K. Maguigan1, B. M. Dennis2, S. Hamblin1, O. Guillamondegui2 1Vanderbilt University Medical Center,Department Of Pharmaceutical Services,Nashville, TN, USA 2Vanderbilt University Medical Center,Division Of Trauma And Surgical Critical Care,Nashville, TN, USA
Introduction:
Hypertonic saline (HTS) is an effective therapy for reducing intracranial pressure (ICP) in patients with traumatic brain injury (TBI). The ideal method of administration is unknown. The purpose of this study was to evaluate the method of HTS infusion and time to goal osmolality. We hypothesized that patients receiving bolus only HTS would reach goal osmolality more rapidly than patients receiving continuous infusion HTS.
Methods:
This is an IRB-approved, retrospective cohort analysis of severe TBI patients at a Level 1 Trauma Center from January 2008 to May 2014 who received at least 2 doses of 3% sodium chloride. Inclusion criteria were ICP monitor or external ventricular drain while on HTS and greater than 48 hour ICU admission. Craniotomy patients were excluded. Eligible patients were identified using the Trauma Registry of the American College of Surgeons. Patients were divided into bolus versus continuous infusion HTS cohorts. The primary outcome was median time in hours to the first osmolality value within goal range of ≥ 310mOsm/kg. Secondary outcomes included percentage of patients reaching goal osmolality, percent time at goal osmolality, mean cerebral perfusion pressure (CPP) and ICP, ICU length of stay, and ICU mortality. Statistical analysis included, the Mann-Whitney U test for continuous data and the Fisher’s Exact test for categorical data.
Results:
Of the 162 patients included (30 bolus and 132 continuous), baseline characteristics were similar. The median injury severity score for the bolus and continuous group was 33.5 (IQR 26-42.8) and 37 (IQR 29-45) respectively. The median Glasgow Coma Scale score was 3 for each group. The median volume of HTS given was significantly higher in the continuous group (1250mL vs 2735mL, p<0.001), with insignificant median total doses of mannitol. Time to goal osmolality was similar between the two groups (bolus 9.78 hr vs continuous 11.4 hr, p=0.817). A significant difference in the percentage of patients reaching goal osmolality favoring the continuous group was found (93.9% vs 73.3%, p=0.003). The continuous group was also maintained at goal osmolality for a higher percentage of osmolality values after reaching goal (80% vs 50%, p=0.032). Median CPP and ICP were similar on HTS therapy, and no differences were observed in ICU length of stay or mortality.
Conclusion:
Although no difference in time to goal osmolality was observed when comparing bolus or continuous infusion HTS, continuous HTS was associated with a higher percentage of patients achieving goal osmolality. Due to the limited sample size, we were unable to find a difference in ICP or CPP. Further studies are needed to definitively assess these methods of administration.