Madhur Malik

Arterial pressure waveform derived cardiac output FloTrac/Vigileo system (third generation software): comparison of two monitoring sites with the thermodilution cardiac output

The present study was conducted to study the effect of monitoring site, radial or femoral, for arterial pressure waveform derived cardiac output using FloTrac/Vigileo system with third generation software version 3.02 during cardiac surgery. The cardiac output derived from the two sites was also compared to the pulmonary artery catheter (PAC) derived cardiac output to reevaluate the relation between them using the newer software. The effect of cardiopulmonary bypass (CPB) was also studied by doing the sub analysis before and after bypass. Forty patients undergoing coronary artery bypass surgery with cardiopulmonary bypass were enrolled in the study. Cardiac output derived from radial artery (RADCO), femoral artery (FEMCO) using FloTrac/Vigileo system with third generation software version 3.02 and cardiac output using pulmonary artery catheter (PACCO) at predefined nine time points were recorded. Three hundred and forty two cardiac output data triplets were analysed. The Bland–Altman analysis of RADCO and FEMCO revealed a mean bias of −0.28 with percentage error of 20%. The pre CPB precision of both RADCO and FEMCO was 1.25 times as that of PACCO. The post CPB precision of FEMCO was 1.2 times of PACCO while that of RADCO was 1.7 times of PACCO. The third generation of FloTrac/Vigileo system shows good correlation between the radial and femoral derived cardiac outputs in both pre and post bypass periods. The newer software correlates better to PAC derived cardiac output in the post bypass period for femoral artery than radial artery.

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 comparison of external and internal jugular venous pressures to monitor pulmonary artery pressure after superior cavopulmonary anastomosis

The internal jugular vein continues to be the preferred site for cannulation to monitor central venous pressure despite the reported evidence of the accuracy of external jugular venous pressure (EJVP) to reliably predict internal jugular venous pressure (IJVP). Internal jugular venous cannulation carries a risk of thrombosis that can be life-threatening in children undergoing superior cavopulmonary anastomosis and a subsequent Fontan procedure. The present study compared IJVP and EJVP in children undergoing superior cavopulmonary anastomosis and found no statistical and clinical difference between IJVP and EJVP. Thus, external jugular vein cannulation reliably predicts IJVP and pulmonary artery pressures in children undergoing superior cavopulmonary anastomosis, and may obviate the risk of life-threatening cavopulmonary thrombosis.

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.

Congenital heart surgery outcome analysis: Indian experience

Background The study aimed to analyze the outcome of congenital heart surgery in a subset of Indian patients, using the Aristotle Basic Complexity score, the Risk Adjustment for Congenital Heart Surgery categories, and the Society of Thoracic Surgeons and European Association for Cardiothoracic Surgery mortality categories. Patients and methods 1312 patients <18 years of age undergoing congenital heart surgery were assigned the 3 scores and studied for outcome indices of difficulty (cardiopulmonary bypass time or duration of surgery >120 min), morbidity (intensive care unit stay >7 days), and mortality. Results The overall mortality was 6.85%, with mean a Aristotle Basic Complexity score, Risk Adjustment for Congenital Heart Surgery category, and Society of Thoracic Surgeons and European Association for Cardiothoracic Surgery mortality category of 7.17 ± 2.04, 2.28 ± 0.78, and 2.24 ± 1.06, respectively. The mortality predictive capacity of the Risk Adjustment for Congenital Heart Surgery category (c = 0.76) was similar to that of the Society of Thoracic Surgeons and European Association for Cardiothoracic Surgery mortality category (c = 0.75); both were better compared to the Aristotle Basic Complexity score (c = 0.66). The Risk Adjustment for Congenital Heart Surgery category and Aristotle Basic Complexity score correlated with morbidity and difficulty outcomes. Conclusion The study shows that the Aristotle Basic Complexity score, the Risk Adjustment for Congenital Heart Surgery category, and the Society of Thoracic Surgeons and European Association for Cardiothoracic Surgery mortality category are tools of case mix stratification to analyze congenital heart surgery outcomes in a subset of the Indian population.

