Conversion during off-pump coronary artery bypass graft surgery: A case–control study

Objectives: Off pump coronary artery bypass (OPCAB) surgery is carried out as an alternative to conventional coronary artery bypass grafting using cardiopulmonary bypass (CPB). At times 'conversion' to CPB may be required to bail out a situation resulting from acute decompensation of the heart. It is reported that such conversion carries significant mortality risk. Since we conduct coronary revascularization by OPCAB technique as the preferred technique, we conducted this study with an aim to identify the markers of adverse outcome during conversion in Indian patients. Design: Case control retrospective study. Setting: Tertiary referral center. Participants: We conducted three thousand two hundred OPAB surgeries in the period between 2013 to16. Ninety patients (3.1%) required conversion to complete the revascularization (Con version group). Twice the number of patients who underwent OPCAB surgery without conver sion were chosen as controls (Control group). Intervention: OPCAB surgery Results: Mortality in the conversion group was 5.56% in contrast to 0.06% in the controls (P = 0.01). The conversion group had higher left ventricular end diastolic pressure, incidence of endarterectomy, and intra-aortic balloon counter pulsation requirement. Female gender was also predictive of conversion. The total chest drain, duration of ventilation, ICU stay and hospital stay were also higher in the conversion group. Conversion was associated with 9.47 times the odds for mortality. Conclusion: Conversion during OPCAB is associated with significantly increased mortality. Female gender, increased left ventricular end diastolic pressure and preoperative requirement of Intra-aortic balloon are markers of increased risk of mortality when converted.

A survey of practices during cardiopulmonary bypass in India: An Indian association of cardiovascular and thoracic anesthesiologist endeavor

Context: Cardiac anesthesiologists play a key role during the conduct of cardiopulmonary bypass (CPB). There are variations in the practice of CPB among extracorporeal technologists in India. Aims: The aim of this survey is to gather information on variations during the conduct of CPB in India. Settings and Design: This was an online conducted survey by Indian College of Cardiac Anaesthesia, which is the research and academic wing of the Indian Association of Cardiovascular Thoracic Anaesthesiologists. Subjects and Methods: Senior consultants heading cardiac anesthesia departments in both teaching and nonteaching centers (performing at least 15 cases a month) were contacted using an online questionnaire fielded using SurveyMonkey™ software. There were 33 questions focusing on institute information, perfusion practices, blood conservation on CPB; monitoring and anesthesia practices. Results: The response rate was 74.2% (187/252). Fifty-one (26%) centers were teaching centers; 18% centers performed more than 1000 cases annually. Crystalloid solution was the most common priming solution used. Twenty-three percent centers used corticosteroids routinely; methylprednisone was the most commonly used agent. The cardioplegia solution used by most responders was the one available commercially containing high potassium St. Thomas solution (55%), followed by Del Nido cardioplegia (33%). Majority of the responders used nasopharyngeal site to monitor intraoperative patient temperature. Antifibrinolytics were commonly used only in patients who were at high risk for bleeding by 51% of responders, while yet, another 39% used them routinely, and 11% never did. About 59% of the centers insist on only fresh blood (<7 days old) when blood transfusion was indicated. The facility to use vaporizer on CPB was available in 62% of the centers. All the teaching centers or high volume centers in India had access to transesophageal echocardiography probe and echo machine, with 51% using them routinely and 38% using them at least sometimes. Conclusions: There is a wide heterogeneity in CPB management protocols among various Indian cardiac surgery centers. The survey suggests that adherence to evidence-based and internationally accepted practices appears to be more prevalent in centers that have ongoing teaching programs and/or have high volumes, strengthening the need to devise guidelines by appropriate body to help bring in uniformity in CPB management to ensure patient safety and high quality of clinical care for best outcomes.

Variations of transesophageal echocardiography practices in India: A survey by Indian College of Cardiac Anaesthesia.

