Background and Goal of Study:
Mannitol therapy causes decrease in intracranial pressure in patients with traumatic brain injury (TBI). However it has a number of complications including hyperosmolality and hypernatremia. There is no evidence to suggest the optimal duration of mannitol therapy based on clinical parameters. Effects of prolonged mannitol therapy on osmolar and biochemical changes are yet to be evaluated. This study aims at studying the time course of osmolality and biochemical changes during mannitol therapy in patients with severe TBI.
The present article is a prospective observational study conducted on patients with traumatic brain injury, who were managed non operatively in an intensive care unit (ICU) of tertiary care hospital. The mannitol was being administered prior to ICU admission based on clinical parameters, (i.e. Glasgow coma score (GCS), pupillary size/reaction, deficits) and imaging studies. In the ICU mannitol was administered as 1gram per kilogram per day in three equal divided doses. Clinical characteristics of patients based on varied scoring system and bio physiological parameters were monitored and measured on daily basis for 14 days from the day of admission to the ICU.
Mean GCS on admission (n = 30) was 5.87 ± 1.137 (4–8). The baseline value of osmolality was 311.6 ± 20.4 mOsm/kg and it increased to a maximum value 318.5 ± 28.9 mOsm/kg in the first 72 hours. However by tenth day the osmolality returned to 304.1 ± 19.3 despite mannitol administration. Serum sodium peaked by the third day with a mean increase of 7 (150.9 ± 11.8) mEq/L. Thereafter it reverted back to normal range with osmolality.
The Osmolar gap was less than 10 mOsm after admission in ICU. The parameters having significant difference among survivors and non-survivors are shown in Table 1.
When mannitol is administered in three equal divided doses up to maximum of 1 g/kg/day, the serum osmolality and serum sodium levels reaches its peak at first 72 hours. Mannitol appears to be cleared effectively from the serum as observed by the osmolar gap. Maximum osmolality and maximum serum sodium levels may influence the outcome in head injured patients.
© 2012 European Society of Anaesthesiology