Evaluation of prognosis in patients with respiratory failure requiring venovenous extracorporeal membrane oxygenation (ECMO)

In this study, we analyzed the respiratory status and the prognosis of patients, including adults with acute respiratory failure requiring venovenous extracorporeal membrane oxygenation (VV ECMO) to maintain respiratory status. We then evaluated the differences between patients who could be removed from VV ECMO and those who could not.

From January 2003 to December 2008, eleven patients in our hospital required VV ECMO for severe acute respiratory failure. All 11 had severe acute respiratory distress syndrome. The age of the patients was 52 ± 24 (range; 8-86) years, and the male/female ratio was 8/3. The acute physiology and chronic health evaluation II (APACHE II) score, ECMO flow, and respiratory parameters, such as PaO2/FiO2 (P/F ratio), pulmonary compliance, and Lung Injury Score (LIS) before and after the introduction of ECMO, were compared among patients in whom ECMO could or could not be removed.

ECMO could be removed from six patients (55%, group A), but in five (45%, group B) could not. The duration of ECMO support was significantly shorter in group A than in group B (111 ± 68 hr vs. 380 ± 233 hr, p = 0.011). The pre-ECMO ventilator time was shorter in group A than in group B. Significant differences were found between the two groups in the P/F ratio and LIS from pre-ECMO introduction to 72 hours after. ECMO flow in group A could be weaned for 48 hours after introduction, significantly different compared with group B.

The early introduction of ECMO may be desirable if the causes of respiratory failure are recoverable. It is presumed that VV ECMO removal will be difficult if the ECMO flow cannot be weaned within 48 hours after ECMO introduction in patients with severe respiratory failure.