Dialysis Disequilibrium Syndrome and Intracranial Pressure Fluctuations in Neurosurgical Patients Undergoing Renal Replacement Therapy: Systematic Review and Pooled Analysis

Dialysis disequilibrium syndrome is a rare, well-known, potentially life-threatening complication of renal replacement therapy (RRT), often involving cerebral edema and increased intracranial pressure (ICP). However, the impact of RRT on ICP and rate of dialysis disequilibrium syndrome in neurosurgical patients have not been systematically assessed. In February 2022, a systematic review following PRISMA guidelines was conducted using various combinations of 9 keywords in the MEDLINE database. Eleven papers were selected. Individual patient data were extracted, pooled, and analyzed. Fifty-eight patients, 44 men and 14 women with a mean age of 48 years (6–78 years), were analyzed. Neurosurgical conditions included the following: spontaneous intracranial hemorrhage (n = 27), traumatic brain injury (n = 16), ischemic stroke/anoxic brain injury (n = 6), intracranial tumor (n = 6), and others (n = 3). Neurosurgical interventions included the following: craniotomy/craniectomy (n = 23), external ventricular drain or ICP monitor placement (n = 16), and burr hole or twist drill craniostomy (n = 4). Intermittent dialysis was used in 33 patients, continuous RRT in 20, and a combination thereof in 4. During RRT, ICP increased in 35 patients (60.3%), remained unchanged in 20, and decreased in 3. Thirty-four patients (65.4%) died. Intermittent dialysis was associated with increased ICP (73% vs. 37.5%, P = 0.01) and mortality (75% vs. 39.1%, P = 0.01). In neurosurgical patients, ICP increases during RRT are common, affecting up to 60%, and potentially life-threatening, with mortality rates as high as 65%. The use of a continuous rather than intermittent RRT technique may reduce the risk of this complication. Prospective studies are warranted.