Preanesthesia assessment clinic for cardiac surgery by cardiac anesthesiologist: A practice statement

1. Rodríguez‐Niedenführ M, Vázquez T, Nearn L, Ferreira B, Parkin I, Sañudo JR. Variations of the arterial pattern in the upper limb revisited: A morphological and statistical study, with a review of the literature. J Anat 2001;199:547‐66. 2. Wood SJ, Abrahams PH, Sañudo JR, Ferreira BJ. Bilateral superficial radial artery at the wrist associated with a radial origin of a unilateral median artery. J Anat 1996;189:691‐3. 3. Sen S, Chini EN, Brown MJ. Complications after unintentional intra‐arterial injection of drugs: Risks, outcomes, and management strategies. Mayo Clin Proc 2005;80:783‐95. 4. Ghouri AF, Mading W, Prabaker K. Accidental intraarterial drug injections via intravascular catheters placed on the dorsum of the hand. Anesth Analg 2002;95:487‐91.

In response to, "The application of European system for cardiac operative risk evaluation II and society of thoracic surgeons risk score for risk stratification in Indian patients undergoing cardiac surgery"

only and accurate estimation in low and moderate risk patients. 2. The authors have pointed out only 10% of their patients had RHD, which is a major cause for patients undergoing cardiac surgery in India. Our study had approximately 571 (57.1%) patients with RHD. The authors did not include patients undergoing off‐pump coronary artery bypass grafting (CABG). One of the largest series of off‐pump CABG is from India[3] and India is one of the leading countries in terms of the number of off‐pump CABG performed annually. Therefore, we believe that the population sample studied by the authors does not truly reflect Indian population. 3. The authors have also shown that Indian patients are younger at the time of cardiac surgery. In addition, they found a higher prevalence of peripheral arterial disease, chronic obstructive pulmonary disease and history of cerebrovascular accident at a young age, which is alarming. However, our study showed low prevalence of these factors, the discrepancy could be ascribed to the inclusion of the higher number of patients with RHD and younger age at surgery.[2]

Anesthesia for an infant with Beckwith-Wiedman syndrome who underwent open heart surgery for complete atrioventricular canal defect.

