Feasibility of profound hypothermia as part of extracorporeal life support in a pig model

J Thorac Cardiovasc Surg. 2017 Sep;154(3):867-874. doi: 10.1016/j.jtcvs.2017.03.055. Epub 2017 Mar 24.

Abstract

Objective: To investigate the feasibility of a refined aortic flush catheter and pump system to induce emergency preservation and resuscitation before extracorporeal cardiopulmonary resuscitation in a normovolemic cardiac arrest swine model simulating near real size/weight conditions of adults.

Methods: In this feasibility study, 8 female Large White breed pigs weighing 70 to 80 kg underwent ventricular fibrillation cardiac arrest for 15 minutes, followed by 4°C aortic flush (150 mL/kg for the brain; 50 mL/kg for the spine) via a new hardware ensued by resuscitation with extracorporeal cardiopulmonary resuscitation.

Results: Brain temperature was lowered from 39.9°C (interquartile range [IQR] 39.6-40.3) to 24.0°C (IQR 20.8-28.9) in 12 minutes (IQR 11-16) with a median cooling rate of 1.3°C (IQR 0.7-1.6) per minute. A median of 776 mL (IQR 673-840) per minute with a median pump pressure of 1487 mm Hg (IQR 1324-1545) were pumped to the brain.

Conclusions: With the new hardware, we were able to cool the brain within a few minutes in a large pig cardiac arrest model. The exact position; the design, diameter, and length of the flush catheter; and the brain perfusion pressure seem to be critical to effectively reduce brain temperature. Redistribution of peripheral blood could lead to sterile inflammation again and might be avoided.

Keywords: ECLS; EPR; cardiac arrest; eCPR; extracorporeal life support; hypothermia; preservation; resuscitation; target temperature management.

MeSH terms

  • Animals
  • Aorta*
  • Body Temperature
  • Brain Ischemia / prevention & control*
  • Catheters*
  • Epinephrine / administration & dosage
  • Equipment Design
  • Extracorporeal Membrane Oxygenation*
  • Feasibility Studies
  • Heart Arrest / therapy*
  • Heparin / administration & dosage
  • Hypothermia, Induced / instrumentation
  • Hypothermia, Induced / methods*
  • Infusions, Intra-Arterial
  • Models, Animal
  • Resuscitation / instrumentation
  • Resuscitation / methods
  • Sodium Chloride / administration & dosage
  • Swine
  • Vasopressins / administration & dosage

Substances

  • Vasopressins
  • Sodium Chloride
  • Heparin
  • Epinephrine