The Diagnostic And Prognosis Value Of Brain Natriuretic Peptide In Critically Ill Patient With Acute Cardiogenic Pulmonary Edma

Objective: By detecting the variation of plasma brain natriuretic peptide(BNP) in critically ill patients with acute pulmonary edema(CPE), we can investigate the differentiating diagnosis value of BNP in cardiogenic and noncardiogenic pulmonary edema. We also compare the plasma BNP level of diastolic heart falure and that of systolic heart failure,and study the effect of positive pressure ventilation on BNP ,analyse prognosis value of BNP among these critically ill patients with CPE.Background: Acute pulmonary edma is a common critical illness,and acute cardiogenic pulmonary edma is the most serious type of acute decompensated heart failure.However acute lung injury/acute respiratory distress syndrome is a much different pulmonary edema .These two types of pulmonary edema have similar manifestation and are hard to differentiate .BNP is a specific heart failure factor which can effectively discriminate cardiogenic and noncardiogenic cause of apnea ,and many researches have proved BNP an independent predictive factor of cardiovascular risk,but research on diagnostic and prognosis value of BNP in acute cardiogenic pulmonary edema is rare,and there is no domestic report.Methods: 1)From Jan 2007 to Oct 2008 total 85 patients diagnosed as acute pulmonary edema admitted in our intensive care unit were included in this study. Inclusion criteria as follow:acute onset of dyspnea with hyoxemia, aterial blood analysis revealing PaO2 less than 60mmHg,pulmonary edema manifestation on cheat X-ray .Exclusion criteria:severe renal failure need blood purification,acute myocardial infarction,pregnant women,malignant tumor and patient with acute stroke. 2) Every patient received continuous cardiogram monitor and the routine test including plasma BNP test,bedside echocardiography,chest X-ray,aterial blood gas analysis,renal function,blood troponin I. Accoding to corresponding diagnostic criteria ,all paitent are divided into two groups: 45 patients with cardiogenic pulmonary edema and 40 patients with noncardiogenic pulmonary edema,and basic clinical character and BNP level of the two groups were analysed.3)According to the 2005 acute heart failure guideline endorsed by Europe Society of cardiology,intravenous drug such as diuretic agent , vasodilator and inotrope were routinely used in the management of CPE, all CPE patients simultaneously received noninvasive positive pressure ventilation. 2 hours afer NPPV treatment the second arterial blood analysis test was performed,and 24h after NPPV another BNP test was done.According the prior confirmed strategy,a decision was made to initiate a intuabation and invasive positive pressure ventilation.All 45 CPE patients were followed regularly through hospital visits or telephone conversation till Feb 1st 2009, the endpoint included death of all cause and combined adverse cardiac events,which defined as all cause death or re-hospitalization due to reworsening heart failue.4)Based on echocardiography ,all CPE patients were divided into normal left ventricular ejection fraction (LVEF>0.5)group(also defined as diastolic heart failure) and decreased LVEF group(LVEF≤0.5 as systolic heart failure),the baseline character and demographic data of two groups were compared separately, and data including BNP level pre and post NIPPV treatment also were compared.5)According to result of followup,all 45 paients were divided into combined adverse event group and no event group,the first BNP level and BNP change after NIPPV were compared.Results: 1)Cardiogenic pulmonary edema has a higher BNP level than noncardiogenic pulmonary edema(1258±575pg/ml versus 192±181pg/mL,P<0.01). A cutoff value of 500pg/mL got a diagnostic sensitivity of 96% and specificity of 90%.2) BNP level of systolic HF group is higher than that of diastolic HF group(1508±540 pg/ml versus 805±293,P<0.01), and combined adverse group had a higher BNP level than no event group(1493±603 versus 906±287 pg/ml,P<0.01),but the BNP level change after NIPPV is lower(225±162 versus 513±297 pg/ml,P<0.01).3) The all cause mortality of diastolic HF groupe and systolic HF group were 25% and 31% respectively(P=0.74),the combined adverse cardiac events rate were 44% and 69%(P=0.12).After analysing followup data by Cox multivariate regression model,the first BNP level and BNP change after NIPPV were indepent predictive factor of adverse cardiovascular events.Conclusions: 1) Rapid BNP measurement of acute pulmonary edema is an effective tool to discriminate cardiogenic pulmonary edema from noncardiogenic pulmonary edema.2) Heart failure with normal LVEF is a common cause of acute cardiogenic pulmonary edema,which had a lower BNP level than systolic heart failure group.3) The heart failure patients complicated CPE had a bad prognosis, the first BNP level and BNP change after NIPPV can serve as a prognosis factor of mortality and worsening heart failure among crtically ill patients with acute CPE .4)The first plasma BNP level of CPE correlated negatively with LVEF.