Fig. 3.

Expanded view of cooling and arrest periods showing only key parameters. Notice that the measured rSO2 regional oxygenation index rises with falling temperature and returns quickly to near pre-arrest values after initiation of selective perfusion. However, this index does not approach zero during arrest, as might be expected if the drop in RSO2 was due to residual metabolism. At the beginning of circulatory arrest, BFI drops quickly to ~0, while RSO₂ decays more slowly.