Prospective Randomized Trial of Patient-Controlled Analgesia: PATIENTS AND METHODS part 2

4 Dec
2010

Before the hysterectomy procedure, each patient received ranitidine 150 mg orally. The general anesthetics thiopental and propofol were used for all patients. Rocuronium or vecuronium was used for muscle relaxation. A preoperative antibiotic, either cefazolin (1 g) or cefotetan (1 g), was given intravenously. PCA was started in the Post-Anesthetic Care Unit. The PCA device was programmed to deliver 1-mL doses of medication— either ketamine and morphine combined or morphine alone—with a bolus dose of 2 mL permitted and a lock-out time of 6 min. The aim of the lock-out period is to prevent overdose through excessive demands for analgesia. Postoperative antiemetics were allowed at the discretion of the anesthesiologist, who used a standard­ized postoperative nausea and vomiting protocol specific to the hospital. If nausea and vomiting occurred, the patient was to receive dimenhydrinate initially, followed by metoclopramide. If nausea and vomiting continued, ondansetron was to be given.

The pharmacist collected data on postoperative days 1, 2, and 3 during ward rounds, using validated tools to assess pain, nausea and vomiting, sedation, dizziness, hallucination, nightmares, and dreams. The visual analogue scale is a sound methodologic instru­ment for quantitative assessment of postoperative pain at rest, and is more sensitive than a verbal rating scale. Therefore, a visual analogue scale was used in this study to assess the level of pain at rest (0 = no pain, 10 = worst pain). The level of nausea and vomiting was assessed with a numeric 5-point verbal rating scale (0 = no nausea, 5 = extreme nausea, followed by vomiting). Level of sedation was assessed by the 5-point Observer’s Assessment of Alertness/Sedation scale (where 1 = responds to name, 2 = lethargic, 3 = responds to name presented in a loud tone, 4 = responds after shaking, and 5 = does not respond). Dysphoric experi­ence, which includes dizziness, hallucinations, nightmares, and dreams, was also assessed with a 5-point scale (0 = none, 5 = extreme dizziness, hallucinations, night­mares, and dreams). Total consumption of the treatment drug was recorded on a pain assessment sheet, using data from the PCA device; the standard in-house preprinted physician’s order for PCA was used for all patients. levitra professional

The outcomes for the 2 treatment groups were compared with the Mann-Whitney U test, which is appropriate for comparing 2 unpaired groups with ordinal data for the outcome measures. To ensure a conservative analysis, given the small sample size and use of convenience sampling, the Mann-Whitney U test was also used to examine differences between groups in terms of demographic data and total consumption of medication.

top