Efficacy and safety of hypertonic saline solutions in the treatment of severe head injury

Background: The present study was undertaken to evaluate the efficacy and safety of hypertonic saline (HS) in the treatment of intracranial hypertension after severe head injury. Methods: This prospective, observational study was performed in an 11-bed neurosurgery intensive care unit of a teaching hospital. From February 2002 to September 2004, 18 severely head-injured patients with elevated intracranial pressure (ICP) and Glasgow Coma Scale scores of 5 to 8 (mean, 5.9 ± 1.2) were admitted to the unit and treated according to a standard protocol. One dose per day of 3% saline was administered by rapid infusion (300 mL/20 min) when ICP values exceeded 20 mm Hg. After infusion, cerebral blood flow, ICP, blood pressure, end-tidal carbon dioxide, and heart rate were monitored continuously for 60 minutes and recorded. Serum osmolarity, sodium, potassium, chloride, arterial carbon dioxide pressure, arterial oxygen pressure, hemoglobin, lactic acid, and pH were measured immediately before infusion (zero time) and 20 and 60 minutes after infusion. Mean arterial pressure, cerebral perfusion pressure (CPP), mean flow velocity (MFV), and pulsatility index (PI) were also recorded and analyzed. Results: Intracranial pressure fell immediately after initiation of infusion with further significant decreases observed at 20 and 60 minutes (30.4 ± 8.5, 24.3 ± 7.4, and 23.8 ± 8.3 mm Hg, respectively; P < .01). At these respective times CPP increased significantly (78.7 ± 8.7, 83.2 ± 7.8, and 87.2 ± 12.8 mm Hg), PI dropped rapidly (1.51 ± 0.42, 1.38 ± 0.32, and 1.34 ± 0.33) and MFV increased (66.26 ± 25.91, 71.92 ± 28.13, and 68.74 ± 28.44). Serum sodium increased from 141.3 ± 7.2 to 146.3 ± 7.2 mmol/L after 20 minutes and returned to 144.3 ± 7.36 mmol/L at 60 minutes. Potassium concentrations decreased significantly from 3.9 ± 0.39 to 3.55 ± 0.35 mmol/L after 20 minutes (P < .01). Lactic acid values at 0, 20, and 60 minutes were 1.6 ± 0.5, 1.47 ± 0.48, and 1.38 ± 0.53 mmol/L, respectively (P < .01). Conclusion: Rapid infusion of single dose daily of HS is a safe alternative for the treatment of elevated ICP in severe head injury. Further evaluations of long-term consequences and complications and of maximal tolerance to this treatment are required.