Recurrent Pulmonary Barotrauma in a Diver: Research Summary

By Rubicon Foundation editorial team

5 min read · 1 November 2026

Recurrent pulmonary barotrauma (PBT) in a previously healthy male scuba diver who suffered from repeated pneumomediastinum after shallow-water scuba dives is a 1998 journal article by Tetzlaff K and Reuter M, published in Undersea Hyperb Med 25(2). Its subject is repeated lung-pressure injury and pneumomediastinum in a scuba diver—a problem that matters because serious pressure-related injury can occur even on shallow dives.

What do pulmonary barotrauma and pneumomediastinum mean?

Pulmonary barotrauma is injury to the lungs caused by a pressure difference between gas inside the lungs and the surrounding environment. During ascent, gas in the lungs expands as ambient pressure falls. If that gas cannot escape normally, lung tissue may be overstretched and damaged.

Pneumomediastinum means that air has entered the mediastinum, the central space in the chest between the lungs. In pulmonary barotrauma, air can move from damaged lung tissue into this space. The condition is distinct from pneumothorax, in which air collects between a lung and the chest wall and can interfere with lung expansion.

How can a shallow dive lead to pressure injury?

Depth is only part of the pressure calculation. As a diver ascends, ambient pressure decreases; gas already in the lungs expands in response. The change in volume is proportionally greatest near the surface, so a relatively shallow dive does not remove the need for a controlled ascent and continuous breathing.

Breath-hold ascent is a central hazard because expanding gas may become trapped in the lungs. Airway obstruction, lung disease or other factors affecting gas flow can also matter, though the clinical circumstances vary. A diver should not assume that a shallow profile makes pulmonary barotrauma impossible.

Pulmonary barotrauma: lung injury from an unequal pressure across lung tissue.
Gas expansion: a decrease in ambient pressure increases the volume of gas in the lungs.
Pneumomediastinum: air in the central chest space, potentially arising from injured lung tissue.
Recurrent injury: repeated episodes raise questions about predisposing factors and the safety of returning to diving.

Why does recurrence matter in dive medicine?

A repeated episode changes the clinical question. In addition to treating the current injury, clinicians need to consider whether there is an underlying reason for gas trapping or vulnerability to lung damage, and whether the diver could face another event underwater. These are assessment questions, not assumptions about the cause in an individual case.

Pulmonary barotrauma also matters because air from injured lungs can enter other body spaces or the circulation. The resulting conditions differ in mechanism and urgency; chest symptoms after diving therefore call for medical evaluation rather than self-diagnosis. A diving-medicine physician can assess the event and advise on fitness to dive.

How does this subject fit into diving research?

Diving medicine examines how pressure, breathing gas and human physiology interact, from routine exposure to uncommon but potentially serious injuries. Case-based clinical work on barotrauma adds to that field by focusing attention on a particular presentation and the diagnostic questions it creates. The subject connects lung mechanics with dive planning, emergency recognition and decisions about future exposure.

For clinicians, distinguishing pneumomediastinum from other pressure-related injuries is important because symptoms and appropriate investigations can overlap. For divers, the practical point is broader: ascent control and uninterrupted breathing are basic safeguards, but suspected injury still requires professional assessment. Return-to-diving decisions depend on the individual clinical evaluation.

Frequently asked questions

Can pulmonary barotrauma happen on a shallow dive?

Yes. Gas expands as ambient pressure falls during ascent, including during ascent from shallow water. Shallow depth does not eliminate the risk.

Is pneumomediastinum the same as a collapsed lung?

No. Pneumomediastinum is air in the central space between the lungs. A pneumothorax is air between a lung and the chest wall and may prevent the lung from expanding normally.

When should a diver seek medical assessment?

Chest pain, breathing difficulty or other concerning symptoms after a dive warrant prompt medical evaluation. A diving-medicine physician should guide diagnosis, treatment and any decision about returning to diving.

Citation details

Title: Recurrent pulmonary barotrauma (PBT) in a previously healthy male scuba diver who suffered from repeated pneumomediastinum after shallow-water scuba dives
Authors: Tetzlaff K; Reuter M
Year: 1998
Published in: Undersea Hyperb Med 25(2)
Identifiers: PMID 9670439
Record type: Journal article
Repository record: Rubicon Research Repository, handle 123456789/2412

This page is an original summary written by the Rubicon editors from the publication’s bibliographic record. It does not reproduce the paper, its abstract or its data; consult the publication itself for its methods and findings.