Implementing prehospital invasive arterial blood pressure monitoring in critically ill patients-a prospective observational first year analysis.

Background: Exposure to hypotension is linked to increased morbidity and mortality. Invasive blood pressure (IBP) measurement might be superior to non-invasive blood pressure measurement in detecting hypotension. The feasibility of IBP in prehospital care for selected patients by specialized rescue teams has been demonstrated. Therefore, we tested the hypothesis that the implementation of prehospital IBP measurement is feasible in a German emergency system by emergency teams with limited exposure to critically ill patients.

Methods: This single center study was conducted with two emergency physicians vehicles. Indications for IBP measurement were adults requiring airway management, catecholamine therapy or fluid resuscitation. IBP was performed using either direct or Seldinger technique. Physicians recorded the puncture attempts, cannulation sites, and techniques. Patients with IBP attempt were visited the first three days to report complications. Emergency physicians documented a reason if they decided not to perform IBP. Data were analyzed to find operational differences between IBP attempts and no IBP attempts and IBP success and failure. Multiple linear regression was used to measure the influence of prehospital IBP attempts on the on-scene time.

Results: During the study period, 3887 emergency responses occurred, with 2.8% (n = 108) meeting IBP criteria. Reasons for an IBP were catecholamine therapy (74%), airway management (73%) and fluid resuscitation (51%). 68 (63%) of the patients meeting IBP criteria received an IBP attempt with a success rate of 88%. While difficult extrication (p = 0.002) and longer transportation time (p = 0.009) were associated with a high IBP attempt rate, IBP attempts in nursing homes were less often performed (p = 0.002). Most common reason for not performing IBP was a transport priority and poor puncturing condition. Multiple regression analysis showed IBP attempts prolonged the on-scene time by 7.4 min (p = 0.013).

Conclusions: Prehospital IBP can be performed safely even by teams with limited exposure to critically ill patients, with low failure and complication rates across a wide range of indications. Based on these data, IBP measurement prolonged the on-scene time by 7.5 min. Even though exposure to critically ill patients is rare, teams should consider performing an IBP if indicated.

Trial registration: Study was a part of the PHINIABP (PreHospital Invasive vs. Non-Invasive Blood Pressure) study and was registered with German Clinical Trials (ID DRKS00030477) and approved by the regional ethics committee (Ärztekammer Saarland, Saarbrücken, Germany, Identification Number 158/22, September 13, 2022). Written informed consent was obtained from patients or their legal representatives.