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. CLINICAL TRIAL REGISTRATION: NCT04206566.

A Protocol for Helicopter In-Cabin Intubation.

OBJECTIVE: The gold standard for prehospital intubation is to avoid intubating in confined spaces. For our helicopter service, this is not always realistic. Operating in a rural region with a subarctic, cold climate, our crews are frequently forced to intubate inside ambulances or in our helicopter. This article describes a protocol for in-cabin intubation and compares it with standard open space conditions. METHODS: Fourteen prehospital physicians were randomized to solve a simplified clinical scenario during which they were to intubate a mannequin either inside the helicopter, in accordance with our in-cabin protocol, or outside on an ambulance stretcher. Participants scored intubating conditions using a visual analog scale (VAS) and the Cormack-Lehane classification. The number of intubation attempts was recorded. Three timing end points were also measured. RESULTS: All intubations were successful on the first attempt. All participants reported an optimal glottic view of Cormack-Lehane 1 in both scenario conditions. Participants perceived in-cabin intubation to be less difficult than intubating outdoors. (VAS 1 vs. VAS 2, P = .02). We found no difference in the duration of intubation. Scene time was 53.5 seconds (P = .04) shorter in the in-cabin group. In-cabin intubation delayed the establishment of a secure airway by 63 seconds (P = .01). CONCLUSION: Our study suggests that protocolized in-cabin intubation can be performed in a timely manner under conditions that are equal to or better than when intubating outside on a stretcher with 360-degree patient access. Although delaying the establishment of a secure airway, in-cabin intubation may reduce scene times.

Evaluation of hydration status calculated from differences in venous and capillary plasma dilution during stepwise crystalloid infusions: A randomized crossover study in healthy volunteers.

BACKGROUND AND OBJECTIVE: A mini volume loading test (mVLT) was proposed for estimating hydration status and interstitial fluid accumulation during stepwise infusion of crystalloids. The method is based on both the transcapillary reflux model and the hypothesis that when subjects are dehydrated, venous plasma dilution induced by a fluid challenge is higher than in the capillaries, and that difference is diminished when the fluid challenge is given to more hydrated individuals. Our objective was to test that hypothesis by evaluating the veno-capillary dilution difference during mVLT in subjects with different hydration status. MATERIALS AND METHODS: In a prospective randomized crossover study, three mini fluid challenges were given to 12 healthy volunteers on two occasions. The subjects were either dehydrated or hydrated before the experiments. RESULTS: In dehydrated subjects only, capillary plasma dilution was significantly lower than venous (P=0.015, 0.005 and 0.006) after each mini fluid challenge. CONCLUSIONS: Veno-capillary dilution difference during mVLT depends on the hydration status. The mVLT method could possibly discriminate between the different states of hydration.