Comparison of Survival and Function after Traumatic Brain Injury among Patients Exposed to Hypertonic Saline and Mannitol: A Case Control Study

Abstract

Object: Hyperosmolar agents are used for several purposes, of which one of the most common is to diminish pressure within contained compartments. The most commonly used hyperosmolar agents include Hypertonic Saline (HTS) and Mannitol (MA). The most commonly treated compartment is the cranial vault. While both HTS and MA are known to reduce compartment pressures, there is some data suggesting that HTS may be more effective than MA. However, there is virtually no data comparing the effect of HTS and MA on survival, function, nor length of stay. The goal of this study is to compare HTS and MA according to the outcomes of survival, function, and length of stay and to compare the effect of HTS and MA on the sodium flux and osmolality. Methods: We conducted a case-control study to compare HTS and MA according to the outcomes of survival, neurological function, and length of stay. We reviewed all patients admitted to the Neurosciences and General Systems Intensive Care Units at the University of Alberta Hospital with a diagnosis of Traumatic Brain Injury (TBI) for a one-year period from Jan 1 2018 until Dec 31, 2018. Results: Ninety-two patients with TBI were found in the database from January 1 2018 till December 31 2018. Twentythree patients were treated with osmotherapy, 15 patients were treated with 3% HTS and 8 patients were treated with 20% MA. Comparison between patients receiving osmotherapy and patients not receiving osmotherapy was made. Survival was no different between the HTS (x%, 95% CI) and the MA (y%, 95% CI) groups, p=. Likewise there was no difference in the hospital length of stay between groups, x +/- days versus y=/- days in the HTS and MA groups respectively, p=. The HTS group had significantly higher initial GCS presentation compared to MA group, despite that HTS failed to show improved survival or LOS compared to MA treated patients. The mean delta serum osmolality and mean delta Na were wider in the MA group, this wide delta serum osmolality and Na was not seen in the HTS group. Conclusion: Our study challenges the multiple recent literatures favouring HTS in TBI patients. Also, our study indicates MA and HTS may not be equiosmolar and have different influence on serum electrolytes and osmolality. A large sample size multi center RCT is needed to compare between different osmotherapies and their effect on mortality and neurological outcome.