Anesthesia and analgesia
-
Anesthesia and analgesia · Jan 2002
Randomized Controlled Trial Clinical TrialCisapride does not prevent postoperative vomiting in children.
The peripherally acting prokinetic drug cisapride can overcome opioid-induced gastrointestinal paresis and may thereby eliminate a stimulus for postoperative vomiting. We conducted a prospective, randomized, double-blinded, controlled trial of 96 children undergoing inguinal surgery to determine whether cisapride would reduce the incidence of postoperative vomiting after general anesthesia supplemented with morphine. Group C1 patients (n = 38) received cisapride 0.3 mg/kg orally 1 h before surgery and placebo 6 h later, Group C2 (n = 28) received cisapride both before and after surgery, and Group P (n = 30) received placebo. Mean age (5.0 +/- 2.7 yr) and weight (21.0 +/- 8.6 kg), median pain scores and parent satisfaction scores, and incidence of rescue analgesic administration were similar across groups. Contrary to our hypothesis, incidences of postoperative vomiting in the hospital (32% vs 20%, P = 0.33) and at home (53% vs 46%, P = 0.33) did not vary by treatment group (with [C1 and C2] and without [P] cisapride, respectively). There was a trend toward more severe postoperative vomiting (three or more episodes) in children who received cisapride versus those who did not, both in hospital (6% vs 0%, P = 0.3) and at home (22% vs 8%) (P = 0.13). We conclude that cisapride does not prevent postoperative vomiting in this patient population and speculate that factors other than reduced gastrointestinal motility associated with general anesthesia and opioids are more important determinants of postoperative vomiting. ⋯ Cisapride does not prevent postoperative vomiting in children and may increase its severity.
-
Anesthesia and analgesia · Jan 2002
Randomized Controlled Trial Clinical TrialEsmolol and anesthetic requirement for loss of responsiveness during propofol anesthesia.
The administration of esmolol decreases the propofol blood concentration, preventing movement after skin incision during propofol/morphine/nitrous oxide anesthesia. However, interaction with esmolol has not been tested when propofol is infused alone. Accordingly, we tested the hypothesis that esmolol decreases the propofol blood concentration, preventing response to command (CP50-awake) when propofol is infused alone in healthy patients presenting for minor surgery. With approval and consent, we studied 30 healthy patients, who were randomized to esmolol bolus (1 mg/kg) and then infusion (250 microg x kg(-1) x min(-1)) or placebo. Five minutes later, a target-controlled infusion of propofol was commenced. Ten minutes later, responsiveness was assessed by a blinded observer. Oxygen saturation, heart rate, and noninvasive arterial blood pressure were recorded every 2 min. Arterial blood samples were taken at 5 and 10 min of propofol infusion for propofol assay. Results were analyzed with a generalized linear regression model: P <0.05 was considered statistically significant. The probability of response to command decreased with increasing propofol blood concentration (CP50-awake = 3.42 microg/mL). Esmolol did not alter the relative risk of response to command. We conclude that the previously observed effect of esmolol on propofol CP50 was not caused by an interaction between these two drugs. ⋯ There is no evidence to suggest that esmolol, an ultra-short-acting cardioselective beta-blocker, affects anesthetic requirement for loss of responsiveness during propofol anesthesia.
-
Anesthesia and analgesia · Jan 2002
Randomized Controlled Trial Clinical TrialThe efficacy of preemptive Milrinone or Amrinone therapy in patients undergoing coronary artery bypass grafting.
Acute deterioration in ventricular function and oxygen transport is common after cardiac surgery. We hypothesized that milrinone or amrinone may reduce their occurrence and catecholamine requirements and increase cellular enzyme levels in patients undergoing coronary artery bypass. In 45 patients, we randomly administered milrinone 50 microg/kg plus 0.5 microg x kg(-1) x min(-1) infusion for 10 h, amrinone 1.5 mg/kg plus 10 microg x kg(-1) x min(-1) infusion for 10 h, or placebo at release of aortic cross-clamp. Hemodynamic variables, dopamine requirement, and laboratory values were recorded. At the postoperative nadir, stroke volume index was higher in the Milrinone and Amrinone groups (mean +/- SD, 27.8 +/- 4.0 and 26.1 +/- 3.2 vs. 20.4 +/- 5.1 mL x min (-1) x m(-2) per beat, P < 0.0001), and oxygen transport index was higher (354.7 +/- 57.8 and 353.7 +/- 91.2 vs 283.0 +/- 83.9 mL. min(-1) x m(-2), P = 0.009). The postoperative dopamine requirement was less (6.6 +/- 2.7 and 6.8 +/- 2.6 vs 10.4 +/- 2.0 mg/kg, P < 0.008), and postoperative serum lactate, alanine and aspartate aminotransferase, lactate dehydrogenase, creatinine kinase, C-reactive protein, and glucose levels were less (P < 0.01). The mean postoperative heart rate was faster in the Milrinone group than in the Amrinone and Placebo groups (96.8 +/- 10.3 vs. 86.9 +/- 9.5 and 87.8 +/- 10.8 bpm, P < 0.01). Milrinone and amrinone administered preemptively reduce postoperative deterioration in cardiac function and oxygen transport, dopamine requirement, and increases in serum lactate, glucose, and enzyme levels, although milrinone may increase heart rate. ⋯ Preemptive milrinone or amrinone administration before separation from cardiopulmonary bypass in cardiac surgical patients not only ameliorates postoperative deterioration in cardiac function and oxygen transport, but also reduces dopamine requirement and increases serum lactate, glucose, and cellular enzyme levels, although milrinone may increase heart rate.
