Comparison of Patient-Controlled Analgesia With and Without a Background Infusion After Lower Abdominal Surgery in Children

Abstract

Forty children aged 6-12 yr undergoing appendicectomy were allocated randomly to receive postoperative i.v. morphine by a patient-controlled analgesia (PCA) system (bolus dose 20 micrograms kg-1 with a lockout interval of 5 min) or the same PCA with a background infusion of morphine 20 micrograms kg-1 h-1. Patients breathed air and oxygen saturation was monitored by continuous pulse oximetry. Scores for pain, sedation and nausea were recorded hourly. Patients with PCA + background infusion received significantly more morphine than those with PCA only. Both groups self-administered similar amounts of morphine using the PCA machine. There were no significant differences in the pain scores of the two groups. Patients with PCA+background infusion suffered more nausea (P < 0.01), more sedation (P < 0.05) and hypoxaemia (P < 0.001) than those with PCA only. They also had a better sleep pattern than those with PCA only.

Compatibility and Stability of Morphine Sulphate and Naloxone Hydrochloride in 0.9% Sodium Chloride for Injection

“…Stock solutions of morphine SO 4 and naloxone HCl were prepared from commercially available (premixed) solutions. These stock solutions were prepared in a laminar flow hood using aseptic technique.…”

“…Standards were prepared by combining commercially available morphine SO 4 1 mg/mL (Sandoz Canada; lot AR6494) and naloxone HCl 1 mg/mL (diluted in 0.9% NaCl to a concentration of 0.1 mg/mL) as required to obtain the following concentrations: 300 and 10 µg/mL, respectively; 250 and 6 µg/mL, respectively; 200 and 5 µg/mL, respectively; 150 and 2.5 µg/mL, respectively; 100 and 1.5 µg/mL, respectively; and 50 and 0.5 µg/mL, respectively. The internal standard was prepared by diluting ketamine HCl 25 mg/mL (Sandoz Canada; lot AP8595) in 0.9% NaCl to a concentration of 250 µg/mL and then adding this internal standard to the prepared standards to a final concentration of 25 µg/mL.…”

“…[1][2][3][4][5][6][7][8] One common adverse effect of morphine is pruritus. In a small study of 25 adult patients receiving morphine by patient-controlled analgesia (PCA) for postoperative pain, 40% were reported to have pruritus.…”

“…31 However, to the authors' knowledge, based on a search of tertiary compatibility references and the primary literature (i.e., MEDLINE and Embase databases), there have been no studies investigating the chemical and physical compatibility of morphine and naloxone in the same minibag at the standard concentrations used at the authors' institution. The standard concentrations at the authors' institution are morphine SO 4 1 mg/mL in 0.9% sodium chloride (NaCl) for PCA and naloxone HCl 4 µg/mL in 0.9% NaCl for prevention of itching or urinary retention during epidural administration of morphine. For the stability study reported here, 3 concentrations of naloxone (4 µg/mL, 12.5 µg/mL, and 25 µg/mL) were tested.…”

“…The purpose of this study was to determine the compatibility of morphine SO 4 and naloxone HCl when combined and stored in minibags at room temperature and under refrigeration.…”