Cerebrospinal fluid protein reactions during non-neurological surgery

Objective- To study changes in cerebrospinal fluid (CSF) protein markers of blood-CSF barrier integrity and immunological reactions during surgical stress. Methods- Thirty-five patients without neurological or psychiatric disorders undergoing knee replacements had CSF and serum samples drawn from spinal and arterial catheters before, 3 h after and the morning after surgery. Results- Serum albumin decreased during surgery and CSF albumin decreased during and after surgery, and, as a consequence, the CSF/serum albumin ratio decreased significantly during the study period, especially after the intervention. In contrast, CSF concentrations of beta-2-microglobuline (beta 2M) increased significantly during surgery and remained high. The CSF general marker beta-trace protein (beta TP) remained unchanged. Conclusins- Central nervous system protein reactions to a non-neurological surgical intervention include sharply decreased permeability of albumin into the CSF and signs of intrathecal inflammatory activity.