Jayaprakash Krishnamoorthy

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.

Minimally invasive compared to conventional approach for coronary artery bypass grafting improves outcome

Introduction: Minimally invasive (MI) cardiac surgery is a rapidly gaining popularity, globally as well as in India. We aimed to compare the outcome of MI to the conventional approach for coronary artery bypass graft (CABG) surgery. Methods: This prospective, comparative study was conducted at a tertiary care cardiac surgical center. All patients who underwent CABG surgery via MI approach (MI group) from July 2015 to December 2015 were enrolled and were compared against same number of EuroSCORE II matched patients undergoing CABG through conventional mid-sternotomy approach (CON group). Demographic, intra- and post-operative variables were collected. Results: In MI group, duration of the surgery was significantly longer (P = 0.029). Intraoperative blood loss lesser (P = 0.002), shorter duration of ventilation (P = 0.002), shorter Intensive Care Unit stay (P = 0.004), shorter hospital stay (P = 0.003), lesser postoperative analgesic requirements (P = 0.027), and lower visual analog scale scores on day of surgery (P = 0.032) and 1 st postoperative day (P = 0.025). No significant difference in postoperative blood loss, blood transfusion, or duration of inotrope requirement observed. There was no conversion to mid-sternotomy in any patients, 8% of patients had desaturation intraoperatively. There was no operative mortality. Conclusion: MI surgery is associated with lesser intraoperative blood loss, better analgesia, and faster recovery.

Decrease in pulmonary artery pressure after administration of thoracic epidural anesthesia in a patient with Marfan syndrome awaiting aortic valve replacement procedure

Thoracic epidural anesthesia is an adjunct to general anesthesia in cardiac surgery. Decrease in heart rate and blood pressure are frequently seen beneficial effects. There are several other hemodynamic effects of thoracic epidural anesthesia such as decrease in systemic vascular resistance, cardiac index, left ventricular stroke work index among others. However, the effect of thoracic epidural anesthesia on pulmonary artery pressure (PAP) has not been studied extensively in humans. Thoracic epidural anes-thesia decreased pulmonary artery pressure in experimen-tally induced pulmonary hypertension in animals. The mechanisms involved in such reduction are ill understood. We describe in this report, a significant reduction in PAP in a patient with Marfan’s syndrome scheduled to under-go aortic valve replacement. The possible mechanisms of decrease in pulmonary artery pressure in the described case are, decrease in the venous return to the heart, decrease in the systemic vascular resistance, decrease in the right ventric-ular function and finally, improvement in myocardial contraction secondary to all the above. The possibility of Marfan’s syndrome contributing to the decrease in PAP appears remote. The authors present this case to generate discussion about the possible mechanisms involved in thoracic epidural anesthesia producing beneficial effects in patients with secondary pulmonary hypertension. Thoracic epidural anesthesia appears to decrease pulmonary artery pressure by a combination of several mechanisms, some unknown to us. This occurrence, if studied and understood well could be put to clinical use in pulmonary hypertensives.Thoracic epidural anesthesia is an adjunct to general anesthesia in cardiac surgery. Decrease in heart rate and blood pressure are frequently seen beneficial effects. There are several other hemodynamic effects of thoracic epidural anesthesia such as decrease in systemic vascular resistance, cardiac index, left ventricular stroke work index among others. However, the effect of thoracic epidural anesthesia on pulmonary artery pressure (PAP) has not been studied extensively in humans. Thoracic epidural anes-thesia decreased pulmonary artery pressure in experimen-tally induced pulmonary hypertension in animals. The mechanisms involved in such reduction are ill understood. We describe in this report, a significant reduction in PAP in a patient with Marfan’s syndrome scheduled to under-go aortic valve replacement. The possible mechanisms of decrease in pulmonary artery pressure in the described case are, decrease in the venous return to the heart, decrease in the systemic vascular resistance, decrease in the right ventric-ular function and finally, improvement in myocardial contraction secondary to all the above. The possibility of Marfan’s syndrome contributing to the decrease in PAP appears remote. The authors present this case to generate discussion about the possible mechanisms involved in thoracic epidural anesthesia producing beneficial effects in patients with secondary pulmonary hypertension. Thoracic epidural anesthesia appears to decrease pulmonary artery pressure by a combination of several mechanisms, some unknown to us. This occurrence, if studied and understood well could be put to clinical use in pulmonary hypertensives.

