Effects on brain edema of crystalloid and albumin fluid resuscitation after brain trauma and hemorrhage in the rat.
BACKGROUND
It has been hypothesized that resuscitation with crystalloids after brain trauma increases brain edema compared with colloids, but previous studies on the subject have been inconclusive. To test this hypothesis, the authors compared groups resuscitated with either colloid or crystalloid.


METHODS
After fluid percussion injury, rats were subjected to a controlled hemorrhage of 20 ml/kg and were randomized to 5% albumin at 20 ml/kg (A20), isotonic Ringer's acetate at 50 ml/kg (C50), or 90 ml/kg (C90). After 3 or 24 h, water content in the injured cortex was determined using a wet/dry weight method. Blood volume was calculated from plasma volume, measured by 125I-albumin dilution, and hematocrit. Oncotic pressure and osmolality were measured with osmometers.


RESULTS
At 3 h, blood volume was equal in the A20 and C90 groups and lower in the C50 group. Oncotic pressure was reduced by 35-40% in the crystalloid groups and unchanged in the albumin group. Cortical water content in the A20 group was lower than in the C90 group (81.3 +/- 0.5% vs. 82.1 +/- 1.1%, P < 0.05), but it was not different from the C50 group (81.8 +/- 1.1%). At 24 h, oncotic pressure and blood volume were normalized in all groups, and cortical water content was significantly lower in the albumin group than in the crystalloid groups. Osmolality and arterial pressure were equal in all groups throughout the experiment.


CONCLUSIONS
When given to the same intravascular volume expansion, isotonic crystalloids caused greater posttraumatic brain edema than 5% albumin at 3 and 24 h after trauma.
Jungner
Mårten
M
Department of Anesthesiology and Intensive Care, Lund University and Lund University Hospital, Lund, Sweden. marten.jungner@med.lu.se
Grände
Per-Olof
PO
Mattiasson
Gustav
G
Bentzer
Peter
P
D000418:Albumins / Q000008:administration & dosage / Q000009:adverse effects*; D000818:Animals; D001810:Blood Volume / Q000502:physiology; D001929:Brain Edema / Q000139:chemically induced / Q000188:drug therapy* / Q000503:physiopathology; D001930:Brain Injuries / Q000150:complications / Q000188:drug therapy* / Q000503:physiopathology; D002543:Cerebral Hemorrhage / Q000150:complications / Q000188:drug therapy* / Q000503:physiopathology; D000077324:Crystalloid Solutions; D007552:Isotonic Solutions / Q000008:administration & dosage / Q000009:adverse effects*; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D012151:Resuscitation / Q000009:adverse effects*
D000418:Albumins; D000077324:Crystalloid Solutions; D007552:Isotonic Solutions