Hyperbaric Equipment in Use at the Royal Adelaide Hospital
IMED Gemini PC 2 Infusion Pump. This 2 channel pump has worked well for a number of years and replaced earlier IMED models used in the Unit. To make the pump safe for hyperbaric use our biomedical engineering department; degreased the motor, soldered the battery connections and vented all the touch pads.
Although this pump performed well over the years that we used it, there were a few operational problems. At times the rechargeable batteries did not give the expected life and pumps had to be changed out during a treatment. Needing a Gemini specific giving set posed a few problems when the patient's home unit was using a different brand of pump. Periods of low use with the pumps constantly on charge seemed to reduce battery life, although subsequent testing by regularly draining batteries and then recharging did not support this.
Baxter Colleague Infusion Pump: Function Test of Baxter Colleague Infusion Pump Under Hyperbaric Conditions
Alaris ASena 65 Syringe Driver. This syringe driver underwent the same type of testing as that carried out on the Baxter infusion pump. The pump was degreased and lubricated with Krytox oxygen compatible lubricant. Under a variety of test pressures and infusion amounts the driver performed well with only an average +/-3.6% discrepancy over its range. We accepted the driver into service and it has functioned without a problem ever since.
Note: The manufacturers of both the Baxter Colleague infusion pump and the Alaris ASena syringe driver will not recommend their equipment as safe for use in hyperbaric environments.
Dräger Hyperlog Hyperbaric Ventilator. This ventilator was developed by Dräger specifically for hyperbaric use. It is a time-cycled, constant volume ventilator with a minute volume range variable between 2 and 20 liters per minute and a respiratory rate variable range between 10 and 35 per minute. Once set, the respiratory rate and minute volume do not need to be readjusted after changes in chamber pressure as there is a reference line which needs to be plugged into a through-hull penetrator to track environmental pressure differences. Works well to 30msw, however, only basic ventilation parameters are available and there is no disconnect alarm. This ventilator is no longer in production.
SCOTT Pressure-Vak II Inhalator BIBS system. Just a quick note on these units. We have received a few HIMS reports where the exhaust valve has been reassembled incorrectly post cleaning, this has caused the diaphragm to invert and the valve to fail 9in the open position. Twice there have been instances of the mask being sucked onto the face causing some facial barotrauma. This problem is not always picked up by testing at surface. As the only people in our Unit who have cause to use the Scott system are the inside attendants, we stop the compression at 2msw and check the system.
Contributing Author: Stephen John Goble
Steve
has held the position of head hyperbaric technical officer at Royal Adelaide
Hospital, in Adelaide, Australia, since 1985. He arrived in Adelaide by way of
the British Royal Navy (Clearance Diver) and the offshore commercial diving industry.
Steve is a founding member of the Hyperbaric Technicians and Nurses Association
(HTNA) and edits their journal (‘Offgassing’). Steve is closely associated
with, and intimately involved in, HIMS (Hyperbaric Incident Monitoring Study),
and is extensively published on topics ranging from technical and safety issues,
standards, incident reporting and decompression accidents.