Anesthesia and analgesia
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Anesthesia and analgesia · Mar 1998
Randomized Controlled Trial Comparative Study Clinical TrialVomiting after adenotonsillectomy in children: a comparison of ondansetron, dimenhydrinate, and placebo.
We compared the effectiveness of ondansetron, dimenhydrinate, and placebo for the prevention of postoperative vomiting in children after adenotonsillectomy. In a randomized, placebo-controlled, double-blind study, 74 children, 2-10 yr of age scheduled for adenotonsillectomy as outpatients were given a single i.v. dose of ondansetron (0.1 mg/kg, n = 26), dimenhydrinate (0.5 mg/kg, n = 25), or placebo (saline, n = 23) at induction of anesthesia. The incidence of retching and vomiting (POV) and side effects observed 24 h after surgery were recorded. Demographic data were similar among the three groups. The 24-h incidence of POV was 42%, 79%, and 82% in the ondansetron, dimenhydrinate, and placebo groups, respectively (ondansetron compared with dimenhydrinate [P < 0.02] or placebo [P < 0.01]). The study was stopped after two children vomited large volumes of bloody fluid 9 and 22 h after surgery without previous signs of occult bleeding. Both children had received ondansetron. We conclude that ondansetron is superior to dimenhydrinate or placebo for the prevention of POV after adenotonsillectomy in children. Antiemetics may mask the signs of bleeding after adenotonsillectomy. ⋯ I.v. ondansetron (0.1 mg/kg) is more effective than both dimenhydrinate and placebo in preventing vomiting after adenotonsillectomy in healthy children. However, antiemetics may also mask the presence of blood in the stomach by preventing vomiting, and this should be appreciated when adenotonsillectomy is performed on an outpatient basis.
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Anesthesia and analgesia · Mar 1998
Randomized Controlled Trial Clinical TrialFactors that predict the use of positive inotropic drug support after cardiac valve surgery.
Left ventricular dysfunction is common after cardiac surgery and is often treated with positive inotropic drugs (PIDs). We hypothesized that the use of PIDs after cardiac valve surgery would have significant associations with the valvular pathophysiology and surgical procedure, and unlike the case for patients undergoing coronary artery surgery, would be unrelated to duration of cardiopulmonary bypass (CPB) or of aortic clamping. One hundred forty-nine consenting patients undergoing cardiac valve surgery were studied. Patients with hepatic or renal failure, or New York Heart Association class IV cardiac symptoms, were excluded. Patients were considered to have received PIDs if they received an infusion of amrinone, dobutamine, epinephrine, or dopamine (> or = 5 microg x kg[-1] x min[-1]). PIDs were received by 78 patients (52%). In a univariate model, older age, history of congestive heart failure, decreasing left ventricular ejection fraction, longer durations of CPB, and concurrent coronary artery surgery significantly increased the likelihood of PID support. There was also significant variation by anesthesiologist in the administration of PIDs. The specific diseased valve and valvular stenosis or insufficiency did not influence the likelihood of receiving PID support. In a multivariable model, age, history of congestive heart failure, decreasing left ventricular ejection fraction, and anesthesiologist were significantly associated with the likelihood of PID support, but duration of CPB and concurrent coronary artery surgery were not. In conclusion, patient age and ventricular function, as well as physician preferences, predicted the need for inotropic drug support; however, neither the specific valvular lesion, nor duration of CPB were strongly predictive in a multivariable model. ⋯ We evaluated factors related to use of positive inotropic drugs after cardiac valve surgery. The likelihood of a patient receiving these drugs increases with advancing age and with more severe preoperative left ventricular dysfunction, but was not influenced by the specific diseased valve or the duration of cardiopulmonary bypass.
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Anesthesia and analgesia · Mar 1998
Randomized Controlled Trial Comparative Study Clinical Trial0.125% ropivacaine is similar to 0.125% bupivacaine for labor analgesia using patient-controlled epidural infusion.
