Complications from Multimodal Monitoring Do not Affect Long-Term Outcomes in Severe Traumatic Brain Injury

Background: Invasive neuromonitoring is a mainstay of modern management of severe traumatic brain injury (TBI). Complication rates of neuromonitor placement are widely reported, but their effects on long-term outcomes are less studied. We evaluated the association of neuromonitor complications on long-term outcomes in a prospective severe TBI cohort. Methods: We reviewed 599 patients with severe TBI from November 2002 through 2018 for neuromonitor-associated hemorrhage and infection. We compared outcome differences between patients with and without neuromonitoring-associated complications using the Glasgow Outcomes Scale (GOS) at 3, 6, 12, and 24 months post trauma. When analyzing neuromonitoring infections, we removed all patients who expired before discharge as early mortality was associated with reduced infection rates. Results: Neuromonitor-associated hemorrhage occurred in 62 out of 534 patients with post placement imaging (11.6%) and was increased in patinets who underwent a craniotomy (24% vs. 11%, P = 0.005). Clinical outcomes did not differ in patients with neuromonitor-associated hemorrhage. Neuromonitor-associated infection occurred in 30 of 389 patients (7.7%) who survived to discharge. Infection was associated with worse outcomes at 3 months (P = 0.03), where the proportion of patients with favorable outcomes (P = 0.02) was decreased despite similar mortality (P = 0.24). Patients with an infection recovered by 6 months, at which point there were no differences in total GOS or rates of favorable outcomes then or at later time points (P > 0.26). Neuromonitor-associated infection was associated with increased length of stay (P = 0.01) and depressed skull fractures (P = 0.03) but did not affect rates of shunting (P = 0.99). Conclusions: Complications of neuromonitoring in severe TBI are associated with delayed recovery but not long-term outcomes.