Intravenous sedation for gastrointestinal endoscopy in very elderly patients of Thailand.

Background: The use of sedation for gastrointestinal endoscopy (GIE) procedures in elderly patients has been established as a safe and effective technique. However, it is still uncertain whether the situation is valid for Asians. Objective: Evaluate the outcome of intravenous sedation (IVS) for GIE procedures in very elderly patients (>86 years old) in Thailand and compare the clinical efficacy of IVS between very elderly and those younger (<86 years old) Methods: We undertook a retrospective review of the sedation service records of patients who underwent GIE procedures between 2007 and 2008 at Siriraj Hospital, Thailand. All sedations were administered by anesthetic personnel in the endoscopy room. The cohort was divided into three groups, <65 years old (group 1), 65-85 years old (group 2), and >86 years old (group 3). Results: Sedation was provided for 1,779 patients (965, 687, and 127 patients in group 1, 2, and 3, respectively) in 2,061 GIE procedures. Fentanyl, midazolam and propofol were the most common IVS drugs used in all three groups. Patients in group 3 required lower mean doses of these intravenous sedatives than those in group 1 or 2 (p <0.001). Mean procedure time in group 3 was longer than in group 1 or 2 (p=0.010). Adverse events in group 3 occurred more frequently when compared to group 1 or 2 (p <0.001). Transient hypotension was the main complication across all aged groups. Conclusion: IVS for GIE procedure in very elderly patients was associated with higher minor advance events but relatively safe and effective when carried out by trained anesthetic personnel with appropriate monitoring and dose adjustment.

Arrhythmia in early post cardiac surgery in pediatrics: Siriraj experience.

OBJECTIVES: To determine the incidence, risk factors and outcome of early postoperative arrhythmias in pediatric patients with congenital heart disease. MATERIAL AND METHOD: A prospective study was conducted in every pediatric patient who consecutively underwent open-heart surgery at Siriraj Hospital from January 1st to December 31st, 2006. The collected data were demographic data, diagnosis, pre-operative arrhythmia, cardiac surgical data and continuous electrocardiographic monitoring data throughout the post operative intensive care period. RESULTS: A total of 191 pediatric patients underwent cardiac surgery. Forty-five cases (23.5%) developed early post operative cardiac arrhythmias i.e. junctional ectopic tachycardia 18 cases (40%), heart block 7 cases (15.6%), supraventricular tachycardia 2 cases (4.4%). Cardiac arrhythmia occurred mostly within 24 hours after the operation. Patients with single ventricle physiology repaired developed the highest incidence of acute post operative arrhythmia (36.4%). Longer, cardiopulmonary bypass time- and redo-operation were the risk factors. Thirty-nine cases were treated with medications, 7 cases with temporary pacing, and 1 case with electrical cardioversion. Four patients needed long-term anti-arrhythmic agents. Cardiac arrhythmia played role in the causes of death in 2 cases (1.1% of total cases). CONCLUSIONS: Post operative arrhythmias remained common and important complications of pediatric open-heart surgery. Long cardiopulmonary bypass time and redo-operation were risk factors for early post operative arrhythmia.

Predictors of intra-operative recall of awareness: Thai Anesthesia Incidents Study (THAI Study): a case-control study.

BACKGROUND: The authors determined predictors of intra-operative recall of awareness in the Thai Anesthesia Incidents Study (THAI Study). OBJECTIVE: To study a multi-centered registry of anesthesia in 20 hospitals across Thailand. MATERIAL AND METHOD: Structured data collection forms of patients who underwent general anesthesia and experienced intra-operative recall of awareness between March 1, 2003 and February 28, 2004, were reviewed by three independent anesthesiologists. One case of awareness was matched to four controls by age, gender, and level of hospitals. Univariate analysis (p < 0.1) and logistic regression (p < 0.05) identified characteristics associated with intra-operative recall of awareness. RESULTS: Eighty-one cases were matched with 324 controls in the nested case control study. From univariate analysis, risk factors were cardiac surgery, cesarean delivery, upper abdominal surgery, i.v. anesthetics, depolarizing muscle relaxant, non-depolarizing muscle relaxant, and nitrous oxide (p < 0.1). The predictors from multivariable logistic regression were cesarean delivery p < 0.001, OR 6.48 (95% CI 2.03, 20.71), and cardiac surgery p < 0.001, OR 10.37 (95% CI 3.37, 31.89). Decreased risk was associated with intra-operative use of nitrous oxide p = 0.02, OR 0.42 (95% CI 0.20, 0.88). CONCLUSION: In the THAI Study, predictors of intra-operative recall of awareness were cesarean delivery and cardiac surgery. Use of nitrous oxide attenuates the risk of awareness.

Anesthesia for arterial switch operation in simple transposition of the great arteries: experience at Siriraj Hospital.

