Early Recognition of Lumbar Overdrainage by Lumboventricular Pressure Gradient

BACKGROUND: Lumbar drainage (LD) represents a promising treatment strategy for prevention of vasospasm after aneurysmal subarachnoid hemorrhage (SAH). OBJECTIVE: To report on transient herniation caused by lumbar overdrainage in 3 patients with severe SAH who were treated with early LD within an ongoing feasibility study. METHODS: Patients with first-time aneurysmal SAH received LD within 72 hours of symptom onset, after aneurysm clipping or coiling. LD, with a target drainage amount of 5 to 10 mL, was continued for 6 to 9 days. External ventricular drainage (EVD) was begun on admission when hydrocephalus was present. With both catheters in place, intracranial pressure (ICP) and lumbar pressure (LP) were monitored simultaneously. RESULTS: Three of 22 patients developed a progressive lumboventricular pressure gradient, likely due to cerebrospinal fluid (CSF) overdrainage. Two patients showed signs of herniation. Clamping of LD resulted in complete reversal of symptoms in those patients. The lumboventricular pressure gradient began to evolve at least 12 hours before clinical symptoms developed, and gradually disappeared in all 3 patients after LD clamping. CONCLUSION: Lumbar overdrainage should be avoided in severe SAH, and lumboventricular pressure measurement may be a useful monitoring tool. Herniation due to lumbar overdrainage is a feared complication that can be avoided by following a strict LD management protocol.