Effect of methylprednisolone on reperfusion injury in severe uncontrolled hemorrhagic shock.
OBJECTIVE
To study the effect of methylprednisolone (MP) on reperfusion injury in severe uncontrolled hemorrhagic shock and explore the possible mechanism involved.


METHODS
Twelve dogs were randomly divided into two groups, control group (Group I, n=6) and MP group (Group II, n=6). The animals were bled continuously from a femoral artery catheter to produce uncontrolled hemorrhagic shock models. Resuscitation with lactated Ringer's (LR) solution was initiated when mean arterial pressure (MAP) decreased to 20 mm Hg, and MAP was maintained at 30-40 mm Hg. MP (4 mg/kg) was injected intravenously in Group II when resuscitation began. While in Group I, normal saline (NS) was injected instead. The levels of superoxide dismutase (SOD) and malondialdehyde (MDA) were measured before exsanguination (T(1)), when MAP decreased to 20 mm Hg (T(2)), 60 min (T(3)) and 120 min (T(4)) after resuscitation. Heart rate, MAP and cardiac output (CO) levels were recorded concomitantly.


RESULTS
Infusion volume and hemorrhage volume shed from the superior mesenteric artery in Group I were higher than those in Group II (P<0.01 and P<0.05). After reperfusion, blood SOD levels decreased progressively and MDA levels increased rapidly in Group I. In Group II, blood SOD levels at T(3) and T(4) decreased as compared with that at T(1) but a stepwise increase was present. At T(4), blood SOD level was significantly higher in Group II than in Group I (Plt;0.01). At T(3) and T(4), MDA levels were markedly lower in Group II than in Group I. During reperfusion, MAP was more steady in Group II than in Group I and survival rate after 120 min (at T(4)) was higher in Group II than in Group I (P<0.05).


CONCLUSIONS
MP has a protective effect on severe uncontrolled hemorrhagic shock and subsequent reperfusion injury. The mechanism mainly involves the anti-lipid peroxidation activity of MP.
Xia
Fang
F
Department of Anesthesiology, Renmin Hospital, Wuhan University, Wuhan 430060, China.
Cao
Jing-shan
JS
Zhan
Li-ying
LY
Xia
Zhong-yuan
ZY
Xia
Zheng-yuan
ZY
Huang
Hai-bo
HB
D000704:Analysis of Variance; D000818:Animals; D004195:Disease Models, Animal; D004305:Dose-Response Relationship, Drug; D004334:Drug Administration Schedule; D005260:Female; D015227:Lipid Peroxidation; D008297:Male; D008775:Methylprednisolone / Q000494:pharmacology*; D011336:Probability; D011897:Random Allocation; D012016:Reference Values; D015427:Reperfusion Injury / Q000188:drug therapy* / Q000503:physiopathology; D012680:Sensitivity and Specificity; D012771:Shock, Hemorrhagic / Q000188:drug therapy* / Q000503:physiopathology; D015996:Survival Rate
D008775:Methylprednisolone