Intraoperative Changes in Cerebrospinal Fluid Gas Tensions Reflect Paraplegia During Thoracoabdominal Aortic Surgery: A Proof-of-Principle Study.

BACKGROUND In this study, gas tensions in cerebrospinal fluid (CSF) were prospectively evaluated as intraoperative markers for the detection of neurological deficits. METHODS Spinal fluid, serum, and heart lung machine (HLM) perfusate were monitored for gas tensions (po 2/pCo 2) and related parameters (pH, lactate, and glucose) during thoracoabdominal aortic repair and correlated with perioperative neurological examination and electrophysiological testing. RESULTS Forty-seven patients were assessed for the study, and 40 consecutive patients were finally included. The patients were divided into 3 groups: group A (23 patients, 57.5%): no clinical or laboratory signs of neurological damage; group B (14 patients, 35%) who developed subclinical deficits; and group C (3 patients, 7.5%) who had paraplegia. Significant intraoperative changes in CSF gas tensions were observed with postoperative paraplegia. Glucose ratio between serum and CSF showed higher variability in group C, confirming a damage of the blood-brain barrier (BBB). CONCLUSION Major neurological damage is reflected by early changes in CSF gas tensions and glucose variability, suggesting damage of the BBB in these patients.