Effect Of Etomidate Induced Myoclonus And Intubation Response By Multi-step Dosage In Adult Patients

Background: Etomidate which is rapid onset, short duration of action, have minimalimpact on hemodynamics is a commonly used agent in clinical intravenousanesthetics. But its high incidence of myoclonus induced by the administration at thetime can impact the anesthesia comfort even elevate security risk. The current methodof inhibiting myoclonus occur for many reasons, but there are limitations, can not bewidely used in a variety of surgical anesthesia.Objective: To investigate the effect of etomidate induced myoclonus and theendotracheal intubation response by multi-step dosage compare with single step inadult patients during intuction period.Methods: Choose adult patients; ASA physical status Ⅰ-Ⅱ；Mallampati status Ⅰ-Ⅱ; planed totally intravenous anesthesia (TIVA), apply endotracheal intubation formaintaining mechanical ventilation, patients with a total of120cases, randomlyassigned to the E1, E2and E3group (n=40). Etomidate induction dosage was0.3mg/kg. The injection was arranged like this: Group E1was one-time injection; GroupE2intravenous injected first1/2dose, administrated the remaining1/2dosage after15s; Group E3first intravenous injected a quarter, then1/2dosage after10s, the lastquarter after10s. Intravenous injection velocity in each group were2ml/s. Andmeasured and recorded the heart rate (HR), mean arterial pressure (MAP) at5times，which were before the induction (T0), immediately after induction (T1), immediatelyafter intubation (T2),1min after intubation (T3),3min after intubation (T4).Comparison among every group with myoclonus incidence and myoclonus extent,myoclonus extent is on the basis of Blitt classification scores. Blitt classificationscores, from weak to strong is divided into four classes: Class0, no visible muscle contraction; Class Ⅰ, body limb, mild contraction; Class Ⅱ, face, trunk and limbsmuscle of mild contraction; Class Ⅲ, face, trunk and limbs muscles strongcontraction. Intubation response assessed by heart rate (HR), mean arterial pressure(MAP).Results: Group E3(22.5%), the incidence of myoclonus was lower than that in groupE1(82.5%) and E2group (65.0%)(P <0.05), besides E3group was no incidence ofgrade Ⅲ myoclonus. Group E3heart rate (75.9±8.0times/min) significantly lowerthan the group E1(80.1±8.3times/min) and group E2(79.6±6.0times/min) at T3moment(P <0.05). At T4moment the group E3heart rate (72.9±8.2times/min) wasobviously lower than group E1(77.7±8.9times/min) and group E2(76.3±5.9times/min)(P <0.05).Conclusion: Adult patients with TIVA during induction period etomidate multi-stepdosage compared with single step can better inhibit its induced myoclonus, abatemyoclonus degree, and can suppress the endotracheal intubation response.