Pulmonary Artery Diastolic-Pulmonary Wedge Pressure Gradient

Q: What is the clinical significance of Pulmonary Artery Diastolic-Pulmonary Wedge Pressure Gradient (PADP - PAOP)?

Answer: Once the PADP - PAOP gradient starts to exceed 6 mm Hg or more, the patient has shown to have a much poorer prognosis, particularly in septic patients. The probable explanation is pulmonary venous vasoconstriction induced by endotoxemia in sepsis or postcapillary leukocyte aggregation in the development of ARDS.

At least one study suggests that although an initial PAD-PWP gradient in patients with sepsis is associated with high mortality, a much more sensitive indicator is to follow the trend. There was a 91% mortality in patients with persisting or increasing gradients.

#hemodynamic

References:

1. Pulmonary hypertension in sepsis: Measurement by the pulmonary arterial Diastolic-pulmonary wedge pressure gradient and the influence of passive and active factors. Chest 1978; 73:583-91

2. Significance of the pulmonary artery diastolic-pulmonary wedge pressure gradient in sepsis. Crit Care Med 1982; 10:658-61

3. Pulmonary artery diastolic and wedge pressure relationships in critically and injured patients. Arch Surg 1988; 123:933-6

4. Increased Pulmonary Venous Resistance Contributes to Increased Pulmonary Artery Diastolic-Pulmonary Wedge Pressure Gradient in Acute Respiratory Distress Syndrome - Anesthesiology: Volume 102(3) March 2005 pp 574-580