Anesthetic management of cardiac patients with complete transposition of the great arteries (TGA) undergoing arterial switch operation (ASO) is challenging. The anesthetic course and perioperative problems were studied. A prospective data collection study of 87 patients was performed between January 1991 and February 2002. The patients were divided into 3 groups: Group 1; 27 neonates with TGA with an intact ventricular septum (IVS), Group 2; 21 with TGA, with IVS who underwent two-stage ASO, and Group 3; 39 with TGA, with a large VSD. The anesthesia consisted of low-dose fentanyl, thiopental, atracurium and isoflurane. Monitoring included ECG, radial or femoral arterial pressure, CVP, LAP, core temperature, SpO2, P(E)CO2, urine output, ABG's, Hct, ACT, serum glucose and potassium. Fortunately the courses of anesthesia were uneventful. Usual vasoactive medication administered following CPB included nitroglycerin, dobutamine and dopamine. Groups I, 2 and 3 contained 18.5 per cent, 14.3 per cent and 33.3 per cent of patients who required adrenaline respectively. And only 7.7 per cent of patients in Group 3 had milrinone as an inotrope. Early tracheal extubation, 2 hours after admission to ICU was performed in 3 patients. Perioperative complications included bleeding, low cardiac output, diaphragmatic paresis, digitalis intoxication, metabolic alkalosis, convulsion, pulmonary hypertensive crisis and death. Two patients who developed a pulmonary hypertensive crisis were successfully managed with inhaled nitric oxide. The overall hospital mortality rate was 19.54 per cent. In conclusion, the anesthetic management for ASO in 87 simple dTGA patients was uneventful at Siriraj Hospital. The major perioperative morbidity and hospital mortality were not directly anesthetic contribution.

Hypothermic circulatory arrest and retrograde cerebral perfusion for aortic surgery at Siriraj Hospital: a preliminary review of anesthetic management.

OBJECTIVE: To evaluate the anesthetic management in patients undergoing aortic surgery cerebral perfusion; with particular emphasis on under hypothemic circulatory arrest and retrograde intraoperative brain protection, blood salvage and postoperative outcomes. MATERIAL AND METHOD: Retrospective case series. Data on medical conditions, anesthesia, surgery and postoperative care from patients who underwent operation between June 1993 and December 1999 were analyzed. RESULTS: There were 53 patients involved in this study. They all received general balanced anesthesia; 70.6 per cent had single-lumen endotracheal intubation, while the remaining required double-lumen endotracheal intubation. The duration of the anesthetic procedure, aortic cross-clamping and circulatory arrest, were 365.58 +/- 89.21, 126.35 +/- 34.64 and 48.35 +/- 19.47 min respectively. The lowest nasopharyngeal and rectal temperature were 17.42 +/- 1.40 degrees C and 21.26 +/- 2.80 degrees C respectively. Thiopental 804.68 +/- 353.93 mg and dexamethasone 14.41 +/- 7.88 mg were administered for brain protection, in addition to retrograde cerebral perfusion; 82.35 per cent received 785.71 +/- 273.86 mg of tranexamic acid and only 23.52 per cent received aprotinin in order to reduce blood loss. However, massive blood replacement therapy was always necessary. In the postoperative period, the patients were ventilated for 39.18 +/- 59.53 h, the length of hospital stay was 14.58 +/- 5.83 d, and the mortality was 13.2 per cent. CONCLUSION: This preliminary data indicate that hypothermic circulatory arrest in aortic surgery is associated with a high mortality rate, despite attempts to provide adequate cerebral protection as well as intraoperative blood salvage.

Tranexamic acid as a means of reducing the need for blood and blood component therapy in children undergoing open heart surgery for congenital cyanotic heart disease.

Children undergoing cardiac operations using cardiopulmonary bypass (CPB) are at risk of significant postoperative bleeding and the need for transfusion. The antifibrinolytic drug, tranexamic acid, decreases blood loss in adult patients undergoing cardiac surgery. However, its efficacy has not been extensively studied in patients with cyanotic congenital heart defects (CHD). Using a prospective, randomized, double-blind study design, we examined 67 children undergoing repair of cyanotic CHD. After induction of anesthesia and prior to skin incision, patients received 15 mg/kg of tranexamic acid intravenously. At the end of CPB, a second bolus of tranexamic acid (15 mg/kg) or saline placebo was administered. Postoperative blood loss and transfusion requirements from the period after protamine administration until 24 hours after admission to the intensive care unit were recorded. In addition, the hematocrit, platelet count and other indices of coagulation were recorded every 6 hours. There was no significant difference in postoperative blood loss between the treated and the placebo group (12.51 +/- 13.20 ml/kg per 24 hours, in the tranexamic acid group, vs 10.68 + 6.38 ml/kg per 24 hours, in the placebo group). Also there was no significant difference in the amounts of blood and blood products administered between the two groups. No adverse effects of tranexamic acid were found in this study. In conclusion, there was no significant difference in postoperative blood loss or blood and blood product requirement between those children with cyanotic CHD undergoing open heart surgery who received a single dose of tranexamic acid compared with those who received two doses.

Awareness under general anesthesia.

