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

Abstract

Background: Many critically ill patients require supplemental oxygen. However, the optimal oxygen saturation measured by pulse oximetry (SpO₂) in intensive care unit patients is unknown.

Objective: To evaluate clinical practice in Australia and New Zealand ICUs in relation to SpO₂monitoring, prescription of SpO₂targets by doctors, and upper and lower limits of tolerance of high and low SpO₂levels 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. SpO₂alarms 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 SpO₂limit and the ICU bedside nurses' stated limits for action for low SpO₂levels were 92% (interquartile range, 90%-94%). Upper SpO₂limits were less frequently prescribed than lower SpO₂limits (4.9% [95% CI, 3.0%- 7.7%] v 36.6% [95% CI, 31.7%-41.7%]); P < 0.01) and the observed SpO₂exceeded 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 SpO₂compared with low SpO₂for adult patients in Australian and New Zealand ICUs.