What Are The Common Dangers of Scuba Diving

Dangers of scuba diving, by its nature, either with or without scuba, involves certain respiratory patterns that are potentially hazardous under water. Hyper­ventilation and breath holding, for example, may initiate cardioinhibitory and vasodepressor re­flexes capable of causing syncope, cardiac arrhyth­mias, and arrest. Bradycardia, apparently more pronounced than might occur simply from breath- holding and the head-down position, and various cardiac arrhythmias have also been reported dur­ing breath-hold diving.

Vigorous hyperventilation by skin divers prior to a dive may lead to lowering of arterial Pco₂ sufficient to abolish the stimulus to breathe and may allow dangerous levels of hypox­emia to develop. In addition, compression of air within the lungs during descent may maintain adequate alveolar Po₂ levels despite a diminishing oxygen supply. Distress from air hunger may not occur because alveolar Pco₂ has been reduced by prior hyperventilation. During ascent the expan­sion of the air remaining within the lungs results in a sharp reduction in Po₂, possibly to levels that result in loss of consciousness before the diver is able to reach the surface, and he may drown un­less help is available for prompt rescue and re­suscitation.

Why Scuba Diving Hazards Is Painful,If you Don’t Care

Divers using properly functioning open-circuit scuba are unlikely to experience hypoxia if they restrict their dives to well within the limits of their air supply. The rate of air util­ization increases in proportion to the increase in absolute pressure when using open-circuit scuba. Total duration of air supply is for example, only one-third as long at 66 feet as at the surface. Increased utilization from heavy exertion causes a proportionately greater expenditure of air.

The availability of scuba has enabled large numbers of untrained people to enter an unfamil­iar and hostile environment previously restricted to trained professional divers. The increasing number of serious diving accidents attests to a general lack of understanding of basic underwater principles. As in any sport, accidents are unavoid­able, but most scuba-diving casualties can be pre­vented.The greatest medical problem is education of those who participate in this sport. Physicians in almost any locality may now be called upon to manage a diving emergency. Excellent pub­lications concerning this subject, such as the United States Navy Diving Manual and others, should be available for this purpose.