# Occurrence of Hypoxemia the First Day After Trauma Assessed by Continuous Pulse Oximetry

## TL;DR

This study found that trauma patients experience hypoxemia episodes at similar rates during the day and night in their first 24 hours of hospitalization.

## Contribution

The study provides new evidence on the frequency and timing of hypoxemia in trauma patients using continuous pulse oximetry.

## Key findings

- Hypoxemic episodes occurred at a rate of 5.1 per 100 participant-hours during the first 24 hours after trauma.
- No significant difference was found in hypoxemia incidence between daytime and nighttime periods.
- Continuous monitoring is highlighted as important for trauma patients during transfers between hospital units.

## Abstract

Trauma is a leading cause of death and disability in young adults. Although supplemental oxygen is recommended early after trauma to prevent hypoxemia, evidence regarding the occurrence and distribution of hypoxemic episodes, to raise awareness on potential clinical implications, is sparse. The aim of this study was to investigate the occurrence and daily distribution of hypoxemia within the first day of admission after trauma using continuous pulse oximetry.

Adult trauma patients admitted through the trauma centre at Rigshospitalet, Denmark, between February 20 and August 24, 2024, were included in this observational study irrespective of subsequent admission department. Arterial oxygen saturation measured by pulse oximetry (SpO2) was continuously monitored for 24 h to identify clinically relevant hypoxemic episodes, defined as SpO2 < 90%, for > 5 min. The incidence of episodes was compared regarding the occurrence between daytime and nighttime. Hypoxemic episodes were hypothesized to be more frequent during nighttime.

Among 165 included participants, data from 155 were analyzed. Median age was 49 years (IQR 31–62), 74.8% were male, and median Injury Severity Score was 13 (IQR 9–19). In total 146 episodes were recorded, and both daytime and nighttime periods showed incidence rates of 5.1 episodes per 100 participant‐hours, yielding an incidence rate ratio (IRR) of 1.01 (95% CI, 0.73–1.4; p = 0.95) between daytime and nighttime. No differences between daytime and nighttime were found in cumulative hypoxemia duration, prolonged hypoxemic episodes, or across hospital locations.

On average, 5.1 clinically relevant hypoxemic episodes occurred per 100 participant‐hours of continuous SpO2 monitoring during the first 24 h of hospitalization following trauma. The study found similar incidence rates of clinically relevant hypoxemic episodes at daytime and nighttime.

Supplementary oxygen is recommended in the early phase after trauma to prevent hypoxaemia. This single center study confirmed that clinically relevant hypoxaemic episodes occur on average five times per 100 participant‐hours during the first 24 h of hospitalization following trauma, with similar incidences during both day and night. The study highligths the importance of continuous monitoring of peripheral oxygenation including if trauma patients are transferred from high‐depency units to the wards.

Trial Registration:
ClinicalTrials.gov: NCT06256692