Anesthesia and analgesia
-
Anesthesia and analgesia · Apr 2004
Randomized Controlled Trial Clinical TrialEpidural infusions of ropivacaine and bupivacaine for labor analgesia: a randomized, double-blind study of obstetric outcome.
Studies have shown better obstetric outcome when ropivacaine 0.25% was used for labor epidural analgesia compared with bupivacaine 0.25%, but it is controversial whether there is any difference at smaller concentrations. In a prospective, double-blind trial, we randomized 350 ASA physical status I and II parturients with term cephalic singleton pregnancies to receive epidural labor analgesia using ropivacaine or bupivacaine. Analgesia was initiated with a 0.25% solution and maintained with a continuous infusion of a 0.1% solution with fentanyl 0.0002%. Supplementary boluses of 0.25% solution were given when requested. Labor was managed according to institutional standard labor ward protocols. Among patients who delivered vaginally, the duration of the first stage of labor was shorter in the ropivacaine group (median, 520 min; interquartile range, 377-745 min) compared with the bupivacaine group (645 min; interquartile range, 460-820 min; P = 0.009), but there was no difference in any other obstetric or neonatal outcomes. The mode of delivery was similar between groups, with operative (instrumental vaginal and cesarean) delivery rates of 61.8% (95% confidence interval, 54.4%-68.8%) in the ropivacaine group and 58.4% (95% confidence interval, 50.9%-65.5%) in the bupivacaine group (P = 0.72). ⋯ In a randomized-controlled study, we found no major outcome advantage of continuous epidural infusion of ropivacaine 0.1% with fentanyl 0.0002% over bupivacaine 0.1% with fentanyl 0.0002% for labor analgesia. Although ropivacaine was associated with a shorter first stage of labor, the relative difference is probably of limited clinical importance, and there was no difference in the mode of delivery.
-
Anesthesia and analgesia · Apr 2004
Randomized Controlled Trial Clinical TrialSingle-dose haloperidol for the prophylaxis of postoperative nausea and vomiting after intrathecal morphine.
Postoperative nausea and vomiting (PONV) occurs frequently with the use of intrathecal morphine. We studied the ability of a single, small dose of the inexpensive, long-acting, dopamine receptor-blocking drug, haloperidol, to prevent PONV after spinal anesthesia using local anesthetic with morphine 0.3 mg. One-hundred-eight adult patients undergoing elective lower limb orthopedic or endoscopic urologic procedures under spinal anesthesia were randomized to receive IM haloperidol 1 mg (H1), haloperidol 2 mg (H2), or placebo (P) after an intrathecal injection. Patients were assessed for 24 h after surgery, with treatment failure being defined as nausea >1 on a 10-cm visual analog scale or any vomiting or request for rescue antiemetic. Most treatment failures occurred during the first 12 h (60% overall), and haloperidol led to a dose-dependent decrease in PONV (first 12 h: 76% P, 56% H1, and 50% H2; P = 0.012). A history of PONV was strongly associated with PONV in the current study, regardless of treatment group. There were no dystonic reactions noted to either dose of haloperidol. We conclude that haloperidol reduces the incidence of PONV after intrathecal morphine, although this incidence remains a significant problem even with treatment. ⋯ In this randomized, double-blinded, placebo-controlled trial, a single, small IM dose of haloperidol 1 mg or 2 mg reduced the incidence of postoperative nausea and vomiting after spinal anesthesia with local anesthetic and intrathecal morphine.
-
Anesthesia and analgesia · Apr 2004
Randomized Controlled Trial Clinical TrialInotropes improve right heart function in patients undergoing aortic valve replacement for aortic stenosis.
The administration of inotropes after aortic valve replacement (AVR) for aortic stenosis (AS) is controversial. Issues include the risk of left ventricular (LV) systolic outflow obstruction (LVOTO) and the proper treatment of diastolic dysfunction for patients in whom LV systolic function is often preserved and subsequently improved. In this study, we assessed the hemodynamic benefits of inotropes for patients undergoing AVR for AS. Thirty-four patients were prospectively randomized to one of three groups: epinephrine, milrinone, or placebo. Hemodynamic and echocardiographic data were obtained before and immediately after cardiopulmonary bypass (CPB). Data were also obtained before and after increases in ventricular preload to assess the effects of inotropes on diastolic function. The use of inotropes was associated with significantly larger increases in right ventricular (RV) (placebo, 0.5%; epinephrine, +9%; milrinone, +8%; P < 0.01) and LV (placebo, +7%; epinephrine, +18%; milrinone, +20%; P = 0.07) ejection fractions (EF) and cardiac output after CPB. Changes in cardiac output and index were more strongly correlated with changes in RVEF (r = 0.56, P < 0.01; r = 0.47, P < 0.01, respectively) than with LVEF (r = 0.22, r = 0.08). Of all patients receiving epinephrine or milrinone, only one (1 of 22) had a decrease in RVEF, whereas 6 of 12 patients receiving placebo had a reduction in RVEF from pre-CPB to post-CPB. Correspondingly, for LVEF, 1 of 22 patients receiving inotropes had a decrease in LVEF, whereas 3 of 12 placebo patients had a reduction in LVEF from pre-CPB to post-CPB. No patient had evidence of LVOTO. Inotropes improved hemodynamics after AVR for AS. This was attributable more to improved RV function than to changes in LV function. Although there were no changes in diastolic function, it is possible that this study did not allow significant timing to observe benefits of inotropes on diastolic function in this setting. ⋯ Compared with placebo, both epinephrine and milrinone similarly improved biventricular performance after aortic valve replacement, with a greater impact on right ventricular function. Choice of either inotropic drug should be driven by blood pressure and hemodynamic goals in this setting.