Context: Use of perioperative transesophageal echocardiography (TEE) has expanded in India. Despite attempts to standardize the practice of TEE in cardiac surgical procedures, variation in practice and application exists. This is the first online survey by Indian College of Cardiac Anaesthesia, research and academic wing of the Indian Association of Cardiovascular Thoracic Anaesthesiologists (IACTA). Aims: We hypothesized that variations in practice of intraoperative TEE exist among centers and this survey aimed at analyzing them. Settings and Design: This is an online survey conducted among members of the IACTA. Subjects and Methods: All members of IACTA were contacted using online questionnaire fielded using SurveyMonkey™ software. There were 21 questions over four pages evaluating infrastructure, documentation of TEE, experience and accreditation of anesthesiologist performing TEE, and finally impact of TEE on clinical practice. Questions were also asked about national TEE workshop conducted by the IACTA, and suggestions were invited by members on overseas training. Results: Response rate was 29.7% (382/1222). 53.9% were from high‑volume centers (>500 cases annually). TEE machine/probe was available to 75.9% of the respondents and those in high‑volume centers had easier (86.9%) access. There was poor documentation of preoperative consent (23.3%) as well as TEE findings (66%). Only 18.2% of responders were board qualified. Almost 90% of the responders felt surgeons respected their TEE diagnosis. Around half of the responders felt that new intraoperative findings by TEE were considered in decision‑making in most of the cases and 70% of the responders reported that surgical plan was altered based on TEE finding more than 10 times in the last year. Despite this, only 5% of the responders in this survey were monetarily awarded for performing impactful skill of TEE. Majority (57%) felt that there is no need for overseas training for Indian cardiac anesthesiologists. Conclusions: In this survey of members of the IACTA, use of TEE has increased substantially, but still a lot of variations in practice patterns exist in India. There is urgent need for improving TEE certification and upgrade documentation standards, motivate use of TTE across all centers, promote awareness and usefulness of TEE use among surgical fraternity, monitor impact of TEE, and support separate remuneration policy in India.

Anesthetic implications of subxiphoid coronary artery bypass surgery.

Background: Minimal invasive surgeries are carried out to benefit the patient with less pain, blood loss, mechanical ventilation and hospital stay; a smaller scar is not the aim. Minimal invasive cardiac surgeries are carried out via small sternotomy, small thoracotomy and via robotic arms. Subxiphoid route is a novel method and avoids sternotomy. Aim: This case series is an attempt to understand the anesthetic modifications required. Secondly, whether it is feasible to carry out subxiphoid coronary artery bypass surgery. Methods: Elective patients scheduled to undergo subxiphoid coronary artery bypass surgery were chosen. The surgeries were conducted under general anesthesia with left lung isolation via either endobronchial tube or bronchial blocker. Results: We conducted ten (seven males and 3 females) coronary artery bypass graft surgeries via subxiphoid technique. The mean EuroSCORE was 1.7 and the mean ejection fraction was 53.6. Eight patients underwent surgery via endobronchial tube, while, in the remaining two lung isolation was obtained using bronchial blocker. Mean blood loss intraoperatively was 300 ± 42 ml and postoperatively 2000 ± 95 ml. The pain score on the postoperative day ‘0’ was 4.3 ± 0.6 and 2.3 ± 0.7 on the day of discharge. Length of stay in the hospital was 4.8 ± 0.9 days. There were no complications, blood transfusions, conversion to cardiopulmonary bypass. The modifications in the anesthetic and surgical techniques are, use of left lung isolation using either endobronchial tube or bronchial blocker, increased duration for conduit harvesting, grafting, requirement of transesophageal echocardiography monitoring in addition to hemodynamic monitoring. Other minor requirements are transcutaneous pacing and defibrillator pads, a wedge under the chest to ‘lift’ up the chest, sparing right femoral artery and vein (to serve as vascular access) for an unlikely event of conversion to cardiopulmonary bypass. Any anesthesiologist wishing to start this technique must be aware of these modifications. Conclusions: Subxiphoid route is safe to carry out coronary artery bypass graft surgery using the minimal invasive cardiac surgery. It is reproducible and has undeniable benefits. We plan to conduct such surgeries in awake patients under thoracic epidural anesthesia thus making it even less invasive and amenable for fast tracking.

Dilemma with the route of venous access for hemodialysis catheter insertion in a patient with dilated ischemic cardiomyopathy treated by cardiac resynchronization therapy.

