Characteristics and Outcomes of Eligible Nonenrolled Patients in a Mechanical Ventilation Trial of Acute Respiratory Distress Syndrome.

RATIONALE: Patients eligible for randomized controlled trials may not be enrolled for various reasons. Nonenrollment may affect study generalizability and lengthen the time required for trial completion. OBJECTIVES: To describe characteristics and outcomes of eligible nonenrolled (ENE) patients in a multicenter trial of mechanical ventilation strategies. METHODS: Within the OSCILLATE trial of high-frequency oscillation (HFO) versus conventional ventilation (CV) in adults with adult respiratory distress syndrome, and with approval from research ethics boards, we collected a minimal dataset on patients who satisfied eligibility criteria but were not enrolled. We categorized ENE patients as ENE-HFO and ENE-CV based on receipt of HFO at any time. We used multivariable logistic regression to assess the association between ENE status and mortality. MEASUREMENTS AND MAIN RESULTS: A total of 548 patients were randomized, and 546 were ENE. The most common reasons for ENE were no consent (42%), physician refusal (24%), missed randomization window (15%), and current HFO use (14%). Compared with randomized patients in respective arms of the trial, ENE-HFO patients were younger and had worse lung injury, whereas ENE-CV patients had lower illness severity. ENE status was independently associated with mortality (adjusted odds ratio, 1.39; 95% confidence interval, 1.06-1.84; P = 0.02), with no significant interaction with ventilation treatment group. CONCLUSIONS: Nonenrollment was common, with approximately one ENE patient for every randomized patient. Our study suggests that enrollment in trials of mechanical ventilation may be associated with improved outcomes compared with standard care and highlights the need for prospective tracking and transparent reporting of ENE patients as part of trial management.

Two decades' experience with interfacility transport on extracorporeal membrane oxygenation.

BACKGROUND: Interfacility transport of patients on extracorporeal membrane oxygenation (ECMO) has been performed in large numbers at only a few programs. Limited data are available on outcomes after ECMO transport to justify expanding or discontinuing these programs. METHODS: This was a retrospective review of a 20-year, single-institution experience with interhospital ECMO transport as well as a systematic review of reports of transfers of patients on ECMO. Results of both were compared with historical data from the international registry of the Extracorporeal Life Support Organization (ELSO). RESULTS: Between 1990 and 2012, ECMO was used to facilitate transport of 221 patients to our institution, and 135 (62%) survived to discharge. Review of an additional 27 case series describing ECMO transport of 643 patients showed an overall survival of 61%. After stratifying by age and primary indication for ECMO, survival of transported patients was not significantly different compared with all ECMO patients in the ELSO registry, with the exception of pediatric patients treated for respiratory failure (transported patients in this category had higher survival than those in the ELSO registry). CONCLUSIONS: Interfacility transport on ECMO is feasible and can be accomplished safely in the critically ill. Survival of transported patients is comparable to age-matched and treatment-matched ECMO patients at large.