Gas exchange and cardiovascular responses during breath-holding in divers

Anna Taboni; Nazzareno Fagoni; Christian Moia; Giovanni Vinetti; Guido Ferretti

doi:10.1016/j.resp.2019.06.002

Gas exchange and cardiovascular responses during breath-holding in divers

Respir Physiol Neurobiol. 2019 Sep:267:27-34. doi: 10.1016/j.resp.2019.06.002. Epub 2019 Jun 12.

Authors

Anna Taboni¹, Nazzareno Fagoni², Christian Moia³, Giovanni Vinetti², Guido Ferretti⁴

Affiliations

¹ Department of Anaesthesiology, Pharmacology, Intensive Care, and Emergencies, University of Geneva, rue Michel Servet 1, CH-1211, Geneva, Switzerland. Electronic address: anna.taboni@unige.ch.
² Department of Molecular and Translational Medicine, University of Brescia, Viale Europa 11, 25123, Brescia, Italy.
³ Department of Anaesthesiology, Pharmacology, Intensive Care, and Emergencies, University of Geneva, rue Michel Servet 1, CH-1211, Geneva, Switzerland; Department of Basic Neurosciences, University of Geneva, rue Michel Servet 1, CH-1211, Geneva, Switzerland.
⁴ Department of Anaesthesiology, Pharmacology, Intensive Care, and Emergencies, University of Geneva, rue Michel Servet 1, CH-1211, Geneva, Switzerland; Department of Molecular and Translational Medicine, University of Brescia, Viale Europa 11, 25123, Brescia, Italy; Department of Basic Neurosciences, University of Geneva, rue Michel Servet 1, CH-1211, Geneva, Switzerland.

PMID: 31201868
DOI: 10.1016/j.resp.2019.06.002

Abstract

To check whether the evolution of alveolar pressures of O₂ (P_AO₂) and CO₂ (P_ACO₂) explains the cardiovascular responses to apnoea, eight divers performed resting apnoeas of increasing duration in air and in O₂. We measured heart rate (f_H), arterial pressure (AP), and peripheral resistances (TPR) beat-by-beat, P_AO₂ and P_ACO₂ at the end of each apnoea. The three phases of the cardiovascular response to apnoea were observed. In O₂, TPR increase (9 ± 4 mmHg min l^-1) and f_H decrease (-11 ± 8 bpm) were lower than in air (15 ± 5 mmHg min l^-1 and -28 ± 13 bpm, respectively). At end of maximal apnoeas in air, P_AO₂ and P_ACO₂ were 50 ± 9 and 48 ± 5 mmHg, respectively; corresponding values in O₂ were 653 ± 8 mmHg and 55 ± 5 mmHg. At end of phase II, P_AO₂ and P_ACO₂ in air were 90 ± 13 mmHg and 42 ± 4 mmHg respectively; corresponding values in O₂ were 669 ± 7 mmHg and 47 ± 6 mmHg. The P_ACO₂ increase may trigger the AP rise in phase III.

Keywords: Alveolar gas; Apnoea; Conventional breaking point; Diving response; Physiological breaking point.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Adult
Blood Pressure / physiology*
Breath Holding*
Diving / physiology*
Heart Rate / physiology*
Humans
Male
Pulmonary Gas Exchange / physiology*