Scuba diving offers a unique experience of the underwater world, yet for individuals with asthma, safety questions arise. While asthma presents unique challenges in the diving environment, it is not an absolute barrier. Careful medical assessment and adherence to safety guidelines are crucial for those considering scuba diving with a history of asthma.
Why Asthma Matters for Scuba Divers
Asthma poses significant concerns for scuba divers due to physiological changes underwater. A primary concern is air trapping in the lungs during ascent. As a diver ascends, the surrounding pressure decreases, causing air within the lungs to expand. If airways are constricted due to asthma, this expanding air can become trapped, leading to lung overexpansion injuries, known as pulmonary barotrauma. This can result in conditions like pneumothorax or arterial gas embolism, where air bubbles enter the bloodstream and can travel to vital organs.
Bronchospasm, a sudden tightening of the airways, can be triggered by several factors encountered during a dive. Breathing cold, dry air from a scuba tank can irritate airways. Physical exertion, anxiety, or allergens present in the diving environment or equipment can trigger an attack. An asthma attack underwater can impair a diver’s ability to exchange gases effectively, leading to insufficient oxygen uptake and impaired carbon dioxide elimination.
The Medical Evaluation Process
A thorough medical evaluation is necessary for individuals with asthma considering scuba diving. Consulting a dive medicine specialist or hyperbaric medicine physician is highly recommended, as these specialists possess the specific expertise for diving-related medical assessments and understand how asthma interacts with diving’s physiological demands.
The medical evaluation involves a comprehensive review of medical history. This includes details about the type and severity of asthma, the frequency and triggers of attacks, any history of hospitalizations, and current medication use. Particular attention is paid to exercise-induced asthma, as physical exertion is often a component of diving.
Lung function tests are a standard part of the assessment. Spirometry, which measures how much air can be inhaled and exhaled and how quickly, is commonly performed both at rest and sometimes after exercise or bronchodilator administration. Peak expiratory flow (PEF) measurements, which gauge how fast air can be exhaled, may also be assessed, with some guidelines suggesting daily monitoring. Challenge tests, such as exercise or methacholine tests, may be used to assess airway reactivity. Medical clearance for diving is generally considered for individuals with well-controlled asthma, no recent attacks (e.g., within 48 hours), normal lung function test results, and no asthma triggered by cold, exercise, or emotion.
Safe Diving Practices for Asthmatic Individuals
For individuals with asthma who have received medical clearance to dive, adhering to specific safe diving practices is crucial. Before each dive, perform pre-dive checks, ensuring overall well-being and absence of respiratory symptoms. Monitoring peak flow readings before a dive is recommended; avoid diving if readings show a significant drop (e.g., 10% or more below best values) or if a rescue inhaler was needed within the preceding 48 hours.
Medication management is crucial. Divers should have their prescribed rescue inhalers readily accessible, typically on the boat or shore, rather than underwater. Adhere to maintenance medication schedules and discuss potential interactions of asthma medications with the dive doctor. Using a preventive bronchodilator before a dive may be suggested.
Avoiding known triggers is essential. Minimize exposure to cold water, avoid strenuous activity, and ensure dive equipment is clean to prevent allergen exposure. Inform a dive buddy and the dive leader about one’s asthma condition and emergency plan; this is an important safety measure. During the dive, maintaining a slow, controlled ascent is crucial to allow expanding air to escape and minimize air trapping. If any respiratory symptoms develop or if a diver feels unwell at any point, abort the dive immediately and safely ascend; post-dive monitoring for any developing symptoms is also advised.