Pre-emptive Circulatory Support Before Emergency Tracheal Intubation: A Systematic Review

Emergency tracheal intubation is associated with peri-intubation cardiovascular collapse, and pre-emptive circulatory support is frequently used to mitigate this risk despite uncertain evidence.We conducted a systematic review of randomised and comparative non-randomised studies evaluating pre-emptive circulatory support initiated before or at induction in adults undergoing emergency or urgent tracheal intubation.Eligible interventions included prophylactic vasopressors, intravenous fluid boluses, hypertonic saline, blood products, deliberate circulation-first strategies, and multi-component care bundles.The primary outcome was peri-intubation cardiovascular collapse within 30 minutes of induction, defined according to individual study criteria.MEDLINE via PubMed, the Cochrane Central Register of Controlled Trials, Scopus, and Web of Science Core Collection were searched from inception to 30 August 2026, with additional searches of ClinicalTrials.govand citation lists.Risk of bias (RoB) was assessed using the Cochrane Risk of Bias 2 (RoB 2) tool for randomised trials and the Risk of Bias In Non-randomized Studies of Interventions (ROBINS-I) tool for non-randomised studies.Fourteen independent cohorts comprising two randomised trials and 12 comparative non-randomised studies, with more than 7,400 participants overall, were included.Two randomised trials evaluated a preemptive 500 mL crystalloid bolus and found no reduction in peri-intubation cardiovascular collapse.Observational evidence for prophylactic vasopressors was inconsistent, with substantial changes between crude and adjusted estimates and substantial concerns regarding confounding.Studies evaluating circulation-first strategies or pre-intubation blood products generally reported associations favouring earlier circulatory resuscitation, but these findings were strongly influenced by confounding and treatment selection.Multi-component care bundles were also associated with fewer peri-intubation complications, but the independent contribution of their circulatory components could not be determined.Overall, the available evidence indicates that pre-emptive crystalloid administration does not reduce periintubation cardiovascular collapse, while evidence for prophylactic vasopressors, circulation-first strategies, and multi-component interventions remains insufficient to support routine use.Further randomised trials are needed, particularly among physiologically high-risk adults.