Brain oxygen metabolism may relate to the temperature gradient between the jugular vein and pulmonary artery after cardiopulmonary resuscitation.
OBJECTIVE
A gradient between the jugular vein temperature and core body temperature has been reported in animal and clinical studies; however, the pathophysiological meaning of this phenomenon remains unclear. This study was conducted to identify the temperature gradient between the jugular vein and pulmonary artery in comatose patients after cardiopulmonary resuscitation.


MATERIALS AND METHODS
The temperatures of the jugular vein and pulmonary artery were measured in 19 patients at 6 and 24 hours after cardiopulmonary resuscitation. Jugular venous blood saturation (SjO2; %) was also measured concomitantly. The patients were divided into 2 groups: high SjO2 (SjO2 > 75%: H-group; n = 10) and normal SjO2 (SjO2 < or = 75%: N-group; n = 9). The temperature gradient was calculated by subtracting the temperature of the pulmonary artery from that of the jugular vein (jugular - pulmonary = dT degrees C). Statistical significance was defined as p < 0.05.


RESULTS
dT was significantly lower in the H-group than in the N-group at 6 hours (0.120 +/- 0.011: mean +/- SD vs. 0.389 +/- 0.036: p = 0.0012) and 24 hours (0.090 +/- 0.005 vs. 0.256 +/- 0.030: p = 0.0136) after cardiopulmonary resuscitation.


CONCLUSION
The temperature gradient between the jugular vein and pulmonary artery was significantly lower in patients with high SjO2 after cardiopulmonary resuscitation. This temperature gradient may be reflected in brain oxygen metabolism.