Prehospital tracheal intubations by anaesthetist-staffed critical care teams: a prospective observational multicentre study

Background Prehospital tracheal intubation is a potentially lifesaving intervention, but is associated with prolonged time on-scene. Some services strongly advocate performing the procedure outside of the ambulance or aircraft, while others also perform the procedure inside the vehicle. This study was designed as a non-inferiority trial registering the rate of successful tracheal intubation and incidence of complications performed by a critical care team either inside or outside an ambulance or helicopter. Methods This observational multicentre study was performed between March 2020 and September 2021 and involved 12 anaesthetist-staffed critical care teams providing emergency medical services by helicopter in Denmark, Norway, and Sweden. The primary outcome was first-pass successful tracheal intubations. Results Of the 422 drug-assisted tracheal intubations examined, 240 (57%) took place in the cabin of the ambulance or helicopter. The rate of first-pass success was 89.2% for intubations in-cabin vs 86.3% outside. This difference of 2.9% (confidence interval −2.4% to 8.2%) (two sided 10%, including 0, but not the non-inferiority limit Δ=−4.5) fulfils our criteria for non-inferiority, but not significant superiority. These results withstand after performing a propensity score analysis. The mean on-scene time associated with the helicopter in-cabin procedures (27 min) was significantly shorter than for outside the cabin (32 min, P=0.004). Conclusions Both in-cabin and outside the cabin, prehospital tracheal intubation by anaesthetists was performed with a high success rate. The mean on-scene time was shorter in the in-cabin helicopter cohort.