Low-flow oxygen therapy in intensive care: an observational study

Background: There is scant published evidence that explains how ICU nurses' manage low-flow oxygen therapy; and, hence little is known about how low-flow oxygen therapy is delivered on a daily basis.

Aim: The aims of this study were first to observe how ICU nurses' manage low-flow oxygen therapy and then to compare observed nursing practice on the management of oxygen therapy with patients' documented measures of oxygen saturation (SpO2) and respiratory rate (RR).

Method: From May to July 2009, eight 2h observation periods were conducted in one ICU of a metropolitan hospital in Melbourne, Victoria. Data were collected at using a structured observation tool, field notes and chart review. Quantitative data were analysed using descriptive and frequency statistics, and textual data were reviewed using a content analysis procedure.

Results: Over the 16 h of observed nursing practice, there were 96 points of measurement involving 16 patients and 16 ICU nurses. The management of low-flow oxygen therapy varied between nurses and data revealed that nurses did not always promote effective oxygenation. Documented SpO2 was 98.0% (SD 2.8%) and observed SpO2 was 96.3% (SD 1.8%). Documented RR was 19.6 breaths/min (SD 3.5) and observed RR was 21.0 breaths/min (SD 16.8). Episodes of hypoxaemia and tachypnoea occurred while patients were receiving oxygen and nurses did not always respond appropriately.

Conclusion: ICU nurses' management of low-flow oxygen therapy was suboptimal and documentation of oxygenation and respiratory rate was inaccurate. Further exploration of how ICU nurses manage low-flow oxygen therapy is a necessary prelude to the conduct of interventional studies and the development of better guidance to support low-flow oxygen therapy in the ICU.