients versus 40.8% in placebo-treated patients, P: < 0.001). Droperidol, ondansetron, and promethazine were equally effective in treating established PONV, without significant differences in side effects or time to postanesthesia care unit discharge. ⋯ Droperidol 0.625 mg IV before emergence from general anesthesia effectively reduces postoperative nausea and vomiting (PONV) in the general surgical population. Our randomized, double-blinded, placebo-controlled study demonstrated a reduction in PONV from 41% to 7%. Droperidol is a safe and inexpensive alternative to ondansetron. Droperidol, ondansetron, and promethazine are also equally effective in treating PONV in the postanesthesia care unit.
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Anesthesia and analgesia · Nov 2000
Randomized Controlled Trial Comparative Study Clinical TrialA comparison of remifentanil and sufentanil as adjuvants during sevoflurane anesthesia with epidural analgesia for upper abdominal surgery: effects on postoperative recovery and respiratory function.
We compared the recovery profile and postoperative SpO(2) after the administration of general anesthesia with either sevoflurane-remifentanil or sevoflurane-sufentanil in 30 healthy patients undergoing upper abdominal surgery. They were randomly allocated to receive general anesthesia with sevoflurane and small doses of either remifentanil (n = 15) or sufentanil (n = 15), followed by postoperative epidural analgesia. The median sevoflurane minimum alveolar anesthetic concentration-hour was 2.3 (1.2-6.3) in group Remifentanil and 2.6 (1.4-5.2) in group Sufentanil (P: = 0.39), while the median consumption of remifentanil was 1.3 mg (0.7-3.4 mg) and sufentanil 0.09 mg (0.05-0.6 mg). Tracheal extubation required 10 min (6-18 min) with remifentanil and 14 min (8-24 min) with sufentanil (P: = 0.05); however, no differences in time to discharge from the recovery area were reported (24 min [12-75 min] with remifentanil and 30 min [12-135 min] with sufentanil; P: = 0. 35). From the first to seventh hour after surgery, SpO(2) was decreased more in the sufentanil than in the remifentanil group (P: = 0.001), and seven patients in the sufentanil group showed at least one episode with SpO(2) < or = 90% for more than 1 min (P: = 0.006) (median: 1 episode; range: 0-17 episodes; P: = 0.003). When added to sevoflurane, remifentanil is as effective as sufentanil during the intraoperative period, but provides shorter time to tracheal extubation and fewer effects on postoperative SpO(2) in the first 7 h after surgery. ⋯ In this double-blinded study, we evaluated the effects of adding small infusions of either remifentanil or sufentanil to sevoflurane in combination with postoperative epidural analgesia for upper abdominal surgery. We demonstrated that remifentanil is as effective as sufentanil during the intraoperative period, but that it provides shorter time to extubation and fewer effects on postoperative SpO(2) in the first 7 h after surgery.
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Anesthesia and analgesia · Nov 2000
Comparative Study Clinical TrialThromboelastography as a perioperative measure of anticoagulation resulting from low molecular weight heparin: a comparison with anti-Xa concentrations.
Low molecular weight heparin (LMWH) is commonly used to prevent postoperative thromboembolism. Currently, there is no convenient test to measure the degree of anticoagulation from LMWH. This prospective study examines the relationship of thromboelastography and serum anti-Xa concentration in patients treated with enoxaparin. Twenty-four adult patients scheduled for orthopedic surgery using epidural anesthesia were enrolled. Epidural catheters were removed the morning after surgery before the commencement of subcutaneous enoxaparin 30 mg twice daily. Venous blood samples were obtained at 1) the induction of anesthesia (baseline), 2) immediately before the third dose of enoxaparin postoperatively (Day 2-trough), 3) 4 h after the third dose postoperatively (Day 2-peak), and 4) immediately before the fifth dose postoperatively (Day 3-trough). Whole blood samples were obtained for thromboelastography, activated clotting time, and anti-Xa level analyses at each of the four time intervals. At the four sample intervals, the r time (mean +/- SEM). (20 +/- 1, 25 +/- 2, 51 +/- 6, 31 +/- 3 mm) and the k time (9 +/- 0. 7, 12 +/- 1, 27 +/- 5, 14 +/- 2 mm) of the thromboelastograph were significantly correlated with the expected peak and trough levels of LMWH and serum anti-Xa levels (P: < 0.05). At the Day 3-trough, thromboelastograph r times exceeded the normal range in 6 of 25 patients (25%). Prolongation of r time and k time on postoperative Day 3 may indicate an exaggerated response to LMWH. Thromboelastography is a test that could potentially correlate with the degree of anticoagulation produced by low molecular weight heparin. ⋯ Thromboelastography is a test that could potentially correlate with the degree of anticoagulation produced by low molecular weight heparin. The r time from the thromboelastogram correlates with serum anti-Xa concentration.