Return to diving after COVID-19.

I read with great interest the position statement on cardiopulmonary assessment prior to returning to high-hazard occupations post-symptomatic COVID-19 infection.[1] This guidance is of great relevance to all colleagues assessing the fitness of their patients after a symptomatic COVID-19 infection before returning to high-hazard occupations, or high-hazard exposures for leisure.

In their position paper, the authors suggest a clinical risk triage that is based on the assessment of symptoms, evidence of hypoxia, or ECG abnormalities, which is a reasonable and pragmatic approach in the context of the most high-hazard occupations as listed in Table 1 of the paper. However, divers are exposed to substantial changes in barometric pressure and are eventually facing unique risks that may not apply to other high-hazard exposures. While an evaluation of a divers’ cardiopulmonary fitness is paramount during routine fitness to dive testing, there are serious hazards inherent to diving that must be considered when assessing the fitness to dive, particularly when returning to diving after potential pulmonary illness. Such a unique hazard during scuba diving is pulmonary barotrauma, which may cause serious cerebral arterial gas embolism. Pulmonary barotrauma may be precipitated by trapped intrapulmonary gas that is expanding during ascent.[2]

As stated by the authors, patients with pulmonary fibrosis post-COVID-19 often have little or no abnormality on spirometry. However, the subsequent statement that ‘limited scarring seen in many individuals is likely to have little, if any, physiological impact, unless extensive’ needs to be interpreted with great caution for divers. In fact, even minor abnormalities such as pleural adhesions, scarring, or minor blebs have been associated with the risk of pulmonary barotrauma of ascent.[2,3] Therefore, imaging of the chest is currently considered mandatory in the post-COVID-19 assessment of fitness to dive; this includes subjects with mild symptoms during COVID-19 infection.[4]

Although it is mentioned that ‘further environmental assessment may be deemed necessary to ensure employees meet their employers risk tolerance in these climates’, it may be worthwhile to point out that scuba divers, including amateur divers, deserve special attention post-COVID-19. The summary that ‘even in those with abnormal cardiovascular MRI and thoracic CT results the severity of pathology appears mild in most cases and is likely to be of limited long-term consequences for most’ is certainly true also for divers during life at atmospheric pressure, but exposure to a rapidly changing ambient pressure during diving necessitates the exclusion of even subtle pulmonary lesions that may predispose to barotrauma.