Edward R. Johnson

Effects of Prophylactic Nalmefene on the Incidence of Morphine-related Side Effects in Patients Receiving Intravenous Patient-controlled Analgesia

BACKGROUND Opioid-related side effects associated with intravenous patient-controlled analgesia can be reduced by a low-dose naloxone infusion. The influence of nalmefene, a pure opioid antagonist with a longer duration of action, on opioid-related side effects has not been evaluated. This study was designed to determine the dose-response relation for nalmefene for the prevention of morphine-related side effects in patients receiving intravenous patient-controlled analgesia. METHODS One hundred twenty women undergoing lower abdominal surgery were enrolled in the study. General anesthesia was induced using thiopental and rocuronium and maintained with desflurane, nitrous oxide, and fentanyl or sufentanil. All patients received neostigmine and glycopyrrolate to reverse residual neuromuscular blockade. No prophylactic antiemetics were administered. At the end of surgery, patients were randomized to receive saline, 15 microg nalmefene, or 25 microg nalmefene intravenously. The need for antiemetic and antipruritic drugs and the total consumption of morphine during the 24-h study were recorded. The incidences of postoperative nausea, vomiting, pruritus, and pain were recorded 30 min after patients were admitted to the postanesthesia care unit. In addition, patient remembrance of these side effects was noted at 24 h after operation. RESULTS The need for antiemetic and antipruritic medications during the 24-h study period was significantly lower in the patients receiving nahmefene compared with those receiving placebo. However, the need to treat side effects was similar in the two nahmefene groups. Prophylactic administration of nalmefene reduced the patients remembrance of nausea and itching as assessed 24 h after operation. Although the total consumption of morphine during the 24-h study period was similar in the three groups, retrospectively patients who received nalmefene characterized their pain as less severe in the previous 24 h. CONCLUSION Compared with placebo, prophylactic administration of nalmefene significantly decreased the need for antiemetics and antipruritic medications in patients receiving intravenous patient-controlled analgesia with morphine.

Effect of preincision versus postincision infiltration with bupivacaine on postoperative pain

STUDY OBJECTIVE To compare the efficacy of preincision wound infiltration with bupivacaine to wound infiltration at the end of the operation. DESIGN A prospective, randomized, double-blind study. SETTING University medical center. PATIENTS 56 ASA status I and II women scheduled for abdominal hysterectomy were randomly assigned to one of three treatment groups. INTERVENTIONS Group 1 (control) received no local anesthetic infiltration. Group 2 received subcutaneous infiltration with 40 ml of bupivacaine 0.5% (pH 6.9) 15 minutes prior to incision. Group 3 received wound infiltration with a similar solution at the end of surgery. Anesthesia was induced with thiopental 3.0 mg/kg i.v., droperidol 50 micrograms/kg i.v., and sufentanil 0.5 microgram/kg i.v. and maintained with nitrous oxide 67% in oxygen and sufentanil 0.1 microgram/kg IV boluses as required. Postoperative pain was treated with morphine via a patient-controlled analgesia delivery system for 24 hours, followed by oral hydrocodone for 3 days. MEASUREMENTS AND MAIN RESULTS The opioid consumption was recorded for 4 days postoperatively. Pain scores were measured at 4 to 8-hour intervals using 100 mm visual analog scales. There was no difference in either the opioid analgesic requirements or the pain scores between the three study groups. CONCLUSIONS Wound infiltration, either preincision or postincision, had no clinically significant effect on the pain scores or analgesic requirements following abdominal hysterectomy.

Interactions between mivacurium, rocuronium, and vecuronium during general anesthesia.

This study was designed to examine the interactions between mivacurium and rocuronium or vecuronium when administered during a standardized anesthetic technique.Seventy healthy women undergoing abdominal hysterectomy procedures with a standardized thiopental-sufentanil-desflurane-nitrous oxide anesthetic technique were randomly assigned to one of seven treatment groups (10 patients each). After a tracheal intubating dose of vecuronium 100 micro gram/kg (Groups 1 and 2), rocuronium 600 micro gram/kg (Groups 3 and 4), or mivacurium 250 micro gram/kg (Groups 5, 6, and 7), patients received vecuronium, 25 micro gram/kg (Groups 1 and 6), rocuronium 150 micro gram/kg (Groups 3 and 7), or mivacurium 50 micro gram/kg (Groups 2, 4, and 5) for maintenance of neuromuscular blockade. Neuromuscular function was assessed using electromyography, with a train-of-four mode of stimulation at the wrist every 10 s. The clinical duration (time for T1 to return to 25% of baseline) of the maintenance dose of mivacurium was significantly longer after an intubating dose of rocuronium (40 +/- 8 min) and vecuronium (28 +/- 6 min) than after mivacurium (12 +/- 3 min). The clinical duration of maintenance doses of vecuronium (18 +/- 6 min) and rocuronium (13 +/- 2 min) were significantly shorter after an intubating dose of mivacurium than that after an intubating dose of vecuronium (30 +/- 5 min) or rocuronium (42 +/- 12 min), respectively. These data suggest that with consecutive administration of neuromuscular blocking drugs, the initial duration of action depends more on the kinetics of the first neuromuscular blocking drug than the subsequent drug. Thus, there appears to be no clinical advantage in using mivacurium for maintenance of neuromuscular blockade after initial administration of rocuronium or vecuronium. (Anesth Analg 1996;83:818-22)

Abdominal Wound Problems After Hysterectomy With Electrocautery vs. Scalpel Subcutaneous Incision

The purpose of this study was to evaluate the relationship between postoperative abdominal incision problems and opening subcutaneous tissues with electrocautery or scalpel. Women scheduled for elective abdominal hysterectomy who gave informed consent were randomly assigned to subcutaneous abdominal wall tissue incision by electrocautery or scalpel. Postoperative abdominal wound problem diagnoses included seroma, hematoma, infection, or dehiscence without identifiable etiology. Fifteen of 380 women (3.9%) developed a wound problem; six had scalpel and nine had electrosurgical subcutaneous incisions (P = 0.4). Thicker subcutaneous tissues (P = 0.04) and concurrent pelvic infection (P < 0.001) were significant risk factors for postoperative wound problems. Only two women (0.5%) developed an infection. We conclude that the method of subcutaneous tissue incision was unrelated to the development of postoperative abdominal incision problems in 380 women undergoing elective abdominal hysterectomy.