When it comes to the dangers associated with scuba diving, lung overexpansion injuries are definitely at the top of the list. Understanding what factors lead to these injuries and taking simple precautionary measures to prevent them go a long way to mitigate that risk; here, we take a closer look at lung overexpansion injuries and discuss some methods for avoiding them.
What are Lung Overexpansion Injuries?
The human lungs are only able to expand to a certain size, and though they are flexible, it is possible to overinflate them and cause an overexpansion injury. To better understand this, it’s important to have basic knowledge of lung anatomy.
Inside the lungs are chambers, and inside the chambers are tiny sacs known as alveoli. When you inhale, these sacs, which function to distribute oxygen to your bloodstream, expand. When the lungs are overinflated, the alveoli tear, causing air to be distributed into areas not meant to be exposed to gases. This can lead to further damage to body tissues and organs; without the alveoli intact, the rest of the body cannot be properly oxygenated.
What Causes Lung Overexpansion Injuries?
To understand what causes lung overexpansion injuries, it’s vital that you understand Boyle’s Law, which states that volume is inversely proportional to pressure. The greater the pressure air molecules are under, the smaller they are, and vice versa. When you begin to ascend to the surface, pressure decreases in direct proportion to your rate of ascent. The higher you travel in the water column, the less pressure is exerted on your lungs. As a result, the volume of air in your lungs increases as the air molecules expand. If you hold your breath while ascending, the expanding air molecules have no way out, which can cause the walls of the alveoli to rupture.
Classification of Lung Overexpansion Injuries
Lung overexpansion injuries are classified as follows:
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Arterial Gas Embolism (AGE): When a person suffers from AGE, air diffuses into the blood and makes its way up the minuscule capillaries of the brain, forming an air bubble and consequently blocking the blood carrying vessels. This obstructs the flow of blood in the body and oxygen supply is cut off to vital body tissues. The consequences can be as deadly as paralysis, brain damage, heart stroke and death. AGE is the most deadly consequence of a lung overexpansion injury and is potentially fatal. AGE affects the body at a more rapid rate than any of the other manifestation of lung overexpansion injury.
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Mediastinal Emphysema is a condition in which air is entrapped in the cavities that surround the delicate heart muscles. This air in turn places a pressure on the heart muscles, which in turn stop functioning properly; as a result, blood supply to the body becomes erratic. This condition is not as serious as AGE but extreme Mediastinal Emphysema can lead to heart failure.
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Pneumothorax: In this condition the air is collected at the outer side of the lungs causing the lungs to cave in upon themselves. The victim may end up with partial or completely collapsed lungs. Since Pneumothorax involves injury to lungs, it causes acute pain in the chest which may be accompanied by coughing up blood. Pneumothorax worsens as a diver ascends because the pressure on the damaged lung increases with ascent.
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Subcutaneous Emphysema: Probably the least damaging of all common lung overexpansion injuries, Subcutaneous Emphysema is a condition in which air pockets are formed near the collar bone and the neck. With subcutaneous Emphysema, there is irritation and squishiness in the skin, which may even crack if it is touched.
What are the Most Common Causes of Lung Overexpansion Injuries?
There are a number of common causes of lung overexpansion injuries, as well as some contributing factors to keep in mind. The most common of all is lack of knowledge or panicking, in which case a diver could hold his or her breath while ascending without realizing that an injury could occur as a result. Choking and nausea can also lead to lung overexpansion injuries.
Smoking is bad for everyone, but it’s even worse for divers, particularly since it can contribute to lung overexpansion injuries. When lung tissue is compromised by disease, it is not as strong as it should be, and this can cause problems. Lung collapse is a real risk for smokers, and if it happens, the affected person may be forced to hold his or her breath while ascending, leading to lung overexpansion injury.
Preventing Lung Overexpansion Injuries
Fortunately, there are some simple ways to prevent lung overexpansion injuries:
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Never hold your breath while diving, particularly during an ascent.
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Avoid diving if you are suffering from even a minor chest infection or any type of congestion. Do not dive if you have even a slight cough.
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If you are a smoker, quit. If you can’t bring yourself to quit, cut back as much as you can, and avoid smoking for at least a few hours before each dive.
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If you have a history of lung disease, diving may not be for you. Be honest with your physician if this is the case. If you have any type of lung injury, be sure you are medically cleared to dive before getting back to scuba.
Signs and Symptoms of Lung Overexpansion Injuries
Lung overexpansion injuries are typically serious and can be life-threatening. If you start to suffer from pain in your lungs while diving, suspect an overexpansion injury and get to the surface. Most of the time, fellow divers are the first to detect a lung overexpansion injury in another person; usually due to the following symptoms:
- Paralysis, particularly on one side of the body
- Coughing up blood
- Heavy chest pain and difficulty breathing
- Loss of vision
- Unconsciousness
- Dizziness and confusion
- Change in voice
Dealing with Lung Overexpansion Injuries
If a diver has suffered a lung overexpansion injury, call for help immediately. While waiting for help to arrive, or while getting the party to shore for medical transport, administer oxygen after ensuring that the victim’s airway is clear. CPR may be required.
While lung overexpansion injuries are serious and can threaten your life, taking steps to prevent them is an effective way to ensure they won’t happen to you. By diving only when you are fit to do so, and by never holding your breath while scuba diving or ascending, you are doing everything you can to maintain lung health and ensure you are able to enjoy a happy, healthy future filled with pleasant underwater adventures.