Adrenomedullin and endothelin-1 are associated with myocardial injury and death in septic shock patients.

BACKGROUND: Adrenomedullin and endothelin-1 are hormones with opposing effects on the cardiovascular system. Adrenomedullin acts as a vasodilator and seems to be important for the initiation and continuation of the hyperdynamic circulatory response in sepsis. Endothelin-1 is a vasoconstrictor and has been linked to decreased cardiac performance. Few studies have studied the relationship between adrenomedullin and endothelin-1, and morbidity and mortality in septic shock patients. High-sensitivity troponin T (hsTNT) is normally used to diagnose acute cardiac injury but is also prognostic for outcome in intensive care. We investigated the relationship between mid-regional pro-adrenomedullin (MR-proADM), C-terminal pro-endothelin-1 (CT-proET-1), and myocardial injury, measured using transthoracic echocardiography and hsTNT in septic shock patients. We were also interested in the development of different biomarkers throughout the ICU stay, and how early measurements were related to mortality. Further, we assessed if a positive biomarker panel, consisting of MR-proADM, CT-proET-1, and hsTNT changed the odds for mortality. METHODS: A cohort of 53 consecutive patients with septic shock had their levels of MR-proADM, CT-proET-1, hsTNT, and left ventricular systolic functions prospectively measured over 7 days. The relationship between day 1 levels of MR-proADM/CT-proET-1 and myocardial injury was studied. We also investigated the relationship between biomarkers and early (7-day) and later (28-day) mortality. Likelihood ratios, and pretest and posttest odds for mortality were calculated. RESULTS: Levels of MR-proADM and CT-proET-1 were significantly higher among patients with myocardial injury and were correlated with left ventricular systolic dysfunction. MR-proADM and hsTNT were significantly higher among 7-day and 28-day non-survivors. CT-proET-1 was also significantly higher among 28-day but not 7-day non-survivors. A positive biomarker panel consisting of the three biomarkers increased the odds for mortality 13-fold to 20-fold. CONCLUSIONS: MR-proADM and CT-proET-1 are associated with myocardial injury. A biomarker panel combining MR-proADM, CT-proET-1, and hsTNT increases the odds ratio for death, and may improve currently available scoring systems in critical care.

Extravascular lung water index improves the diagnostic accuracy of lung injury in patients with shock.

INTRODUCTION: The diagnosis of acute lung injury (ALI) may be more robust if more accurate physiological markers can be identified. Extravascular lung water (EVLW) is one possible marker, and it has been shown to correlate with respiratory function and mortality in patients with sepsis. Whether EVLW confers diagnostic value in a general population with shock, as well as which index performs best, is unclear. We investigated the diagnostic accuracy of various EVLW indices in patients with shock. METHODS: We studied a prospective, observational cohort of 51 patients with shock admitted to a tertiary ICU. EVLW was measured within 6 hours of ICU admission and indexed to actual body weight (EVLW/ABW), predicted body weight (EVLW/PBW) and pulmonary blood volume (EVLW/PBV). The relationship of these indices to the diagnosis and severity of lung injury and ICU mortality were studied. Positive and negative likelihood ratios, pre- and posttest odds for diagnosis of lung injury and mortality were calculated. RESULTS: All EVLW indices were higher among patients with lung injury and significantly correlated with respiratory parameters. Furthermore, all EVLW indices were significantly higher in nonsurvivors. The use of EVLW improves the posttest OR for the diagnosis of ALI, acute respiratory distress syndrome (ARDS) and severe lung injury (sLI) by up to eightfold. Combining increased EVLW and a diagnosis of ALI, ARDS or sLI increases the posttest odds of ICU mortality. EVLW/ABW and EVLW/PBV demonstrated the best diagnostic performance in this population. CONCLUSIONS: EVLW was associated with degree of lung injury and mortality, regardless of the index used, confirming that it may be used as a bedside indicator of disease severity. The use of EVLW as a bedside test conferred added diagnostic value for the identification of patients with lung injury.