Simultaneous Assessment of Microvascular Oxygen Saturation and Laser-Doppler Flow in Gastric Mucosa
Positive end-expiratory pressure (PEEP) during controlled mechanical ventilation has been shown to reduce the oxygen saturation of hemoglobin in gastric mucosa (μHbO2)1 and splanchnic microvascular blood flow.2 The effects of PEEP on these microcirculatory variables could be separated from the impact of PEEP on systemic circulation and oxygenation: Normalization of cardiac output and oxygen transport capacity, depressed due to reduced preload during ventilation with PEEP, did not restore microvascular blood flow2 nor 1.μHbO2.3 Similarly, in healthy volunteers breathing continuous positive airway pressure (CPAP) reduced tHbO2 despite unchanged systemic hemodynamics and stable systemic oxygen saturation.4 The mechanism for this obvious different response to PEEP and CPAP in systemic and regional intestinal circulation remains unclear.
KeywordsOxygen Saturation Continuous Positive Airway Pressure Gastric Mucosa Spontaneous Breathing Reactive Hyperemia
Unable to display preview. Download preview PDF.
- 3.T. W. L. Scheeren, L. A. Schwarte, S. A. Loer, O. Picker, and A. Foumell, Dopexamine but not dopamine increases gastric mucosal oxygenation during mechanical ventilation in dogs, Crit. Car. Med. 30, 881887 (2002).Google Scholar
- 4.A. Foumell, L. A. Schwarte, F. Wenzel, O. Picker, and T. W. L. Scheeren, Continuous positive airway pressure during spontaneous ventilation attenuates gastric mucosal oxygenation, Intensive Care Med. 26, S343 (2000)Google Scholar
- 7.A. Foumell, L. A. Schwarte, T. W. L. Scheeren, D. Kindgen-Milles, P. Feindt, and S. A. Loer, Clinical evaluation of reflectance spectrophotometry for the measurement of gastric microvascular oxygen satu- ration in patients undergoing cardiopulmonary bypass, J. Cardiothorac. Vasc. Anesth. 16, 576–581Google Scholar