Oxygenation targets and monitoring in the critically ill: a point prevalence study of clinical practice in Australia and New Zealand

Background: Many critically ill patients require supplemental oxygen. However, the optimal oxygen saturation measured by pulse oximetry (Spo(2)) in intensive care unit patients is unknown. Objective: To evaluate clinical practice in Australia and New Zealand ICUs in relation to sSpo(2) monitoring, prescription of Spo(2) targets by doctors, and upper and lower limits of tolerance of high and low Spo(2) levels by ICU bedside nurses. Method: Cross-sectional, observational study conducted on 2 days in 2013 involving adult patients in Australia and New Zealand ICUs. Results: Data from 350 adult ICU patients were included. Spo(2) alarms were less likely to be disabled in patients who were invasively ventilated than in patients not receiving supplemental oxygen (4.8% v 15.1%; P=0.02). In mechanically ventilated patients and non-ventilated patients receiving supplemental oxygen, the lower prescribed Spo(2) limit and the ICU bedside nurses' stated limits for action for low Spo(2) levels were 92% (interquartile range, 90%-94%). Upper Spo(2) limits were less frequently prescribed than lower Spo(2) limits (4.9% [95% Cl, 3.0% 7.7%] v 36.6% [95% Cl, 31.7%-41.7%]); P<0.01) and the observed Spo(2) exceeded the prescribed upper limit on 10/17 occasions (59%) when an upper limit was prescribed. Conclusion: Our findings suggest a relatively low level of vigilance in relation to prevention of high Spo(2) compared with low Spo(2) for adult patients in Australian and New Zealand ICUs.