Hands-free continuous carotid Doppler ultrasound for detection of the pulse during cardiac arrest in a porcine model

Bjørn Ove Faldaas; Erik Waage Nielsen; Benjamin Stage Storm; Knut Tore Lappegård; Ole-Jakob How; Bent Aksel Nilsen; Gabriel Kiss; Eirik Skogvoll; Hans Torp; Charlotte Ingul

doi:10.1016/j.resplu.2023.100412

Hands-free continuous carotid Doppler ultrasound for detection of the pulse during cardiac arrest in a porcine model

Resusc Plus. 2023 Jun 20:15:100412. doi: 10.1016/j.resplu.2023.100412. eCollection 2023 Sep.

Authors

Bjørn Ove Faldaas^{1

2}, Erik Waage Nielsen^{2

3

4

5}, Benjamin Stage Storm^{2

3

4

6}, Knut Tore Lappegård^{3

7}, Ole-Jakob How⁸, Bent Aksel Nilsen^{2

4}, Gabriel Kiss⁹, Eirik Skogvoll^{1

10}, Hans Torp¹, Charlotte Ingul^{1

2}

Affiliations

¹ Department of Circulation and Medical Imaging, Norwegian University of Science and Technology (NTNU), Trondheim, Norway.
² Faculty of Nursing and Health Sciences, Nord University, Bodø, Norway.
³ Department of Clinical Medicine, Faculty of Health Sciences, UiT the Arctic University of Norway, Tromsø, Norway.
⁴ Department of Anesthesia, Surgical Clinic, Nordland Hospital Trust, Bodø, Norway.
⁵ Department of Immunology, Oslo University Hospital, University of Oslo, Oslo, Norway.
⁶ Research Laboratory, Nordland Hospital Trust, Bodø, Norway.
⁷ Department of Medicine, Nordland Hospital Trust, Bodø, Norway.
⁸ Department of Medical Biology, Faculty of Health Sciences, UiT the Arctic University of Norway, Tromsø, Norway.
⁹ Department of Computer Science (IDI), Faculty of Information Technology and Electrical Engineering, Norwegian University of Science and Technology (NTNU), Trondheim, Norway.
¹⁰ Clinic of Anesthesia and Intensive Care Medicine, St Olav University Hospital, Trondheim, Norway.

Abstract

Background/purpose: Pulse palpation is an unreliable method for diagnosing cardiac arrest. To address this limitation, continuous hemodynamic monitoring may be a viable solution. Therefore, we developed a novel, hands-free Doppler system, RescueDoppler, to detect the pulse continuously in the carotid artery.

Methods: In twelve pigs, we evaluated RescueDoppleŕs potential to measure blood flow velocity in three situations where pulse palpation of the carotid artery was insufficient: (1) systolic blood pressure below 60 mmHg, (2) ventricular fibrillation (VF) and (3) pulseless electrical activity (PEA). (1) Low blood pressure was induced using a Fogarty balloon catheter to occlude the inferior vena cava. (2) An implantable cardioverter-defibrillator induced VF. (3) Myocardial infarction after microembolization of the left coronary artery caused True-PEA. Invasive blood pressure was measured in the contralateral carotid artery. Time-averaged blood flow velocity (TAV) in the carotid artery was related to mean arterial pressure (MAP) in a linear mixed model.

Results: RescueDoppler identified pulsatile blood flow in 41/41 events with systolic blood pressure below 60 mmHg, with lowest blood pressure of 19 mmHg. In addition the absence of spontaneous circulation was identified in 21/21 VF events and true PEA in 2/2 events. The intraclass correlation coefficient within animals for TAV and MAP was 0.94 (95% CI. 0.85-0.98).

Conclusions: In a porcine model, RescueDoppler reliably identified pulsative blood flow with blood pressures below 60 mmHg. During VF and PEA, circulatory arrest was rapidly and accurately demonstrated. RescueDoppler could potentially replace unreliable pulse palpation during cardiac arrest and cardiopulmonary resuscitation.

Keywords: Cardiac arrest monitor; Carotid artery blood flow; Doppler ultrasound; Experimental model; PEA; Ventricular fibrillation.