OBJECTIVE: To determine the occurrence and associated factors of awareness in the patients undergoing elective surgery under general anesthesia. METHODS: A prospective cohort study of 802 patients, scheduled for elective general and gynecological surgery under endotracheal anesthesia was performed at Siriraj Hospital. Balanced general endotracheal anesthesia was performed as routine practice. Standard monitoring and clinical observation for movement, tear, sweat, and eye-lid opening were obtained. They were interviewed during the first 12 hours after a surgical completion. If the patient was suspected to have awareness, then a second interview was performed on postoperative day 3. RESULTS: The ages of the study population were 16-84 years. There were 659 females and 143 males. Awareness was found in 5 patients (3 females, 2 males) as an occurrence of 0.62 per cent. The only positive clinical observation found was hand movement. The cause of awareness should be inadequate anesthesia. Apart from that, data gathered from interviews with the group who had no awareness (797 patients), the last thing they could remember before unconsciousness was auditory perception. Also hearing someone calling was the first thing upon awakening. Most of the patients did not dream during anesthesia. No serious psychological disorder occurred. CONCLUSION: The occurrence of awareness was 0.62 per cent in the patients undergoing surgery under anesthesia. Inadequate anesthesia was the most likely cause of awareness. No postoperative sequelae of awareness occurred.

Comparison of sufentanil and fentanyl for surgical repair of congenital cardiac defects.

In the present study, the authors compared sufentanil to fentanyl in pediatric patients undergoing congenital cardiac repair. The purpose of the study was to evaluate the hemodynamic variables, time of awakening and successful extubation of the two groups. A prospective, randomized study of 60 children scheduled for elective surgery of congenital cardiac defects was made. Patients were randomly divided into two groups: Group I; sufentanil and Group II; fentanyl (mean body weight, 16.02 +/- 6.67 kg; range 4 to 35 kg; mean age, 5.22 +/- 3.55 years; range 4 months to 1 year). All were premedicated with oral chloralhydrate 50 mg/kg, one hour preoperatively. Anesthesia was induced with sufentanil 1 microg/kg (Group I) or fentanyl 2 microg/kg (Group II) and thiopenthal 2 mg/kg, followed by atracurium 0.6 mg/kg. All patients were intubated with atracurium 0.6 mg/kg. Anesthesia was maintained using isoflurane in oxygen, nitrous oxide (in non-cyanotic patients). In Group I, sufentanil 0.5 microg/kg was administered intravenously prior to skin incision, median sternotomy, cardiopulmonary bypass (CPB) and after coming off CPB. In Group II, fentanyl 1 mg/kg was administered at the same time periods. Hemodynamic parameters, heart rate (HR), systolic (SBP), diastolic (DBP) and mean arterial blood pressure (MAP), central venous pressure (CVP) were recorded. The administration of pain therapy was determined postoperatively. There was no statistical difference in the demographic data between the patients in the two groups. Following induction of anesthesia, the systolic, diastolic and mean arterial pressures and heart rate decreased. Following tracheal intubation, all hemodynamic parameters in the sufentanil group remained below the baseline values, while the fentanyl group showed an increase above baseline values. An increase above control values of all hemodynamic variables was detected in both groups following skin incision and sternotomy, except that the mean systolic blood pressure and heart rate in the sufentanil group was less than the baseline values. No differences in hemodynamic variables were detected between the two groups following median sternotomy and skin closure. There were significant differences in mean arterial pressure at the time of intubation and skin incision between the two groups. No significant changes in CVP occurred. There were no significant differences in the average time of awakening from anesthesia. The average time before postoperative tracheal extubation was 171.38 +/- 112.74 and 113.72 +/- 67.83 minutes in the sufentanil group and fentanyl group respectively, which was statistically significant. There was no difference in the requirements for morphine (pain relief) and sedation with chlolorahydrate between the groups. Bradycardia was found in 7 and 3 patients receiving sufentanil and fentanyl respectively which was not statistically significantly different. The bradycardia recovered in a few minutes, following intravenous injection of atropine. Slow injection of the anesthetic drugs can protect patients against serious bradycardia. In conclusion, the safety and efficacy of sufentanil in patients undergoing repair of complex congenital heart defects was the same as fentanyl. There were no significant differences in times of awakening in the two groups. The patients in sufentanyl group had a longer time to extubate than the fentanyl group. The need of postoperative sedation and analgesia was the same in both groups.

Pain relief for post thoracotomy.

Fifty-nine patients undergoing thoracotomy were randomly divided into four groups to compare the postoperative analgesic effect of intraoperative intercostal nerve blocks with bupivacaine (group 2),or installation of bupivacaine into the pleural s pace (group 3), or epidermal morphine of 4 mg (group 4), as against a control group given intravenous morphine (group 1). The pain score was evaluated by visual analogue scale (VAS). The additional morphine intravenously administered was required for postoperative pain relief in all groups. Anyhow the group 4 patient had the lowest pain scores during the first 24-hours postoperative period.