Divers with large or normal lungs: is the difference justified?

Area of Science:

• Pulmonary physiology
• Diving medicine
• Radiology

Background:

• Divers often exhibit larger lung volumes compared to the general population.
• Pulmonary barotrauma can lead to bullae or decompression illness (DCI), potentially more frequent in individuals with larger lungs (LLs).

Purpose of the Study:

• To compare lung function, high-resolution CT (HRCT) scan findings, fitness-to-dive rates, and DCI prevalence in divers with LLs versus normal lungs (NLs).

Main Methods:

• Retrospective analysis of fitness examinations, lung function tests, and HRCT results from 2011-2020.
• Divers were categorized into LLs (FVC z-score > 1.96) and NLs (FVC z-score ≤ 1.96).
• Comparison of bullae, DCI, and unfit-to-dive rates between the two groups.

Main Results:

• 65 male divers met criteria for LLs out of 1,069 total subjects.
• LL group showed higher FVC and FEV1 z-scores but a lower FEV1/FVC ratio compared to NLs.
• No significant differences were observed in the rates of bullae, DCI, or unfit-to-dive between LL and NL groups.

Conclusions:

• Despite a lower FEV1/FVC ratio in the LL group, bullae and DCI rates were comparable to the NL group.
• Individuals with LLs do not appear to have an elevated risk of developing bullae or DCI compared to those with NLs.