Lung squeeze, also known as pulmonary barotrauma, is a pressure-related injury affecting the lungs. It occurs when individuals are exposed to significant changes in ambient pressure, most commonly during activities like diving. This condition involves the compression of gases within the lungs, which can lead to discomfort and tissue damage. Understanding its causes and effects is important for those in activities involving pressure changes.
The Physics of Pressure and Lungs
Lung squeeze occurs due to Boyle’s Law, which states that for a fixed amount of gas at constant temperature, pressure and volume are inversely related. As an individual descends in water, the surrounding pressure increases, causing the air volume within the lungs to decrease proportionally. For example, descending to 33 feet (10 meters) of saltwater doubles the ambient pressure, halving the air volume in the lungs.
When lung volume reduces significantly, especially during a deep breath-hold dive, the internal pressure within the lungs can become lower than the surrounding tissues and blood vessels. This difference in pressure creates a suction effect. It draws fluid, and sometimes blood, from capillaries into the tiny air sacs of the lungs, known as alveoli, which can damage the delicate alveolar membranes and lung tissue.
Identifying the Symptoms
Recognizing the signs of lung squeeze is important. Individuals experiencing this condition might first notice discomfort or tightness in their chest. This can progress to distinct chest pain, ranging from mild to severe depending on the injury’s extent.
Coughing is a common symptom, initially dry but potentially producing frothy sputum. In severe cases, the cough might include streaks of blood or appear pinkish. Shortness of breath can also develop, making normal breathing difficult.
Prevention and Emergency Response
Preventing lung squeeze involves specific practices to manage pressure changes within the body. Divers, particularly free-diving, must equalize pressure in their ears and sinuses during descent; it is also important to manage lung volume. Avoiding forced breath-holding during descent allows for gradual lung volume compression, reducing the risk of a severe pressure differential. Proper training in breath-hold techniques and physical conditioning can enhance an individual’s ability to manage pressure changes safely.
Listening to one’s body and ascending if discomfort or pain is felt in the chest can help prevent the condition from worsening. If lung squeeze is suspected, cease the activity and rest. Seek medical attention from healthcare professionals experienced in diving medicine. Self-treatment is not advised; a medical evaluation is needed to assess the injury and determine treatment.