Lung function over six years among professional divers

Abstract

Aims: To analyse longitudinal changes in pulmonary function in professional divers and their relation with cumulative diving exposure. Methods: The study included 87 men at the start of their education as professional divers. At follow up one, three, and six years later, 83, 81, and 77 divers were reexamined. The median number of compressed air dives in the 77 divers over the follow up period was 196 (range . A group of non-smoking policemen (n = 64) were subjected to follow up examinations in parallel with the divers. Assessment of lung function included dynamic lung volumes, maximal expiratory flow rates, and transfer factor for carbon monoxide (Tl CO ). The individual rates of change of the lung function variables were calculated by fitting linear regression lines to the data, expressed as percent change per year. Results: The annual reductions in forced vital capacity (FVC) and forced expired volume in one second (FEV 1 ) were 0.91 (SD 1.22) and 0.84 (SD 1.28) per cent per year in divers, which were significantly higher than the reductions in the policemen of 0.24 (SD 1.04) and 0.16 (SD 1.07) per cent per year (p < 0.001). The annual reduction in the maximal expiratory flow rates at 25% and 75% of FVC expired (FEF 25% and FEF 75% ) were related to the log 10 transformed cumulative number of dives in a multiple regression analysis (p < 0.05). The annual reductions in Tl CO were 1.33 (SD 1.85) and 0.43 (SD 1.53) per cent per year in divers and policemen (p < 0.05). Conclusions: FVC, FEV 1 , maximal expiratory flow rates, and Tl CO were significantly reduced in divers over the follow up period when compared with policemen. The contrasts within and between groups suggest that diving has contributed to the reduction in lung function. D ivers are exposed to several factors that have effects on lung function. During diving the lungs are exposed to increased partial pressure of oxygen (pO 2 ) and venous gas microembolism caused by decompression stress. These factors may induce inflammatory reactions in the lungs and gas exchange abnormalities.

Chronic adaptations of lung function in breath-hold diving fishermen

“…In contrast to our results, many researchers have observed a decline in FEV 1 [9,[10][11][12] and FVC in divers [8,9,11,12]. Of these studies, only Tetzllaf et al [3] evaluated pulmonary function in free divers who, because they had competitive goals, dived to depths greater than the subjects in the present study.…”

“…Changes in lung volumes have been described showing increased TLC (total lung capacity) and FVC (forced vital capacity) and anomalies in the pattern of expiratory airflow with reduced FEV 1 (forced expiratory volume in one second), as well as the FEV 1 /FVC ratio [3,[8][9][10][11][12]. Reduction in expiratory flows, seen in divers, suggests the occurrence of disorders in small airways, supporting the assumption of the development of an obstructive disease [13].…”

Short- and long-term effects of diving on pulmonary function

“…Including the three search terms "lung" or "pulmonary", plus "physiology" or "function" plus "diving" revealed 799 hits. 17 publications provided data on 12 longitudinal cohort studies [54,56,[58][59][60][61][62][63][64][65][66][67][68][69][70] and two studies that reported pulmonary function long-term follow-up testing after single deep dives [55,57]. Studies were heterogeneous in regards to their methodology, study populations, observation period and outcomes.…”

Prevalence and characteristics of lung function changes in recreational scuba divers

“…4 Researchers have reported significant reductions in pulmonary function among professional divers over periods of only three to six years. 5,6 In commercial divers, Skogstad et decreased by 0.91% per year, FEV1 by 0.84% per year, and pulmonary diffusing capacity by 1.3% a year over six years. 5 An earlier study identified 22% of divers with pre-dive FEV 1/FVC ratio values below normal signifying mild airways obstruction.…”

“…5,6 In commercial divers, Skogstad et decreased by 0.91% per year, FEV1 by 0.84% per year, and pulmonary diffusing capacity by 1.3% a year over six years. 5 An earlier study identified 22% of divers with pre-dive FEV 1/FVC ratio values below normal signifying mild airways obstruction. 7 In addition, 63.8% were overweight and 30.6% regularly took medication for hypertension, asthma, hypercholesterolaemia and cardiac irregularities.…”