Unmasking of patent ductus arteriosus on cardiopulmonary bypass: role of intraoperative trans-esophageal echocardiography in a patient with severe pulmonary hypertension due to pulmonary vein stenosis and cor triatriatum.

venous obstruction. After induction of general anesthesia, transesophageal echocardiography (TEE) probe was inserted. TEE confirmed the diagnosis made earlier. Further, a restrictive fleshy membrane in the left atrium (cor triatriatum) contributing to pulmonary vein stenosis was observed. Surgery commenced via mid-sternotomy. Total body heparinisation was achieved with 6000 IU of heparin; the resultant activated clotting time was 450 s. The pulmonary artery (PA) pressure measured via a fine needle inserted in the main pulmonary artery revealed supra-systemic PA pressure. The systemic pressure was 73/56 and mean 63 mmHg, while the PA pressure was 98/60 mmHg. Cardiopulmonary bypass (CPB) was instituted without events after cannulation of ascending aorta and cannulation of superior and inferior vena cavae. It is our institution policy to confirm the empty status of the heart with adequate venous return and absence of aortic regurgitation after establishing CPB using TEE. During such routine examination in this patient, hitherto unreported ductal flow was detected and patent ductus arteriosus (PDA) was diagnosed [Video 1]. PDA was visualized in the upper esophageal view. As the tee probe is withdrawn gradually from the mid-esophageal position, just beyond A 15-year-old African girl, weighing 27 kilos, with a height of 148 cm was admitted to the hospital for repair of pulmonary venous obstruction and cor triatriatum. She was comfortable at rest, but had severe limitation of activities beyond those of daily living. Pulse oximetry on room air was 92%, which improved to 95% with oxygen.

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.

Comparison of two doses of heparin on outcome in off-pump coronary artery bypass surgery patients: A prospective randomized control study

Introduction: While off pump coronary artery bypass surgery is practiced with an intention to reduce the morbidity associated with cardiopulmonary bypass, the resultant ′hypercoagulability′ needs to be addressed. Complications such as cavitary thrombus possibly due to the hyper coagulability after off pump coronary artery bypass surgery have been described. Many clinicians use higher doses of heparin - up to 5 mg/kg in order to thwart this fear. Overall, there appears to be no consensus on the dose of heparin in off pump coronary artery bypass surgeries. Aim of the Study: The aim of the study was understand the differences in outcome of such as transfusion requirement, myocardial ischemia, and morbidity when two different doses were used for systemic heparinization. Methods: Elective patients scheduled for off pump coronary artery bypass surgery were included. Ongoing anti platelet medication was not an exclusion criteria, however, anti platelet medications were ceased about a week prior to surgery when possible. Thoracic epidural anesthesia was administered as an adjunct in patients who qualified for it. By computer generated randomization chart, patients were chosen to receive either 2 or 3 mg/kg of intravenous unfractioned heparin to achieve systemic heparinization with activated clotting time targeted at >240 secs. Intraoperative blood loss, postoperative blood loss, myocardial ischemic episodes, requirement of intraaortic balloon counter pulsation and transfusion requirement were analyzed. Results: Sixty two patients participated in the study. There was one conversion to cardiopulmonary bypass. The groups had comparable ACT at baseline (138.8 vs. 146.64 seconds, P = 0.12); 3 mg/kg group had significantly higher values after heparin, as expected. But after reversal with protamine, ACT and need for additional protamine was similar among the groups. Intraoperative (685.56 ± 241.42 ml vs. 675.15 ± 251.86 ml, P = 0.82) and postoperative blood loss (1906.29 ± 611.87 ml vs 1793.65 ± 663.54 ml , p value 0.49) were similar among the groups [Table 4]. The incidence of ECG changes of ischemia, arrhythmias, conversion to CPB, or need for intra-aortic balloon counter pulsation were not different. Conclusions: Use of either 2 or 3 mg/kg heparin for systemic heparinization in patients undergoing OPCAB did not affect the outcome.

