Effect of Push-Dose Adrenaline on Peri-intubation Hypotension During Rapid Sequence Intubation in the Emergency Department

Rapid sequence intubation is a standard advanced airway procedure used in emergency departments for critically ill patients who require rapid and secure airway control. Although this procedure is clinically necessary, it may be associated with peri-intubation hypotension, commonly defined as systolic blood pressure below 90 mmHg or mean arterial pressure below 65 mmHg during or after the intubation period. This hemodynamic deterioration may result from the patient's underlying critical illness, the cardiovascular effects of induction agents, reduced venous return after initiation of positive-pressure ventilation, or a combination of these factors.

Preventing hypotension during rapid sequence intubation is an important component of peri-intubation resuscitation. Intravenous fluids and vasopressor infusions are frequently used when hypotension develops, but these interventions may not always be fast enough to prevent early hemodynamic collapse. Push-dose vasopressors are used in emergency and critical care practice to provide short-term hemodynamic support. However, prospective randomized evidence regarding the preemptive use of push-dose adrenaline during emergency department rapid sequence intubation remains limited.

This is a single-center, prospective, randomized, double-blind, placebo-controlled trial conducted in the emergency department of Marmara University Pendik Training and Research Hospital. Adult patients undergoing rapid sequence intubation, who are hypotensive or considered to be at significant risk of hypotension, will be enrolled after informed consent is obtained from the patient or legally authorized representative when applicable.

Participants will be randomized in a parallel-group design to receive either 10 mcg intravenous adrenaline or 1 mL of 0.9% sodium chloride placebo immediately before the administration of induction agents. The intervention and placebo syringes will be identical in volume and appearance. Syringes will be prepared according to the randomization list by an independent non-blinded nurse who will not participate in clinical care, outcome assessment, or data collection. Treating physicians, participants, investigators, care providers, and outcome assessors will remain blinded to group allocation.

The decision to perform intubation, selection and dosing of induction and neuromuscular blocking agents, endotracheal tube size, and post-intubation management will be determined by the treating physician according to standard emergency department practice and current clinical guidance. Study procedures will not delay airway management or standard resuscitative care.

Hemodynamic variables, including systolic blood pressure, diastolic blood pressure, mean arterial pressure, and heart rate, will be recorded at baseline and during the first 60 minutes after intubation. The study will evaluate peri-intubation hypotension, changes in mean arterial pressure, post-intubation vasopressor requirements, new ventricular or supraventricular arrhythmias, reactive hypertension, cardiac arrest, and mortality at predefined time points. The planned enrollment is 128 participants.

• Change in mean arterial pressure from baseline [Time frame: Baseline, 1, 5, 10, 15, 30, 45, and 60 minutes after intubation]
• Change in heart rate from baseline [Time frame: Baseline, 1, 5, 10, 15, 30, 45, and 60 minutes after intubation]
• Post-intubation vasopressor requirement [Time frame: 1 hour and 24 hours after intubation]
• Adverse events [Time frame: Within 24 hours after intubation]