Meta-analysis Comparing Continuous and Intermittent Cerebrospinal Fluid Drainage in Aneurysmal Subarachnoid Hemorrhage

Objective: Patients who develop hydrocephalus following aneurysmal subarachnoid hemorrhage (aSAH) often require an external ventricular drain (EVD) for intracranial hypertension management. Continuous cerebrospinal fluid (CSF) drainage was initially hypothesized to be more beneficial than intermittent drainage in these patients as a result faster of “spasmogen” and blood clot clearance and consequent reduction in vasospasm, ventriculitis, shunt-dependency and other morbidities. However, recent evidence has not demonstrated this benefit. In this study, we performed a meta-analysis of existing data comparing the incidence of complications in continuous and intermittent CSF drainage in hydrocephalus after aSAH.

Method: We systematically searched the PUBMED and MEDLINE databases for studies discussing complications related to continuous and intermittent CSF drainage in patients with EVD for hydrocephalus following aSAH. We used meta-analysis to combine the data and to calculate an overall odds ratio (OR) for each complication comparing patients continuously drained to those who were intermittently drained.

Results: We identified nine applicable studies. Four of these presented data that allowed for OR calculation and inclusion in our meta-analysis. Overall, continuous drainage conferred significantly increased odds of any complication relative to intermittent drainage (OR 3.51, 95% CI 1.44–8.53). When complications were analyzed individually, continuous drainage only increased odds of EVD obstruction compared with intermittent drainage (OR 4.05, 95% CI 1.48–11.12). Continuous drainage did not increase ventriculitis (OR 2.20, 95% CI 0.76–6.35), shunt dependency (OR 1.39, 95% CI 0.51–3.82), vasospasm (OR 0.77, 95% CI 0.32–1.87), catheter self-removal by the patient (OR 1.09, 95% CI 0.23–5.20), death (OR 2.36, 95% CI 0.56–9.96), or CSF leak or hemorrhage (OR 4.31, 95% CI 0.47–39.4) relative to intermittent drainage. Furthermore, the majority of evidence in our review demonstrated no added benefit conferred by continuous drainage that may offset the increased morbidity it imposes. Continuous drainage does not significantly decrease peak CSF pressure, total CSF volume drained, ICU stay, hospital stay, EVD dwell time, or disability upon discharge.

Conclusion: In patients who necessitate an EVD for hydrocephalus following aSAH, continuous drainage of the CSF is associated with more morbidity when compared with intermittent drainage and does not provide significant benefits over intermittent drainage. For this reason, intermittent drainage is favorable in these patients.