Effect of preoperative ivabradine on hemodynamics during elective off-pump CABG.

Background: Ivabradine is a specific heart rate (HR)-lowering agent which blocks the cardiac pacemaker If channels. It reduces the HR without causing a negative inotropic or lusitropic effect, thus preserving ventricular contractility. The authors hypothesized that its usefulness in lowering HR can be utilized in patients undergoing off-pump coronary artery bypass (OPCAB) surgery. Objective: To study the effects of preoperative ivabradine on hemodynamics (during surgery) in patients undergoing elective OPCAB surgery. Methods: Fifty patients, New York Heart Association (NYHA) class I and II, were randomized into group I (control, n = 25) and group II (ivabradine group, n = 25). In group I, patients received the usual anti-anginal medications in the preoperative period, as per the institutional protocol. In group II, patients received ivabradine 5 mg twice daily for 3 days before surgery, in addition to the usual anti-anginal medications. Anesthesia was induced with fentanyl, thiopentone sodium, and pancuronium bromide as a muscle relaxant and maintained with fentanyl, midazolam, pancuronium bromide, and isoflurane. The hemodynamic parameters [HR and mean arterial pressure (MAP)] and pulmonary artery (PA) catheter-derived data were recorded at the baseline (before induction), 3 min after the induction of anesthesia at 1 min and 3 min after intubation and at 5 min and 30 min after protamine administration. Intraoperatively, hemodynamic data (HR and MAP) were recorded every 10 min, except during distal anastomosis of the coronary arteries when it was recorded every 5 min. Post-operatively, at 24 hours, the levels of troponin T and brain natriuretic peptide (BNP) were measured. This trial's CTRI registration number is CTRI/005858. Results: The HR in group II was lower when compared to group I (range 59.6-72.4 beats/min and 65.8-80.2 beats/min, respectively) throughout the study period. MAP was comparable [range (78.5-87.8 mm Hg) vs. (78.9-88.5 mm Hg) in group II vs. group I, respectively] throughout the study period. Intraoperatively, 5 patients received metoprolol in group I to control the HR, whereas none of the patients in group II required metoprolol. The incidence of preoperative bradycardia (HR <60 beats/min) was higher in group II (20%) vs. group I (8%). There was no difference in both the groups in terms of troponin T and BNP level after 24 hours, time to extubation, requirement of inotropes, incidence of arrhythmias, in-hospital morbidity, and 30-day mortality. Conclusion: Ivabradine can be safely used along with other anti-anginal agents during the preoperative period in patients undergoing OPCAB surgery. It helps to maintain a lower HR during surgery and reduces the need for beta-blockers in the intraoperative period, a desirable and beneficial effect in situations where the use of beta-blockers may be potentially harmful. Further studies are needed to evaluate the beneficial effects of perioperative Ivabradine in patients with moderate-to-severe left ventricular dysfunction.

Transesophageal echocardiography probe induced recurrent VF in a child with severe RV dysfunction: Report of a rare case.

The safety of transesophageal echocardiography (TEE) probes has been documented in pediatric patients (neonates, infants, and small children even < 2.5 kg). The overall safety profile of TEE probe is quite favorable with a reported incidence of complications of 1%-3%. However, insertion of the TEE probe can induce vagal and sympathetic reflexes such as hypertension or hypotension, nonsustained ventricular and supraventricular tachyarrhythmias, or bradyarrhythmias (third degree heart block), and even angina and myocardial infarction. We hereby document a repeated intraoperative ventricular fibrillation precipitated by TEE probe in a 2-year-old, 10 kg pediatric patient diagnosed with ostium secundum-atrial septal defect, supravalvular pulmonary stenosis, and severe right ventricular dysfunction. The international review board approval or waiver and clinical trial registrations are not applicable for this case report publication.

Vasoplegic syndrome after cardiovascular surgery: A review of pathophysiology and outcome-oriented therapeutic management.

