CLINICAL EVALUATION OF THE AUGMENTED DELTA QUOTIENT MONITOR FOR INTRAOPERATIVE ELECTROENCEPHALOGRAPHIC MONITORING OF CHILDREN DURING SURGERY AND CARDIOPULMONARY BYPASS FOR REPAIR OF CONGENITAL CARDIAC DEFECTS

To assess the augmented delta quotient (ADQ) monitor as a monitorof cerebral function during cardiac surgery, we monitored duringoperation the electroencephalograms of 48 young subjects (aged2 weeks to 19 yr). We found ADQ patterns produced by cardiopulmonarybypass, hypothermia and general anaesthetic agents correlatedwith those obtained from a compressed spectral array (CSA) monitorand could be differentiated from changes caused by cerebralischaemia, except in the youngest group of patients ( 18 months)undergoing deep hypothermia (19.4 (SD 0.8) °C nasopharyngeal).In all other age groups the ADQ proved to be a simple monitorof the adequacy of cerebral perfusion. Neurological deficitoccurred only if the ADQ was abnormal during hypotension fora period exceeding 7 min. ADQ evaluation of cerebral functionwas limited by events which produced artificially normal ADQreadings such as low amplitude EEG activity and the describedisoflurane effect that was demonstrated to occur in some cardiacpatients. The results obtained by the ADQ were comparable tothose obtained by compressed spectral array and the ADQ waseasier to use and interpret. ^*Present address: Department of Anaesthesia and Intensive Care,Basingstoke District Hospital, Basingstoke, Hants.