The Clinical Research Of Deliberate Hypotension Induced By Sevoflurane-Remifentanil Compounded Anesthesia In The Clamp Operation Of Intracranial Aneurysm

[Objective] To explore the feasibility and anesthetic effect ofDeliberate Hypotension Induced by Sevoflurane-RemifentanilCompounded Anesthesia in the Clamp Operation of IntracranialAneurysm[Methods] Thirty-six ASA I~II patients undergoing electiveclipping surgery of intracranial aneurysm were randomly divided into2 groups(n=18each): Group A deliberated hypotension withsevoflurane inhalation (sevoflurane group); group B deliberatedhypotension with nitroglycerin administration (nitroglycerin group).Transfuseing 10~15ml/kg colloid fluid in 30~40min. Monitoring BP,ECG, SpO2, PETO2, invasive BP (arteriopuncture after inducing).Setting respiratory parameter: VT 8~12ml/kg, frequency 10~12/min,inspiratory/expiratory 1:2. All the patients were induced withmadazolam 2mg, fentanyl 3~5μg/kg, etomidate 0.3mg/kg, vecuronium0.08~0.1mg/kg. In group A anesthesia was maintained withremifentanil 8μg/ml + sevoflurane (initial concentration 0.5MAC,increase 0.5MAC every 3 respirations till the inhalation concentrationreach to 1.0~1.5MAC); in group B with remifentanil 8μg/ml +propofol 6~8mg/(kg·h), interruptable intravenous injection ofvecuronium was administrated as needed. Regulating theconcentration of sevoflurane and the pumping speed of propofol ineach group depending on the vital signs. After the dura was opened, gradually increased the inhalation concentration of sevoflurane (1~3MAC) in group A and started to pump nitroglycerin at a speed of 3μg/(kg·min)in group B to make SBP go down 25%~40% and maintain the MAP at a level about 60mmHg, the MAP shoule be further decreased at the time of clipping the intracranial aneurysm. Decreased the inhaled concentration of sevoflurane(0.5~1MAC) in group A and stopped pumping the nitroglycerin in group B after clipping to recover BP as the level that before Deliberate Hypotension. Stopped the application of sevoflurane and propofol in each groups 20mins before the completion of surgery. Remifentanil should be stopped using at the time of suturing the skin. The patients were extubated and breathing spontaneously with SPO2>93% and could open eyes on verbal command before being transferred to wards. Recorded the urinary volume, transfusion volume, losing volume of blood; Noted the BP and HR before and after Deliberate Hypotension. Blood gas analysis was undertaken at 5 time points: T0 (started to Deliberate Hypotension),T1(20min after Deliberate Hypotension),T2(40min after Deliberate Hypotension),T3(60min after Deliberate Hypotension)and T4 (the end of the surgery). The duration time of achieving Deliberate Hypotension and recovering from it were recorded. The data of time lasting from complecation of surgery to extubation should also be recorded.[Results] The urinary volume of both groups were in normal range(>1ml/(kg·h)), the effect of Deliberate Hypotension in tow groups was stabile and satisfied. The duration time of achieving Deliberate Hypotension and recovering from it in group B is shorter than that of group A, HR became decreased after Deliberate Hypotension in group A(no statistical significance, P>0.05)while that became increased in group B(statistical significance, P<0.05 ).There was statistical significance between T3 and T0 in pH value(P<0.05), and the statistical significances were also shown at the time point of T0, T3 and T2 in BE and T-CO2(P<0.05). On the other hand, the blood gas analysis results in group A were all in normal range and no statistical significances. The comparation between tow groups at the same time point shows that there was statistical significances at T3 in pH and T2, T3 in BE, T-CO2 (P<0.05).[Conclusion] The effect of Deliberate Hypotension Induced by Sevoflurane-Remifentanil Compounded Anesthesia is satisfied without combining with other hypotension drug. Moreover, the controllability of sevoflurane is better than that of nitroglycerin according to the more stable variety of BP, costing shorter time to recovery from anesthesia and more gentle influence to the tissue metabolism our trail. Thus, sevoflurane-remifentanil Compounded Anesthesia Inducing Deliberate Hypotension is a suitable method for neurosurgery.