Anesthetic management for coronary bypass patients on hemodialysis: report of 4 patients.

We reported our own experience in four patients with chronic renal failure on maintenance hemodialysis undergoing coronary artery bypass graft surgery (CABGS). A balanced general anesthesia with endotracheal intubation was successfully achieved by using midazolam, atracurium, fentanyl, pentothal, nitrous oxide in oxygen and isoflurane. All patients were hemodialyzed within 24 hours before operation. One patient started peritoneal dialysis 10 hours after surgery. Three other patients were managed by hemodialysis the day after surgery. There was no hospital mortality. Many aspects of management of these patients which differ from those of routine cardiac surgical patients are outlined and discussed.

Utility of intraoperative transesophageal echocardiogram in congenital heart disease.

Intraoperative transesophageal echocardiogram (TEE) has improved the perioperative outcome in adult patients. The purpose of the current study was to assess the benefit of intraoperative TEE in patients with congenital heart disease undergoing surgical correction (repair). The results of the patients who had consecutively undergone intraoperative TEE during their congenital heart surgery between January 1998 to June 2000 were reviewed. There were 104 patients (whose ages ranged from one week old to 50 years old (median 5 years old) and their weights from 3 kg to 79 kg (median 15 kg). A significant impact was said to have occurred if these findings prompted a change in surgical procedure following a prebypass study or rebypass for repair of a residual defect. Prebypass TEE had a significant impact in seven patients (6.7%). TEE could be used as a guide to help repair in three patients. The postbypass TEE examination had a significant impact in 15 patients (14.4%). Of these 15 patients, eight were detected primarily by TEE examination. The group of patients in whom TEE had the most significant impact was in patients who had surgery related to the repair of the atrioventricular valve (complete or partial atrioventricular (AV) canal repair, Ebstein's anomaly; 9 out of 22 patients; 41%). A less significant impact was found in surgery for other complex congenital defects (single ventricle or complete transposition of great arteries; eight out of 46 patients; 17.4%). TEE had limited impact in simple congenital lesion. Intraoperative TEE is valuable in the perioperative care of patients with congenital heart defects. We found the most benefit in patients with complete or partial AV canal and Ebstein's anomaly.

The Fontan operation: experience at Siriraj Hospital.

Seventy five patients underwent modified Fontan operation at Siriraj Hospital from October 1987 to December 1998. Cardiology data was analyzed retrospectively. Four patients' data was unavailable. Median age at operation was 9.7 (1.8-34) years old. Tricuspid atresia accounted for 38 per cent of the patients. Ten patients (14.1%) died in the acute post operative period due to consequence of low cardiac output. Another 3 patients (4.2%) expired in the intermediate and late post operative period. Age at operation, pulmonary artery size, pre-operative oxygen saturation, and mean pre-operative pulmonary artery pressure were not different between those who survived and those who died. Abnormal pulmonary vein, atrioventricular valve regurgitation, and underlying ventricular morphology statistically affected the acute survival of modified Fontan operation. Intraoperative aortic cross clamp time, and post operative mean pulmonary artery pressure on day 0, 1 and 2 post operation were found statistically shorter and lower in the survival group. Survival rate at 5 years was 83 per cent. Modified Fontan operation is the final palliative operation of choice for low risk single ventricle physiology in our institution with acceptable outcome. Thorough pre-operative hemodynamic and anatomic studies and staging modified Fontan procedure may include a higher number of candidates and improve the outcome of the operation.

Epidural analgesia for pain relief in thoracic surgery.

The effectiveness and adverse effects of continuous epidural analgesia was studied in 104 patients undergoing thoracic operations at Siriraj Hospital. Patients were divided into 3 groups according to the type of surgical approach and the technique of epidural analgesia. Group 1 patients (n = 72) received thoracic epidural block using bupivacaine and morphine combined with light general anesthesia for exploratory thoracotomy; group 2 patients (n = 21) received the identical anesthetic technique, the operation was achieved through median sternotomy; group 3 patients (n = 11) had a similar type of operation to group 1, the anesthetic technique was lumbar epidural block using morphine and combined with light general anesthesia. Continuous epidural morphine infusion was given 0.1-0.4 mg/h during postoperation in all patients for providing adequate pain relief. The results revealed that a 10 cm visual analogue scale (VAS) pain scores were satisfactory and comparable in all groups. Lumbar epidural patients consumed a significantly larger dose of morphine than thoracic epidural groups (P < 0.01). Intraoperative hypotension occurred 43.05 per cent and 19.05 per cent in group 1 and 2, but none was found in group 3 (P < 0.05). Postoperative respiratory depression was found 54.16 per cent in group 1, 33.33 per cent in group 2 and 9.09 per cent in group 3 (P < 0.05), and was mostly mild to moderate, except three patients in group 1 and one in group 2 who needed mechanical ventilatory support. There were no differences among the groups in the incidence of nausea/vomiting and pruritus. It is concluded that both thoracic and lumbar epidural morphine provide excellent postthoracotomy pain relief, whereas, respiratory depression is more common with thoracic than lumbar epidural morphine.

