Dynamic prediction of fluid responsiveness during positive pressure ventilation: a review of the physiology underlying heart-lung interactions and a critical interpretation

摘要

Objective Cardiovascular responses to hypovolemia and hypotension are depressed during general anesthesia. A considerable number of anesthetized and critically ill animals may not benefit hemodynamically from a fluid bolus; therefore, it is important to have measures for accurate prediction of fluid responsiveness. Static measures of preload, such as central venous pressure, do not provide accurate prediction of fluid responsiveness, whereas dynamic measures of cardiovascular function, obtained during positive pressure ventilation, are highly predictive. This review describes key physiological concepts behind heart-lung interactions during positive pressure ventilation, factors that can modify this relationship and provides the basis for a rational interpretation of the information obtained from dynamic measurements, with a focus on pulse pressure variation (PPV).