Vishwas Malik

Myocardial injury in coronary artery bypass grafting: On-pump versus off-pump comparison by measuring high-sensitivity C-reactive protein, cardiac troponin I, heart-type fatty acid-binding protein, creatine kinase- MB, and myoglobin release

OBJECTIVES We sought to investigate the release pattern of different cardiac biomarkers (high-sensitivity C-reactive protein, cardiac troponin I, heart-type fatty acid-binding protein, creatine kinase-MB, and myoglobin) and to establish the diagnostic discrimination limits of each marker protein to evaluate perioperative myocardial injury in patients undergoing coronary artery bypass grafting with or without cardiopulmonary bypass. METHODS Fifty patients were randomly assigned to on-pump or off-pump coronary artery bypass grafting. All cardiac biomarkers were measured in serial venous blood samples drawn before heparinization in both groups and after aortic unclamping at 1, 2, 4, 8, 24, 48, and 72 hours in the on-pump group. In the off-pump group samples were taken after the last distal anastomosis and at same time intervals as in the on-pump group. RESULTS The total amount of heart-type fatty acid-binding protein, cardiac troponin I, and high-sensitivity C-reactive protein released was significantly higher in the on-pump group than in the off-pump group. Receiver operating characteristic curve analysis of cardiac biomarkers indicated cardiac troponin I and heart-type fatty acid-binding protein as the superior diagnostic discriminators of myocardial injury, with an optimal cutoff value of greater than 0.92 ng/mL (area under the curve, 0.95 [95% CI, 0.88-1.00]; sensitivity, 92%; specificity, 92%; likelihood ratio [+], 11.50) and greater than 6.8 ng/mL (area under the curve, 0.94 [95% CI, 0.88-1.00]; sensitivity, 88%; specificity, 88%; likelihood ratio [+], 7.33), respectively. Logistic regression analysis revealed that patients with increased cardiac troponin I levels of greater than 0.92 ng/mL and heart-type fatty acid-binding protein levels of greater than 6.8 ng/mL were at 132.25 (95% confidence interval, 17.14-1020.49) times and 53.77 (95% confidence interval, 9.76-296.12) times higher risk of myocardial injury after on-pump coronary artery bypass grafting. CONCLUSIONS Off-pump coronary artery bypass grafting provides better myocardial protection than on-pump coronary artery bypass grafting. Cardiac troponin I and heart-type fatty acid-binding protein, but not high-sensitivity C-reactive protein, served as superior diagnostic discriminators of perioperative myocardial damage after on-pump coronary artery bypass grafting.

Extra corporeal membrane oxygenation after pediatric cardiac surgery: a 10 year experience.

Indications for extra corporeal membrane oxygenation (ECMO) after pediatric cardiac surgery have been increasing despite the absence of encouraging survival statistics. Modification of ECMO circuit led to the development of integrated ECMO cardiopulmonary bypass (CPB) circuit at the authors institute, for children undergoing repair of transposition of great arteries among other congenital heart diseases (CHD). In this report, they analyzed the outcome of children with CHD, undergoing surgical repair and administered ECMO support in the last 10 years. The outcome was analyzed with reference to the timing of intervention, use of integrated ECMO-CPB circuit, indication for ECMO support, duration of ECMO run and the underlying CHD. The results reveal a significantly improved survival rate with the use of integrated ECMO-CPB circuit and early time of intervention rather than using ECMO as a last resort in the management. The patients with reactive pulmonary artery hypertension respond favorably to ECMO support. In all scenarios, early intervention is the key to survival.