Results of rapid two-stage arterial switch operation in patients with transposition of the great arteries: one-year postoperation.

The rapid two-stage arterial switch operation is an alternative therapy for patients with simple transposition of the great arteries who present beyond the neonatal period and have low left ventricular pressure. It provides normal ventricular function compared to the atrial switch operation. Between July 1994 and February 1997, there were 13 such infants who had rapid two-stage arterial switch operation performed at Siriraj Hospital. There was 1 late death (11 months after the operation). All 12 survivors (mean age 22.4 +/- 5.7 months) were clinically evaluated and had echocardiography performed at 14.8 +/- 4.9 months after the operation. All were asymptomatic. Echocardiogram revealed a residual small atrial septal defect (1 case), small ventricular septal defect (1 case), mild supravalvar neopulmonary stenosis (2 cases), bicuspid neoaortic valve without stenosis (2 cases), dilated neoaortic sinus of Valsalva (6 cases, 50%) and mild neoaortic insufficiency (11 cases, 91.7%). The left ventricular function was hyperdynamic after pulmonary artery banding and significantly decreased to normal level at the time of study (shortening fraction of 43.8 +/- 10.7 vs 29.2 +/- 3.8%, respectively, p = 0.0005). The wall thickness was significantly increased after pulmonary artery banding and decreased overtime (0.48 +/- 0.08 vs 0.32 +/- 0.05 cm, respectively, p < 0.0005). The left ventricular dimension was significantly increased both after pulmonary artery banding and at the time of study (2.06 +/- 0.42 vs 3.32 +/- 0.30 cm, respectively, p < 0.0005). The left ventricular mass was significantly increased after pulmonary artery banding and at the time of study (21.79 +/- 7.79 vs 33.08 +/- 7.40 g/m2, respectively, p = 0.0005). The mortality and morbidity of rapid two-stage arterial switch operation are low. However, long-term follow-up should be monitored.

Early extubation following open heart surgery in pediatric patients with congenital heart diseases.

The study of tracheal extubation time in pediatric patients who underwent open heart surgery was performed in the period of 1990-1991 (group 1) and 1992-May 1994 (group 2), composed of 174 and 208 cases in group 1 and group 2 respectively. The criteria for extubation in these patients are convention regimens with considered subsequent standard of CPB, such as fully rewarmed, hemodynamic stable with adequate cardiac output with low-dose or no inotropes/ vasodilator, without significant dysrhythmias and no significant mediastinal bleeding. The difference of postoperative fluid management between the two groups include the regimens of total fluid intake of two-thirds of daily maintenance fluid in group 1, whereas, the total fluid therapy of group 2 depended on the patients' age and body weight. The results show that, early extubation within 8 hours of ICU arrival were 20.5 per cent and 61.7 per cent in group 1 and group 2 respectively. All of the patients in group 2, after extubation, were discharged to the ward on the first postoperative day. The overnight ventilation was about 74.1 per cent and 30.6 per cent in the first and second groups respectively. The prolonged intubation (more than 24 hours) was almost the same in two groups. There was no significant complication of early extubation with the limitation of daily total fluid intake. The causes of tracheal reintubation in both groups were fluid overload and residual cardiac lesions. The prior etiology occurred in group 1 more than group 2. It was concluded that, after the change in postoperative fluid therapy regimens, early extubation following open-heart pediatric surgery is highly successful with no significant complication. The benefits of early extubation include cost savings, patient comfort, early patient mobilization, improved cardiac function, reduced respiratory complications and reduction of case cancellation due to early ICU discharge.

Combined thoracic epidural with light general anesthesia for thymectomy in myasthenia gravis.

