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Page last updated
11th April, 2014

About the Unit

outside of chamberThe Hyperbaric Medicine Unit is based at Aberdeen Royal Infirmary (ARI) and is located in the National Hyperbaric Centre (NHC). The Unit is funded by the National Services Division of NHS Scotland to provide medical treatment and advice for diving related illness. The Unit also provides treatment for other conditions that have been shown to respond well to Hyperbaric Oxygen Therapy.

There are four classifications of chamber used by the British Hyperbaric Association (BHA). Our Unit is classed as the highest, category 1 - the only one in Scotland capable of providing intensive care support in a hyperbaric environment.

The Unit has access to the hospital's on-site helipad for reception of casualties from distant locations either directly from the scene via coastguard, navy or airforce rescue helicopter or from another facility. Patients may also arrive by fixed-wing aircraft at Aberdeen airport.

The graph below indicates the number of individual patients treated at the Unit - not the number of total treatments. Elective patients, for example, typically undergo 30 treatment sessions.

Hyperbaric Treatments 2000 - 2009


The Unit's staff consists of the following personnel:

  • Seven specialist medical consultants.
  • One Charge Nurse / Co-ordinator.
  • Two senior staff nurses.
  • Nineteen staff nurses.
  • Life Support Technicians employed by the National Hyperbaric Centre.

Medical, nursing and technical staff are on call 24 hours per day. The nurses who cover routine treatments and emergency cases at the Unit are based in the Intensive Therapy Unit of ARI and have all undergone training in hyperbaric nursing in addition to existing critical care training. We also support diving related NHS cases treated elsewhere in Scotland, with the consultants providing medical advice. The Charge Nurse acts as the co-ordinator for the National Registration Service for chambers in Scotland. The Unit provides hyperbaric nursing and medical training for other facilities.

The Hyperbaric Chamber

Hyperbaric chamberThe Unit's chamber is maintained by the National Hyperbaric Centre Ltd. who also provide support staff to enable the Unit's chamber to operate 24 hours per day at 30 minutes notice.

The chamber is 7.8m long, 2.2m in diameter, 30.4m³ in volume and is rated to a working depth of 300msw (31ata). There are two fixed bunks and a moveable Stryker trolley as used in some Accident and Emergency departments.

A respiratory ventilator, suction apparatus and electronic monitoring equipment enable the chamber to be used for the treatment of critically ill patients, including children. There is also a full range of adult and paediatric resuscitation equipment available including a cardiac defibrillator and emergency drugs.

The chamber is linked to several others operated by the NHC, which can be used to treat multiple casualties. The interlock between them allows equipment and additional personnel to be compressed to the working depth as required. Small items, food, drugs or samples can be passed in or out through a small air-lock (medical lock). The diagrams below show plan views of the chamber complex. It also includes a large capacity dry / wet chamber (not shown) located immediately below the main transfer lock.

Plan of hyperbaric chamber

Plan of hyperbaric chamber system

Patient monitorPatient monitoring options include electrocardiography (ECG), oxygen saturation (SpO2), invasive blood pressure, central venous pressure (CVP) and body temperature, measured using a GE Marquette monitor that shows values and waveforms on an external display. Staff inside the chamber and in the nursing office can also view the results using separate screens.

There is also a video camera monitoring the inside of the chamber that can be viewed in the control room and the nursing office. During most emergency treatments the patient is nursed on the Stryker trolley - allowing the best camera view.

In the offshore diving industry, casualties can be treated on scene by using divers trained in advanced first aid (diver medics), the vessel medic and onshore based doctors who are retained by companies to provide medical support to diving companies. On occasion, however, medical and nursing staff from the Unit have supported the treatment of critically ill divers on board commercial vessels.

The majority of cases dealt with by the Unit are recreational SCUBA divers, CO poisoning and elective HBOT therapy, although the number of CO poisoning cases has dropped markedly in the past few years.