Implementation of a point-of-care ultrasound archiving system and governance framework in a UK physician-paramedic staffed helicopter emergency medical service.

INTRODUCTION: There has been a rapid expansion in the use of point-of-care ultrasonography (POCUS) by emergency medical services (EMS). However, less than a third of UK EMS utilise imaging archiving for POCUS, and fewer review saved images as part of a clinical governance structure. This paper describes the implementation of a novel image archiving system and a robust clinical governance framework in our UK physician-paramedic staffed helicopter emergency medical service (HEMS). METHODS: A retrospective database review was conducted of all patients attended by East Anglian Air Ambulance (EAAA) between the introduction of a new POCUS device and image archiving system on 1 December 2020 to 31 January 2024. All patients with recorded POCUS examinations were included. Images from POCUS examinations at EAAA are archived on a cloud-based server, and retrospectively reviewed within 24 h by an EAAA POCUS supervisor. Image quality is graded using a 5-point Likert-type scale, agreement between reviewer and clinician is recorded and feedback is provided on scanning technique. T-tests were used to assess the difference in image quality between physicians and paramedics. Inter-rater reliability between reviewers and clinicians was assessed using Cohen's kappa (κ). RESULTS: During the study period, 5913 patients were attended by EAAA. Of these, 1097 patients had POCUS images recorded. The prevalence of POCUS during the study period was 18.6%. 1061 patient examinations underwent quality assurance (96.7%). The most common POCUS examination was echocardiography (60%), predominantly during cardiac arrest. The primary scanning clinician was a paramedic in 25.4% of POCUS examinations. Across all examination types; image quality was not significantly different between physicians and paramedics and agreement between reviewers and clinicians was strong (κ > 0.85). CONCLUSIONS: In this service evaluation study, we have described outcomes following the introduction of a new POCUS device, image archiving system and governance framework in our HEMS. Paramedics were the primary scanning clinician in a quarter of scans, with image quality comparable to physicians. Almost all scans underwent quality assurance and inter-rater reliability was strong between clinicians and reviewers. Further research is required to investigate the diagnostic accuracy of POCUS and to demonstrate the effect of utilising prehospital POCUS to refine diagnosis on clinical outcomes.

Prehospital invasive arterial blood pressure monitoring in critically ill patients attended by a UK helicopter emergency medical service- a retrospective observational review of practice.

BACKGROUND: Accurate haemodynamic monitoring in the prehospital setting is essential. Non-invasive blood pressure measurement is susceptible to vibration and motion artefact, especially at extremes of hypotension and hypertension: invasive arterial blood pressure (IABP) monitoring is a potential solution. This study describes the largest series to date of cases of IABP monitoring being initiated prehospital. METHODS: This retrospective observational study was conducted at East Anglian Air Ambulance (EAAA), a UK helicopter emergency medical service (HEMS). It included all patients attended by EAAA who underwent arterial catheterisation and initiation of IABP monitoring between 1st February 2015 and 20th April 2023. The following data were retrieved for all patients: sex; age; aetiology (medical cardiac arrest, other medical emergency, trauma); site of arterial cannulation; operator role (doctor/paramedic); time of insertion and, where applicable, times of pre-hospital emergency anaesthesia, and return of spontaneous circulation following cardiac arrest. Descriptive analyses were performed to characterise the sample. RESULTS: 13,556 patients were attended: IABP monitoring was initiated in 1083 (8.0%) cases, with a median age 59 years, of which 70.8% were male. 546 cases were of medical cardiac arrest: in 22.4% of these IABP monitoring was initiated during cardiopulmonary resuscitation. 322 were trauma cases, and the remaining 215 were medical emergencies. The patients were critically unwell: 981 required intubation, of which 789 underwent prehospital emergency anaesthesia; 609 received vasoactive medication. In 424 cases IABP monitoring was instituted en route to hospital. CONCLUSION: This study describes over 1000 cases of prehospital arterial catheterisation and IABP monitoring in a UK HEMS system and has demonstrated feasibility at scale. The high-fidelity of invasive arterial blood pressure monitoring with the additional benefit of arterial blood gas analysis presents an attractive translation of in-hospital critical care to the prehospital setting.