Equipment for mixed gas and oxygen therapy

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.

What is the evidence for the use of high flow nasal cannula oxygen in adult patients admitted to critical care units? A systematic review

BACKGROUND

Humidified high flow nasal cannula oxygen therapy is increasingly available in Australian adult intensive care units. Its use in paediatric populations has been extensively studied and has shown positive effects however its clinical effectiveness in adults has not been established.

PURPOSE

A systematic review of the literature was conducted to critique current evidence, inform nursing practice and make recommendations for nursing research.

METHODS

An extensive search strategy identified clinical studies comparing standard oxygen therapy with high flow therapy in critical care units. Two reviewers independently assessed articles for eligibility, methodological quality and inclusion. Outcomes of interest included oxygenation, ventilation, work of breathing, positive airway pressure, patient comfort and long term effect. A narrative synthesis was conducted to describe the emerging evidence.

FINDINGS

Eight studies were included for review. All were abstracts or poster presentations from scientific meetings therefore the quality of data available for analysis was poor. Findings indicated there was preliminary evidence to support the use of high flow therapy to optimise oxygenation in adults. This therapy may reduce the effort of breathing and provide augmented airway pressures. Patients described the therapy as comfortable. No definitive evidence supported the claim that ventilation is improved or conclusively demonstrated a long-term effect.

CONCLUSION

Humidified high flow nasal cannula may be used as an intermediate therapy to improve oxygenation in adult critical care patients. Further research is required to determine the duration of effect of the therapy, identify the patient population for whom it is most beneficial and evaluate long-term outcomes; to enable definitive recommendations for practice to be made.