A comparison of complete blood replacement with varying hematocrit levels on neurological recovery in a porcine model of profound hypothermic (<5 degrees C) circulatory arrest.


Journal Article

Profound hypothermia (<5 degrees C) may afford better neurological protection after circulatory arrest; however, there are theoretical concerns related to microcirculatory sludging of blood components at these ultra-low temperatures. We hypothesized that at temperatures <5 degrees C, complete blood replacement results in superior neurological outcome. Twelve Yorkshire pigs (30 kg) underwent thoracotomy, cardiopulmonary bypass (CPB), and were randomly assigned to one of three target hematocrits during circulatory arrest: 0%, 5%, 15%. Hextend (6% hetastarch in a balanced electrolyte vehicle) was used for the CPB prime and as an exchange fluid. Animals were cooled to a temperature <5 degrees C, underwent 1-h circulatory arrest, and were warmed to 35 degrees C with administration of blood to increase the hematocrit to >25% before separation from CPB. The primary outcome, peak postoperative neurobehavioral score, was compared between groups. The 0% group (mean +/- SD) had significantly (P: < 0.02) better neurobehavioral scores than the 5% and 15% groups (6.0 +/- 2.9 vs 1.3 +/- 1.0 and 1.5 +/- 0.6) respectively. Other variables (e.g., intracranial pressure) were similar between groups. In a porcine model of profound hypothermia (<5 degrees C) and circulatory arrest, complete blood replacement resulted in superior neurological outcome. This finding suggests that at ultralow temperatures, the presence of some blood component (e.g., erythrocytes, leukocytes) may be deleterious.

Full Text

Cited Authors

  • Sekaran, P; Ehrlich, MP; Hagl, C; Leavitt, ML; Jacobs, R; McCullough, JN; Bennett-Guerrero, E

Published Date

  • February 2001

Published In

Volume / Issue

  • 92 / 2

Start / End Page

  • 329 - 334

PubMed ID

  • 11159225

Pubmed Central ID

  • 11159225

Electronic International Standard Serial Number (EISSN)

  • 1526-7598

International Standard Serial Number (ISSN)

  • 0003-2999

Digital Object Identifier (DOI)

  • 10.1097/00000539-200102000-00008


  • eng