Transcranial Doppler Assessment of the Cerebral Hemodynamic Effect of Cardiopulmonary Resuscitation in Fatal Cardiac Arrest

The intracranial circulation of 22 patients who had nontraumatic fatal cardiac arrest was monitored using transcranial Doppler (TCD) ultrasound during cardiopulmonary resuscitation (CPR). The internal carotid artery (ICA) was most easily accessible with the least amount of artifact. The duration of the cardiac arrests varied from 6 to 70 minutes (mean, 63), and the TCD‐monitoring time from 1 to 33 minutes (mean, 9). Maximal ICA mean velocities obtained during CPR ranged between 8 and 66 cmjsec (mean, 38) while minimal mean velocities varied between 2 and 22 cmjsec (mean, 12). Although 3 patients developed spontaneous cardiac rhythm during TCD monitoring, all died. Minute‐to‐minute comparison of ICA mean velocities obtained during the last 1 0 minutes of arrest monitoring showed a statistically significant difference following a deeremental trend (p = 0.05). In patients undergoing CPR, cerebral blood flow velocities as measured by TCD decrease progressively. In addition, changes in Doppler waveform suggest this decrease is secondary to progressively increased flow resistance. The clinical and prognostic significance of these findings awaits definition.