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

Thijs T Wingelaar,Frank J Nap,Edwin L Endert,Pieter-Jan A M Van Ooij,Leonie Bakker,Rob A Van Hulst

doi:10.3389/fphys.2020.613398

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.

Highlights

Intrapulmonary pathology, such as bullae or blebs, can cause pulmonary barotrauma when diving
None of the chest X-rays (CXR) findings of bullae or blebs could be confirmed on high-resolution computed tomography (HRCT)
This study provides evidence that routine CXR in asymptomatic military divers as part of a medical assessment of fitness to dive does not contribute to the identification of intrapulmonary abnormalities, such as bullae or blebs, and has a high false negative rate (32%)

Summary

Introduction

Intrapulmonary pathology, such as bullae or blebs, can cause pulmonary barotrauma when diving. Pulmonary barotrauma (PBT) is a serious adverse event in divers that can lead to (fatal) diving accidents (Russi, 1998; Vann et al, 2011). To assess the architectural aspects of the lungs and to determine the presence of obstruction, many pre-course fitness to dive screenings routinely include imaging of the thorax and pulmonary function tests (British Thoracic Society Fitness to Dive Group, 2003). Technical advances have significantly improved the clarity of CXRs, the a priori likelihood of detecting a relevant lung disease that could result in air trapping or PBT when diving, such as extensive lung diseases and infectious diseases such as tuberculosis, is relatively low due to successful public health interventions and lower incidences of these diseases (World Health Organisation., 2016; Xie et al, 2020). Because the incidence of relatively rare conditions, such as lung cysts, bullae and blebs, are likely to have remained constant over the years, these conditions may be more readily identified due to the increased usage of CXR in general and in emergency medicine (Tigges et al, 2004; Plurad et al, 2007)

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