-
Anesthesia and analgesia · Jan 2002
Randomized Controlled Trial Clinical TrialThermoregulatory response to intraoperative head-down tilt.
Thermoregulation interacts with cardiovascular regulation within the central nervous system. We therefore evaluated the effects of head-down tilt on intraoperative thermal and cardiovascular regulation. Thirty-two patients undergoing lower-abdominal surgery were randomly assigned to the 1) supine, 2) 15 degrees -20 degrees head-down tilt, 3) leg-up, or 4) combination of leg-up and head-down tilt position. Core temperature and forearm minus fingertip skin-temperature gradients (an index of peripheral vasoconstriction) were monitored for 3 h after the induction of combined general and lumbar epidural anesthesia. We also determined cardiac output and central-venous and esophageal pressures. Neither right atrial transmural pressure nor cardiac index was altered in the Head-Down Tilt group, but both increased significantly in the Leg-Up groups. The vasoconstriction threshold was reduced in both leg-up positions but was not significantly decreased by head-down tilt. Final core temperatures were 35.2 degrees C +/- 0.2 degrees C (mean +/- SEM) in the Supine group, 35.0 degrees C +/- 0.2 degrees C in the Head-Down Tilt group, 34.2 degrees C +/- 0.2 degrees C in the Leg-Up group (P < 0.05 compared with supine), and 34.3 degrees C +/- 0.2 degrees C when leg-up and head-down tilt were combined (P < 0.05 compared with supine). These results confirm that elevating the legs increases right atrial transmural pressure, reduces the vasoconstriction threshold, and aggravates intraoperative hypothermia. Surprisingly, maintaining a head-down tilt did not increase right atrial pressure. ⋯ Intraoperative hypothermia is exaggerated when patients are maintained in the leg-up position because the vasoconstriction threshold is reduced. However, head-down tilt (Trendelenburg position) does not reduce the vasoconstriction threshold or aggravate hypothermia. The head-down tilt position thus does not require special perioperative thermal precautions or management unless the leg-up position is used simultaneously.
-
Anesthesia and analgesia · Jan 2002
Randomized Controlled Trial Clinical TrialThe preemptive analgesic effect of rofecoxib after ambulatory arthroscopic knee surgery.
Nonsteroidal antiinflammatory drugs (NSAIDs) provide effective postoperative analgesia after arthroscopic knee surgery. Some investigators have suggested that the preemptive administration of NSAIDs may reduce postoperative analgesic requirements and hypersensitivity. We evaluated the analgesic effect of administering rofecoxib either before or after surgical incision in patients undergoing arthroscopic knee surgery under local anesthesia. Sixty patients undergoing arthroscopic meniscectomy were randomized into three groups. All patients received intraarticular bupivacaine 0.25% pre- and postsurgery together with IV sedation using midazolam and propofol. The Preincisional group received a single 50 mg dose of rofecoxib 1 h before surgery, the Postincisional group received rofecoxib 50 mg after the completion of surgery, and the Placebo group received a placebo tablet before surgery. Pain scores, the time to first opioid use, and 24-h analgesic use were recorded. Analgesic duration, defined as the time from completion of surgery until first opioid use, was significantly longer in those patients receiving pre- (803 +/- 536 min) versus postincisional (461 +/- 344 min) rofecoxib or placebo (318 +/- 108 min). The 24 h acetaminophen/oxycodone use was less in the Preincisional group (1.5 +/- 0.6 pills) versus the Postincisional group (3.3 +/- 1.3 pills) or the Placebo group (5.5 +/- 1.6 pills). Pain scores with movement were lower in the Preincisional group at all postoperative time intervals. We conclude that rofecoxib provides effective postoperative analgesia for arthroscopic meniscectomy. Further, the administration of rofecoxib 50 mg before surgery provides a longer duration of postoperative analgesia, less 24 h opioid use, and lower incidental pain scores compared with administering the drug after the completion of surgery. ⋯ The administration of rofecoxib 50 mg before arthroscopic knee surgery provides a longer duration of analgesia, less 24-h opioid use, and lower pain scores than administering the drug after the completion of surgery.