||9. McLean AS, Huang SJ, Nalos M, Tang B, Stewart DE. The confounding effects of age, gender, serum creatinine, and electrolyte concentrations on plasma B-type natriuretic peptide concentrations in critically ill patients. Crit Care Med. 2003 Nov;31(11):2611-8. 18 mm Hg or signs of elevated PAOP in echocardiography. RESULTS 1) Fifty (58. 1%) patients showed LVDD. The most frequently observed pattern was impaired relaxation (n = 35), followed by the restrictive (n = 9) and the pseudonormal (n = 6) patterns. BNP concentrations in restrictive and pseudonormal patterns were higher than in normal and impaired relaxation patterns, while NT-proBNP only showed differences between normal and pseudonormal or restrictive patterns. Cut-off values using ROC curve analyses to detect LVDD were 125 ng/L for BNP (p 0. 001) and 390 ng/L NT-proBNP (p = 0. 004). BNP and NT-proBNP concentrations were higher in the 15 patients that showed elevated PAOP than in those patients with normal PAOP. Cut-off values using ROC curve analyses to detect elevated PAOP were 254 ng/L for BNP (p 0. 001) and 968 for NT-proBNP (p 0. 001). Both natriopeptides performed in a similar way to detect LVDD and elevated PAOP. 2) Thirty-two patients failed the SBT, 12 due to HF and 20 due to respiratory failure (RF). Before SBT, BNP and NT-proBNP were higher in patients failing due to HF than RF or in successfully weaned patients. Cutoff values using ROC curve analyses to predict HF were 263 ng/L for BNP (p 0. 001) and 1343 ng/L for NTproBNP (p = 0. 08). BNP and NTproBNP increased significantly during SBT in patients failing due to HF. Increases in BNP and NT-proBNP of 48 and 21 ng/L, respectively, showed a diagnostic accuracy for HF of 88. 9 and 83. 3% (p 0. 001). BNP performed better than NT-proBNP for HF prediction (p = 0. 01) and diagnosis (p = 0. 009). CONCLUSIONS Both BNP and NT-proBNP are useful screening tools to detect LVDD and to rule out elevated PAOP in critically ill patients. B-type natriuretic peptides, particularly BNP, can predict weaning failure due to HF before an SBT; increases in natriuretic peptides during SBT are diagnostic of HF as the cause of weaning failure. BIBLIOGRAPHY 1. Yancy CW, Lopatin M, Stevenson LW, De Marco T, Fonarow GC. Clinical presentation, management, and in-hospital outcomes of patients admitted with acute decompensated heart failure with preserved systolic function: a report from the Acute Decompensated Heart Failure National Registry (ADHERE) Database. J Am Coll Cardiol. 2006 Jan 3;47(1):76-84. 2. Bhatia RS, Tu JV, Lee DS, Austin PC, Fang J, Haouzi A, et al. Outcome of heart failure with preserved ejection fraction in a population-based study. N Engl J Med. 2006 Jul 20;355(3):260-9. 3. Marcelino PA, Marum SM, Fernandes AP, Germano N, Lopes MG. Routine transthoracic echocardiography in a general Intensive Care Unit: an 18 month survey in 704 patients. Eur J Intern Med. 2009 May;20(3):e37-42. 4. Chockalingam A, Mehra A, Dorairajan S, Dellsperger KC. Acute left ventricular dysfunction in the critically ill. Chest. 2010 Jul;138(1):198-207. 5. Richard C, Teboul JL. Weaning failure from cardiovascular origin. Intensive Care Med. 2005 Dec;31(12):1605-7. 6. Chatterjee K. The Swan-Ganz catheters: past, present, and future. A viewpoint. Circulation. 2009 Jan 6;119(1):147-52. 7. Nagueh SF, Appleton CP, Gillebert TC, Marino PN, Oh JK, Smiseth OA, et al. Recommendations for the evaluation of left ventricular diastolic function by echocardiography. J Am Soc Echocardiogr. 2009 Feb;22(2):107-33. 8. Vieillard-Baron A, Slama M, Cholley B, Janvier G, Vignon P. Echocardiography in the intensive care unit: from evolution to revolution? Intensive Care Med. 2008 Feb;34(2):243-9. 9. McLean AS, Huang SJ, Nalos M, Tang B, Stewart DE. The confounding effects of age, gender, serum creatinine, and electrolyte concentrations on plasma B-type natriuretic peptide concentrations in critically ill patients. Crit Care Med. 2003 Nov;31(11):2611-8.