Information for referring clinicians

Practical guidance, common pitfalls and the principles that underpin the SPOA referral pathway.

This service is for healthcare professionals

The HBOT Single Point of Access is designed for clinicians referring patients with suspected iatrogenic gas embolism. If you are a member of the public with an urgent medical need, please contact 999. For diving-related emergencies, contact the BHA Diving Accident Helpline on 07831 151523.

You do not need to be certain of the diagnosis before calling

If gas embolism is in the differential, that is enough to justify the call. The Hyperbaric Physician can help you work through the clinical picture. Early discussion — even when the diagnosis is uncertain — is always preferable to a delayed referral after the window for effective treatment has narrowed.

Imaging should not delay the call

Urgent CT head and chest are appropriate to exclude other pathology, but in clinically obvious cases the referral call should be made in parallel with arranging imaging, not after results are available. Gas may no longer be visible on CT by the time the scan is performed. CT sensitivity is approximately 67% — meaning roughly one in three cases with gas embolism will have a normal scan.

The patient does not need to be stable before you call

If the patient is too unwell to transfer, the Hyperbaric Physician can provide telephone advice on immediate management while you stabilise the patient. Fitness for transfer should be reviewed regularly. The hyperbaric team can help coordinate retrieval if needed.

Patients can relapse after initial improvement

An initial clinical improvement does not mean the patient is out of danger. Relapse after apparent recovery is a recognised pattern in gas embolism. Early hyperbaric referral remains appropriate even when the patient appears to be improving.

Do not delay referral on account of the interval since the event

Cases of meaningful clinical improvement following HBOT initiated more than 24 hours after the event have been reported. There is no firmly established cut-off beyond which referral is futile. If gas embolism is suspected, contact the SPOA regardless of elapsed time and discuss with the Hyperbaric Physician.

Key references

  • Intensive Care Society. Management of Patients With Gas Embolism — Guidance for Intensive Care and Resuscitation Teams (2019).
  • NHS England. HBOT Service Specification (January 2025).
  • NHS England. Clinical Commissioning Policy: Hyperbaric oxygen therapy for decompression illness / gas embolism (all ages).
  • Fakkert RA, Karlas N, Schober P, et al. Early hyperbaric oxygen therapy is associated with favorable outcome in patients with iatrogenic cerebral arterial gas embolism: systematic review and individual patient data meta-analysis of observational studies. Critical Care 2023; 27: 282.
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