A 68 year old patient requiring urgent dialysis due to raising potassium was referred to our center. He had 3 indwelling catheters in his heart via right subclavian vein. His left subclavian and interngal jugular veins were thrombosed possibly due to earlier indwelling catheters. The dilemma was if right internal jugular venous route could be used for insertion of dialysis catheter. Under fluoroscopic guidance, right internal jugular vein was cannulated with the dialysis catheter without problems. This case is being presented to highlight the need for imaging both by ultrasound and radiography during the procedure.

Elevated postoperative serum procalcitonin is not indicative of bacterial infection in cardiac surgical patients.

Background: Identifying infections early, commencing appropriate empiric antibiotic not only helps gain control early, but also reduces mortality and morbidity. Conventional cultures take about 5 days to identify infections. To identify the infections early biomarker like serum procalcitonin (SPC). Aims: We studied the correlation of an elevated level of SPC and positive culture in elective adult patients undergoing cardiac surgery. Methods: This prospective study was conducted from January to December 2013. SPC was checked in patients showing evidence of sepsis. Simultaneously, relevant culture was also undertaken. Correlation, specificity, and sensitivity of elevated SPC were checked. Results: A total of 819 adult patients were included in the study. 43 of them had signs of infection and SPC levels were checked. Based on the level of SPC criteria, 10 patients were diagnosed as “nil”, out of them, 4 had culture‑positive infections, 17 were suggested to have “mild infection,” 3 out those had culture positivity. None among the eleven patients suggested to have “moderate infection,” had a positive culture, and one among the five suggested to have a severe infection had a positive culture. The sensitivity was 50% and the specificity 17%. The positive predictive value was 12% and the negative predictive value 60%. Conclusions: We failed to elicit positive correlation between elevated SPC levels and postoperative infection in cardio surgical patients.

Induced apnea enhances image quality and visualization of cardiopulmonary anatomic during contrast enhanced cardiac computerized tomographic angiography in children.

Objective: The purpose of our study was to determine the effect of induced apnea on quality of cardiopulmonary structures during computerized tomographic (CT) angiography images in children with congenital heart diseases. Methods: Pediatric patients with congenital heart defects undergoing cardiac CT angiography at our facility in the past 3 years participated in this study. The earlier patients underwent cardiac CT angiography without induced apnea and while, later, apnea was induced in patients, which was followed by electrocardiogram gated cardiac CT angiography. General anesthesia was induced using sleep dose of intravenous propofol. After the initial check CT, on request by the radiologist, apnea was induced by the anesthesiologist by administering 1 mg/kg of intravenous suxamethonium. Soon after apnea ensued, the contrast was injected, and CT angiogram carried out. CT images in the “apnea group” were compared with those in “nonapnea group.” After the completion of the procedure, the patients were mask ventilated with 100% oxygen till the spontaneous ventilation was restored. Results: We studied 46 patients, of whom 36 with apnea and yet another 10 without. The quality of the image, visualization of structures such as cardiac wall, outflow tracts, lung field, aortopulmonary shunts, and coronary arteries were analyzed and subjected to statistical analysis (Mann–Whitney U, Fischer’s exact test and Pearson’s Chi‑square test). In the induced apnea group, overall image quality was considered excellent in 89% (n = 33) of the studies, while in the “no apnea group,” only 30% of studies were excellent. Absent or minimal motion artifacts were seen in a majority of the studies in apnea group (94%). In the nonapnea group, the respiratory and body motion artifacts were severe in 50%, moderate in 30%, and minimal in 20%, but they were significantly lesser in the apnea group. All the studied parameters were statistically significant in the apnea group in contrast to nonapnea group (P < 0.000). Conclusion: The image quality of cardiac CT angiography greatly improves, and motion artifact significantly decreases with the use of induced apnea in pediatrics patients being evaluated for congenital heart disease. This technique poses no additional morbidity of significance.

Practice guidelines for perioperative transesophageal echocardiography: Recommendations of the Indian association of cardiovascular thoracic anesthesiologists.

