Hypertonic saline resuscitation of head injury: effects on cerebral water content

Ideal resuscitation would simultaneously replete intravascular volume and minimize cerebral edema. We assessed the effects of hypertonic saline (HS) shock resuscitation on cerebral edema after head injury. Rats were subjected to hemorrhagic shock (40 mm Hg for 1 hour) in the presence or absence of mechanical brain injury, followed by 1 hour of resuscitation with either hypertonic saline (6.5%) or lactated Ringer's (LR). After resuscitation, animals were sacrificed and brain water contents determined.

Less HS than LR was needed for resuscitation both in animals without brain injury (7 +/- 2 ml/kg vs. 97 +/- 16 ml/kg; p less than 0.0003) and with brain injury (10 +/- 1 ml/kg vs. 68 +/- 6 ml/kg; p less than 0.0001). Brain water content (ml H2O/gm dry wt) after HS resuscitation was decreased compared to LR resuscitation in animals without brain injury (3.36 +/- 0.12 vs. 3.74 +/- 0.08; p less than 0.025) and in the uninjured hemisphere of head-injured animals (3.29 +/- 0.11 vs. 3.78 +/- 0.09; p less than 0.025). Brain water content was increased in injured brain in both resuscitation groups, but the increase was the same (HS 4.10 +/- 0.13; LR 4.25 +/- 0.17; p greater than 0.05).

HS resuscitation of hemorrhagic shock decreases brain water content in uninjured but not injured brain. HS may be useful in resuscitation of combined hemorrhagic shock and head injury.