A New Solution for Life Without Blood

Background The benefits of hypothermia for preventing ischemic injury are well known, but its application in surgery to protect the whole body during procedures requiring circulatory arrest is currently limited to Methods and Results With the use of extracorporeal cardiac bypass, 14 adult dogs were exsanguinated during cooling; 11 dogs were blood substituted using in combination the “purge” and “maintenance” solutions (group 1), and 3 dogs were perfused throughout with the “purge” solution alone as controls (group 2). After cardiac arrest, the solutions were continuously circulated for 3 \batchmode \documentclass[fleqn,10pt,legalpaper]{article} \usepackage{amssymb} \usepackage{amsfonts} \usepackage{amsmath} \pagestyle{empty} \begin{document} \(\frac{1}{2}\) \end{document} hours by the extracorporeal pump (flow rate, 40 to 85 mL · kg −1 · min −1 ; mean arterial blood pressure, 25 to 40 mm Hg). The temperature was maintained at P P P =.03), and for CK-BB, the group 1 value was 108±22 versus 617±154 for group 2 ( P =.03). Neurological evaluation using deficit scores (NDS) was based on a modification of the Glasgow Coma Scale score: 0, normal; 1, minimal abnormality; 2, weakness; 3, paralysis; 4, coma; and 5, death. At days 1 and 2 after surgery, NDS (mean±SEM) were 0±0 for the experimental group versus 1.5±0.5 for the control group. At days 3 and 7 after surgery, NDS were 0±0 for group 1 versus 1.0±1.0 for group 2. Conclusions The faster neurological recovery of dogs treated with the “intracellular-type” maintenance solution supports the biochemical data showing the benefits of this type of blood substitute for extending the safe limits of hypothermic cardiac arrest procedures to >3 hours.