Ask DAN
DAN medical specialists and researchers answer your dive medicine questions
Orbital implant and diving
Q: I lost one of my eyes in an accident. I have an opportunity to learn how to scuba dive, but I have heard that I would not be allowed to do so because I have an orbital implant. Is that true? A: It’s important to understand that people who have undergone enucleation and have been fitted with a hollow orbital implant are generally advised not to dive due to the risk of a pressure-induced collapse. These are known to occur mainly in hollow silicone orbital implants and can happen as shallow as 3m deep. Diving with vision in only one eye can be considered in the absence of associated problems that may affect dive safely and provided that visual acuity is sufficient.
Lung squeeze while freediving
Q: ls there any reason cold water might increase the likelihood of lung squeeze while freediving? I have experienced lung squeeze a few times, but only in cold water (around 7°C). l was shallower than 30m. In warm water, I can reach 50m, so I believe the squeeze is somehow related to the water temperature. A: You described your condition as lung squeeze, but it sounds like your question is really about what might have caused you to cough up blood from your lungs (presumably) under the conditions you describe. Given the variable impact of depth on the development of the condition, you could be experiencing a form of immersion pulmonary edema (IPE). IPE is a multifactorial condition, largely a net effect of increased central blood volume, pressures within the chest and, for compressed-gas divers, increased breathing resistance. The squeeze is a primary component, but only part of the story. Immersion produces a shift in blood from
the periphery to the core, and this effect can be magnified in cold water or partially replicated by wearing a tight wetsuit. Excessive fluid intake (hyperhydration) increases the risk. For compressed-gas divers, respiratory loading (most important, the effort to inhale) increases with water immersion, with breathing through a mouthpiece that adds resistance (particularly as gas density increases) and with exertion. Using compressed gas or freediving, if the net effect of the various stressors is a sufficient increase in the pulmonary artery pressure, capillary stress failure can produce a shift of blood into the lungs. Symptoms of IPE can include the perception of strain or stiffness in breathing, coughing and the coughing up of small amounts of blood. While I cannot confirm that this is what you are experiencing, it may be that the central blood volume increase magnified by the cold water is the stressor that takes you over the edge that you skirt in warmer water exposures. IPE is most likely to appear when multiple predisposing factors are acting in concert. You may have found your own threshold. I encourage you to consult with your medical monitors, keeping in mine! that the classic squeeze is not the only risk that freedivers face. Join DAN to get a number of benefits, including answers to all your diving-related medical questions: www.daneurope.org
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