-
Anesthesia and analgesia · Apr 2004
Randomized Controlled Trial Clinical TrialPreoperative oral rofecoxib reduces postoperative pain and tramadol consumption in patients after abdominal hysterectomy.
We designed this study to determine whether the administration of a preoperative dose of rofecoxib to patients undergoing abdominal hysterectomy would decrease patient-controlled analgesia (PCA) tramadol use or enhance analgesia. Sixty patients were randomized to receive either oral placebo or rofecoxib 50 mg 1 h before surgery. All patients received a standard anesthetic protocol. Intraoperative blood loss was determined. At the end of surgery, all patients received tramadol IV via a PCA-device. Pain scores, sedation scores, mean arterial blood pressure, heart rate, and peripheral oxygen saturation were assessed at 1, 2, 4, 6, 8, 12, and 24 h after surgery. Total and incremental tramadol consumption at the same times was recorded from the PCA-device. Antiemetic requirements and adverse effects were noted during the first postoperative 24 h. Duration of hospital stay was also recorded. The pain scores were significantly lower in the rofecoxib group compared with the placebo group at 6 times during the first 12 postoperative h (P < 0.05). The total consumption of tramadol (627 +/- 69 mg versus 535 +/- 45 mg; P < 0.05) and the incremental doses at 1, 2, 4, 6, 8, and 12 h after surgery were significantly more in the placebo group than in the rofecoxib group. There were no differences between groups in intraoperative blood loss, sedation scores, hemodynamic variables, peripheral oxygen saturation, antiemetic requirements, or adverse effects after surgery. The length of hospital stay was also similar in the groups. We conclude that the preoperative administration of oral rofecoxib provided a significant analgesic benefit and decreased the opioid requirements in patients undergoing abdominal hysterectomy. ⋯ This study was designed to determine whether the administration of a preoperative dose of rofecoxib to patients undergoing abdominal hysterectomy would decrease patient-controlled analgesia tramadol use or enhance analgesia. We conclude that the preoperative administration of oral rofecoxib provided a significant analgesic benefit and decreased the opioid requirements in patients undergoing abdominal hysterectomy.
-
Anesthesia and analgesia · Apr 2004
Randomized Controlled Trial Clinical TrialSkin sensitivity to rocuronium and vecuronium: a randomized controlled prick-testing study in healthy volunteers.
Prick tests are frequently used for the authentication of neuromuscular blocking drugs (NMBDs) as causative drugs for anaphylactic reactions during anesthesia. Unfortunately, the actual threshold concentration for skin testing remains debatable for most NMBDs. We studied the flare and wheal responses to prick tests with rocuronium and vecuronium. Thirty healthy, nonatopic, anesthesia-naive male and female volunteers (14 men and 16 women) from 18 to 40 yr of age were assigned randomly to receive a total of 10 prick tests-4 ascending dilutions (1:1000, 1:100, 1:10, and 1) of rocuronium and vecuronium and 2 controls-on both forearms. An assessor blinded to the assignment monitored systemic and skin responses to NMBDs and measured wheal and flare surfaces immediately after and 15 min after prick tests. None of the volunteers experienced any immediate systemic or cutaneous responses to rocuronium or vecuronium. Although a dilution of 1:1000 of both NMBDs failed to promote any skin response at 15 min, 50% and 40% of the subjects had a positive skin reaction to undiluted rocuronium and vecuronium, respectively. We demonstrated a sex effect related to smaller threshold concentration-induced cutaneous reactions in female volunteers to both muscle relaxants. Our observation questions the reliability of prick testing with undiluted solutions of rocuronium and vecuronium for the diagnosis of allergy. ⋯ Building concentration-skin response curves to prick tests with rocuronium and vecuronium in healthy, nonatopic, anesthesia-naive male and female volunteers demonstrated that the nonreactive concentration for both muscle relaxants is the 1:1000 dilution of the stock solutions. Our observation calls into question the past practice of prick-testing skin for sensitivity to neuromuscular blocking drugs by using undiluted solutions.