Barotrauma of ascent
Tissue damage from gas expansion during ascent.
Barotrauma of ascent, also called decompression barotrauma, is a form of physical damage to body tissues caused by a difference in pressure between a gas space inside or in contact with the body and the surrounding gas or liquid. It occurs when the free change of volume of gas in a closed space in contact with a diver is prevented during ascent, causing a pressure difference that results in tension in the surrounding tissues which exceeds their tensile strength. This condition is a significant hazard in diving and hyperbaric medicine, as it can lead to life-threatening injuries such as pulmonary barotrauma and arterial gas embolism.
- field
- Diving medicine, hyperbaric medicine
- known_for
- Lung over-pressure injury, pulmonary over-inflation syndrome, arterial gas embolism
- causes
- Prevention of free gas volume change during ascent, explosive decompression, mechanical ventilation
- affected_organs
- Lungs, middle ear, inner ear, sinuses, teeth, intestines
Lore & Background
Barotrauma of ascent is caused when the free change of volume of the gas in a closed space in contact with the diver is prevented. In this case the pressure difference causes a resultant tension in the surrounding tissues which exceeds their tensile strength. A scuba or surface-supplied diver breathing gas at depth fills their lungs with gas at ambient pressure greater than atmospheric pressure; at 10 metres the lungs contain twice the amount of gas they would at atmospheric pressure, and if they ascend without exhaling the gas will expand until the lungs reach their elastic limit and begin to tear, very likely causing life-threatening lung damage.
Reader's Guide
Barotrauma of ascent is a critical concept in diving safety and hyperbaric medicine because it can cause pulmonary over-inflation syndrome (POIS), also known as lung over-pressure injury or burst lung. Consequent injuries may include arterial gas embolism, pneumothorax, mediastinal, interstitial and subcutaneous emphysemas. Arterial gas embolism occurs when gas enters the arterial system and can be carried to the blood vessels of the brain and other vital organs, typically causing transient embolism similar to thromboembolism but of shorter duration, and may lead to symptoms resembling stroke. The condition is also associated with explosive decompression of hyperbaric environments, such as the Byford Dolphin incident, and can occur during rapid uncontrolled decompression from caissons, airlocks, pressurised aircraft, spacecraft, and pressure suits. Mechanical ventilation can also cause barotrauma of ascent, particularly when high tidal volumes or high peak pressures are used, leading to alveolar rupture and conditions like pneumothorax and pulmonary interstitial emphysema.
Did You Know?
- Barotrauma of ascent is also called decompression barotrauma.
- A scuba diver ascending without exhaling at 10 metres depth risks lung over-pressure injury because the lungs contain twice the amount of gas as at the surface.
- Pulmonary barotrauma of ascent can lead to arterial gas embolism, which may cause symptoms resembling stroke.
- The Byford Dolphin incident is an example of explosive decompression producing severe barotrauma.
Frequently Asked Questions
What is Barotrauma of ascent?
Barotrauma of ascent, often called decompression barotrauma, is tissue damage that happens when gas trapped in a body cavity can't expand freely as a diver rises. The resulting pressure differential stretches surrounding tissues past their breaking point, producing injury.
What causes Barotrauma of ascent in divers?
It is triggered whenever the free volume change of gas in a closed space touching the diver is blocked during ascent—whether by explosive decompression, a mechanical ventilator, or simply holding one's breath. The gas expands against rigid or obstructed boundaries, generating dangerous internal pressure.
Which organs or body parts does Barotrauma of ascent affect?
The lungs are the most commonly injured, but the condition can also damage the middle ear, inner ear, sinuses, teeth, and even the intestines. Any gas-filled space whose expansion is restricted is at risk.
What are the most dangerous complications of Barotrauma of ascent?
Lung over-pressure injury and pulmonary over-inflation syndrome are the hallmark threats, and they can progress to arterial gas embolism, a life-threatening emergency. These outcomes are why the condition is treated as a critical hazard in both diving medicine and hyperbaric medicine.
Why is Barotrauma of ascent important in diving and hyperbaric medicine?
It represents one of the most significant pressure-related hazards a diver or hyperbaric patient can face, with the potential to cause fatal internal injuries in seconds. Understanding its mechanism and prevention is a core part of safety training in both fields.
More in Medical emergencies 1-24
Spotted an error? Know more?
This is a living reference — every entry is fact-audited, and reader corrections feed straight into our audit queue. Suggest an edit · See this site's audit record