Difference in pulmonary permeability between indirect and direct acute respiratory distress syndrome assessed by the transpulmonary thermodilution technique: a prospective, observational, multi-institutional study

Abstract

BackgroundAcute respiratory distress syndrome (ARDS) is characterized by the increased pulmonary permeability secondary to diffuse alveolar inflammation and injuries of several origins. Especially, the distinction between a direct (pulmonary injury) and an indirect (extrapulmonary injury) lung injury etiology is gaining more attention as a means of better comprehending the pathophysiology of ARDS. However, there are few reports regarding the quantitative methods distinguishing the degree of pulmonary permeability between ARDS patients due to pulmonary injury and extrapulmonary injury.MethodsA prospective, observational, multi-institutional study was performed in 23 intensive care units of academic tertiary referral hospitals throughout Japan. During a 2-year period, all consecutive ARDS-diagnosed adult patients requiring mechanical ventilation were collected in which three experts retrospectively determined the pathophysiological mechanisms leading to ARDS. Patients were classified into two groups: patients with ARDS triggered by extrapulmonary injury (ARDSexp) and those caused by pulmonary injury (ARDSp). The degree of pulmonary permeability using the transpulmonary thermodilution technique was obtained during the first three intensive care unit (ICU) days.ResultsIn total, 173 patients were assessed including 56 ARDSexp patients and 117 ARDSp patients. Although the Sequential Organ Failure Assessment (SOFA) score was significantly higher in the ARDSexp group than in the ARDSp group, measurements of the pulmonary vascular permeability index (PVPI) were significantly elevated in the ARDSp group on all days: at day 0 (2.9 ± 1.3 of ARDSexp vs. 3.3 ± 1.3 of ARDSp, p = .008), at day 1 (2.8 ± 1.5 of ARDSexp vs. 3.2 ± 1.2 of ARDSp, p = .01), at day 2 (2.4 ± 1.0 of ARDSexp vs. 2.9 ± 1.3 of ARDSp, p = .01). There were no significant differences in mortality at 28 days, mechanical ventilation days, and hospital length of stay between the two groups.ConclusionsThe results of this study suggest the existence of several differences in the increased degree of pulmonary permeability between patients with ARDSexp and ARDSp.Trial registrationThis report is a sub-group analysis of the study registered with UMIN-CTR (IDUMIN000003627).

Effect of a selective neutrophil elastase inhibitor on mortality and ventilator-free days in patients with increased extravascular lung water: a post hoc analysis of the PiCCO Pulmonary Edema Study

“…The current study was a post hoc analysis of the PiCCO Pulmonary Edema Study, a prospective cohort study that examined patients with respiratory-distress who were admitted to 23 participating institutions in Japan [ 16 , 17 , 19 - 22 ]. This study was approved by the ethics committee of the Nippon Medical School Hospital, and all the other 22 participating institutional ethics committees, and written informed consent was provided by all of the patients’ next of kin.…”

WITHDRAWN: Association Between Inflammatory Biomarkers and Acute Respiratory Distress Syndrome or Acute Lung Injury Risk: A Systematic Review and Meta-analysis

“…Indirect injuries associated with ARDS/ALI include severe systemic infection, severe non-pulmonary trauma, acute pancreatitis, major blood transfusion, and disseminated intravascular coagulation. [4,5] Patients exposed to the abovementioned factors are at high risk for developing ARDS/ALI. Although the mechanisms underlying ARDS/ALI pathogenesis remain unclear, inflammation has been considered as one of its major inducing factors.…”

Effect of protective lung ventilation strategy combined with lung recruitment maneuver in patients with acute respiratory distress syndrome (ARDS)

“…The main pathological mechanism of pulmonary ARDS is primary alveolar damage; and the main mechanism of extrapulmonary ARDS is the pulmonary capillary endothelial injury caused by extrapulmonary factors [25,26]. However, a series of studies based the classification system failed to achieve consistent conclusion in radiological manifestations, the degree of lung inflammation, reactivity to respiratory therapy, in-hospital mortality, and so on in the two subtypes of ARDS patients [27,28]. Most scholars believe that the response of extrapulmonary ARDS to lung recruitment is much better than pulmonary ARDS [29,30], and a multi-center study in 2007 shows that the pulmonary ARDS and extrapulmonary ARDS reactivity to lung recruitment are similar [31].…”