The Effects Of Etomidate For Continuous Infusion On Adrenocortical Function In Hemorrhagic Shock Dogs

Objectives:To study the adrenocortical function after continuous etomidate infusion of different doses in hemorrhagic dogs.Methods:Twenty-four healthy adult male mongrel dogs were randomly divided into control group(group C,n=6)and shock group with only sodium pentobarbital anesthesia,and other experimental groups received infusion of etomidate at the rate of10μg·kg-1.min-1(group E1,n=6)20μg·kg-1.min-1(group E2,n=6)respectively. The dogs were also anesthesitized with2.5%sodium pentobarbitone(25mg/kg)intraperitoneally and cathetered in femoral artery and femoral vein.Sodium Heparin was infused via an indwelling venous (3mg/kg).MAP、CVP、ECG、SpO2、PETCO2、BIS were monitored.Group C were anesthtized with2.5%sodium pentobarbitone(12.5mg/kg) at intervals by intraperitoneal injection appropriatly and maintained3h with the BIS value40-60;The experimental groups were build the hemorrhagic shock dog model after tracheal intubation,maintained1h with the MAP40-50mmHg.The etomidate groups were continuously infused etomidate1h respectively and were monitored1h on withdrawal.All groups were added vecuronium (0.05mg/kg) to maintain muscle relaxation every30minutes.Radioimrnunoassay was used to detect serum cortisol,aldosterone and ACTH concentrations before shock(T]),at1h after shock(T2),2h after recovery (T3.4).Results:No statistically significant differences were found at each time point in cortisol,aldosterone,ACTH concentrations(P>0.05) in group C.The cortisol,aldosterone and ACTH concentrations in group S were significantly higher than that in group C at T2(P<0.01)and not significantly at T3,T4.The cortisol,aldosterone concentrations in group E1and E2were significantly lower at T2,T3,T4than that at T1(P<0.05or P<0.01) and ACTH concentrations were significantly higher at T2,T3,T4than that at T1(P<0.05); although they were increased after stopping the etomidate at T3-4, they were still lower than the level of Ti, and ACTH concentrations were still higher than that at T1. Conclusion:The cortisol and aldosterone concentrations were decreased and ACTH concentrations were increased with infusion of continuous etomidate during the stage in hemorrhagic shock dogs. As etomidate of10μg.kg-1.min-1for a short time has little effect on adrenocortical function,it may be safe for the clinical continuous maintenance of anesthesia for hemorrhagic shock patients.