Time-limited trials in the ICU: a mixed-methods sequential explanatory study of intensivists at two academic centres

Objective To understand intensivist perceptions of the appropriateness of time-limited trials (TLTs) - a strategy to align life-sustaining care with patient goals and values in the midst of clinical uncertainty. Design We conducted a mixed-methods sequential explanatory study of intensive care unit (ICU) intensivists regarding appropriateness of utilising TLTs in three vignettes centred on invasive mechanical ventilation (IMV); continuous renal replacement therapy (CRRT); and heated high-flow nasal cannula (HHFNC). Semistructured interviews were conducted using the Tailored Implementation of Chronic Diseases framework. Data were analysed using thematic and matrix analysis. Setting Two academic medical centres in the USA participated in the randomised surveys and one centre participated in the semistructured interviews. Participants Pulmonary and critical care intensivists and fellows. Primary and secondary outcomes To understand intensivists perceptions of the appropriateness in using TLTs. Results Of 115 physicians surveyed, 71 initiated the survey and 44 completed the entire survey with a response rate of 38% (N=44/115) and a completion rate of 62% (N=44/71). While 35% (N=23/66) of intensivists had never heard of a TLT, of the intensivists who had heard of a TLT, 77% (N=33/43) had participated in one. In response to the vignettes, appropriateness of using a TLT varied (IMV: 74% (N=46/62); CRRT 78% (N=49/63); HHFNC 92% (N=56/61) as did the durations of the TLT. Semistructured interviews with 11 intensivists revealed having clarity about patient goals and clinical endpoints facilitated successful TLTs while lack of an evidenced-based framework was a barrier. Conclusion More than half of the physicians who responded had conducted or participated in a TLT. To increase the use of TLTs in the ICU, clinicians desire a more robust, evidence-based framework on how to conduct TLTs.