Recompression procedure



Diving Related Illnesses fall into 3 categories:

  1. Decompression sickness (DCS, also called 'the bends' or caisson disease) is the result of inadequate decompression following exposure to increased pressure (depth) over a period of time. It is predominantly a neurological condition, presenting itself as pain, weakness or altered sensation after a dive. In some cases, the disease is mild and not an immediate threat. In other cases, serious injury can occur; when this happens, the quicker treatment begins, the better the chance for a full recovery
  2. Barotrauma specifically refers to injury to air-filled spaces in the body, such as ears, sinuses, lungs and gastrointestinal tract following a rapid ascent from any depth
  3. For the purpose of this document, Environmental Injury or Illness is considered any injury or illness not related to decompression illness and barotrauma in a diving context, but are frequently associated with diving activity

Decision – Hyperbaric Chamber vs ED

On receipt of a diving related call the doctor should:

  1. Establish location of the casualty:
    1. At Sea or in a Helicopter
    2. Self-Presenting to a GP or ED
    3. On Land and in an Ambulance
  2. Decide EM vs Hyperbaric Specialist review, guided by the following 4 steps below:

Step 1

Is the casualty unconscious?
Have they massive bleeding?
Have they difficulty speaking?
Have they difficult or painful breathing?
Are they breathing faster than 20 breaths per minute or slower than 8 breaths per minute?
Are there any injuries to their chest?
Is there any blood stained or frothy sputum?
"Take your thumb and push on the casualties forehead until the skin goes white, tell me how many seconds it takes for the colour to come back…"
Does this take longer than  3 seconds?
Do they have any broken or deformed limbs?
If Yes To Any Question
Dispatch Sar Asset
Transport To Nearest Major Trauma Centre

Step 2

If NO to All Divers at ↑ Risk of Decompression Illness or Art. Gas Embolism If YES To Any
Transport To Nearest Emergency Department Dive Deeper than 30m? Contact National Hyperbaric Medicine Unit at University Hospital Galway
For Specialist Opinion
UHG on 091 524222; Ask for 3rd on-call Anaesthetist on bleep 112
Trimix / technical diver?
Closed Circuit (re-breather)?
Localised deep pain or pain in joints?
Itching or crawling sensation?
Mottled or marbled skin rash?
Visual abnormalities?
Tingling or numbness?
Amnesia?
Headache?
Seizures?
Weakness or Paralysis?
Loss of Balance/coordination?
Vertigo?
Extreme & Unusual Fatigue?
Difficulty Urinating

Step 3

The below list require Emergency Medicine assessment first and most do not require recompression.

If in doubt Contact National Hyperbaric Medicine Unit at UCHG for specialist opinion:

  • All Barotrauma
  • Pulmonary over inflation syndrome
  • Oxygen Toxicity
  • Nitrogen Narcosis
  • Caustic Cocktail (inhalation soda lime)
  • Mediastinal / subcutaneous emphysema
  • "Reversed ears"
  • Otitis Externa "swimmers ear"
  • Pneumothorax
  • Alternobaric vertigo
  • Caloric vertigo
  • Drowning
  • Vomiting underwater
  • Underwater blast injuries
  • Hypothermia
  • Heat exhaustion

Step 4

Obtain a brief diving history:

  • Ascertain and summarise any available information surrounding the mechanism of injury, which must include depth, time at depth and if the ascent from death was controlled (all decompression stops adhered too) or rapid
  • A description of the casualties signs and symptoms

Obtain a brief Medical and Medication (including over-the-counter) history.


Hyperbaric Referrals

all hyperbaric medicine enquiries must go through the National Hyperbaric Medicine Unit at University Hospital Galway. Contact via:

  • A conference call with NEOC or IRCG Controller (preferred option)
  • Call GUH Switch on 091 524222; Ask for 3rd on-call Anaesthetist on bleep 112

It is the Hyperbaric Specialists' decision to recompress or not.

Hyperbaric Facilities:

  • Note that it is the Hyperbaric Medicine Specialists responsibility, regardless of where the patient is, to arrange Recompression Therapy. If the NHMU is not available, the Hyperbaric Medicine Specialist in Galway is responsible for arranging alternative facilities in the UK
  • Ireland has one HSE managed Recompression Chamber referred to as the National Hyperbaric Medicine Unit at University Hospital Galway (NHMU). It does not have a permanent staffing arrangement and operation at any given time may be subject to staff availability
  • Northern Ireland has one recompression chamber located at Craigavon Area Hospital. All referrals must be arranged through NHMU
  • Other UK facilities include Isle of Man (Cat 2) Plymouth, Wiral and Aberdeen (all Cat1). Again, all referrals to these facilities must be arranged by UHG
  • The Navy have a recompression chamber. It is a mobile chamber, based in Haulbowline, but frequently on-board naval vessels in support of military diving duties. It is therefore not a declared chamber for emergency use. In Emergencies, there may be merit in enquiring about its availability, through Naval Command at Haulbowline
  • A few privately operated recompression chambers exist in the country and are used for sports and other soft tissue injuries and a range of chronic neurological conditions. None of these facilities are capable of accepting an acute patient. None of these chambers are options

Transfer to a Hyperbaric Chamber:

NEOC and IRCG Controllers work in tandem to arrange transportation to recompression therapy for all patients. Hence it is best to keep all communications with the NHMU, or any other parties, as conference calls. NEOC or IRCG are very experienced at managing these transports.

If a patient is still on scene, following a CG helicopter or ambulance response, the on-scene paramedic will have an opportunity to make a further medical assessment, which could include a revised decision. At this point a link call between MEDICO Cork and the on-scene paramedic to further aid appropriate decision making will be made.

The divers, Diving Computer and Dive Buddy (diving colleague) should also travel with the diver as a dive buddy may have a similar dive profile and could also develop diving illness.

If a casualty is initially delivered to an Emergency Department, further transportation to a Recompression Chamber may be required after assessment.

If any questions, please refer to on-call EM Consultant or Dr. van der Velde.



Content by Dr Jason van der Velde, Dr Íomhar O' Sullivan. Last review Dr ÍOS 14/04/24.