Hyperbaric Chamber

A fully equipped hyperbaric recompression centre located at the Guernsey's Ambulance Headquarters. This is a dedicated centre housing a large recompression chamber, a compressor room and an adjoining treatment and recovery room.

The centre is maintained primarily to treat divers with the "bends" but is also available to provide hyperbaric treatment in acute medical conditions such as carbon monoxide poisoning.

As with the Service's other rescue functions, it is operated by Emergency Medical Technicians or Paramedics who are additionally trained in the specific techniques needed to operate a hyperbaric recompression centre.

Selected staff operate the Centre's complex controls, or accompany patients under pressure in the chamber to monitor their condition and render any immediate treatment necessary.

general description

The main chamber has two compartments: a 23 metre-long main treatment compartment and a 1.1metre outer air lock which can be separately pressurised to enable an attendant to enter or leave the main compartment without reducing the main compartment pressure.

The chamber is pressurised from an air bank, with oxygen from an oxygen bank supplying breathing masks or oxygen hoods for patients inside the chamber.

An adjoining treatment room houses a hospital bed, drugs cabinet and other equipment to facilitate a patient's recovery after treatment in the main chamber.

Although charges are sometime made to cover the costs of specific treatments, the Centre relies on public generosity and donations, as with other ancillary and rescue functions operated by the Ambulance & Rescue Service.

staffing

The Centre is operated by Emergency Medical Technicians and Paramedics from the Ambulance & Rescue Service, who have been additionally trained in the treatment requirements of decompression illness and related events. A panel of local doctors provide medical supervision and an on-call medical response.

Staff are trained in three categories, as Team Principal, Operator or Attendant.

The Team Principals are in overall control of a treatment session. A doctor is normally called in to examine a patient, to make a diagnosis and confirm with the Principal the treatment regime to be followed. He / she normally then leaves the Principal to arrange the treatment and refer to the doctor as necessary if any changes in symptoms occur. In urgent cases a Team Principal can make the decision to start a treatment regime without waiting for a doctor to attend.

The Operators are those who run the chamber controls, ensuring the required pressure is maintained, regulating the oxygen and carbon dioxide levels, monitoring the pressure guages, the temperature and other controls and generally being responsible for the well-being of the patient and for following the treatment tables specified for the patient.

The Attendant is the Emergency Medical Technician or Paramedic who accompanies the patients inside the chamber, and stays with the patient whilst under pressure, taking observations of pulse, respiration and other signs, administering drugs or providing other treatment necessary whilst under pressure.

They are responsible for the patient's safety and medical needs, operating internal controls and communicating with the Operators outside via the intercom.

When a patient is released from the chamber after treatment, they will usually remain under supervision in the treatment room for a specified time to ensure that symptom relief is permanent and that re-admission to the chamber is not required. Depending on the severity of the case, the patient may be discharged home or to Guernsey's hospital for further treatment.

Technical Description

The Recompression Centre comprises a Chamber Room, a Treatment Room and  a Compressor Room.

The Chamber Room contains a "Siebe Gorman" two compartment (Air lock and Main), eight place, static chamber and an air bank of four cylinders at a pressure of 280 bar linked to the chamber by high pressure Tungum pipe. The chamber has a medical lock for the transfer of medicines, food and other small items without the need to use the air lock.

A main oxygen bank outside the building uses four "J" size cylinders in multiples of two with a four branch main manifold to a reducer and two "j" cylinders in a reserve rack. The reducer is set to 40 bar and oxygen from this is pied to the chamber which has a working pressure of 137 bar but is used at the reduced pressure of 40 bar.

A gas analyzing system monitors oxygen or carbon dioxide in the chamber and an external gas analyser check the air supply pumped into the high pressure compressor. A carbon dioxide scrubber is fitted to remove any build up of CO2 without having to flush the chamber with large amounts of air.

Digital and analogue pressure gauges give readings to a decimal point of a meter and individual gauges are fitted to the air bank cylinders and to medical locks.

A closed circuit colour television camera in the main chamber is monitored on the main panel allowing doctors and operators to observe the area at all times and in all light levels.

Internal safety is provided by a hyperbaric fire extinguisher and temperature and humidity gauges in the main chamber. The chamber is painted with fire resistant paint inside and HSE approved acrylic viewing ports with Perspex covers give visual monitoring of the inside of the chamber to supplement the CCTV picture.

An intercom enables the operator to monitor sounds inside the chamber and to exchange conversation with the attendant or patient inside.

Internal systems for patients include three Built-in Breathing Systems (BIBS) to offer oxygen therapy to patients, and an oxygen hood system has been built by Service staff with advice from the Defence Research Agency, which enables oxygen therapy to be given to a patient who is unable to use the BIBS system.

An entertainment centre, consisting of tape player and radio has been wired in to an internal speaker for the benefit of patients and attendants. Patients may have to remain in the chamber for up to 36 hours.

The Treatment Room is used for the reception of any casualty and observation of their condition after treatment. It contains a hospital bed and full medical examination equipment. Patients may have to remain in this room for some time after treatment, in case they need to be readmitted to the chamber for further treatment under pressure.

The Compressor Room is equipped with a "Williams and James" three stage, water cooled compressor capable of pumping high pressure air at 850 litres a minute to a pressure of 280 bars. This is connected to the air bank. The room also contains a small workshop area for the maintenance of associated equipment.

History

Prior to 1969, divers in Guernsey suffering from decompression sickness had to be transported off the Island for treatment. In that year the Ambulance & Rescue Service received a donation from the Hayward Foundation in England, to purchase a portable, one-man recompression chamber and associated high pressure air compressor.

In its first 3 years the unit treated 19 patients, but those needing complex treatments still had to be flown to England or France inside the portable chamber, to be transferred under pressure to a multiplace facility. In 1972 the Hayward Foundation financed a multiplace "recompression centre" at the service headquarters.

This consisted of a treatment room, chamber room and a compressor room and was the first civilian hyperbaric unit in the British Isles.

During the following years the centre treated not only victims of diving accidents but also patients suffering from multiple sclerosis, motor neurone disease, gas gangrene and carbon monoxide events.

Under a Senior Officer, work began on a modernisation programme, mostly undertaken by the Service's own personnel.

The programme was completed in 1999 bringing the Centre up to the latest modern standards. One of the consequences of the modernisation was that use of the original monoplace portable chamber was discontinued, and this was placed in the local Maritime Museum which is open to the public.