The World

Abstract

(Smart D. Health risk management in the Tasmanian abalone diving industry. Diving and Hyperbaric Medicine. 2010;40(2):83-7.) Risk management is a systematic process applied to all aspects of diving operations. The process aims to reduce accidents and adverse outcomes to a minimum. Risk results from a combination of probability and consequence, and where this combination has major or extreme impact, the risk should not be tolerated. Over the four years 2001−2004, the incidence of decompression illness amongst abalone divers in Tasmania was 1.4 cases per 100 divers per year. Risk management in diving encompasses medical fi tness, education and training, dive planning, equipment and maintenance, emergency procedures and equipment, and continual vigilance to remedy new risks as they are identifi ed. There is still much to achieve Diving and Hyperbaric Medicine Volume 40 No. 2 June 2010 84 the AS2299.1 recommendation for annual diving medical assessments. An equally important principle is that divers take responsibility for their own day-to-day fi tness to dive. It goes without saying that many long-term health issues result from individual choices regarding consumption of alcohol, tobacco and other drugs. In abalone divers, longterm health problems from ear and sinus barotrauma are commonly encountered by diving physicians. Time spent in the short term recovering from such conditions is well spent, rather than ‘soldiering on’, thus causing permanent hearing impairment or sinus injury. Divers are encouraged to seek early advice from a diving medicine specialist if they experience health problems after diving. The most common clinical syndrome of DCI resembles a bout of influenza: tiredness and lethergy, inability to concentrate, headache and non-specifi c migratory muscle and joint pains. Occasionally there may be nausea and vomiting. Musculoskeletal pains are common and may be restricted to one joint, most frequently the shoulder, or develop in multiple joints. Skin rashes occur on rare occasions. Other non-neurological symptoms include chest pain, shortness of breath and abdominal pain. Neurological syndromes can range from minor paraesthesiae, numbness and slight unsteadiness, through to paraplegia, hemiplegia, severe cognitive defi cits and even loss of consciousness and seizures. Any of these symptoms and signs may be worsened by ascent to altitude (>300 m) after diving; a signifi cant issue in Tasmania (see below). Early treatment of diving-related illness results in faster and more complete recovery. It is recognised that earlier treatment of DCI results in better outcomes for the diver. For serious neurological DCI, recompression treatment is even more time-critical. In Tasmania, there is a 24-hour diving emergency contact via the Ambulance Tasmania 000 number. The diving medicine specialist is contacted once the alarm is raised, and provides input at the earliest stage to management and transport of the diving casualty. In the majority of cases, divers are treated in the hyperbaric chamber within four hours of an emergency call. Early treatment also prevents long-term sequelae of diving, such as bone necrosis. 2. EDUCATION AND TRAINING Industry-specifi c education and training is an essential process supporting diving safety. Well-trained divers have the skills and knowledge to recognise and prevent hazards, and respond to emergencies. In Tasmania, all abalone divers undergo training in accordance with the Tasmanian Abalone Industry Code of Practice, and this code outlines many risk management procedures. This training constitutes a minimum entry platform from which to launch an abalonediving career. From a medical perspective, additional training beyond the basic minimum is always an advantage, as is the revision of skills, particularly in the area of diver rescue and management of emergencies. Because diving accidents are infrequent, divers and their tenders are at risk of deskilling if emergency procedures are not revised and practised regularly. The divers’ tender is an integral part of the diving team, and has great responsibility in supporting the diver. The current code of practice requires that tenders possess an up-to-date fi rst-aid certifi cate that includes an oxygen therapy course. However, there is no clear process by which currency in fi rst-aid skills is monitored. In addition, there does not appear to be any requirement for rescue training for divers or tenders, or training regarding the specifi c aspects of administration of 100% oxygen to the injured diver. In many situations, the tender is alone on board the dive boat. Whilst the probability of needing to rescue an incapacitated or unconscious diver from the water is low, the consequence of a delay in rescue, or rescue in a vertical position could be catastrophic. It is doubtful whether, currently within the industry, rescue drills and oxygen administration are practised regularly. 3 . D I V E P L A N N I N G A N D E M E R G E N C Y PROCEDURES Planning of the dive is an essential part of risk management. There are several areas that have impacted on the health of Tasmanian abalone divers in recent years. One of the most common problems experienced by abalone divers requiring recompression at RHH is failure of the surface air supply, resulting from compressor malfunction or severance of air hoses (usually due to boat propellers). This forces the diver to undertake an emergency ascent to the dive boat, leading to DCI. At present, emergency bail-out air cylinders with regulators and contents gauges are mandated only for dives deeper than 15 metres’ seawater (msw). It is the author’s opinion that bail-out air supply should be required during all abalone diving, regardless of depth. In an out-of-air situation, this simple risk-management procedure allows the diver to undertake a controlled ascent, thus preventing a potentially fatal rapid ascent in a state of extreme stress. Gas embolism with neurological defi cit has resulted from depths as shallow as 2 msw. The planning process must also consider the remoteness of the dive location, since greater degrees of self-suffi ciency will be required for remote locations. Divers should be in peak physical health when diving in remote areas. Emergency equipment, procedures and links to emergency assistance and recompression facilities must be checked and tested prior to departure. Supplies of oxygen must be suffi cient to provide continuous treatment of an injured diver for the full return distance from the most remote site, with a 50% reserve. Emergency contact numbers should be checked. Remote diving also mandates greater conservatism in diving practice to reduce the risk of accidents.