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))less than or equal to 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. (C) 1999 Elsevier Science Ireland Ltd. All rights reserved.