Is EuroSCORE applicable to Indian patients undergoing cardiac surgery

Indian patients undergoing cardiac surgery have different demographics, clinical profile as well as risk profile, compared to the western population. The purpose of this study was to validate the European System for Cardiac Operative Risk Evaluation (EuroSCORE) risk stratification model in Indian patients undergoing cardiac surgery in a single cardiac center. Data from 1000 consecutive adult patients undergoing cardiac surgery (coronary artery bypass grafting or valve surgery) were prospectively collected as per the EuroSCORE model. The models validity was assessed on the basis of its calibration power (Hosmer-Lemeshow test) and discriminatory power [area under receiver operating characteristic curve]. The patients were divided into three risk groups on the basis of their EuroSCORE. The Hosmer-Lemeshow test revealed a good calibration power (P = 0.73) and the area under the ROC curve was 0.8278, suggesting a good discriminative power. The predicted mortality was similar to observed mortality in low- and moderate-risk patients but the observed mortality in high-risk patients (15.6%) was double that of predicted mortality (7.5%). The risk factors prevalent in European population were not observed in Indian population. EuroSCORE accurately predicts mortality in low and moderate-risk Indian patients undergoing cardiac surgery but is less predictive for high-risk Indian patients. Updating and improvisation of EuroSCORE by incorporation of risk factors associated with rheumatic valvular heart disease which is more prevalent in India, may enable it to accurately predict mortality in high-risk patients also.

A Randomized Controlled Study to Compare the Total and Hidden Blood Loss in Computer- Assisted Surgery and Conventional Surgical Technique of Total Knee Replacement

Background Total knee arthroplasty (TKA) is associated with considerable blood loss. Computer-assisted surgery (CAS) is different from conventional TKA as it avoids opening the intramedullary canal. Hence, CAS should be associated with less blood loss. Methods Fifty-seven patients were randomized into two groups of CAS and conventional TKA. In conventional group intramedullary femoral and extramedullary tibial jigs were used whereas in CAS group imageless navigation system was used. All surgeries were done under tourniquet. Total and hidden blood loss was calculated in both groups and compared. Results The mean total blood loss was 980 mL in conventional group and 970 mL in CAS group with median of 1,067 mL (range, 59 to 1,791 mL) in conventional group and 863 mL (range, 111 to 2,032 mL) in CAS group. There was no significant difference in total blood loss between the two groups (p = 0.811). We have found significant hidden blood loss in both techniques, which is 54.8% of the total loss in the conventional technique and 59.5% in the computer-assisted navigation technique. Conclusions There is no significant difference in total and hidden blood loss in the TKA in CAS and conventional TKA. However, there is significant hidden blood loss in both techniques. There was no relation of tourniquet time with blood loss.

Ketamine-etomidate for children undergoing cardiac catheterization.

The purpose of this study was to determine the effects of combined low-dose ketamine and etomidate on hemodynamics during cardiac catheterization in children with congenital cardiac shunts. Sixty children undergoing routine diagnostic cardiac catheterization were included: 30 had a right-to-left shunt, and 30 had a left-to-right shunt. Both groups were given a single dose of etomidate 0.3 mg·kg−1 with ketamine 1 mg·kg−1. There were no hemodynamic changes in the group with a right-to-left shunt. In cases of left-to-right shunt, there were significant differences in heart rate, right atrial pressure, mean arterial pressure, mean pulmonary artery pressure, pulmonary artery wedge pressure, and systemic vascular resistance index. Decreases in pulmonary blood flow and pulmonary-systemic shunt ratio were also observed. Further studies are required with dose titration of this anesthetic combination in pediatric patients with congenital heart disease involving a left-to-right shunt.

Recombinant activated factor VII in cardiac surgery: single-center experience

Background the widespread off-label use of recombinant activated factor VII for the control of refractory postoperative hemorrhage continues despite a warning from the Food and Drug Administration. Although effective in reducing the need for transfusion of blood and blood products, safety concerns still prevail. Objective to compare the dosing and efficacy of recombinant activated factor VII between pediatric and adult patients, and in the operating room and intensive care unit. Methods the records of 69 patients (33 children and 36 adults) who underwent cardiovascular surgery and received recombinant activated factor VII were reviewed retrospectively. The dose of recombinant activated factor VII, mediastinal drainage, use of blood and blood products, incidence of thrombosis, and 28-day mortality were studied. Results the efficacy of recombinant activated factor VII was comparable in adults and children, despite the lower dose in adults. Prophylactic use of recombinant activated factor VII decreased the incidence of mediastinal exploration and the duration of intensive care unit stay. A 4.3% incidence of thrombotic complications was observed in this study. Conclusion the efficacious dose of recombinant activated factor VII is much less in adults compared to children. Prophylactic use of recombinant activated factor VII decreases the dose required, the incidence of mediastinal exploration, and intensive care unit stay, with no survival benefit.

