CT-pro-endothelin-1 and prognosis in critically ill patients with respiratory failure
© Meyer et al; licensee BioMed Central Ltd. 2009
Published: 13 March 2009
Endothelin-1 is known to be elevated in patients with various pulmonary and nonpulmonary diagnoses. CT-pro-endo-thelin-1 (CT-pro-ET-1) is a stable precursor molecule of endothelin-1. In the present study we tested whether CT-pro-ET-1 is elevated in critically ill patients admitted to the ICU with respiratory failure. Moreover, we tested whether an elevation of CT-pro-ET-1 is a predictor of an adverse outcome.
In this prospective observational study we included 78 patients with documented respiratory failure on ICU admission and 266 patients with various other diagnoses and without respiratory failure. Blood samples for determination of CT-pro-ET-1 were obtained in all patients on ICU admission. CT-pro-ET-1 was determined by use of a new sandwich immunoassay.
Respiratory failure was attributed to a primary pulmonary cause in 66 patients: chronic obstructive pulmonary disease (n = 15), pulmonary hypertension (n = 7), pneumonia (n = 17), acute respiratory distress (n = 3), pulmonary embolism (n = 6), postoperative respiratory failure (n = 12) and various/mixed causes (n = 6). A total of 12 patients had respiratory failure because of primary cardiogenic edema. Patients presenting with primary pulmonary failure on ICU admission had significantly higher CT-pro-ET-1 levels compared with patients with diagnosis of cardiogenic pulmonary edema and patients without respiratory failure (193 ± 117 vs. 160 ± 67 vs. 148 ± 94 pmol/l, P = 0.007). In patients with primary pulmonary failure and in patients with cardiogenic edema, there was no statistically significant difference in CT-pro-ET-1 levels between ICU survivors and ICU nonsurvivors (195 ± 155 vs. 191 ± 127 pmol/l, P = 0.908 and 160 ± 75 vs. 164 ± 5 pmol/l, P = 0.940). In contrast, in the mixed cohort of critically ill patients without respiratory failure, CT-pro-ET-1 levels were statistically significantly lower in ICU survivors compared with ICU nonsurvivors (140 ± 93 vs. 179 ± 95 pmol/l, P = 0.007).
CT-pro-ET-1 plasma levels are increased in patients admitted to the ICU because of respiratory failure. Elevated plasma levels of CT-pro-ET-1 are a potent marker of adverse outcome in our mixed cohort of critically ill patients. In the subgroup of patients admitted to the ICU because of respiratory failure due to a primary pulmonary cause or due to cardiogenic edema, however, elevation of CT-pro-ET-1 did not provide statistically significant prognostic information.
This article is published under license to BioMed Central Ltd.