Delayed institution of extracorporeal membrane oxygenation is associated with increased mortality rate and prolonged hospital stay

Background/purpose: Severe meconium aspiration syndrome (MAS) is a frequent indication for extracorporeal membrane oxygenation (ECMO). Trials of less invasive cardiopulmonary support may result in fewer infants treated with ECMO but could delay institution of ECMO. The authors hypothesized that those infants with severe MAS who are treated with ECMO early will have a lower mortality rate and a shorter hospital course than those who receive delayed ECMO.

Methods: A retrospective review of all patients with MAS in the national extracorporeal life support (ELSO) registry for the decade 1989 through 1998 was performed. Data from the ELSO registry were examined for demographics, clinical parameters, and treatment course. Patients were divided into 3 groups based on the time from birth to institution of ECMO: group 1, 0 to 23 hours; group 2, 24 to 96 hours; and group 3, greater than 96 hours. These groups were compared for survival, duration of extracorporeal support, and duration of ventilatory support after ECMO. Statistical relevance was determined by analysis of variance (ANOVA) and Tukey's post-hoc test.

Results: A total of 3,235 of 4,002 patients with MAS had complete information on duration of mechanical ventilation. Overall mortality rate was 5.8%. The mortality rate in group 1 (n = 1,266) was 4.8%, group 2 (n = 1,568) 6.0%, and group 3 (n = 401) 7.7%. An increased time to ECMO was associated with a significant increase in mortality rate (P <.05). This also was associated with significant increases in the length of the ECMO run (157 +/- 4 v 130 +/- 2 hours, P =.02) and duration of post-ECMO ventilation (157 +/- 17 v 118 +/- 3 hours; P <.001). Those patients in groups 1 and 2 who did not respond to a trial of high-frequency oscillatory ventilation had significantly longer ECMO runs (129 +/- 2 v 113 +/- 1 hours; P =.001) and longer post-ECMO ventilator courses (137 +/- 2 v 114 +/- 1 hours; P =.002) than those who did not.

Conclusions: Delay in institution of ECMO for MAS results in prolonged ECMO and need for post-ECMO ventilation. Consideration should be given to instituting ECMO earlier in patients with severe MAS.