Influence Of Anisodamine On Hemodynamics And Plasma Renin Activity During Hypotensive Anesthesia Induced By Nicardipine

Objective: To study the influence of anisodamine on hemodynamics and plasmarenin activity during hypotensive anesthesia induced by nicardipine in patientsundergoing nasal endoscopic operation.Methods: Recruited patients undergoing nasal endoscopic operation under generalanesthesia, ASA Ⅰ-Ⅱ; normotension (SBP≤140mmHg, DBP≤90mmHg); normallevel of blood ion, no sodium and potassium disorders; no histories of cardiovasculardisease, hepatic/renal disorders and endocrine disease; no contraindications foranisodamine.Patients were randomly assigned to two groups, group A (anisodamine group),group C(control group). After general anesthesia, intravenous infusion of nicardipine tocontroll hypotension, a few patients were excluded in the study because of failing toinduce hypotension,22patients (male17cases, female5cases) were finally included,11cases in group A,11cases in group C. Anesthesia was induced with midazolam0.03mg/kg, sufentanil0.6μg/kg, cisatracurium0.2mg/kg, etomidate0.2-0.4mg/kgintravenously. After tracheal intubation, anesthesia machine was connected to controlventilation. Anesthesia was maintained with propofol l6-8mg/kg/h, according to thesituation in operation intravenous sufentanil cisatracurium. The patients in group Awere given anisodamine0.1mg/kg5min before controlling hypotension. Before the startof operation, nicardipine was infused at the initial rate of5μ g/kg/min, infusion ratewas regulated according to the dynamic blood pressure to reduce the MAP value by30%of basic value as the goal, and maintaining period of the hypotension for30mins.Observing and recording changes in blood pressure, heart rate during operativeperiod; Venous blood was collected to evaluate rennin activity before initiation of hypotension and30minutes after hypotension.Results: Controlled hypotension were achieved in22patients of both groups.MAP values after hypotension were lower than basic values of blood pressure (is about30%), the difference was statistically significant (P<0.01);25min after hypotensionMAP value was significantly lower in group A than in group C (P<0.01); the heart rateof the patients were higher in group A than in group C during intraoperative, andbefore initiation of hypotension,5min、10min、15min after hypotension, the differenceswere statistically significant (P<0.01); Nicardipine infusion rate was slower in thegroup A compared to the rate in the group C, the difference was statistically significant(P<0.01); plasma renin activity was upregulated30min after controlled hypotensioncompared to the baseline values in the two group, the differences were statisticallysignificant (P<0.01), however there was no difference between the two groups.Conclusion: controlled hypotension induced by nicardipine during nasalendoscopic operation increases plasma renin activity in general anesthesia patients.Preoperative infusion of anisodamine at0.1mg/kg intravenously has no effect on reninactivity; anisodamine can reduce the dose of nicardipine for controlled hypotension,anisodamine moderately increase heart rate of patients during hypotension process,improve perfusion of peripheral tissues, help to alleviate sympathetic activatity inducedby the controlled hypotension.