Different Tidal Volumes On The Impact Of ET-I And CGRP In Brain During Craniocerebral Operations

Objective:Observed in craniocerebral operations with different tidal volumes on ET-1 and CGRP of B。Methods:30 ASAⅠ-Ⅱpatients who aged 18-55 years old undergoing craniocerebral operations with dorsal position,Hb>100g/l and Hct>0.3,rule out hypertension,coronary heart disease,diabetes and other cardiovascular diseases。Preoperative brain CT or MRI revealed the tumor between 2cm-5cm, no significant midline shift and ventricular compression, without symptoms and signs of intracranial hypertension. The patients are randomized to two groups(n=15):groupA(VT=12ml/kg), groupB(VT=7ml/kg).Fixed tidal volume and accommodate respiratory rate to sustain PaCO2 during 30-40mmHg, Draw blood synchronously from sigmoid sinus after intubation of internal jugular vein,before operation(Tl), afer resection of tumor(T2) and at the end of operation,before extubation (T3) to measure of endothelin-1 and calcitonin gene-related peptide. Results:(1) At T1 the ET-1 and CGRP content of groups A and B in little difference (P>0.05) (2)Two groups of patients from T1-T3 time ET-1 levels is gradually increased, and the rate of increase of group A is greater than group B. (P<0.05) (3) Two groups of patients from T1-T3 time brain CGRP levels increased gradually between the two groups showed no significant difference(P>0.05).Conclusion:1,Craniotomy, the small tidal volume ventilation (7ml/kg) cause ET-1 of brain is increased in the range of less than conventional tidal volume (12ml/kg).2,Craniotomy, low tidal volume ventilation induced increased rate of brain CGRP levels and no significant difference between conventional tidal volume.