Ask DAN
DAN medical specialists and researchers answer your dive medicine questions
TROUBLE BREATHING AFTER CLEARING MASK Q: During dive training in the pool, I couldn’t breathe after clearing my mask with my regulator in my mouth. After surfacing, I took six to eight wheezing breaths and then could breathe normally again. It’s possible I inhaled water during the exercise, but my instructor and I could not recall when or how that would have happened. Someone at the training centre suggested that something might be wrong with my epiglottis. Is there a way to inspect the epiglottis to ensure it is functioning properly? What causes it to relax and open back up? A: It is not uncommon for new divers to have some anxiety when fully removing their mask underwater. When you expose your nose to the water, it’s natural to feel uncomfortable if water enters the nasopharynx. Our bodies are trained not to take a breath while underwater, but it is possible if you can relax and focus on breathing through your regulator. If water entered the larynx, the epiglottis’ natural response would be to close the airways to prevent aspiration. The larynx would reflexively trigger coughing to expel the fluid, or you would try to remove the fluid through exhalation. Even a small amount of fluid can induce laryngospasm, which will stimulate this powerful reflex. This passage from Marieb and Hoehn’s Human Anatomy and Physiology is a good overview of how the epiglottis works: ‘When only air is flowing into the larynx, the inlet to
the larynx is wide open and the free edge of the epiglottis projects upward. During swallowing, the larynx is pulled superiorly and the epiglottis tips to cover the laryngeal inlet. Because this action keeps food out of the lower respiratory passages, the epiglottis has been called the guardian of the airways. Anything other than air entering the larynx initiates the cough reflex to expel the substance’. Another possibility is that you had an anxiety-induced laryngospasm, which can be triggered by discomfort, panic, or high anxiety. Some physicians think this spasm is part of the body’s natural defence against accidental drowning or suffocation and may be part of the body’s response to fluid in the larynx. Your breathing problem may be an issue with your comfort level and experience, but it’s possible there are other complications we cannot identify based on the information you provided. Discuss these concerns with your physician and request a fitness-to-dive evaluation to ensure that you have no physical contraindications to dive activity. Your physician may refer you to an ENT for further investigation, if needed. If your physician clears you for diving, we recommend that you complete additional, rigorous pool time to work on skills with your instructor before proceeding any further in your training.
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