Developing protocols for administering anesthesia

The industrial sector especially the aviation industry has shown the world that by using check lists and protocols, disasters could be prevented. It is now a common practice in many fields to establish protocols to standardize the practices. Such standardization makes the processes similar despite various users practicing the procedure. Although in anesthesia, there are several guidelines suggested by bodies such as the American society of anesthesiologists and Indian society of anaesthetists, strict protocols are not available even for the commonly undertaken procedures. Anesthesia is akin in many respects to flying an aircraft. The induction of anesthesia compared to take off of an aircraft, maintenance to cruising and extubation to landing. It was therefore thought that anesthesia similar to aircraft flying could be made safer by using protocols and checklists. However it may take a while for the practice of anesthesia to get to the “6 Sigma” safety that the airline industry currently enjoys. It is our effort to standardize the commonly performed surgeries at our institution. “The protocols in Anesthesia” emerged as a result of the back breaking work of the consultants in the department of anesthesia. The intention of this effort was to standardize the practice of anesthesia in our institution and to showcase the benefits of such standardization. It is hoped that other institution interested in standardizing their practice could formulate their own protocols. It is also desirable that a “copy and paste” of other protocols in unlikely to benefit the end users. The authors wish to bring forth the point that customized protocols should emerge with the efforts of the users themselves. It becomes more pertinent to suit ones protocol to the prevailing infrastructure, availability of therapeutic agents and economic conditions. The authors sincerely hope this endeavour might stimulate others to put their systems in place, if not pre-existing

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.

An unusual radio-opaque shadow in the chest radiograph after coronary artery bypass surgery.

Fig 1. The chest radiograph showing the “foreign body” (arrow). A50-YEAR-OLD, 175-cm, 140-lb man requiring a triple-vessel coronary artery bypass was admitted to the authors’ hospital. The preoperative chest radiograph was normal. Per institutional protocol, a femoral arterial catheter and a pulmonary artery catheter (PAC) were inserted under local anesthesia. During the insertion of the PAC, it was noted that the catheter had to be advanced beyond 50 cm to achieve a wedge position. During surgery, the left anterior descending coronary artery and the first and second obtuse marginal coronary arteries were grafted by the off-pump method. At the end of the surgical procedure, the count of equipment, needles, and gauze pieces were correct. The patient was transferred to the intensive care unit for postoperative management. A routine postoperative chest radiograph revealed a crescent-shaped “foreign body” superimposed on the cardiac shadow in the region of the main pulmonary artery (Fig 1). Initially, it was suspected that one of the intracoronary shunts used was left behind inadvertently in the chest, but the instrument count was correct. The decision whether to re-explore to retrieve the “foreign body” had to be made. What is the diagnosis?

Spontaneous Respiration for Endoscopic Cauterization and Stenting of a Tracheal Tumor Under Thoracic Epidural Anesthesia

p r r a i s c BSTRUCTING TRACHEAL TUMORS can lead to serious consequences during anesthesia and excision. The uthors performed excision and stenting of a tracheal tumor hat was obstructing 90% of the tracheal lumen under thoracic pidural anesthesia (TEA) with spontaneous ventilation. This ermitted the planned operative procedure without the use of ositive-pressure ventilation or inhalation anesthetic agents. he patient tolerated the procedure well and had improved ulmonary function after the intervention.