Variation in Postoperative Analgesic Requirements in the Morbidly Obese Following Gastric Bypass Surgery

Abstract

Patient-controlled analgesia is a relatively new method of administering intravenous narcotics for postoperative pain relief. The technique involves the self-administration of a given analgesic in a bolus dose with the aid of a timed infusion and sequencing device. Ten morbidity obese patients undergoing elective gastric bypass surgery were treated in a prospective, unblinded, pilot project to evaluate the efficacy of patient-controlled analgesia. Analgesic therapy was satisfactory in all patients. The mean total dose of morphine sulfate administered during the first 36 hours postoperatively was 66 mg, an average of 1.7 mg/hr. There was a tenfold variation (17.5-175 mg) in the 36 hr total dose. The total dose was not related to body surface area, age, sex, dose per injection, or anesthetic agent. The large variation in individual narcotic analgesic requirements could be a major factor in the suboptimal management of postoperative pain with conventional dosing. Patient-controlled analgesia may circumvent these problems.

Anesthetic impact of body mass index in patients undergoing assisted reproductive technologies

“…However, reduced postoperative analgesic requirements have been observed in patients with high BMI [30,31], which was consistent with the greater pain experienced by overweight versus obese patients in our study population. The large variation in postoperative analgesic requirements in patients with high BMI makes adequate control of postoperative pain a challenge [32]. Overall, no relationship with BMI was found in the few individuals who required treatment with antiemetics (Table 4), an observation in keeping with a TIVA technique based predominantly on the use of propofol [33].…”

Prescribing and Self-Administration of Morphine in Hispanic and Non-Hispanic Caucasian Patients Treated with Patient-Controlled Analgesia

“…While larger patients might be expected to require more opioid than smaller patients, no clear relationship between opioid dosing and body weight or body surface area has been found. 19,20 Communication differences may also play a role in how much analgesic was prescribed, but this variable was not assessed in this study. Finally, the results are limited to White and Hispanic patients treated under an orthopedic or neurosurgery service in a Southern Arizona teaching hospital.…”

Opioid Safety: Is Your Patient at Risk for Respiratory Depression?

“…PCA use in obese postoperative patients showed as much as a 10-fold range in dose requirements for overweight patients in the same weight range, possibly indicating the variability of drug metabolism in obese patients (Bennett et al, 1982).…”