[Catecholamine levels in plasma and cerebrospinal fluid of neurosurgical patients with normal and elevated intracranial pressure].

Objective: Catecholamine levels in the plasma and cerebrospinal fluid of 21 neurosurgical patients with hydrocephalus and with normal and elevated intracranial pressure were determined prospectively in a clinical study.

Methods: The study comprised 11 patients with normal intracranial pressure (8 female, 3 male, group 1) and 10 patients with elevated intracranial pressure (6 female, 4 male, group 2). The patients underwent a ventriculo-peritoneal shunt operation, external ventricular drainage or ventriculocisternostomy. The measuring times were set as follows: time 1: pre-operative; time 2: intra-operative; time 3: post-operative. The anaesthetic for the operations was administered as a total intravenous anaesthesia with propofol and alfentanil, muscle relaxation being achieved with rocuronium bromide or cis-atracurium.

Results: Measurements of the catecholamine levels (adrenaline, noradrenaline and dopamine) at the three set times revealed an intra-operative fall compared to the initial pre-operative value and a rise in the catecholamine level again after the operation. It is likely that this largely reflects the course of the anaesthetic. The fall in the plasma catecholamine level was much slighter in group with elevated intracranial pressure. But in the group of patients with elevated intracranial pressure the catecholamine levels found in the plasma were much higher than those of the patients without elevated pressure. In the case of adrenaline, it was possible to demonstrate a statistically significant difference at the three measuring times. This suggests that especially the analyzed adrenaline level in the plasma could take on the role of a marker in cases of elevated intracranial pressure. In group 2, with elevated intracranial pressure, the catecholamine levels in the cerebrospinal fluid (CSF) were considerably higher than those in group 1, but the difference did not reach the significance level. The lack of correlation between the catecholamine values in the plasma and CSF described in the literature (comparison of the corresponding values at time 2) was confirmed for noradrenaline and dopamine in patients with elevated intracranial pressure (group 2). In both groups of patients there was a CSF plasma gradient for dopamine at time 2, i. e. the dopamine level was higher in cerebrospinal fluid than in the plasma.

Conclusion: The study shows that even a slight rise in intracranial pressure without clinically detectable ischaemia may result in elevated plasma and CSF catecholamine levels. Although catecholamine values are not routine parameters, they can be used in developing procedures to protect the brain in neurosurgical patients.