Circulation
-
Recent studies have demonstrated that for the same chest compression force during mechanical cardiopulmonary resuscitation (CPR), the carotid artery-to-jugular vein pressure gradient and carotid blood flow are increased when the phasic rise of intrathoracic pressure is enhanced by abdominal binding and simultaneous ventilation at high airway pressure with each chest compression (SCV). The objective of the present study was to assess whether cerebral blood flow is also enhanced, since it is known that fluctuations in intrathoracic pressure are transmitted to the intracranial space and affect intracranial pressure (ICP). In two series of pentobarbital-anesthetized dogs, one of two CPR techniques was initiated immediately after inducing ventricular fibrillation. ⋯ However, the net brain perfusion pressure gradient (carotid artery pressure - ICP) was greater with SCV (14 +/- 3 mm Hg) than with conventional CPR (5 +/- 0.4 mm Hg). Cerebral blood flow was significantly greater during SCV CPR (32 +/- 7% of prearrest cerebral flow) than during conventional CPR (3 +/- 2%). We conclude that SCV CPR combined with abdominal binding substantially improved brain perfusion by enhancing cerebral perfusion pressure in this experimental model.
-
We studied regional blood flow (QR) using radiolabeled microspheres and measured hemodynamic variables in 20 anesthetized dogs in normal sinus rhythm and during ventricular fibrillation treated with cardiopulmonary resuscitation (CPR). Nonsimultaneous compression and ventilation CPR (NSCV-CPR) was performed in seven dogs with a pneumatic piston that gave 50 chest compressions/min with an open airway with 10 ventilations at an airway pressure of 33 mm Hg interposed between each fifth and sixth compression. ⋯ Regional blood flow (mean +/- SD) to the cerebral hemispheres, cardiac ventricles, and kidneys, expressed as ml/min/100 g tissue, was 3.1 +/- 4.0, 3.4 +/- 3.3 and 1.5 +/- 1.5, respectively, during NSCV-CPR; 11.5 +/- 5.9, 4.9 +/- 4.7 and 2.7 +/- 2.7 during SCV-CPR (vest); and 16.2 +/- 7.2, 11.0 +/- 4.0 and 20.1 +/- 20.2 during SCV-CPR (piston) (all p less than 0.05 compared with NSCV-CPR). These results indicate that QR to all organs studied is reduced below normal sinus rhythm levels during CPR for ventricular fibrillation, QR to the brain is proportionately greater than QR to the heart and kidneys, and QR to the brain is greater with both forms of SCV-CPR than with NSCV-CPR.