A Clinical Classification of the Acute Respiratory Distress Syndrome for Predicting Outcome and Guiding Medical Therapy*. Issue 2 (February 2015)

• Record Type: Journal Article
• Authors: Villar, Jesús; Fernández, Rosa L.; Ambrós, Alfonso; Parra, Laura; Blanco, Jesús; Domínguez-Berrot, Ana M.; Gutiérrez, José M.; Blanch, Lluís; Añón, José M.; Martín, Carmen; Prieto, Francisca; Collado, Javier; Pérez-Méndez, Lina; Kacmarek, Robert M.
• Is Part Of: Critical care medicine. Volume 43:Issue 2(2015)
• Publication Date: 2015-02
• Subjects: Critical care medicine -- Periodicals; Soins intensifs -- Périodiques; 616.028
• DOI: 10.1097/CCM.0000000000000703
• Languages: English
• ISSNs: 0090-3493

Abstract

<abstract> <title> <x xml:space="preserve">Abstract</x> </title> <sec> <title>Objective:</title> <p>Current in-hospital mortality of the acute respiratory distress syndrome (ARDS) is above 40%. ARDS outcome depends on the lung injury severity within the first 24 hours of ARDS onset. We investigated whether two widely accepted cutoff values of PaO<sub>2</sub>/FIO<sub>2</sub> and positive end-expiratory pressure (PEEP) would identify subsets of patients with ARDS for predicting outcome and guiding therapy.</p> </sec> <sec> <title>Design:</title> <p>A 16-month (September 2008 to January 2010) prospective, multicenter, observational study.</p> </sec> <sec> <title>Setting:</title> <p>Seventeen multidisciplinary ICUs in Spain.</p> </sec> <sec> <title>Patients:</title> <p>We studied 300 consecutive, mechanically ventilated patients meeting American-European Consensus Conference criteria for ARDS (PaO<sub>2</sub>/FIO<sub>2</sub> ⩽ 200 mm Hg) on PEEP greater than or equal to 5 cm H<sub>2</sub>O, and followed up until hospital discharge.</p> </sec> <sec> <title>Interventions:</title> <p>None.</p> </sec> <sec> <title>Measurements and Main Results:</title> <p>Based on threshold values for PaO<sub>2</sub>/FIO<sub>2</sub> (150 mm Hg) and PEEP (10 cm H<sub>2</sub>O) at ARDS onset and at 24 hours, we assigned patients to four categories: group I (PaO<sub>2</sub>/FIO<sub>2</sub> ≥ 150 on PEEP < 10), group II (PaO<sub>2</sub>/FIO<sub>2</sub> ≥ 150 on PEEP ≥ 10), group III (PaO<sub>2</sub>/FIO<sub>2</sub> < 150 on PEEP < 10), and group IV (PaO<sub>2</sub>/FIO<sub>2</sub> < 150 on PEEP ≥ 10). The primary outcome was all-cause in-hospital mortality. Overall hospital mortality was 46.3%. Although at study entry, patients with PaO<sub>2</sub>/FIO<sub>2</sub> less than 150 had a higher mortality than patients with a PaO<sub>2</sub>/FIO<sub>2</sub> greater than or equal to 150 (<italic>p</italic> = 0.044), there was minimal variability in mortality among the four groups (<italic>p</italic> = 0.186). However, classification of patients in each group changed markedly after 24 hours of usual care. Group categorization at 24 hours provided a strong association with in-hospital mortality (<italic>p</italic> < 0.00001): group I had the lowest mortality (23.1%), whereas group IV had the highest mortality (60.3%).</p> </sec> <sec> <title>Conclusions:</title> <p>The degree of lung dysfunction established by a PaO<sub>2</sub>/FIO<sub>2</sub> of 150 mm Hg and a PEEP of 10 cm H<sub>2</sub>O demonstrated that ARDS is not a homogeneous disorder. Rather, it is a series of four subsets that should be considered for enrollment in clinical trials and for guiding therapy. A major contribution of our study is the distinction between survival after 24 hours of care versus survival at the time of ARDS onset.</p> </sec> </abstract>