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Splanchnic hemodynamics and gut mucosal-arterial PCO(2) gradient during systemic hypocapnia
1Division of Pulmonary and Critical Care Medicine, Wayne State University School of Medicine, Detroit, Michigan 48201, USA.
Journal of Applied Physiology (Bethesda, Md. : 1985)
|September 14, 1999
Summary
Hypocapnia, or low arterial carbon dioxide levels, significantly reduces splanchnic blood flow and ileal mucosal blood flow in dogs. This condition also increases the gut mucosal-arterial carbon dioxide gradient, indicating impaired tissue oxygenation.
Area of Science:
- Physiology
- Gastroenterology
- Cardiovascular Research
Background:
- Splanchnic hemodynamics are crucial for maintaining gut integrity.
- Hypocapnia is a common physiological state that can affect organ perfusion.
- Understanding the impact of hypocapnia on gut mucosal circulation is vital.
Purpose of the Study:
- To investigate the effects of hypocapnia on splanchnic hemodynamics.
- To assess the impact on ileal mucosal and serosal blood flow.
- To determine changes in gut mucosal-arterial PCO(2) gradient and serosal PO(2) during hypocapnia.
Main Methods:
- Utilized seven anesthetized ventilated dogs for the study.
- Employed laser Doppler flowmetry to estimate ileal mucosal and serosal blood flow.
- Measured mucosal PCO(2) using capnometric recirculating gas tonometry and serosal PO(2) with a polarographic electrode.
Main Results:
- Hypocapnia significantly decreased cardiac output and portal blood flow.
- Ileal mucosal and serosal blood flow reduced by 15% and 34%, respectively.
- Observed increased mucosal-arterial PCO(2) gradient and reduced serosal PO(2) during hypocapnia.
Conclusions:
- Hypocapnia induces ileal mucosal and serosal hypoperfusion.
- A redistribution of blood flow favoring the mucosa occurs during hypocapnia.
- The study highlights the detrimental effects of hypocapnia on gut perfusion and oxygenation.
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