Early prediction of neurological outcome after barbiturate coma therapy in patients undergoing brain tumor surgery

Background: A rapidly increasing intracranial pressure (ICP) is a dangerous situation that can occur after delicate brain tumor surgery. We evaluated early predictor of clinical outcomes of barbiturate coma therapy (BCT) which was performed to prevent or control refractory intracranial hypertension (RICH) after brain tumor surgery, and the clinical characteristics based on neurological outcomes. Methods: Seventy-three adult patients who underwent BCT after brain tumor surgery between January 2010 and December 2016 were included in this retrospective observational study. The primary outcome of the study was neurological status upon hospital discharge, which was assessed with Glasgow Outcome Scale (GOS). Results: Fifty six (76.7%) among 73 patients survived to discharge. Of these 56 survivors, 25 (34.2%) showed favorable neurological outcomes (GOS of 4 and 5). Invasive ICP monitoring was performed in 60 (82.2%) patients. Among those patients, 20 had been confirmed to have refractory intracranial hypertension (RICH) before starting BCT. The ICP after BCT decreased significantly compared with pre-BCT value; the maximal ICP within 6 h after BCT decreased significantly compared with that before BCT (16.2 [11.8 – 22.8] vs. 27.0 [23.0 – 39.0], p < 0.001). ICP monitoring of all the 60 patients revealed that the maximal ICP within 6 h after BCT was significantly lower in patients with favorable neurological outcome and in survivors (p = 0.008 and p = 0.028, respectively). Early controlled ICP after BCT was associated with clinical prognosis. Uncontrolled RICH (ICP ≥ 22 mm Hg within 6 h of BCT) was an important predictor of mortality after BCT (adjusted hazard ratio 12.91, 95% confidence interval [CI] 2.788 – 59.749), and especially ICP ≥ 15 mm Hg within 6 h of BCT was associated with poor neurological outcome (adjusted odds ratio 1.17, 95% CI 1.042 – 1.312). There were no significant differences in complications associated with BCT between the two groups of neurological outcome. Conclusions: BCT is a treatment modality with acceptable safety and may be a reasonable choice as a last resort of medical treatment to control RICH in patients after brain tumor surgery. Active and timely control of RICH may be beneficial for the patients’ outcomes.