Lumber drainage may improve subarachnoid hemorrhage outcomes
MedWire News: Lumber drainage of cerebrospinal fluid (CSF) in patients with subarachnoid hemorrhage (SAH) improves early but not late outcomes relative to standard care, show study results.
"The lack of significant difference in long-term outcome in the current study and the demonstrable safety of lumbar drainage in this setting would support a future study investigating longer periods of drainage with larger volumes of drainage to determine if this increases the beneficial effects of lumbar drainage," the researchers write in Stroke.
The current study included 210 patients with aneurysmal SAH (166 women, median age 54 years) who had World Federation of Neurological Surgeons grades of 1-3. The team excluded patients with grades 4-5 because of the "potential safety issues of lumbar drainage in comatose patients," as well as the difficulty in diagnosing delayed ischemic neurologic deficit (DIND) in these patients.
CSF was drained until it became clear; the average amount drained was 134 mL per 24 hours and the average duration of drainage was 5.0 days.
The primary outcome was the occurrence of DIND, defined as a decrease in consciousness or a new focal neurologic deficit appearing at least 96 hours after SAH. This affected 35.2% of patients given standard care versus 21.0% of those who underwent lumbar drainage, which was a significant difference.
At 10 days, significantly more patients in the drainage than standard care group had good functional outcomes, defined as a modified Rankin Scale score of 0-2, at 55.2% versus 37.5%.
Yahia Al-Tamimi (Leeds General Infirmary, UK) and co-workers say that lumbar drainage may benefit patients by reducing the blood load. "Supporting this hypothesis is the finding that lumbar drains conferred the most benefit to patients with Fisher Grade 3 [aneurysmal] SAH," they say.
But they add that it could also work by reducing intracranial pressure (ICP). "Although drainage of CSF was volume-driven, ICP was likely to have been lowered by the volumes of CSF drained through the lumbar cistern."
Indeed, the team notes that lumbar drainage was associated with "immediate improvements" in the severity of most patients' headaches.
However, the benefits in early clinical outcomes did not translate to improved outcomes at 6 months, at which point 80.2% of patients in the lumbar drainage group and 81.4% of those in the standard care group had good functional outcomes.
The researchers therefore recommend a larger trial, saying: "Although results cannot be extrapolated outside of the study cohort, there is no reason to suggest that poor-grade patients with [aneurysmal] SAH (Grades 4-5) would not benefit from lumbar drainage.
"Patients of poor grade are more likely to have higher blood loads and a higher ICP. They are, however, also more likely to have an intracerebral and extensive intraventricular hemorrhage, which raises the issue of safety."
By Eleanor McDermid