RESUMO
BACKGROUND: Increased pulmonary capillary pressure (PAWP) and decreased serum colloid osmotic pressure (COP) are important factors in pulmonary edema (PE) formation. The aim of this study was to evaluate the clinical usefulness of noninvasive determination of COP, PAWP and COP-PAWP gradient in patients with acute dyspnea. METHODS: Thirty four patients presenting with PE, 19 with preserved left ventricular systolic function (Ia) and 15 with depressed systolic function (Ib), and 26 patients presenting with acute pulmonary diseases (II) were enrolled. COP was estimated using Landis and Pappenheimer formula (COP = 2.1 x P + 0.16 x P2 + 0.009 x P3, P: serum total protein concentration). PAWP was measured by transthoracic Doppler echocardiography using E/Vp and 1000/(2 x IPT + Vp) Doppler indexes. RESULTS: The mean value of the gradient was 0.5 +/- 5, 1.7 +/- 3.4 and 10.4 +/- 4.7 mmHg in Ia, Ib and II respectively (P < 0.001 Ia and Ib vs II). PAWP was higher in Ia and Ib than in II (P < 0.001). However, hypoalbuminemia with COP < or = 18 mmHg was observed in 63% of patients in Ia as compared to those in Ib (7%) and II (8%). CONCLUSIONS: Severe hypoalbuminemia frequently contributes to PE formation in the presence of normal left ventricular systolic function. A COP-PAWP gradient value lower than 6 mmHg is highly predictive of the diagnosis of acute heart failure in these patients presenting with acute dyspnea.
