Routine Chest X-Rays Are Inaccurate in Detecting Relevant Intrapulmonary Anomalies During Medical Assessments of Fitness to Dive

Abstract

Introduction: Intrapulmonary pathology, such as bullae or blebs, can cause pulmonary barotrauma when diving. Many diving courses require chest X-rays (CXR) or high-resolution computed tomography (HRCT) to exclude asymptomatic healthy individuals with these lesions. The ability of routine CXRs and HRCT to assess fitness to dive has never been evaluated.Methods: Military divers who underwent yearly medical assessments at the Royal Netherlands Navy Diving Medical Center, including CXR at initial assessment, and who received a HRCT between January and June 2018, were included. The correlations of CXR and HRCT results with fitness to dive assessments were analyzed using Fisher's exact tests.Results: This study included 101 military divers. CXR identified bullae or blebs in seven divers, but HRCT found that these anomalies were not present in three subjects and were something else in four. CXR showed no anomalies in 94 subjects, but HRCT identified coincidental findings in 23 and bullae or blebs in seven. The differences between CXR and HRCT results were statistically significant (p = 0.023). Of the 34 subjects with anomalies on HRCT, 18 (53%) were disqualified for diving.Discussion: Routine CXR in asymptomatic military divers does not contribute to the identification of relevant pathology in fitness to dive assessments and has a high false negative rate (32%). HRCT is more diagnostic than CXR but yields unclear results, leading to disqualification for diving. Fitness to dive tests should exclude routine CXR; rather, HRCT should be performed only in subjects with clinical indications.

An observational study ascertaining the prevalence of bullae and blebs in young, healthy adults and its possible implications for scuba diving

“…In particular since there has been continuous improvement in the quality and resolution of low-dose CT imaging over the last decades, and this trend is expected to persist in the upcoming years (Withers et al, 2021). As CT images become increasingly detailed, it is logical to anticipate the discovery of more findings of unknown clinical significance in (candidate) divers in the future, which, may lead to disqualifying even more divers, using current guidelines (Wingelaar et al, 2020;Bonnemaison et al, 2022). Visual presentation of location and number of bullae.…”

“…In numerous standards, chest X-ray is still mentioned to exclude clinically relevant pulmonary pathology, but computed tomography (CT) for structural analysis of the pulmonary system has been shown a highly superior imaging technique ( Health and Safety Executive, 2023 ). However, higher-resolution CT scans in healthy individuals can uncover incidental findings of unknown clinical significance, raising concerns for its routine use in fitness to dive assessments in the general population ( Wingelaar et al, 2020 ; Bonnemaison et al, 2022 ). A forensic ( post mortem ) CT study in 130 adults without pulmonary injuries revealed that 33.8% of subjects had bullae/blebs ( de Bakker et al, 2020a ).…”

Chest CT scan for the screening of air anomalies at risk of pulmonary barotrauma for the initial medical assessment of fitness to dive in a military population

“…A Dutch postmortem study of 130 adults aged 21-70 years and all causes of death found a 34% CT scans prevalence of emphysema blebs and bullae, increasing with age (de Bakker et al, 2020). A study conducted at the Royal Netherlands Navy Diving Medical Center compared the sensitivity of chest CT scan to chest radiography in asymptomatic male military subjects (Wingelaar et al, 2021). The characteristics of the study population were similar to those of our study, with subjects of mean age 36.4 years, compared with 25 years in our study.…”