Cautious Application of Pleural N-Terminal Pro-B-Type Natriuretic Peptide in Diagnosis of Congestive Heart Failure Pleural Effusions among Critically Ill Patients

<div><p>Background and Objective</p><p>Several studies on diagnostic accuracy of pleural N-terminal pro-B-type natriuretic peptide (NT-pro-BNP) for effusions from congestive heart failure (CHF) conclude that pleural NT-pro-BNP is a useful biomarker with high diagnostic accuracy for distinguishing CHF effusions. However, its applicability in critical care settings remains uncertain and requires further investigations.</p><p>Methods</p><p>NT-proBNP was measured in pleural fluid samples of a prospective cohort of intensive care unit patients with pleural effusions. Receiver operating characteristic curve analysis was performed to determine diagnostic accuracy of pleural NT-proBNP for prediction of CHF effusions.</p><p>Results</p><p>One hundred forty-seven critically ill patients were evaluated, 38 (26%) with CHF effusions and 109 (74%) with non-CHF effusions of various causes. Pleural NT-proBNP levels were significantly elevated in patients with CHF effusions. Pleural NT-pro-BNP demonstrated the area under the curve of 0.87 for diagnosing effusions due to CHF. With a cutoff of 2200 pg/mL, pleural NT-proBNP displayed high sensitivity (89%) but moderate specificity (73%). Notably, 29 (27%) of 109 patients with non-CHF effusions had pleural NT-proBNP levels >2200 pg/mL and these patients were more likely to experience septic shock (18/29 vs. 10/80, P<0.001) or acute kidney injury (19/29 vs. 9/80, P<0.001).</p><p>Conclusions</p><p>Among critically ill patients, pleural NT-proBNP measurements remain a useful diagnostic aid in evaluation of pleural effusions. However, patients with non-CHF effusions may exhibit high pleural NT-proBNP concentrations if they suffer from septic shock or acute kidney injury. Accordingly, it is suggested that clinical context should be taken into account when interpreting pleural NT-proBNP values in critical care settings.</p></div

Boxplots showing the minimum, 25th, 50th, and 75th percentiles, and the maximum pleural N-terminal pro-B-type natriuretic peptide (NT-proBNP) levels, by etiologies of pleural effusions.

<p>Outliers (open circles) and extremes (stars) are plotted separately.</p

Receiver operating characteristic curve of pleural N-terminal pro-B-type natriuretic peptide levels comparing patients with pleural effusions caused by congestive heart failure to those with pleural effusions attributable to other reasons.

<p>The area under the curve was 0.87 (95% confidence interval 0.81–0.92).</p

Etiologies of pleural effusions.

<p>*Effusions due to atelectasis, hepatic hydrothorax, or nephrotic syndrome.</p>†<p>Effusions due to chylothorax, connective tissue disease, hypothyroidism, lymphangioleiomyomatosis, subphrenic abscess, tuberculosis, or uremia.</p><p>Etiologies of pleural effusions.</p

Diagnostic information for pleural N-terminal pro-B-type natriuretic peptide concentrations in the diagnosis of pleural effusions caused by congestive heart failure.

<p>*NT-proBNP, N-terminal pro-B-type natriuretic peptide.</p>†<p>Optimal cutoff value determined by Youden index.</p><p>Diagnostic information for pleural N-terminal pro-B-type natriuretic peptide concentrations in the diagnosis of pleural effusions caused by congestive heart failure.</p

Characteristics of the study population.

<p>Data are presented as No. (%) or mean ± standard deviation.</p><p>*APACHE, Acute Physiology and Chronic Health Evaluation.</p>†<p>NT-proBNP, N-terminal pro-B-type natriuretic peptide.</p><p>Characteristics of the study population.</p

Association of day 4 cumulative fluid balance with mortality in critically ill patients with influenza: A multicenter retrospective cohort study in Taiwan - Fig 4

<p><b>Kaplan-Meier survival curves for positive (gray) and negative (black) cumulative day 1–4 fluid balance in the ARDS (A) and non-ARDS (B) groups.</b> ARDS: Acute Respiratory Distress Syndrome.</p

Cox proportional hazard regression analysis for 30-day mortality.

<p>Cox proportional hazard regression analysis for 30-day mortality.</p

Daily and cumulative fluid status of the 296 patients with influenza by 30-day mortality.

<p>Daily and cumulative fluid status of the 296 patients with influenza by 30-day mortality.</p

Flow chart of patient enrollment.

<p>Flow chart of patient enrollment.</p