title: Effects of ambient cold and depth on lung function in humans after a single scuba dive.
abstract: This study evaluated the subacute respiratory effects of diving, to try to separate the effects of ambient temperature from those of depth. In the first experiment 10 healthy men made a compressed-air dive to 50 m that exposed them to cold. They were compared with 10 matched control subjects who underwent the same dive profile but were exposed to a comfortable temperature. In the second experiment 16 healthy subjects made randomized cold dives to both 50 m and 10 m. Pulmonary function tests were made before, after 1 h, and 24 h after the dives. In the first experiment there was an increase in residual volume (P < 0.05) and a decrease in forced expiratory volume at 1 s (FEV1), in forced vital capacity (FVC) and in mid-expiratory flow at 75% of FVC (MEF75) 1 h after the cold dives (P < 0.05). In the second experiment significant increases in specific airways resistance (sR(AW)) (P < 0.05) and decreases in FEV1 (P<0.01), in MEF75 (P<0.05), and in mid-expiratory flow at 25% of FVC (P<0.05), were obtained after the 50 m-dives, whereas SR(AW) increased after the 10 m-dives (P<0.05). The respiratory pattern observed 1 h after cold dives to 50 m indicated airway narrowing. The changes after cold dives to 10 m, however, were of minor magnitude. Both cold and depth seemed to contribute to the adverse effects of a single compressed-air dive on pulmonary function.
authors.affiliation: Boehringer Ingelheim Pharma KG, Biberach, Germany. Kay.Tetzlaff@bc.boehringer-ingelheim.com
authors.forename: K
authors.initials: K
authors.lastname: Tetzlaff
authors.forename: L
authors.initials: L
authors.lastname: Friege
authors.forename: A
authors.initials: A
authors.lastname: Koch
authors.forename: L
authors.initials: L
authors.lastname: Heine
authors.forename: B
authors.initials: B
authors.lastname: Neubauer
authors.forename: N
authors.initials: N
authors.lastname: Struck
authors.forename: T S
authors.initials: TS
authors.lastname: Mutzbauer
mesh_terms: D000328:Adult; D001249:Asthma / Q000503:physiopathology; D016084:Bronchoconstriction / Q000502:physiology; D003080:Cold Temperature; D004242:Diving / Q000502:physiology*; D005541:Forced Expiratory Volume / Q000502:physiology; D006801:Humans; D007035:Hypothermia / Q000503:physiopathology; D008168:Lung / Q000502:physiology*; D008297:Male; D011897:Random Allocation; D012115:Residual Volume / Q000502:physiology; D014797:Vital Capacity / Q000502:physiology