NITROUS-OXIDE - A VALUABLE ALTERNATIVE FOR PAIN RELIEF AND SEDATION DURING ROUTINE COLONOSCOPY

Background and Study Aims: Patient-administered nitrous oxide in 50% o xygen has lately come into use as an alternative to combined opioid an d benzodiazepine medication for colonoscopic procedures. A randomized study was carried out comparing intramuscular pethidine hydrochloride 1 mg/kg with inhalation of Medimix (a mixture of nitrous oxide in oxyg en 50%) for relief of pain and anxiety during colonoscopy. Patients an d Methods: Thirty-eight patients (19 in the pethidine group and 19 in the nitrous oxide group) were studied. The following parameters were m easured: blood pressure, pulse rate, and arterial oxygen saturation. A t the end of the colonoscopy and before the patients left the ward, pa in, nausea, and general well-being were evaluated by the patients usin g a visual analogue scale. The colonoscopy time, investigation conditi ons and the total length of hospital stay were registered. Results: Co lonoscopy time and the colonoscopists' opinions concerning the investi gation conditions did not differ between the groups. Pain relief and p atient evaluation of the total procedure were also equal between the p atient groups. However, there was less nausea among the Medimix patien ts. Three patients in the pethidine group had oxygen saturations below 92%. There,vas no desaturation during and five minutes after colonosc opy in the Medimix group. Patients in the Medimix group left the hospi tal on average 34 minutes earlier than patients in the pethidine group . Conclusions: We conclude that the use of nitrous oxide (Medimix) as an analgesic is as good as pethidine for colonoscopy. Medimix has clea r advantages compared to pethidine in terms of reducing nausea and sho rtening the hospital stay.