Transoesophageal Echocardiography (TEE) is now an integral part of practice of cardiac anaesthesiology. Advances in instrumentation and the information that can be obtained from the TEE examination has proceeded at a breath-taking pace since the introduction of this technology in the early 1980s. Recognizing the importance of TEE in the management of surgical patients, the American Societies of Anesthesiologists (ASA) and the Society of Cardiac Anesthesiologists, USA (SCA) published practice guidelines for the clinical application of perioperative TEE in 1996. On a similar pattern, Indian Association of Cardiac Anaesthesiologists (IACTA) has taken the task of putting forth guidelines for transesophageal echocardiography (TEE) to standardize practice across the country. This review assesses the risks and benefits of TEE for several indications or clinical scenarios. The indications for this review were drawn from common applications or anticipated uses as well as current clinical practice guidelines published by various society practicing Cardiac Anaesthesia and cardiology . Based on the input received, it was determined that the most important parts of the TEE examination could be displayed in a set of 20 cross sectional imaging planes. These 20 cross sections would provide also the format for digital acquisition and storage of a comprehensive TEE examination. Because variability exists in the precise anatomic orientation between the heart and the esophagus in individual patients, an attempt was made to provide specific criteria based on identifiable anatomic landmarks to improve the reproducibility and consistency of image acquisition for each of the standard cross sections.

Utility of pulmonary venous flow diastolic deceleration time in an adult patient undergoing surgical closure of atrial septal defect and coronary artery bypass grafting.

Acute left ventricular (LV) failure has been reported after surgical closure of atrial septal defect (ASD) in adult patients. We report acute LV failure in a 56 year old gentleman following coronary artery bypass grafting (CABG) and surgical closure of ASD. Transesophageal echocardiography examination of the patient following closure of ASD and CABG showed a residual ASD and a shunt (Qp :Qs = 1.5). The residual ASD was closed after re-institution of cardiopulmonary bypass (CPB) under cardioplegic cardiac arrest. However, the patient did not tolerate closure of the residual ASD. The CPB was re-established and under cardioplegic cardiac arrest residual ASD was reopened to create a fenestration. This time patient was weaned easily from CPB. Postoperatively, 16 hours after extubation, patient became hemodynamically unstable, the patient was electively put on ventilator and intra-aortic balloon pump. Later the patient was weaned off successfully from ventilator. Retrospective analysis of pulmonary venous flow diastolic deceleration time (PVDT D ) recorded during prebypass period measured 102 msec suggestive of high left atrial pressure which indicate possibility of LV failure after ASD closure.

Myocardial protection during off pump coronary artery bypass surgery: A comparison of inhalational anesthesia with sevoflurane or desflurane and total intravenous anesthesia.

Aims and Objectives: The objective of the study was to evaluate the myocardial protective effect of volatile agents-sevoflurane and desflurane versus total intravenous anesthesia (TIVA) with propofol in offpump coronary artery bypass surgery (OPCAB) by measuring cardiac troponin-T (cTnT) as a marker of myocardial cell death. Materials and Methods: The study was conducted on 139 patients scheduled to undergo elective OPCAB surgery. The patients were randomly allocated to receive anesthesia with sevoflurane, desflurane or TIVA with propofol. The cTnT levels were measured preoperatively, at arrival in postoperative intensive care unit, at 8, 24, 48 and 96 hours thereafter. Results: The changes in cTnT levels at all time intervals were comparable in the three groups. Conclusion: The study did not reveal any difference in myocardial protection after OPCAB with either sevoflurane or desflurane or TIVA using propofol as assessed by measuring serial cTnT values.

A randomized prospective analysis of alteration of hemostatic function in patients receiving tranexamic acid and hydroxyethyl starch (130/0.4) undergoing off pump coronary artery bypass surgery.