SIR—Beckwith–Wiedemann syndrome (BWS), as originally described by Beckwith and Wiedemann, presents clinically as exomphalos, gigantism, and macroglossia (1). The latter feature can lead to sleep apnea and subsequent unfavorable perioperative outcome in terms of hypoxemia, encephalopathy, and postoperative infection in a cardiac surgical patient (2). Although this syndrome is not very rare, Medline search did not display such type of patients who underwent cardiac surgery involving cardiopulmonary bypass (CPB). We report a case of BWS who underwent a complex cardiac surgery under CPB. A 26-day-old full-term infant weighing 2.6 kg with BWS was referred to our center with the diagnosis of complete atrioventricular (AV) canal defect and congestive heart failure. On examination, he had prominent eyes, protruded tongue, macroglossia, omphalocele major, hepato splenomegaly, and clinical features of AV canal defect. His hematological parameters and blood chemistry were within normal range. Chest radiograph, electrocardiograph, and transthoracic echocardiography confirmed the diagnosis. Cardiac catheterization showed the presence of complete atrioventricular canal defect and large dilated pulmonary artery. His pulmonary artery pressure (PAP), pulmonary to systemic blood flow ratio (QP : QS), and pulmonary vascular resistance were 83/25 mmHg, 5.1 : 1.8, and 5.2 Woods unit, respectively. Anesthetic management of such a case requires knowledge of both the clinical conditions. Apart from the routine anesthetic management of a child undergoing cardiac surgery on CPB, special emphasis was placed on anticipated difficult intubation, increased PAPs, and management of blood sugar levels. Macroglossia creates a precarious situation in such cases as a light anesthesia/ awake intubation is not possible for fear of increasing PAP as well as neurological complications (1,3), and a deep anesthesia can cause tongue to fall in retro lingual space resulting in severe airway obstruction (1). We were able to intubate our patient in third attempt with intubation aids. Anesthesia was maintained with air/oxygen mixture (50 : 50) along with intermittent doses of midazolam, fentanyl, and pancuronium bromide. The infant was mechanically ventilated with a tidal volume of 10 ml kg 1 and respiratory rate of 40 per minute and I : E ratio of 1 : 2. A Nasogastric tube was inserted for abdominal decompression. He received injection methylprednisolone 30 mg kg 1 and phenoxybenzamine 1 mg kg 1 postinduction. One episode of sudden ventricular fibrillation occurred during pericardiotomy and reverted with DC shock of five Joules. The pre-CPB blood sugar was 1.38 mM and rose to 2.55 mM with administration of 10% dextrose. CPB was managed with moderate hypothermia and cold blood cardioplegia. The hematocrit was maintained at 30% to avoid the problems related to anemia during perioperative scenario. Increased PAP also poses problem in the form of low cardiac output, right ventricular failure, arrhythmias, etc. Increase in PAP is anticipated at the time of tracheal intubation, incision, sternotomy, weaning off CPB, and in the postoperative period during weaning off ventilator. Good analgesia and sedation given at these points of time help in combating the rise in PAP. Our patient had an increased PAP (58/33 mmHg) at the time of weaning off CPB and required aggressive measures to decrease PAP in the form of diuesis, nitric oxide (20 ppm), nitroglycerine (0.5 lg kg 1 h ), milrinone (1 lg kg 1 h ), and sildenafil (0.25 mg kg 1 eight hourly). He had another episode of increase in PAP (80/ 65 mmHg) on fourth postoperative hour which was probably reactionary, manifested as sudden onset ventricular fibrillation, and managed with an increased dose of all the above medications. Rebound increase in PAP is a known phenomenon during weaning off a patient from nitric oxide for which we reduced the dose at a rate of 1 ppm in every 30 min with a close observation of oxygen saturation, systemic, and pulmonary arterial pressure. Prior to extubation, a soft nasopharyngeal airway formed from a no 4.0 plain portex endotracheal tube was placed to overcome any constriction of pharyngeal space by edema as the later can lead to hypoxia and hypercarbia, the known aggravators of PAP. Modified ultrafiltration was performed after weaning off CPB in our patient to washout inflammatory mediators that are also known to increase PAP (4). Intra-operative hypoglycemia leading to severe pulmonary hypertension has been reported in the literature (5). Administration of 5% dextrose along with lactated Ringer’s solution throughout the perioperative period was found to be adequate to keep the blood sugar and

Incomplete Left Atrial Appendage Ligation Diagnosed Intraoperatively Using Transesophageal Echocardiography Following Mitral Valve Repair

2. Price S, Nicol E, Gibson DG, et al: Echocardiography in the critically ill: Current and potential roles. Intensive Care Med 32:48-59, 2006 3. Cowie B: Focused cardiovascular ultrasound performed by anesthesiologists in the perioperative period: Feasible and alters patient management. J Cardiothorac Vasc Anesth 23:450-456, 2009 4. Feigenbaum H: Masses tumors and source of embolus, in Feigenbaum H, Armstrong WF, Ryan T (eds): Feigenbaums’s Echocardiography. Philadelphia, PA, Lippincott Williams and Wilkins, 2005, pp 730-732 5. Feigenbaum H: ICU and operative/perioperative applications, in Feigenbaum H, Armstrong WF, Ryan T (eds): Feigenbaums’s Echocardiography. Philadelphia, PA, Lippincott Williams and Wilkins, 2005, pp 640-642