Dr Jules Eden, dive medicine specialist and founder of e-med, answers divers' questions - as published in Sport Diver magazine:
Q - Having just done a try dive, I have the bug. My problem is I have been diagnosed with Asbestosis & Pleural Plaques in its early stages, so my question is will this rule me out of doing a Padi open water course or does this put me at a greater risk of lung problems than any one else, or does diving make my condition any worse. I am 48 years old and have a reasonable level of fitness and feel I can cope with diving for a few years at least. Your advise would be greatly appreciated.
A - The situation with lung problems and diving can be summed up in a couple of points. Firstly, is your lung function good enough to ventilate you adequately during a dive and also if that dive were to suddenly become more of an exertion than you had originally planned, e.g. a strong counter current or having to tow your buddy back to a boat a few hundred yards away. This is assessed by lung function studies known as spirometry and should be done by a recognised medical examiner of divers in your area.
Secondly, lung problems that can result in dead air spaces or "bullae" are a definite contraindication as air gets into these spaces under pressure at depth and as you ascend, as the air cannot be expelled it expands and causes bad lung damage called pulmonary barotraumas. Now your problem is not normally associated with these bullae so you should be fine on that count.
However the bad news is that asbestos can lead to rather a nasty piece of medical grief called a "mesothelioma". So to make sure you never get this, have regular high resolution CT scans of the lungs. Even every year or two to be safe, if these are OK then as diving will not make your condition worse, and if you also pass the spirometry, and the asbestosis doesn't affect your fitness you should be fine to do the PADI Open Water course.
Q - What is a pulmonary barotrauma? Is it life threatening? Does it mean you can have a heart attack under the water?
A - Burst lung. Yes. No.
I'd better elucidate a bit more than that! Pulmonary barotrauma happens when the air in the lungs expands on ascent faster than a diver can exhale it. This is why we are all taught to exhale on an emergency ascent on our PADI Open Water course. It's not difficult to imagine what can happen to the lungs if the air inside them expands at a rapid pace. The very tissue and structure will be torn apart. Air bubbles will get into your arterial circulation, go through your heart and off to raise hell in all other parts of your body. But what is life threatening is that without normal functioning lungs there's no oxygen supply to the rest of the body.
How you tell a diver has this problem when they are back on the boat depends on the extent of the lung burst. A very mild case may not be noticed at all. But as it gets more severe problems associated with the actual lung damage such as shortness of breath, blue lips, a cough, and right up to a severe case where the diver is coughing up blood stained frothy sputum and rapidly becoming shocked.
Its not just a panicked diver on a rapid ascent that can get this problem though, its one of the reasons that asthmatics are so strictly controlled as divers. If someone were to get a constriction in the bronchi or lung tubes through which the inhaled and exhaled air flows, then all that air inhaled under pressure at depth can't get out properly on ascent. The resulting problem is this pulmonary barotraumas.
Dealing with it is very simple for the dive crew onshore or the boat. Quickly put the diver on their back, give 100% oxygen and call a chopper in asap. We doctors will do the rest but the key is recognising the problem quickly and not being afraid of calling the Emergency Services as fast as possible.
As for a heart attack underwater, it won't cause this but an indirect effect may be to decrease the amount of oxygenated blood getting to the cardiac muscle so it dies which is by definition a "heart attack". But by this time the diver is so well and truly screwed that it's only of interest to the poor old doc doing the autopsy.
So all you asthmatics, get passed as fit by a diving doc, and for the rest of us, remember the words of the Prodigy…EXHALE.
Q - I sometimes have trouble clearing my ears when I start to descend in the water but I get a clear warning in the form of pain and ascend a little and make sure I clear my ears before I try again. My question is this, would I get a similar pain signal in my chest if I were to ascend and not breath out? I have made ascents breathing out on the way up but I was never daft enough to hold my breath to find out if I would feel any warning pain for fear of an embolism.
A - I must say I've never been asked that before!
I assume you want to know what it would feel like if you weren't exhaling quick enough in relation to your speed of ascent.
Well, my first thoughts are that you must always exhale and never breath hold whilst ascending. Pulmonary barotrauma, or lung damage, is always the result.
So long as your throat is open and epiglottis in the right position the expanding air will always come out and you needn't worry.
As for how it would feel, well, it would be like when you sneeze but stop it just before or similarly letting a full party balloon deflate through your lips when you have just taken a full breath. I don't suggest you try this though, Nugget, just exhale normally.