Maximisation of cerebral blood flow during experimental cardiopulmonary resuscitation does not ameliorate post-resuscitation hypoperfusion

Continuous intra-aortic balloon occlusion has been reported to improve cere bral blood flow during cardiopulmonary resuscitation (CPR) but not to ameli orate the impaired blood recirculation occurring after restoration of spont aneous circulation (ROSC). Volume expansion with hypertonic solutions may i mprove recovery of brain function by enhancing post-resuscitation cerebral blood flow. We hypothesised that the combination of these treatments with o pen-chest CPR would improve cerebral blood flow during CPR, and attenuate p ost-resuscitation flow disturbances. In 32 anaesthetised piglets, catheters were placed for haemodynamic and blood gas monitoring. Open-chest CPR was initiated after 9 min of ventricular fibrillation. The piglets were treated either with 3 ml kg(-1) hypertonic saline and dextran (HSD) (n = 10), HSD and balloon occlusion (n = 10) or with normal saline (n = 12). After 7 min of CPR, internal defibrillatory shocks were administered to restore spontan eous circulation. Haemodynamic variables, continuous cerebral cortical bloo d flow, cerebral tissue pH and pCO2 and blood gas parameters were measured during CPR and up to 210 min after ROSC. Higher cerebral perfusion pressure was found in the balloon-HSD group during CPR. This group exhibited less a rterial hypertension immediately after ROSC compared with the other groups. Thereafter, a fairly rapid decrease of the perfusion pressures was observe d in all groups reaching a minimum level approximately 30 min after ROSC. C erebral cortical blood flow was significantly higher and cerebral oxygen ex traction ratio significantly lower in the balloon-HSD group during CPR, but not after ROSC. In conclusion, a combination of intra-aortic balloon occlu sion and HSD administration improves cerebral blood flow and brain oxygen s upply during experimental open-chest CPR. In contrast, cerebral blood flow after ROSC was not shown to be influenced by this treatment. (C) 1999 Elsev ier Science Ireland Ltd. All rights reserved.