Postoperative hemorrhagic complications is still one of the major problems in cardiac surgeries. It may be caused by surgical issues, coagulopathy caused by the side effects of the intravenous fluids administered to produce plasma volume expansion such as hydroxyl ethyl starch (HES). In order to thwart this hemorrhagic issue, few agents are available. Fibrinolytic inhibitors like tranexamic acid (TA) may be effective modes to promote blood conservation; but the possible complications of thrombosis of coronary artery graft, precludes their generous use in coronary artery bypass graft surgery. The issue is a balance between agents that promote coagulation and those which oppose it. Therefore, in this study we have assessed the effects of concomitant use of HES and TA. Thromboelastogram (TEG) was used to assess the effect of the combination of HES and TA. With ethical committee approval and patient's consent, 100 consecutive patients were recruited for the study. Surgical and anesthetic techniques were standardized. Patients fulfilling our inclusion criteria were randomly allocated into 4 groups of 25 each. The patients in group A received 20 ml/kg of HES (130/0.4), 10 mg/kg of T.A over 30 minutes followed by infusion of 1 mg/kg/hr over the next 12 hrs. The patients in group B received Ringer's lactate + TA at same dose. The patients in the Group C received 20 ml/kg of HES. Group D patients received RL. Fluid therapy was goal directed. Total blood loss was assessed. Reaction time (r), α angle, maximum amplitude (MA) values of TEG were assessed at baseline, 12, 36 hrs. The possible perioperative myocardial infraction (MI) was assessed by electrocardiogram (ECG) and troponin T values at the baseline, postoperative day 1. Duration on ventilator, length of stay (LOS) in the intensive care unit (ICU) were also assessed. The demographical profile was similar among the groups. Use of HES increased blood loss significantly (P < 0.05). Concomitant use of TA reduced blood loss when used along with HES. r value was prolonged at 12 hours in all the groups and α angle was reduced at 12 hours in all the groups, where as MA value was reduced at 12 th hour in the HES group compared to the baseline and increased in TA + HES group. These findings were statistically significant. No significant change in Troponin T values/ ECG, duration of ventilation and LOS ICU was observed. No adverse events was noticed in any of the four groups. HES (130/0.4) used at a dose of 20 ml/kg seems to produce coagulopathy causing increased blood loss perioperatively. Hemodilution produced by fluid therapy seems to produce Coagulopathy as observed by TEG parameters. Concomitant use of TA with HES appears to reverse these changes without causing any adverse effects in patients undergoing OPCAB surgery.

Effect of thoracic epidural anesthesia on oxygen delivery and utilization in cardiac surgical patients scheduled to undergo off-pump coronary artery bypass surgery: A prospective study.

To evaluate the effect of thoracic epidural anesthesia (TEA) on tissue oxygen delivery and utilization in patients undergoing cardiac surgery. This prospective observational study was conducted in a tertiary referral heart hospital. A total of 25 patients undergoing elective off-pump coronary artery bypass surgery were enrolled in this study. All patients received thoracic epidural catheter in the most prominent inter-vertebral space between C7 and T3 on the day before operation. On the day of surgery, an arterial catheter and Swan Ganz catheter (capable of measuring cardiac index) was inserted. After administering full dose of local anesthetic in the epidural space, serial hemodynamic and oxygen transport parameters were measured for 30 minute prior to administration of general anesthesia, with which the study was culminated. A significant decrease in oxygen delivery index with insignificant changes in oxygen extraction and consumption indices was observed. We conclude that TEA does not affect tissue oxygenation despite a decrease in arterial pressures and cardiac output.

Intra-aortic balloon pump use does not affect the renal function in patients undergoing off pump coronary artery bypass surgery.

Renal dysfunction is known to occur during cardiac surgery. A few factors such as perioperative hypotension, use of potential nephrotoxic therapeutic agents, radio opaque contrast media in the recent past, intra-aortic balloon pump (IABP) and cardiopulmonary bypass have been blamed as the contributing factors to the causation of postoperative renal dysfunction in cardiac surgical patients. At times, in patients with renal failure and low cardiac output status, one may face the dilemma if the use of IABP is safe. We undertook this prospective observational study to determine the degree of possible renal injury when IABP is used by measuring serial values of serum creatinine and Cystatin C. Elective patients scheduled for off-pump coronary artery bypass surgery requiring preoperative use of IABP were included in this study. Cystatin C and serum creatinine levels were checked at fixed intervals after institution of IABP. Twenty-two patients were eligible for enrolment to the study. There was no significant change in the values of serum creatinine; from the basal value of 1.10 ± 0.233 to 0.98 ± 0.363 mg /dL (P value >0.05). Cystatin C levels significantly decreased from the basal level of 0.98 ± 0.29 to 0.89 ± 0.23 (P value <0.05). Contrary to the belief, Cystatin C, the early indicator of renal dysfunction decreases suggesting absence of renal injury after the use of IABP. Absence of elevation of cystatin C levels in our study suggests the lack of potential of the IABP to cause renal dysfunction in patients who received elective IABP therapy preoperatively.