Does Nimodipine Interruption due to High Catecholamine Doses Lead to a Greater Incidence of Delayed Cerebral Ischemia in the Setting of Aneurysmal Subarachnoid Hemorrhage?

BACKGROUND

Current guidelines recommend the administration of nimodipine for the prevention of delayed cerebral ischemia (DCI) after aneurysmal subarachnoid hemorrhage (aSAH). However, nimodipine can lead to significant drops in mean arterial pressure and cerebral perfusion pressure. Catecholamines are then used to maintain them while nimodipine is reduced and/or held. There is no evidence that nimodipine retains its neuroprotective effect at lower doses. We aimed to investigate the role of nimodipine interruption in the setting of aSAH and its possible impact on the incidence of DCI.

METHODS

We performed a retrospective analysis in patients with aSAH admitted to our center from January 2012 to October 2015. Nimodipine prophylaxis duration and dosage and the incidence of DCI were recorded. Bivariate correlation with Spearman's rho (ρ) and ordinal regression analyses were performed.

RESULTS

A total of 170 patients were included in the study. Of these, 165 (97.1%) received nimodipine prophylaxis starting on day 0. Nimodipine was interrupted in 85 of 165 (51.5%), whereas dose was reduced in 47 of 165 (28.5%); full dose was received by only 33 of 165 (20%). DCI was observed in 85 of 170 (50%). Nimodipine interruption correlated in a statistically significant way with a greater incidence of DCI (ρ = 0.431, P < 0.001); receiving full doses of nimodipine showed a statistically significant inverse correlation to DCI (ρ = -0.273, P < 0.001). Ordinal regression analysis revealed nimodipine interruption as a statistically significant independent predictor of DCI (odds ratio 0.194; 95% confidence interval 0.079-0.474, P < 0.001).

CONCLUSIONS

Our analysis reveals a greater incidence of DCI in patients with aSAH when nimodipine is interrupted.