End-Expiratory Occlusion Test Predicts Preload Responsiveness Independently of Positive End-Expiratory Pressure During Acute Respiratory Distress Syndrome

• Published in: Critical care medicine Vol. 41; no. 7; pp. 1692 - 1701
• Main Authors: Silva, Serena, Jozwiak, Mathieu, Teboul, Jean-Louis, Persichini, Romain, Richard, Christian, Monnet, Xavier
• Format: Journal Article
• Language: English
• Published: Hagerstown, MD by the Society of Critical Care Medicine and Lippincott Williams & Wilkins 01-07-2013; Lippincott Williams & Wilkins
• Subjects: Adult; Aged; Anesthesia. Intensive care medicine. Transfusions. Cell therapy and gene therapy; Biological and medical sciences; Cardiac Output; Female; Hemodynamics; Hospitals, University; Humans; Intensive care medicine; Intensive Care Units; Male; Medical sciences; Middle Aged; Pneumology; Positive-Pressure Respiration - methods; Prospective Studies; Respiratory Distress Syndrome, Adult - therapy; Respiratory system : syndromes and miscellaneous diseases; Sensitivity and Specificity; Shock - therapy; Heart; Occlusion; fluid responsiveness; Intensive care; heart lung interactions; Respiratory disease; Acute; Lung; Prediction; Respiratory system; passive leg raising; Syndrome; Leg; Positive end expiratory pressure; end-expiratory occlusion test; Respiratory distress; Drug interaction; Circulatory system; Predictive factor; Resuscitation
• ISSN: 0090-3493; 1530-0293
• DOI: 10.1097/CCM.0b013e31828a2323

OBJECTIVE:A 15-second end-expiratory occlusion increases cardiac preload and allows detection of preload dependence. We tested whether the reliability of this test depends upon positive end-expiratory pressure.
DESIGN:Prospective study.
SETTING:Medical ICU.
PATIENTS:Thirty-four patients presenting with acute circulatory failure and acute respiratory distress syndrome ventilated with a tidal volume of 6.7 mL/kg (interquartile range, 6.3–7.1).
MEASUREMENTS:At positive end-expiratory pressure = 5 cm H2O, we measured the changes in cardiac index induced by end-expiratory occlusion and a passive leg raising test. Preload dependence was defined by a passive leg raising–induced increase in cardiac index greater than or equal to 10%. Positive end-expiratory pressure was increased to a plateau pressure of 30 cm H2O, and end-expiratory occlusion and passive leg raising were performed again.
MAIN RESULTS:At positive end-expiratory pressure = 5 cm H2O, 29% of patients were passive leg raising responders. An end-expiratory occlusion–induced increase in cardiac index greater than or equal to 5% detected a passive leg raising–induced increase in cardiac index greater than or equal to 10% with a sensitivity of 90% (95% CI, 56–100) and a specificity of 88% (95% CI, 68–97). At higher positive end-expiratory pressure (15 cm H2O [interquartile range, 13–15]), the plateau pressure – positive end-expiratory pressure difference did not change (15 mm Hg [14–17] vs 15 mm Hg [13–18] before the positive end-expiratory pressure increase). Increasing positive end-expiratory pressure significantly reduced cardiac index in passive leg raising responders (–27% [interquartile range, –6 to –56]) but not in other patients. At high positive end-expiratory pressure, passive leg raising increased cardiac index to a larger extent than at positive end-expiratory pressure = 5 cm H2O (19% [interquartile range, 15–34] vs 16% [interquartile range, 13–23], respectively). The proportion of passive leg raising responders significantly increased (34 vs 29%, respectively), meaning preload dependence had increased. At higher positive end-expiratory pressure, an end-expiratory occlusion–induced increase in cardiac index greater than or equal to 6% detected a passive leg raising–induced increase in cardiac index greater than or equal to 10% with a sensitivity of 100% (95% CI, 75–100) and a specificity of 90% (95% CI, 70–99).
CONCLUSIONS:The end-expiratory occlusion test is reliable for detecting preload dependence whatever the positive end-expiratory pressure during acute respiratory distress syndrome.