Prediction Of Cerebral Outcome Research Articles

Prognostic significance of the difference between mixed venous and jugular bulb oxygen saturation in comatose patients resuscitated from a cardiac arrest

To determine the prognostic significance of the difference between mixed venous and jugular bulb oxygen saturation in survivors and non-survivors of a cardiac arrest, we studied 30 comatose patients (21 non-survivors and 9 survivors) resuscitated from a cardiac arrest. We measured mixed venous oxygen saturation (SmvO 2) and jugular bulb oxygen saturation (SjO 2) immediately after haemodynamic stabilisation (always within 6 h after cardiac arrest) and 6, 12 and 24 h later. In all patients the SjO 2 was about 10% lower than the SmvO 2 in the first measurement. In the survivors the SjO 2 did not change and remained lower than SmvO 2 in eight of nine survivors. However, in the non-survivors the SjO 2 increased significantly and was finally higher than the SmvO 2 in 12 of 20 patients 24 h after cardiac arrest suggesting a decrease in cerebral oxygen consumption due to extensive loss of functional brain tissue. The positive predictive value of (SmvO 2−SjO 2)≤0 for predicting irreversible brain damage at 24 h after cardiac arrest is 93% and the negative predictive value of (SmvO 2−SjO 2)>0 is 53%. Sensitivity and specificity are 65 and 89%, respectively. In a previous study we concluded that early jugular bulb oximetry (within 4 h after cardiac arrest) cannot predict cerebral outcome in comatose patients after cardiac arrest. More studies are needed to clarify the role of prolonged monitoring in the prediction of cerebral outcome after cardiac arrest.

Prediction of cerebral outcome after extracorporeal circulation.

50 open-heart patients were investigated using simultaneous clinical, electroencephalographical (EEG) and neuropsychological evaluation in order to assess the possibilities of predicting the postoperative outcome with preoperative measures. The presence of one or more of the following indices was prognostically unfavourable: a history of cerebrovascular diseases or syncope; delta or sharp wave EEG abnormalities or low quantitative EEG mean frequency; a poor performance score in one of the psychometric tests (colour naming). Using these measures, 28 cases with presumably high risks were indicated, and 24 (86%) sustained cerebral complications attributable to the operation. The observations contrast clearly with previous studies whose predictions, using only one single criterion, have proved invalid. A significant level of prediction seems to be obtainable, but only by the simultaneous consideration of several different cerebral functions. The prognostic approach may offer one way of achieving the necessarily needed improved cerebral safety in cardiac surgery.