Randomised controlled trial of patient controlled sedation for colonoscopy: Patient maintained target controlled infusion of Propofol versus Entonox.

P.Balaji¹, S.Maslekar², B.Culbert¹, G.S.Duthie². 1 Department of Anaesthetics, Hull Royal Infirmary, Hull, HU3 2JZ, UK.  2 Academic Surgical Unit, Castle Hill Hospital, Hull, HU16 5JQ, UK

Introduction:

Intravenous sedation for colonoscopy is associated with cardio-respiratory complications and prolonged drowsiness. Recently, patient maintained sedation using propofol has been described in the literature and has been used in such patients with minimal side-effects¹. We aimed to compare patient maintained target controlled propofol infusion with patient controlled entonox inhalation (50% nitrous oxide: 50% oxygen) for colonoscopy in terms of analgesic efficacy, side-effects, psychomotor recovery, patient and endoscopist satisfaction. 

Methods:

All patients undergoing elective colonoscopy except those with colon resection were included. Ethics committee approval and CTA certificate (clinical trial authorization) from MHRA was obtained and patients were randomized (with adequate allocation concealment) to receive patient maintained target-controlled infusion of propofol or entonox. Patients in propofol group were administered propofol initially with a target value of 1.2 μg/ml using TCI pump and then allowed to administer themselves a bolus of propofol (20µg/kg) using a PCA pump with a handset when required. Patients in the entonox groups inhaled the gas for 60 seconds before the procedure and then as and when required throughout procedure. Heart rate, Blood Pressure, ECG, Saturation monitoring were recorded every 5 minutes. Sedation scoring was done every 5 minutes during the procedure and every 10minutes during recovery. Patients completed anxiety score (HAD questionnaire), baseline letter-cancellation test and pain score on 100 mm-visual analogue scale (VAS) before procedure. Patients then completed letter-cancellation tests and marked pain assessment on VAS immediately after procedure and at discharge. All patients completed satisfaction survey at discharge and 24-hours post-procedure, when they also marked pain assessment. Secondary end-points measured were completion rates, nurse and endoscopist satisfaction and complication rates.

Results

100 patients were randomized to receive Propofol (n=50) or Entonox (n=50). The median dose of propofol was 174mg and median number of bolus of Propofol was 4 presses. There was no difference in the two groups in terms of pain recorded (Entonox group mean score 20 versus 15, p=0.3; Mann Whitney U Test) with similar pre-procedure anxiety scores (p=0.1). Further, there was no difference between the two groups in terms of completion rates, time to caecum, total colonoscopy time and endoscopist and nurse satisfaction. Patient satisfaction was also similar in both groups (mean 98 versus 96). There were no significant complications in both groups.

Conclusion

Patient maintained sedation using target controlled Propofol is well tolerated by patients and provides a high degree of patient satisfaction with less complication. Colonoscopy could be carried out using patient maintained sedation with propofol.

Reference:

1. Campbell L, Imrie G, Doherty P, Porteous C, Millar K, Kenny GN, Fletcher G. Patient maintained sedation for colonoscopy using a target controlled infusion of propofol. Anaesthesia 2004; 59(2): 127-132.