A comparison of nurse-administered and patient-controlled analgesia

Abstract

To determine the safety and effectiveness of nurse-administered propofol sedation using patient-controlled analgesia (PCA) pump in outpatient colonoscopy in a Chinese population.From April to June 2005, 50 consecutive ASA class I or II patients aged 18–65 undergoing outpatient colonoscopy in an endoscopy centre of a regional hospital were prospectively recruited in this study. After a loading dose of 40–60 mg intravenous propofol, a mixture containing 14.3 mg propofol and 35μg alfentanil were delivered via a patient-controlled syringe pump as bolus dose by an endoscopy nurse under the supervision of an endoscopist during the procedure. Lockout time was set to be zero. We aimed to achieve conscious sedation, with an Observer's Scale for Sedation and Alertness (OSSA) score of 3. The primary outcome measure was complications from sedation, which included hypotension, bradycardia and desaturation. Other outcome measures included onset time, patients' pain score, endoscopists' and nurses' satisfaction on the level of sedation, patients' satisfaction regarding the procedure (measured by 10 cm visual analogue scale), and their willingness to repeat the procedure.The mean lowest systolic blood pressure and mean arterial pressure (MAP) were 103.2 ± 12.4 mmHg and 78.3 ± 11.0 mmHg, respectively. The mean percentage drop in MAP was 15.7 ± 11.9%. Six patients (12.2%) developed transient hypotension. Three patients (6.1%) had bradycardia. There was no episode of desaturation. The median onset time to reach OSSA score of 3 was 1 minute (range, 0.5–20.5). The OSSA score of 3 could be maintained throughout the procedure. The mean loading dose of propofol was 48.9 ± 6.7 mg. The mean total dosages of propofol and alfentanil given were 124.2 ± 38.1 mg and 184.3 ± 93.7μg, respectively. Endoscopists, endoscopy nurses and patients were highly satisfied with the sedation. The median pain score was 1 (range, 0–10; 0 = no pain, 10 = very painful), and the mean recovery time was 2.8 ± 2.8 minutes. Most patients (93.9%) were willing to repeat the procedure.Nurse-administered propofol sedation using PCA pump is safe and effective in sedation and pain control in outpatient colonoscopy in a healthy Chinese population.