Logo image
Back
Effects of hyperoxia on ventilation and pulmonary hemodynamics during immersed prone exercise at 4.7 ATA: possible implications for immersion pulmonary edema
Journal article   Open access   Peer reviewed

Effects of hyperoxia on ventilation and pulmonary hemodynamics during immersed prone exercise at 4.7 ATA: possible implications for immersion pulmonary edema

Dionne F Peacher, Shelly R. H Pecorella, John J Freiberger, Michael J Natoli, Eric A Schinazi, P. Owen Doar, Albert E Boso, Aaron J Walker, Matthew Gill, Dawn Kernagis, …
Journal of applied physiology (1985), Vol.109(1), pp.68-78
07/2010
DOI: 10.1152/japplphysiol.01431.2009
PMCID: PMC3774425
PMID: 20431020
url
https://doi.org/10.1152/japplphysiol.01431.2009View
Published (Version of record) Open Access

Abstract

Immersion pulmonary edema (IPE) can occur in otherwise healthy swimmers and divers, likely because of stress failure of pulmonary capillaries secondary to increased pulmonary vascular pressures. Prior studies have revealed progressive increase in ventilation [minute ventilation (V̇e)] during prolonged immersed exercise. We hypothesized that this increase occurs because of development of metabolic acidosis with concomitant rise in mean pulmonary artery pressure (MPAP) and that hyperoxia attenuates this increase. Ten subjects were studied at rest and during 16 min of exercise submersed at 1 atm absolute (ATA) breathing air and at 4.7 ATA in normoxia and hyperoxia [inspired PO2(PiO2) 1.75 ATA]. V̇e increased from early (E, 6th minute) to late (L, 16th minute) exercise at 1 ATA (64.1 ± 8.6 to 71.7 ± 10.9 l/min BTPS; P < 0.001), with no change in arterial pH or Pco2. MPAP decreased from E to L at 1 ATA (26.7 ± 5.8 to 22.7 ± 5.2 mmHg; P = 0.003). V̇e and MPAP did not change from E to L at 4.7 ATA. Hyperoxia reduced V̇e (62.6 ± 10.5 to 53.1 ± 6.1 l/min BTPS; P < 0.0001) and MPAP (29.7 ± 7.4 to 25.1 ± 5.7 mmHg, P = 0.002). Variability in MPAP among subjects was wide (range 14.1–42.1 mmHg during surface and depth exercise). Alveolar-arterial Po2difference increased from E to L in normoxia, consistent with increased lung water. We conclude that increased V̇e at 1 ATA is not due to acidosis and is more consistent with respiratory muscle fatigue and that progressive pulmonary vascular hypertension does not occur during prolonged immersed exercise. Wide variation in MPAP among healthy subjects is consistent with variable individual susceptibility to IPE.

Details

Metrics

23 Record Views
35 Times Cited - Web of Science
Logo image