Postgrad Med J. 2021 Feb 15:postgradmedj-2020-139511. doi: 10.1136/postgradmedj-2020-139511. Online ahead of print.
PURPOSE OF THE STUDY: To evaluate documentation of a target oxygen saturation (SpO2) range and ability to achieve this range in acutely unwell inpatients.
STUDY DESIGN: In this single-centre audit, patients with discharge diagnoses of pneumonia, heart failure and exacerbation of asthma or COPD admitted to Wellington Regional Hospital, New Zealand between 1 June 2019 and 31 August 2019 who received oxygen were identified. In those with a documented target SpO2 range, the proportion of SpO2 measurements in the observation chart which were within, above and below range were determined as well as the maximum and minimum SpO2. Regression analysis was performed to determine whether these outcomes were influenced by the prescribed range, high-dependency care or the number of adjustments to oxygen administration.
RESULTS: 268 admissions were screened. Of the 100 eligible admissions who received oxygen, a target SpO2 range was documented in 62. The mean (SD) proportion of SpO2 measurements within range was 56.2 (30.6)%. A hypercapnic target SpO2 range was associated with a higher probability of an SpO2 above range; multivariate OR 5.34 (95% CI 1.65 to 17.3, p=0.006) and a lower probability of an SpO2 below range; multivariate OR 0.25 (95% CI 0.08 to 0.80) p=0.02. The mean (SD) maximum SpO2 was similar in those with a target range of 92%-96% versus a hypercapnic range; 96.2 (3.0)% and 95.2 (3.4)%, respectively.
CONCLUSIONS: Oxygen prescription and delivery in this clinical setting was suboptimal. SpO2 values above the designated range are common, particularly in patients with a hypercapnic target range.