Correlation of Blood Lactate and Mixed Venous Oxygen Saturation in Off-Pump CABG

Aim: To evaluate the correlation of blood lactate and mixed venous oxygen saturation to predict outcome in off-pump coronary artery bypass grafting. Method: This is a randomized study including 30 patients. Blood lactate and mixed venous oxygen saturation were measured in 4 groups of patients—number of grafts, presence or absence of left main coronary artery disease, ejection fraction and serum creatinine. Blood samples were taken before induction, after grafting, on intensive care unit admission, 24 hours and 48 hours after surgery. The measured blood lactate and mixed venous oxygen saturation are compared to assess the outcomes in terms of duration of ventilation and intensive care unit stay. Results: The blood lactate and mixed venous oxygen saturation values increased post operatively but no statistically significant difference in three groups— number of grafts, left main coronary artery disease and ejection fraction. In serum creatinine group, the blood lactate value was found to be statistically significant after grafting in patients with creatinine <1.5 mg/dl, however, there was a significant disparity in numbers. Conclusion: Mixed venous oxygen saturation is a better predictor of morbidity than blood lactate in terms of intensive care unit stay in patients undergoing off pump coronary artery bypass grafting.

Oxygen Concentration during Reperfusion in Mitral Valve Surgery

Background: By lowering the oxygen fraction of the reperfusate, the reactive oxygen-derived free radicals can be reduced thus facilitating myocardial recovery during weaning from cardiopulmonary bypass and after surgery. Materials & Methods: Thirty patients undergoing mitral valve replacement were randomly exposed to an oxygen fraction of 0.7 (hyperoxic, n = 15) or 0.5 (normoxic, n = 15) during reperfusion. Hemodynamic variables, number of patients requiring additional inotropes and who developed new arrhythmia, duration of ventilation and intensive care unit stay, arterial blood gas and renal function were measured. Results: The demographic data, duration of cardiopulmonary bypass, aortic cross clamp time, duration of mechanical ventilation, intensive care unit stay, additional inotropes, arrhythmia after reperfusion and renal function were similar in both groups. Arterial blood gas analysis was not significantly different, except for the low oxygen partial pressure in the normoxic group during reperfusion. With regard to hemodynamic variables, mean arterial pressure of the hyperoxic group was higher one hour after the cross clamp release. Hemodynamic variables were comparable in all other time periods. Conclusion: By reducing the oxygen concentration during reperfusion, the clinical outcomes in terms of inotropes usage, new arrhythmia after reperfusion, renal function, duration of ventilation and intensive care unit stay were not significantly altered.

Complex TAPVC-Experience with Six Patients

Total anomalous pulmonary venous connection becomes a totally different subset when associated with complex congenital anomalies. The combination of two separate life-threatening congenital heart defects complicates the management of these patients. Six patients with total anomalous pulmonary venous connection associated with complex congenital heart disease were studied. There were 2 girls and 4 boys. Three of them were less than 5 kg in weight, and the other 3 were more than 5 kg in weight. Four patients had severe pulmonary arterial hypertension and 2 patients had pulmonary stenosis. Three patients had supracardiac type with a right vertical vein, one had drainage to the right atrium superior vena cava junction, one patient had supra cardiac type but split flow to both the superior vena cava and one patient had cardiac type. Three patients had double outlet right ventricle. Three patients had atrioventricular canal defect and 2 patients had preoperative pulmonary vein obstruction. All patients underwent rerouting of pulmonary veins. Concomitant procedures included intraventricular tunnel repair of ventricular septal defect and infundibular resection in double outlet right ventricle. Atrioventricular canal repair was done for Rastelli type A atrioventricular canal. Superior vena caval plasty, atrioventricular canal repair and pulmonary artery banding were done in unbalanced atrioventricular septal defect and large double outlet right ventricle. Intracardiac repair through transatrial approach was done for tetralogy of Fallot. Right ventricle-pulmonary artery conduit was done for truncus arteriosus. Single ventricle repair was done for corrected transposition of great arteries. There were 2 hospital deaths.

Three Cases of ALCAPA with Associated Anomalies

There are several potential issues that affect the treatment and diagnostic pattern of anomalous left coronary artery arising from the pulmonary artery. We report three cases of infants who presented with anomalous left coronary artery arising from the pulmonary artery with severe left ventricular dysfunction and severe mitral regurgitation along with associated anomalies. One patient had congenital lobar emphysema of the right midde lobe. Another patient had left main stem bronchus compression, collapse of basal segments of left lower lobe and panlobular emphysema in medial basal segment of right lower lobe. The third patient had cleft lip and palate. All patients underwent successful repair. The hemodynamic stability was compromised when the infant with congenital lobar emphysema had spontaneous pneumothorax after extubation and she needed an intercostal drainage. The infant with lung collapse had to be reintubated on the second day since she became hypoxic due to recollapse of the lung once the airway positive pressure was removed. She needed chest physiotherapy, vigorous endotracheal suctioning and inhaled bronchodilator therapy. The patient who had cleft palate succumbed to aspiration pneumonitis in the postoperative period. Follow-up of other two patients after three months showed very good improvement in left ventricular systolic function.