Modified Blalock Taussig shunt: Comparison between neonates, infants and older children

OBJECTIVE The aim was to compare various pre-and post-operative parameters and to identify the predictors of mortality in neonates, infants, and older children undergoing Modified Blalock Taussig shunt (MBTS). MATERIALS AND METHODS Medical records of 134 children who underwent MBTS over a period of 2 years through thoracotomy were reviewed. Children were divided into three groups-neonates, infants, and older children. For analysis, various pre-and post-operative variables were recorded, including complications and mortality. RESULTS The increase in PaO 2 and SaO 2 levels after surgery was similar and statistically significant in all the three groups. The requirement of adrenaline, duration of ventilation and mortality was significantly higher in neonates. The overall mortality and infant mortality was 4.5% and 8%, respectively. CONCLUSION Neonates are at increased risk of complications and mortality compared with older children. Age (<30 days), weight (<3 kg), packed red blood cells transfusion >6 ml/kg, mechanical ventilation >24 h and post shunt increase in PaO 2 (P Diff) <25% of baseline PaO 2 are independent predictors of mortality in children undergoing MBTS.

Use of extracorporeal membrane oxygenator support to salvage an infant with anomalous left coronary artery from pulmonary artery.

Anomalous left coronary artery from pulmonary artery (ALCAPA) is a congenital acyanotic heart disease where the left coronary artery (LCA) arises from the pulmonary artery. This results in the LCA receiving blood supply from the low-pressure right ventricle having minimal extractable oxygen. The oxygen delivery to the left ventricle (LV) is severely hampered causing severe hypoxic LV dysfunction early in life. Early surgery prior to serious, irreversible LV dysfunction is the key to survival. Children with ALCAPA usually present in their first few weeks of life, with severe LV dysfunction. After surgical correction of the defect, the myocardium may not recover early from the presurgery myocardial dysfunction. We describe a case where extracorporeal membrane oxygenator was utilized as a means of ventricular support during this critical postoperative period resulting in a favorable outcome.

Atrial switch operation in a patient with dextrocardia, bilateral superior vena cavae, left atrial isomerism and unroofed coronary sinus.

The present report describes the technical aspects of the atrial switch operation in the setting of dextrocardia, bilateral superior vena cavae, left atrial isomerism, and unroofed coronary sinus. Augmentation of the right atrial wall using bovine pericardium and in situ pericardial technique for construction of the pulmonary venous baffle ensured unobstructed systemic and pulmonary venous pathways.

A Prospective Randomized Study to Compare Systemic Emboli Using the Computer-Assisted and Conventional Techniques of Total Knee Arthroplasty

BACKGROUND Conventional total knee arthroplasty is performed with use of an intramedullary alignment guide, which produces elevated intramedullary pressure that can create fat emboli. Total knee arthroplasty performed via computer-assisted surgery does not require an intramedullary femoral rod, raising the question of whether computer-assisted surgery generates less embolic material than conventional total knee arthroplasty. The purpose of this study was to compare the emboli produced in the two techniques. METHODS Fifty-seven patients were randomized into two groups: the computer-assisted surgery group (n = 29) and the conventional total knee arthroplasty group (n = 28). An intramedullary femoral alignment jig was used in the conventional total knee arthroplasty group but not in the computer-assisted surgery group. Intraoperative invasive monitoring was performed with use of transesophageal echocardiography and a pulmonary artery catheter. RESULTS The mean embolic score was 6.21 points for the conventional technique group and 5.48 points for the computer-assisted surgery group (p = 0.0161). After tourniquet deflation, fat emboli were observed in the blood of five patients in the conventional surgery group and one patient in the computer-assisted surgery group. CONCLUSIONS The patients in the computer-assisted surgery group had lower embolic loads compared with the patients in the conventional total knee arthroplasty group. In patients with an uncompromised cardiopulmonary system, the embolic load difference between the techniques was not clinically relevant. LEVEL OF EVIDENCE Therapeutic Level I. See Instructions for Authors for a complete description of levels of evidence.