Relationship between Pulmonary Artery End-Diastolic Pressure and Left Ventricular Filling Pressure in Patients in Shock

Abstract

Bedside catheterization permitted 56 simultaneous measurements of left ventricular end-diastolic pressure (LVEDP) and pulmonary artery end-diastolic pressure (PAEDP) in 25 patients in shock. Measurements were made over a wide range of heart rates (60-160 beats/min), arterial oxygen tension (P o o2 ; 33-562 mm Hg), stroke volumes (9-105 ml), and systolic arterial pressures (65-250 mm Hg), and before and during various therapeutic interventions. There was good correlation between PAEDP and LVEDP (r = +0.85) and PAEDP and left ventricular pre-a pressure (r = +0.82). In 16 patients breathing room air, mean arterial P o o2 was 58 ± 15 mm Hg and rose significantly to 282 ± 16 mm Hg after breathing oxygen (P<0.01), but there was no significant change in the correlation between PAEDP and LVEDP before (r = +0.80) or during oxygen breathing (r = +0.80). Similarly, in seven patients treated with inotropic agents there was excellent correlation between PAEDP and LVEDP before (r = +0.96) and during inotropic therapy (r = +0.86). A PAEDP in excess of 15 mm Hg nearly always reflected increased LVEDP while a PAEDP less than 10 mm Hg was always associated with normal LVEDP. Thus in our patients with shock PAEDP represented a good estimate of LVEDP during a variety of therapeutic interventions and therefore represents a useful tool in guiding the therapy of patients in shock.