Forty-seven myasthenia gravis patients undergoing transsternal thymectomy were allocated into 2 groups. Group 1 which consisted of 27 patients was anesthetized using the balanced technique, while 20 patients in group 2 received the combination of thoracic and balanced anethesia. The ventilation was controlled through the endotracheal tube in both groups. The extubation criteria after performing the surgery were good consciousness, adequate muscle strength and adequate respiration. There were 29.2 per cent in group 1 but 77.8 per cent in group 2 (P = 0.002) with successful extubation immediately postoperation. Morphine 15.4 +/- 5.3 mg intramuscularly in group 1, and 6.5 +/- 1.2 mg epidurally in group 2 (P < 0.001) was given for postoperative analgesia. Adequacy of respiration was observed postoperatively in the intensive care unit (ICU). Group 1 patients required 76.9 per cent of further ventilatory support for the period of 37.11 +/- 39.54 hours and duration of the ICU stay was 65.52 +/- 85.84 hours, whereas, the patients in group 2 showed significantly different results, which were 15.8 per cent of ventilatory support (P = 0.002) for 10.33 +/- 6.03 hours (P = 0.014) and 22.8 +/- 8.06 hours for staying in ICU (P = 0.021). This study demonstrated that the combined thoracic epidural with light general anesthesia provides excellent intraoperative anesthesia together with postoperative analgesia, which reduces the need for postoperative respiratory support, as well as decreases the hospital cost.

Intraoperative transesophageal echocardiography: preliminary experience at Siriraj hospital.

In order to evaluate the result of intraoperative TEE monitoring for cardiothoracic surgery, 113 patients were involved in this study. They included 65 males and 48 females, with an average age of 48.8 +/- 16.6 years, ranging from 10 to 74 years. The pre-operative diagnoses consisted of 41.6 per cent coronary artery disease, 34.5 per cent valvular disease, 12.4 per cent congenital heart disease, 8 per cent aortic aneurysm or aortic dissection, and 3.5 per cent of miscellaneous. The TEE appeared to provide accurate information by beating to changes in the left ventricular preload and contractility in all patients. The severity of valvular dysfunction, intracardiac air/mass, Swan Ganz catheter position, sites of congenital heart defect and aortic dissection were either assessed or reconfirmed during the operation. The ease of TEE technique was satisfactory, since unsuccessful attempt was observed in only 1.8 per cent. One patient died from rupture of thoracic aortic dissection which was related to TEE probe insertion. These data suggest the favorable result of intraoperative TEE as a valuable tool for monitoring in cardiothoracic surgery. Although the technique is simple, special precaution must be observed for patients suffering from acute aortic dissection.

Acute hemodilution and autotransfusion in cardiac surgery: a comparison between rather healthy and high risk patients.

The effects of acute normovolemic hemodilution and autologous blood transfusion were studied in open heart patients, compared with rather healthy patients, NYHA class 1-2 and the high risk patients, NYHA class >2. Thirty-nine patients were involved in this study, 15 of them were identified as the rather healthy group while 24 patients belonged to the high risk group. Acute hemodilution was performed after anesthetic induction and before heparinization. Using an equal volume of polygeline 3.5 per cent (Haemaccel) to replace autologous blood removal, the number of patients who needed inotropic support to achieve normal arterial blood pressure was not significantly different between the groups. Following retransfusion of pump perfusate and autologous blood after the termination cardiopulmonary bypass, the number of patients who received additional homologous blood as well as the amount used percase were significantly less in the rather healthy patients. There was none in this group, but half of the high risk patients suffered from serious perioperative complications and one died. We conclude that this technique is safe and benefits blood conservation in rather healthy cardiac patients undergoing open heart surgery, but special precautions against risk should be considered in high risk patients.

Anaesthetic management of a parturient with eisenmenger’s syndrome.

The case of a parturient with Eisenmenger’s syndrome from an uncorrected ASD is reported. She was admintted to the hospital because of tiredness and cyanosis. She had labor pain at the end of 35th week gestational age. The obstetrician decided she should undergo caesarean section. A balanced general anaesthesia with endotracheal tube was successfully achieved by using fentanyl, pentothal, artacurium, midazolam, oxygen and halothane. Mild hypotension which occurred shortly after delivery of the foetus was promptly treated with volume and vasopressor. No serious complication was found in the postpartum period.

Autologous blood and platelet-rich plasma reinfusion reduce post-operative blood and blood component therapy after cardiopulmonary bypass.

