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2232 The efficacy of hyperbaric oxygen therapy and 30-day patient outcomes in delayed treatment of decompression sickness
  1. Sylvia Wilson1,
  2. Charlotte Innes1,
  3. James Moss1,
  4. Pieter Bothma2
  1. 1Imperial College London
  2. 2Hyperbaric Unit, Whipps Cross Hospital


Aims and Objectives Decompression sickness (DCS) occurs due to inert gas bubble formation in tissues and can cause serious injury. Hyperbaric oxygen therapy (HBOT) is the definitive treatment. Dive physicians advocate early therapy, believing it will produce the greatest patient benefit. This audit aims to investigate the relationship between time delay to treatment and its effect on HBOT efficacy and novelly, 30-day patient outcomes, to better support recommendations for healthcare providers.

Method and Design The audit included 33 DCS patients treated at Whipps Cross Hospital, London (May 2021-December 2022). Data was extracted from patient notes, telephone records, HBOT logbook, and REDCap database. Terms were defined as: HBOT duration = total time undergoing HBOT (used to evaluate HBOT efficacy); time delay = interval between last surfacing from a dive to first HBOT; outcomes = residual symptoms 30-days post-HBOT.

Results and Conclusion No significant relationship was found between the duration of HBOT and time delay (R=0.149, p=0.409). Patients with severe DCS produced the strongest relationship (R=0.238, p=0.342), suggesting these patients‘ response to HBOT may be more sensitive to time delays, and hence early recompression may provide greater benefit. No significant difference was found (p=0.82) in HBOT efficacy, comparing patients with non-delayed (<48 hr) and delayed (>48 hr) treatment. All patients who received treatment <48 hours had complete resolution of symptoms at 30-day follow-up, in contrast to those treated >48 hours. Although no statistical significance was found between delayed vs non-delayed HBOT (p=0.133), only patients with delayed HBOT had residual symptoms at 30 days.

No significant decline in the efficacy of HBOT in delayed treatment of DCS was found in our cohort. Early therapy should still be recommended as the small sample size and missing outcome data in the study may preclude demonstrating a benefit. DCS symptom education in first responders and emergency medical staff is paramount in reducing delayed HBOT.

Abstract 2232 Figure 1

HBOT efficacy before and after 48-hour treatment. Bar chart shows median values with error bar representing interquartile range. Dot plots represent individual data points. X-axis represent the time delay to treatment and y-axis, the total time patients spent undergoing HBOT. The purple bar represents patients treated with HBOT <48 hours after surfacing from their last dive (n=9). The orange bar represents patients treated with HBOT >48 hours after surfacing from their last (n=24). Analysis was generated in GraphPad Prism 9.4.1 (458)

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