| Various undesirable stimulations can lead to strong stress reactions in the preoperative period for pediatric patients. Stimulating factors may include nervousness, fear, trauma in the operation and pain, anesthesia, blood volume changes, which can alter stress in the patient, manifesting as imbalance in metabolism and milieu interne . These can cause arrhythmia, higher oxygen demand and more work for the heart. Pediatric hearts are not mature yet, needing more amounts of oxygen and are more sensitive to ischemia , anoxia, and are prone to myocardial damage. Therefore, it is imperative to protect pediatric hearts during the pre-operative period. Have reported that propofol have myocardial protection on heart ischemia-reperfusion injury and effect enzymogram.However, inhaled anesthetics can promote post-ischemic myocardial functional recovery and reduce myocardial infarct size.It simulation ischemic preconditioning,but propofol has no such features .Sevoflurane is a kind of narcotics and its characteristics are: low blood/gas coefficient, non-pungent odor, no respiratory irritability, homodynamic steadiness, rapid onset and offset, etc. It has been widely used in anesthetic induction and maintenance in pediatric field. It has been proved that volatile anesthetic agents mimic IPC, which can directly and indirectly enhance pre-adoption of ischemia by prolonging and decreasing the size of myocardial infarction, improving myocardial contractility recover, and in further to protect the heart away from myocardial infarction and myocardial dysfunction. CTnI is one of the earliest and most sensitive serum indicators for manorial damage; it has high specificity to myocardium, emerges in the earliest stage of myocardial damage, and persists for long period of time. In the light of these statements it has been the best test indicator currently to evaluate and estimate myocardial damage in the clinical field.The experiment is about observing hemodynamic changes and cTnI variation by studying 3-7 yr old patients who had abdominal operation performed in general anesthesia, randomly employing Sevoflurane inhalation narcoticism and propofol intravenous anesthesia. Objective: Comparing the influences of pre-operative hemodynamic and serum cTnI caused by these two drugs (Sevoflurane and propofol) by application of sevoflurance inhalational anesthesia and propofol intravenous narcosis in selecting the time to have surgery in pediatric patients, which in turn provides references for the choice of narcotic agents for pediatric patients.Method:A group of 40 cases of ASA I– II were selected. The ages of the patients ranged from 3 to 7 years old and a time was chosen to preform surgery not to include the heart. The group of 40 patients were divided into two groups of 20 patients each. The first group for Sevoflurane (S group) protocal and the second group for the Propofol (P group) protocal. As a condition for being selected for this study patients could not have any conditions such as: nervous system disorders, metabolic system disorders, respiratory system disorders, hepatic and kidney dysfunction, congenital heart troubles, previous surgical history that involved intubation difficulties. Furthermore, patients who needed blood transfusions and vasoactive drugs were also excluded due to the great changes in hemodynamics during surgery. It is also required that the patient not have anything by mouth (NPO) starting 4 hours before surgery and be administered atropine 0.01 mg/kg intramuscularly 30 minutes previous to the surgery.When visiting patients before surgery, explaining the purpose of inhalational anesthesia and intravenous narcosis to them is a means to obtain the trust of the patients, also talking to pediatric patients sufficiently will help to gain their cooperation. Upon entering the operating theater the surgical staff will being monitoring ECG, BP, and SPO2 as usual, patients in the S group were started on the inhalation of oxygen by mask. In order to reduce fear and anxiety the patients may experience, a fragrance was applied to the mask then the patient was asked to take one or two deep breaths before administering the oxygen without nitrogen. The mask is then moved close to patients face enabling them to inhale oxygen with 8% Sevoflurane at 6L/minute, checking eyelash reaction every 5 seconds until eyelash reaction and pain reaction disappear. After 3 minutes the infusion line is opened and remifentanil is injected, intravenously at 2μg/kg along with Vecuronium Bromide at 0.1 mg/kg. Then performing a trachea cannula incursion, and connecting the patient to the ventilator with the parameter: tidal volume 8-10 ml/kg, RF-25 times/min. Using controllable mechanical ventilation, maintain a respiratory ratio of 1:2 while maintaining PetCO2 at 35-45 mm Hg and maintain anesthesia by inhalation of Sevoflurance constantly during the operation. In the P group the infusion line was opened after 3 minutes and remifentanil was administered by injecting it slowly by IV at the rate of 2 (μg/kg) min-1, propofol at the rate of 7 to 9 (mg/kg) min-1, Bromide 0.1 mg/kg. Then the endotracheal intubation was performed and the patient was connected to a ventilator. The regulated respiratory parameters were the same as in the S group. In order to keep maint- enance narcosis, intravenous propofol was injected continually at the rate of 7 to 9 (μg/kg) h-1. All groups kept maintenance anesthesia by intermittent intravenous injections of Ecuro- nium Bromide and constantly pumping remifentanil at the rate of 0.2 to 0.3 (μg/kg) min-1 (regulated by the BP and HR) and to maintain anesthesia supply fluid by using 5% glucose and 6% Hydroxyethyl Starch Injection. The ratio of Crystal and colloid was 2:1. No blood transfusion and vasoactive drug usage during and after surgery. Before abdominal closure an additional remifentanil injection at 3 to 4 (μg/kg) min-1 was administered. Stopped using propofol, and remifentanil after the operation.Recorded MAP and HR before anesthesia (T0), after induction (T1), the moment performed tracheal cannula (T2), 1 min after endotracheal intubation (T3), 3 minutes after endotracheal intubation (T4), the time started operation (T5), after surgery (T6) individually, also withdrew blood at 4 time spots: before anesthesia (T0), 3 hours after surgery (T7), 24 hours after operation (T8), 72 hours after surgery (T9) to test the amount of cTnI by radio immunoassay.Results: Changes of hemodynamics:①After induction and immediate endotracheal intubation,heart rate was obviously lower than To(P<0.05)in Group P .And after induction , immediate endotracheal intubation , 1 min and 3 min ofter endotracheal intubation, MAP obviously decreased than T0(P<0.05) .②After induction ,MAP was lower than T0,but had no statistical significance in group P. However, there was no significant difference at other time in two groups and there has no statistaical significance between Group P and Group S. 2. The level of cTnI :①had the increasing trend after 3h induction (T7) compared with preanaesthesia (T0) in both of two groups. cTn I increased than normal value at T8(P<0.05), and has statistaical significance than preanaesthesia, however it had the descending trend at T9.②Others has no statistaical significance than before anaesthesia .Conclusions:The study shows that MAP drops after induction in both groups of pediatric patients. However, the dependable BP decreases caused by the Sevoflurane (S group) dosage is mainly due to extra vascular enlargement, not myocardial inhibition, and has no statistical meaning. While, the propofol group (P group) shows a remarkable decrease in MAP.And P group shows a remarkable decrease in HR. In contrast to propofol intravenous anesthesia, homodynamics is steadier in the induction period of the Sevoflurane inhalation narcosis. Meanwhile, P group shows the increasing tendency of the amount of cTnI, which is a dramatic raise in comparison to that in 24 hours before surgery and the time before anesthesia. Whereas they are no remarkable changes in the S group. This means sevoflurane exerts better protective function than propofol . |
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