To study blood and blood component transfusion following reinfusion of platelet-rich plasma (PRP)/and autologous blood, 33 patients undergoing open-heart surgery were randomly divided into three groups. Group I comprised 13 patients as controls; group II, eight patients from whom were collected PRP 15-20 percent of plasma volume with Haemonetics; and group III, 12 patients from whom were collected PRP and whole blood (400-800 ml) before initiating standardized cardiopulmonary bypass. All of them had balanced anesthesia with thiopental, fentanyl, midazolam, atracurium and nitrous oxide in oxygen. After heparin reversal, PRP/PRP and autologous blood were reinfused in groups II and III, respectively. Recording of hematocrit, blood loss as well as the total number of transfusion was performed. In three groups, significant low levels of hematocrit were seen after cardiopulmonary bypass. Groups II and III has less blood loss after the operation as well as less banked blood and blood products transfusion (p<0.05). In conclusion, the reinfusion of PRP/PRP and autologous blood may serve as an effective method for reducing the amount of banked blood and blood products given in transfusion following cardiac operation.

Comparison of the hemodynamic changes following left atrial and peripheral venous administration of protamine during cardiac surgery.

The hemodynamic effects of left atrial administration of protamine for heparin reversal were compared with the peripheral venous route. One hundred patients, undergoing cardiac surgery, using cardiopulmonary bypass (CPB) at Siriraj hospital were randomly allocated into two equal groups of fifty. The preoperative and operative characteristics of the two groups were comparable. After the termination of CPB, protamine sulfate was administered over 3 minutes via the left atrium in group I, and via the peripheral vein in group II. The hemodynamics were measured before and 5, 15 and 30 minutes after protamine administration. There were no statistically significant differences in heart rate (HR), arterial blood pressure (BP), and central venous pressure (CVP) between the groups. After administrating protamine and adequate maintaining the preload in both groups of patients within the normal range, the HR did not change from immediate post CBP control values. The arterial BP was not changed for 5 minutes, thereafter, significantly elevated toward the preoperative baseline values. This data indicates that the left atrial injection of protamine does not provide any hemodynamic advantages over the peripheral venous administration.

The effects of protamine on hemodynamics and oxygenation during cardiac surgery.

The cardiopulmonary effect of protamine for heparin reversal was investigated in 100 patients, undergoing cardiac surgery, using cardiopulmonary bypass (CPB) at Siriraj hospital. Protamine sulfate at approximately equal to the amount of heparin was intravenously administered over 3 minutes after termination of CPB, together with rapid blood transfusion to establish the optimal level of central venous pressure. Following protamine administration, the heart rate was measured at 5, 15 and 30 minutes, and was not significantly different from the preoperative and post CPB values. The blood pressure was significantly decreased in the initial post CPB (P less than 0.05) and remained unchanged 5 minutes following intravenous protamine, thereafter, significantly rose to preoperative values. The arterial oxygen tension post CPB revealed shunting effect, but showed no significant change following protamine administration. The occurrence of cardiopulmonary adverse effect was not demonstrated in this study.

Increased fibrinolysis and changes in blood coagulation during epidural block for transurethral prostatectomy.

Epidural analgesia is the choice of anesthesia for transurethral prostatectomy (TURP). Unfortunately, this technique may increase fibrinolysis as well as decrease in fibrinogen and platelets count, which might cause deleterious bleeding problem during the procedure performed under epidural block. The present study was therefore undertake to assess the degree of increased fibrinolysis and changes in coagulation profiles during epidural anesthesia for TURP. Twenty patients aged from 57 to 83 years were studied. Group 1 of 7 patients did not receive antifibrinolysin (transamin) after 20 minutes following epidural block. Group 11 of 13 patients did not receive transamin intravenously. Blood samples were drawn for euglobulinlysis time (ELT), fibrinogen, platelets, haemoglobin, prothrombin time (PT) and partial thromboplastin time (PTT). The sampling periods included pre-epidural block as baseline values, 10 and 45 minutes after epidural block and the last was obtained immediately after the completion of surgery. The study revealed the same degree of increased fibrinolysis in both groups tested ten minutes after epidural analgesia and throughout the entire operation. There were no statistical significant changes in fibrinogen level, PT and PTT. The platelet counts decreased from the baseline values in group 1 more than group 11, but the quantities were within normal ranges. The results indicated that fibrinolysis following epidural analgesia for TURP increased in the same degree in all patients if either they received transamin or not. Furthermore, the increased fibrinolytic activity did not lead to a problem of blood loss in this study.