Hypercapnia in diving: a review of CO₂ retention in submersed exercise at depth

Sophia A Dunworth; Michael J Natoli; Mary Cooter; Anne D Cherry; Dionne F Peacher; Jennifer F Potter; Tracy E Wester; John J Freiberger; Richard E Moon

doi:10.22462/5.6.2017.1

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Hypercapnia in diving: a review of CO₂ retention in submersed exercise at depth

Journal article

Peer reviewed

Hypercapnia in diving: a review of CO₂ retention in submersed exercise at depth

Sophia A Dunworth, Michael J Natoli, Mary Cooter, Anne D Cherry, Dionne F Peacher, Jennifer F Potter, Tracy E Wester, John J Freiberger and Richard E Moon

Undersea & hyperbaric medicine, Vol.44(3), pp.191-209

05/2017

DOI: 10.22462/5.6.2017.1

PMID: 28779577

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http://hdl.handle.net/10161/15586View

Open Access

Abstract

Carbon dioxide (CO₂) retention, or hypercapnia, is a known risk of diving that can cause mental and physical impairments leading to life-threatening accidents. Often, such accidents occur due to elevated inspired carbon dioxide. For instance, in cases of CO₂ elimination system failures during rebreather dives, elevated inspired partial pressure of carbon dioxide (PCO₂) can rapidly lead to dangerous levels of hypercapnia. Elevations in PaCO₂ (arterial pressure of PCO₂) can also occur in divers without a change in inspired PCO₂. In such cases, hypercapnia occurs due to alveolar hypoventilation. Several factors of the dive environment contribute to this effect through changes in minute ventilation and dead space. Predominantly, minute ventilation is reduced in diving due to changes in respiratory load and associated changes in respiratory control. Minute ventilation is further reduced by hyperoxic attenuation of chemosensitivity. Physiologic dead space is also increased due to elevated breathing gas density and to hyperoxia. The Haldane effect, a reduction in CO₂ solubility in blood due to hyperoxia, may contribute indirectly to hypercapnia through an increase in mixed venous PCO₂. In some individuals, low ventilatory response to hypercapnia may also contribute to carbon dioxide retention. This review outlines what is currently known about hypercapnia in diving, including its measurement, cause, mental and physical effects, and areas for future study.

Humans

Respiratory Dead Space - physiology

Symptom Assessment

Diving - adverse effects

Carbon Dioxide - administration & dosage

Male

Carbon Dioxide - blood

Carbonic Anhydrases - metabolism

Pulmonary Gas Exchange - physiology

Partial Pressure

Cognition Disorders - etiology

Hyperoxia - complications

Pulmonary Ventilation - physiology

Adult

Female

Hypercapnia - etiology

Respiration

Details

Title: Subtitle: Hypercapnia in diving: a review of CO₂ retention in submersed exercise at depth
Creators: Sophia A Dunworth - Center for Hyperbaric Medicine and Environmental Physiology, Duke University Medical Center, Durham, N.C
Michael J Natoli - Center for Hyperbaric Medicine and Environmental Physiology, Duke University Medical Center, Durham, N.C
Mary Cooter - Department of Anesthesiology, Duke University Medical Center, Durham, N.C
Anne D Cherry - Center for Hyperbaric Medicine and Environmental Physiology, Duke University Medical Center, Durham, N.C
Dionne F Peacher - Department of Anesthesia, University of Iowa, Iowa City, Iowa
Jennifer F Potter - Department of Anesthesiology, University of Virginia, Charlottesville, Virginia
Tracy E Wester - Department of Anesthesia and Perioperative Medicine, Medical University of South Carolina, Charleston, S.C
John J Freiberger - Center for Hyperbaric Medicine and Environmental Physiology, Duke University Medical Center, Durham, N.C
Richard E Moon - Department of Medicine, Duke University Medical Center, Durham, N.C
Resource Type: Journal article
Publication Details: Undersea & hyperbaric medicine, Vol.44(3), pp.191-209
DOI: 10.22462/5.6.2017.1
PMID: 28779577
NLM abbreviation: Undersea Hyperb Med
ISSN: 1066-2936
Publisher: United States
Language: English
Date published: 05/2017
Academic Unit: Anesthesia
Record Identifier: 9984007181302771

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