We compared the effects of 0.125% ropivacaine with 0.125% bupivacaine in laboring patients using patient-controlled epidural analgesia (PCEA). Fifty-one ASA physical status I or II term parturients with functioning epidural catheters were randomized to receive ropivacaine or bupivacaine using a prospective, double-blind design. Basal infusions (6 mL/h) were supplemented with patient-controlled boluses (5 mL) every 10 min as required. For inadequate analgesia, patients were administered 10-mL boluses of study solution until comfortable. There were no differences in verbal pain scores, amount of local anesthetics used, sensory levels, motor blockade, labor duration, mode of delivery, side effects, or patient satisfaction between the two local anesthetics. We conclude that 0.125% ropivacaine and bupivacaine are clinically indistinguishable and are both highly effective for labor analgesia using PCEA. ⋯ This study compared labor analgesia from 0.125% ropivacaine and 0.125% bupivacaine using patient-controlled epidural analgesia. We found no significant differences in local anesthetic use, analgesic characteristics, or side effects between 0.125% ropivacaine and 0.125% bupivacaine. We conclude that these two drugs are clinically indistinguishable at this concentration.
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Anesthesia and analgesia · Mar 1998
Randomized Controlled Trial Clinical TrialAlfentanil as an adjuvant to epidural bupivacaine in the management of postoperative pain after laparotomies: lack of evidence of spinal action.
In this double-blind study, we compared the efficacy of epidural versus i.v. administration of alfentanil in combination with small-dose bupivacaine for postoperative pain relief. Thirty-two patients were randomly allocated to one of two study groups. Patients from both groups received an epidural loading dose of 60 mg of bupivacaine (12 mL of 0.5%). Subsequently, patients in the epidural (EPI) group received an infusion (8 mL/h) of 0.125% bupivacaine (10 mg/h) plus alfentanil (0.36 mg/h) and an i.v. infusion (8 mL/h) of NaCl 0.9%. Patients in the i.v. group received an epidural infusion (8 mL/h) of 0.125% bupivacaine (10 mg/h) and an i.v. infusion (8 mL/h) of alfentanil (0.36 mg/h). Infusions were maintained for 24 h. These dose regimens were such that equivalent subanalgesic plasma concentrations of alfentanil were obtained. Patient-controlled analgesia with morphine was available to both groups. Time to onset of postoperative pain and morphine consumption were used as variables to compare the two regimens. Measured plasma concentrations of alfentanil during the postoperative observation period were similar (< 20 ng/mL) in both groups. Median times to onset of postoperative pain (EPI 600 min, i.v. 360 min) and total morphine consumption (EPI 11 mg, i.v. 10 mg) did not differ between the groups (P > 0.2). We conclude that, in combination with epidural bupivacaine 0.125%, an i.v. infusion of alfentanil is equally effective as an epidural infusion of alfentanil if the plasma concentrations are the same. The study did not demonstrate a spinal mechanism of action for alfentanil. ⋯ This randomized, double-blind study showed that, when combined with small-dose bupivacaine (0.125%), epidurally administered alfentanil is not more effective than i.v. administered alfentanil for postoperative pain management when the regimens are such that equivalent subanalgesic plasma alfentanil concentrations are obtained. A spinal mechanism of action for alfentanil could therefore not be demonstrated.
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Anesthesia and analgesia · Mar 1998
Randomized Controlled Trial Clinical TrialAlkalinization of lidocaine does not hasten the onset of axillary brachial plexus block.
We assessed the onset of sensory and motor blockade as well as the distribution of sensory blockade after axillary brachial plexus block with 1.5% lidocaine hydrochloride 1:200,000 epinephrine with and without sodium bicarbonate in 38 patients. The onset of analgesia and anesthesia was recorded over the distributions of the median, ulnar, radial, and medial cutaneous nerves of the forearm, medial cutaneous and lateral cutaneous nerves of the arm, and musculocutaneous nerve. The onset of motor blockade of elbow and wrist movements was also recorded. Data were analyzed by using survival techniques and compared by using log rank tests. Only the onset of analgesia in the medial cutaneous nerves of the arm and forearm, and the onset of anesthesia in the medial cutaneous nerve of the arm were significantly faster (P < 0.05) with alkalinization of lidocaine. Our study showed that alkalinization of lidocaine does not significantly hasten block onset in most terminal nerve distributions. ⋯ We examined whether alkalinizing a local anesthetic would quicken the onset of a regional upper limb nerve blockade. We found that alkalinization of lidocaine did not offer a significant clinical advantage in axillary brachial plexus blockade.