Detection of early ischemia in severe head injury by means of arteriovenous lactate differences and jugular bulb oxygen saturation. Relationship with CPP, severity indexes and outcome. Preliminary analysis.

UNLABELLED: Early ischemia may be highly relevant in patients with severe head injuries. The aims of the study were: 1) to define if abnormal arteriovenous lactate difference (AVDL) and jugular bulb oxygen saturation (SjO2) are found in the early 24 hrs post injury; 2) to compare if abnormalities of SjO2 and of AVDL were associated with a specific typology of severity indexes and outcome; 3) to detect any association between abnormal AVDL and SjO2 with levels of cerebral perfusion pressure (CPP). The study involved 29 patients, with CPP, AVDL and SjO2 measured within 24 hours post-injury.
RESULTS: 1) Abnormal AVDL was found in 21% while abnormal SjO2 was detected in 38% of the patients; 2) abnormal AVDL was associated with cases of most severe injury; 3) CPP level below 60 mmHg was associated with abnormal AVDL and SjO2. Low CPP appeared to be the most likely measurable cause of early ischemia. Abnormalities of AVDL appeared to be more sensitive, than SjO2, with regard to detection of the most severe cases.