DAN Medics Answer Your Diving Questions

From the Medical Line

Q: I have been diagnosed and treated for spontaneous pneumothorax (collapsed lung). Will it keep me from diving?

A: The short answer is yes. If you've experienced a spontaneous pneumothorax it's time to hang up the regulator for good. Here's why:

Your lungs are not attached directly to the chest wall. They remain open and capable of drawing breath by the negative pressure in the intra-pleural space. When too much pressure builds up (when a diver holds his breath while ascending, for example) the lung tissue can tear, allowing air to leak into the intra-pleural space, interrupting the negative pressure that holds the two pleural layers together. Eventually, the entire lung collapses, resulting in rapid, shallow breathing, a bluish cast to lips, skin and fingernails (due to a lack of oxygen) and chest pain.

A collapsed lung that occurs during everyday activities is referred to as a spontaneous pneumothorax and is a particular concern for divers because it can happen again without warning. The root cause is usually weakened lung tissue. Disease, previous injury or inflammation (often caused by smoking) form blister-like swellings in the lung's tiny air sacs. Called blebs, or bullae, these areas of weakened tissue tend to empty air slowly. In divers, the normal pressure build-up that occurs during ascents can cause the blebs to rupture.

Blebs are likely caused by degradation of elastic fibers in the lung and are hard to detect. There are generally no signs or symptoms until they rupture. Blebs are most frequently found in smokers, but they also can appear in nonsmokers. Some lung diseases — such as asthma, emphysema, sarcoidosis, eosinophilic granuloma or interstitial fibrosis — can also lead to spontaneous pneumothorax because they predispose the lung to weakening and possible injury. Other causes of spontaneous pneumothorax include chest injury, such as a penetrating wound and rare cases of congenital weakness.

When spontaneous pneumothorax occurs, it usually causes sharp pain on the affected side of the chest. If the volume of air leaked into the pleural space is large enough, it can cause further collapse of the lung and shortness of breath. There's another level of concern with pneumothorax. Sometimes injuries to the lung can result in the creation of a one-way valve, where air leaks into the pleural space that surrounds the lung and does not return to the lung. This results in a progressive enlargement of the pleural space and compression of the lung. If left untreated, the pleural space can compress the heart and opposite lung and restrict blood from returning to the heart. This is known as a tension pneumothorax and is associated with gasping, low blood pressure, shock and ultimately death if not treated promptly.
Treatment for Pneumothorax
Any form of pneumothorax requires medical treatment. In some cases, a physician may insert a chest tube, withdraw air from the chest cavity and allow the lung to reinflate. If the pneumothorax is small, breathing 100 percent oxygen may hasten the resorption of gas without the need for a chest tube or invasive procedure.

Unless it occurs with decompression illness in divers (where bubbles enter into the aerterial system and affect the brain), pneumothorax does not require recompression. In the event of a chamber treatment, a chest tube may be required to help equalize the pressure and prevent further injury or enlargement.
Long-Term Implications
There are a few treatment options for blebs or recurrent pneumothorax that merit mention. We should stress from the outset, however, that none of the following treatments alter the medical recommendation regarding fitness to dive with a history of spontaneous pneumothorax. Blebs can be removed by surgery. Another approach, called pleurodesis, introduces a substance into the pleural space that causes scarring and permanent obliteration of the pleural cavity. However, after experiencing any form of pneumothorax or treatment, an injured person should not dive until cleared by a physician familiar with dive medicine.

For the reasons explained above, physicians trained in dive medicine would be very reluctant to provide medical clearance for someone with a history of spontaneous pneumothorax. Individuals who have experienced an episode of spontaneous pneumothorax are at a high risk of recurrence. Pneumothorax while diving can lead to a deadly arterial gas embolism, but the biggest risk may come from a tension pneumothorax that can evolve rapidly as gas expands on ascent (or during decompression). The risk of tension pneumothorax is why most dive physicians will recommend that you give up scuba diving to any depth. When you get that yen to be underwater, try snorkeling. You still can get wet and enjoy the sights of the underwater world without the risk of serious injury.

For more information, see DAN's Medical FAQ.

— Richard Moon, M.D.
DAN senior medical adviser


Q: Between two recent shore dives, I slipped and fell resulting in a serious bruise on my left knee. It was almost black. We took about a 20-minute break and back in we went. When I came out after the second dive, the bruise was gone. We were only diving in about 20 ft (6 m) of water. Could the pressure have caused the bruising to go away?

A: It is entirely possible that the blood that collected as a result of broken blood vessels could have been affected by the increased hydrostatic pressure. The pressure is evenly distributed from all directions. The blood may have been compressed into deeper tissue where it was eventually reabsorbed. It was only due to the injury being so recent that this phenomenon occurred.

— Marty McCafferty, EMT-P, DMT-A
DAN medical information specialist


Q: What problems could occur while scuba diving and taking Vicodin?

A: Before we discuss the potential issues associated with diving while taking a narcotic pain reliever, let's discuss the underlying condition or injury that prompts the need for the medication. Any condition or injury that can compromise your ability to function normally is the first concern. You need to be able to physically perform all necessary skills, especially in an emergency. This is not only for yourself but also for your buddy. Be sure to consult a physician knowledgeable about the sport, and make sure you're physically ready to dive. If the pain being treated results from an injury, most dive physicians would recommend waiting until you have recovered more fully before diving. If the pain is due to a chronic condition, then the condition should be as stable as possible.

Also consider the possibility that increased pain after a dive might be mistaken for decompression sickness. Being treated for DCS when it is not really the issue is less problematic than not being treated when DCS is the cause. It is also unknown how potentially injured tissue may respond to inert gas uptake and off-gassing.

As for the drug itself: Narcotic pain medicines, like Vicodin, can affect a diver's mental alertness and physical ability to function and should be avoided. In fact, any medication that carries a warning about consuming alcohol may be problematic with diving. In dives deep enough to create nitrogen narcosis, the diver may find that the narcosis intensifies the effects of the medication.

A dose that is manageable topside may create significant impairment at depth. To avoid these effects, consult a knowledgeable physician who understands dive medicine. If you are cleared to dive, stay conservative in your profiles and limit your depth to avoid narcosis.

— Marty McCafferty, EMT-P, DMT-A
DAN medical information specialist

Ask Us Anything
The DAN Medical Line is here to answer all your medical questions. You can reach the medical staff during regular business hours (Monday through Friday, 9 a.m. to 5 p.m. ET) by calling (919) 684-2948 ext. 222. You can also submit an email through the DAN website.


© Alert Diver — Fall 2009