Diving Emergencies

Scuba diving encompasses a wide range of interests and a variety of participants, including recreational divers who enjoy touring the reefs and looking at marine life, commercial divers who work in underwater construction, and public safety divers who perform search and rescue operations.

Diving emergencies present unique issues for EMS providers, so having a general understanding of concepts related to diving will be valuable in the event you ever need to respond to the scene of a diving emergency.

Overview of Gas Laws

Before discussing diving emergencies, let’s look at how certain gas laws relate to diving emergencies.1

Boyle’s Law states that gas volume is inversely proportional to pressure. A familiar example can be found in the release of a balloon into the air. As the balloon ascends, the pressure on the outside of the balloon is reduced, the air inside it expands and the balloon will eventually burst. If the balloon is taken underwater, it will get smaller. Boyle’s Law also explains why you may feel pain in your ears during take-off and landing when flying. A diver is subject to this same compression and expansion of air, which can lead to barotraumas or pressure injuries.

Dalton’s Law provides that each gas in a gas mixture contributes a portion of the total pressure exerted by the entire gas mixture. Reducing pressure basically makes air “thinner.” For example, the air pressure in Denver is lower than in New York, which is part of the reason why New York athletes may have trouble catching their breath in Denver.

Henry’s Law provides that increased pressure on a gas will force gas into a liquid; decreased pressure will cause gas to be released from a liquid. When you open a soda, the pressure on the soda is reduced and results in “fizzing” as bubbles are released from the liquid. Similarly, gas forced into and released from tissue while diving forms the basis of decompression sickness or “the bends.”

Diving Emergencies

When a diver enters the water, his body responds to the change in temperature, including reducing peripheral blood flow to maintain core temperature. The reaction may also include a gasp for breath, which could escalate into hyperventilation and drowning. Immersion can cause arrhythmias leading to syncope or death. Death is rare from the initial immersion, but if an emergency developed at the beginning of a dive, a reaction to initial immersion should be kept in mind.2

General Environmental Considerations

Although divers take steps to keep warm while diving, heat loss will occur. Divers on vacation often make multiple dives per day and subject themselves to prolonged cooling over the course of the day. Further heat loss (and gain) can occur as divers are exposed to the sun or wind between dives.3

Diving also causes “immersion diuresis,” which can lead to dehydration and associated issues, including syncope and arrhythmias.4 Dehydration is exacerbated by other factors, including carrying equipment, exposure to sun, breathing dry, compressed air, airplane travel and taking diuretic medications.

Hypothermia, hyperthermia and dehydration should be treated in accordance with your local protocols. Keep in mind that certain signs and symptoms of these conditions, such as nausea, are also associated with other diving injuries.

Barotrauma

In much the same way you may feel ear pain during take-off or landing during a flight due to pressure changes, the changes in pressure when diving can cause injury to ears, sinuses and other air spaces. Although decompression illness and other emergencies are dramatic, ear injuries are much more common.