Effect of methylene blue on resuscitation after haemorrhagic shock.
OBJECTIVE
To compare prehospital hypotensive resuscitation with volume resuscitation, and find out whether reagents that inhibit free-oxygen radical formation, such as methylene blue, can improve resuscitation and survival.


METHODS
Randomised controlled trial.


METHODS
Animal laboratory, Israel.


METHODS
48 adult male Wistar rats.


METHODS
After 30 minutes of controlled haemorrhage, rats were subjected to 60 minutes of uncontrolled haemorrhage with simultaneous resuscitation. Hartmann's solution alone, or with blood or with a bolus of methylene blue were infused to maintain the mean arterial pressure (MAP) at 80 or 40 mm Hg. Then haemorrhage was stopped and Hartmann's solution plus whole blood were infused to obtain a MAP that was within normal limits.


METHODS
Volumes of shed blood and resuscitation fluids, MAP, packed cell volume, blood pH and base deficit, and survival.


RESULTS
During uncontrolled haemorrhage. a MAP of 80 mm Hg could not be reached in animals resuscitated with Hartmann's solution alone, and all died. All the rats given Hartmann's solution with a bolus of methylene blue or with whole blood achieved a higher MAP. MAP of 40 mm Hg was attained in all animals regardless of the resuscitation fluid. Only 15 of 24 animals resuscitated to a MAP of 80 mm Hg survived, compared with 22 survivors of the 24 rats resuscitated to a MAP of 40 mm Hg (p <0.04). Methylene blue or whole blood drastically reduced the volumes of shed blood and of fluids required, and moderated the reduction in packed cell volume, particularly during hypotensive resuscitation.


CONCLUSIONS
Hypotensive protocols should be used to improve survival. Methylene blue given with the electrolyte solutions could negate their detrimental effects during resuscitation.
Jeroukhimov
I
I
The Department of Surgery B Sharee Zedek Medical Centre, Jerusalem, Israel.
Weinbroum
A
A
Ben-Avraham
R
R
Abu-Abid
S
S
Michowitz
M
M
Kluger
Y
Y
D000704:Analysis of Variance; D000818:Animals; D016887:Cardiopulmonary Resuscitation / Q000379:methods*; D004195:Disease Models, Animal; D008297:Male; D008751:Methylene Blue / Q000494:pharmacology*; D015999:Multivariate Analysis; D011897:Random Allocation; D051381:Rats; D017208:Rats, Wistar; D012016:Reference Values; D012771:Shock, Hemorrhagic / Q000628:therapy*; D016896:Treatment Outcome
D008751:Methylene Blue