Abstract Rationale Two prior trials evaluated the effectiveness of a 500-mL fluid bolus prior to tracheal intubation in critically ill adults. Neither showed benefit in the pre-specified composite of cardiovascular collapse, defined as the occurrence of at least one of the following: systolic blood pressure (SBP) nadir 65 mmHg, new or increased vasopressor use within 2 minutes of the completion of the procedure, or cardiac arrest or death within 1 hour of the procedure. The binary definition of cardiovascular collapse used in these trials does not account for relative importance of individual elements and is insensitive to less severe post-intubation hypotension. We performed a post-hoc analysis of the trial data using an alternative, hierarchical win ratio approach that ranks patient outcomes across a continuum of hemodynamic sequelae ranging from death to SBP decrease. This approach could be more sensitive to small systematic advantages of the intervention. Methods We performed pooled post-hoc analysis of deidentified data from the PrePARE (NCT03026777) and PREPARE II (NCT03787732) trials. The primary estimand was a hierarchical composite (‘hemodynamic win’) analyzed by group using a win ratio that ranked the worst outcome in the following order (higher wins): 1. death within 1 hour, 2. cardiac arrest within 1 hour, 3. SBP nadir 65 mmHg, 4. new or increased vasopressor use, 5. SBP nadir 90 mmHg,and 6. decrease in SBP from pre-intubation to peri-procedural nadir (mmHg, continuous outcome). The win ratio was computed as the total wins in the intervention arm divided by the total wins in control arm across all active-control pairs without imputation. Uncertainty was quantified by within-arm bootstrap resampling (1,000 replicates), and binary composite estimand used in original trials reanalyzed by X2. Results 1,402 randomized patients were included in cohort (median age 59 years; 42.9% women). No data required for composite analyses were missing (i.e., most severe composite element for each patient was available). Cardiovascular collapse occurred in 146 of 706 patients (20.7%) assigned to a fluid bolus and 127 of 696 patients (18.2%) assigned to no fluid bolus (RR 1.13, 95% CI, 0.92 to 1.40, p = 0.25 by X2). Results of hierarchical win ratio analysis showed no significant difference in ratio of ‘hemodynamic wins’ between groups (win ratio: 1.02; 95% CI, 0.91-1.17; P = 0.71).CONCLUSIONS In a post-hoc analysis of two randomized trials, fluid bolus administration neither compared to no fluid bolus did not reduce the incidence of cardiovascular collapse when analyzed as a binary outcome or using win ratio. This abstract is funded by: None
Daley et al. (2026) studied this question.