PRE-OXYGENATION - AN EASY METHOD FOR ALL ELECTIVE PATIENTS

The transparent plastic facemask has been investigated as a pleasant m ethod of pre-oxygenation for elective non-high risk cases in 60 health y ASA I or II patients randomly allocated to two groups. The patients in the pre-oxgenated group (n=30) received 8 litre min-1 oxygen throug h a plastic facemask for 3 min whereas those in a control group (n=30) were not pre-oxygenated. In all patients anaesthesia was induced with propofol 2.5 mg kg-1, fentanyl 1 ug kg-1 and atracurium 0.6 mg kg-1. Manual ventilation of the lungs using a Mapleson A breathing system wa s performed for 2 min with 50% oxygen in nitrous oxide prior to oral i ntubation. Arterial saturation in the pre-oxygenated group rose signif icantly from a mean baseline value of 96.4 (+/-0.9)% to 99 (+/-0.8)% ( P<0.01) and then remained stable both after induction and intubation: 99.1 (+/-0.8)% and 98.9 (+/-1.1)% respectively. In the control group a rterial saturation dropped sharply within 20 s following induction to a mean of 89.8 (+/-3.1)%, and it was 30 s before arterial saturation r eached the equivalent value in the pre-oxygenated group as a result of manual inflation of the lungs. An 8 litre min-1 oxygen flow via a sta ndard transparent plastic facemask is a simple, feasible and acceptabl e method for routine pre-oxygenation for all elective cases.