BackgroundPlasma concentrations of endocan, a proteoglycan preferentially expressed in the pulmonary vasculature, may represent a biomarker of lung (dys)function. We sought to determine whether the measurement of plasma endocan levels early in the course of acute respiratory distress syndrome (ARDS) could help predict risk of death or of prolonged ventilation.MethodsAll patients present in the department of intensive care during a 150-day period were screened for ARDS (using the Berlin definition). Endocan concentrations were measured at the moment of ARDS diagnosis (T0) and the following morning (T1). We compared data from survivors and non-survivors and data from survivors with less than 10 days of ventilator support (good evolution) and those who died or needed more than 10 days of mechanical ventilation (poor evolution). Results are presented as numbers (percentages), mean ± standard deviation or medians (percentile 25–75).ResultsNinety-six consecutive patients were included [median APACHE II score of 21 (17–27) and SOFA score of 9 (6–12), PaO2/FiO2 ratio 155 (113–206)]; 64 (67%) had sepsis and 51 (53%) were receiving norepinephrine. Non-survivors were older (66 ± 15 vs. 59 ± 18 years, p = 0.045) and had higher APACHE II scores [27 (22–30) vs. 20 (15–24), p < 0.001] and blood lactate concentrations at study inclusion [2.1 (1.3–4.0) vs. 1.5 (0.9–2.6) mmol/L, p = 0.024] than survivors, but PaO2/FiO2 ratios [150 (116–207) vs. 158 (110–206), p = 0.95] were similar in the two groups. Endocan concentrations on the day after ARDS diagnosis were significantly higher in patients with poor evolution than in those with good evolution [12.0 (6.8–18.6) vs. 7.2 (5.4–12.5), p < 0.01].ConclusionBlood endocan concentrations early in the evolution of ARDS may be a useful marker of disease severity.Electronic supplementary materialThe online version of this article (doi:10.1186/s13613-017-0311-4) contains supplementary material, which is available to authorized users.

The muscle NIRS Asc slope after a VOT is altered earlier than global markers of tissue hypoperfusion during sepsis. This simple noninvasive test can detect early changes in peripheral perfusion in sepsis.

BackgroundAcute respiratory distress syndrome (ARDS) is associated with vascular endothelial dysfunction. The resultant microvascular reactivity can be assessed non-invasively using near-infrared spectroscopy (NIRS) and a vascular occlusion test (VOT) and changes have been correlated with severity of organ dysfunction and mortality in other critically ill populations. We used NIRS to study the presence of microcirculatory alterations in patients with ARDS.MethodsWe studied 27 healthy volunteers and 32 ARDS patients admitted to our intensive care department. NIRS measurements were performed within 24 h after diagnosis (Berlin definition). VOTs were performed by inflating an arm-cuff to a pressure greater than the systolic pressure for 3 min, followed by rapid deflation. The descending (Desc) and ascending (Asc) thenar muscle oxygen saturation (StO2) slopes were calculated. We compared data from volunteers with those from ARDS patients, from ARDS survivors and non-survivors, and from ARDS survivors who required <7 days ventilatory support (good evolution) with those who required >7 days support or died (poor evolution).ResultsARDS patients had lower StO2 values [75(67–80) vs 79(76–81) %, p = 0.04] and Asc slopes [185(115–233) vs 258(216–306) %/min, p < 0.01] than healthy volunteers, but Desc slopes were similar. The Asc slope was lower in the patients with a poor evolution than in the other patients [121(90–209) vs 222(170–293) %/min, p < 0.01], and in the non-survivors than in the survivors [95(73–120) vs 212(165–252) %/min, p < 0.01].ConclusionsIn ARDS patients, microvascular reactivity is altered early, and the changes are directly related to the severity of the disease. The ascending slope is the best determinant of outcome.Electronic supplementary materialThe online version of this article (doi:10.1186/s12931-016-0375-y) contains supplementary material, which is available to authorized users.