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Could hyperoxic ventilation impair oxygen delivery in septic patients?
Pascal Rossi1, Laurent Tauzin, Michel Weiss
1Laboratoire de Physiopathologie et Action Thérapeutique des gaz sous pression, IFR Jean Roche, Université de la Méditerranée, Faculté de Médecine Nord, Marseille Cedex, France. pascalrossi@yahoo.com
Clinical Physiology and Functional Imaging
|April 21, 2007
Summary
In septic shock patients, breathing pure oxygen paradoxically reduced oxygen delivery to upper limbs. This study investigated hyperoxia-induced changes in brachial artery circulation and tone during mechanical ventilation.
Area of Science:
- Critical care medicine
- Cardiovascular physiology
- Respiratory medicine
Background:
- Decreased whole body oxygen consumption under hyperoxia is noted in critically ill patients.
- Hyperoxia-induced arterial changes may contribute to reduced oxygen consumption.
Purpose of the Study:
- To investigate changes in brachial artery circulation and tone during short-term hyperoxic ventilation in septic patients.
Main Methods:
- Prospective clinical study in an intensive care unit.
- Fourteen mechanically ventilated sepsis patients underwent 20-minute 100% oxygen ventilation.
- Brachial artery ultrasonography and Doppler, alongside invasive arterial pressure, were used.
Main Results:
- Hyperoxia increased mean arterial pressure but decreased brachial artery cross-sectional area.
- Hemodynamics showed increased resistance and decreased distensibility/compliance.
- Brachial artery blood flow and oxygen delivery decreased during hyperoxia.
Conclusions:
- Hyperoxia paradoxically decreased upper limb oxygen delivery in septic shock.
- Arterial constriction and reduced blood flow contribute to this effect.
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