BACKGROUND: Vasoplegic syndrome (VPS) is defined as systemic hypotension due to profound vasodilatation and loss of systemic vascular resistance (SVR), despite normal or increased cardiac index, and characterized by inadequate response to standard doses of vasopressors, and increased morbidity and mortality. It occurs in 9%-44% of cardiac surgery patients after cardiopulmonary bypass (CPB). The underlying pathophysiology following CPB consists of resistance to vasopressors (inactivation of Ca2+ voltage gated channels) on the one hand and excessive activation of vasodilators (SIRS, iNOS, and low AVP) on the other. Use of angiotensin-converting enzyme inhibitor (ACE-I), calcium channel blockers, amiodarone, heparin, low cardiac reserve (EF < 35%), symptomatic congestive heart failure, and diabetes mellitus are the perioperative risk factors for VPS after cardiac surgery in adults. Till date, there is no consensus about the outcome-oriented therapeutic management of VPS. Vasopressors such as norepinephrine (NE; 0.025-0.2 µg/kg/min) and vasopressin (0.06 U/min or 6 U/h median dose) are the first choice for the treatment. The adjuvant therapy (hydrocortisone, calcium, vitamin C, and thiamine) and rescue therapy (methylene blue [MB] and hydroxocobalamin) are also considered when perfusion goals (meanarterial pressure [MAP] > 60-70 mmHg) are not achieved with nor-epinephrine and/or vasopressin. AIMS: The aims of this systematic review are to collect all the clinically relevant data to describe the VPS, its potential risk factors, pathophysiology after CPB, and to assess the efficacy, safety, and outcome of the therapeutic management with catecholamine and non-catecholamine vasopressors employed for refractory vasoplegia after cardiac surgery. Also, to elucidate the current and practical approach for management of VPS after cardiac surgery. MATERIAL AND METHODS: "PubMed," "Google," and "Medline" weresearched, and over 150 recent relevant articles including RCTs, clinical studies, meta-analysis, reviews, case reports, case series and Cochrane data were analyzed for this systematic review. The filter was applied specificallyusing key words like VPS after cardiac surgery, perioperative VPS following CPB, morbidity, and mortality in VPS after cardiac surgery, vasopressors for VPS that improve outcomes, VPS after valve surgery, VPS after CABG surgery, VPS following complex congenital cardiac anomalies corrective surgery, rescue therapy for VPS, adjuvant therapy for VPS, definition of VPS, outcome in VPS after cardiac surgery, etiopathology of VPS following CPB. This review did not require any ethical approval or consent from the patients. RESULTS: Despite the recent advances in therapy, the mortality remains as high as 30%-50%. NE has been recommended the most frequent used vasopressor for VPS. It restores and maintain the MAP and provides the outcome benefits. Vasopressin rescue therapy is an alternative approach, if catecholamines and fluid infusions fail to improve hemodynamics. It effectively increases vascular tone and lowers CO, and significantly decreases the 30 days mortality. Hence, suggested a first-line vasopressor agent in postcardiac surgery VPS. Terlipressin (1.3µg/kg/h), a longer acting and more specific vasoconstrictor prevents the development of VPS after CPB in patients treated with ACE-I. MB significantly reduces morbidity and mortality of VPS. The Preoperative MB (1%, 2mg/kg/30min, 1h before surgery) administration in high risk (on ACE-I) patients for VPS undergoing CABG surgery, provides 100% protection against VPS, and early of MB significantly reduces operative mortality, and recommended as a rescue therapy for VPS. Hydroxocobalamin (5 g) has been recommended as a rescue agent in VPS refractory to multiple vasopressors. A combination of ascorbic acid (6 g), hydrocortisone (200 mg/day), and thiamine (400 mg/day) as an adjuvant therapy significantly reduces the vasopressors requirement, and provides mortality and morbidity benefits. CONCLUSION: Currently, the VPS is frequently encountered (9%-40%) in cardiac surgical patients with predisposing patient-specific risk factors and combined with inflammatory response to CPB. Multidrug therapy (NE, MB, AVP, ATII, terlipressin, hydroxocobalamin) targeting multiple receptor systems is recommended in refractory VPS. A combination of high dosage of ascorbic acid, hydrocortisone and thiamine has been used successfully as adjunctive therapyto restore the MAP. We also advocate for the early use of multiagent vasopressors therapy and catecholamine sparing adjunctive agents to restore the systemic perfusion pressure with a goal of preventing the progressive refractory VPS.

Spontaneous bag mask ventilation for establishing cardiopulmonary bypass via mid-sternotomy in patients with severe tracheal stenosis: A series of three patients.

In patients with critical tracheal stenosis, particularly involving the lower part of trachea, a highly experienced team of anesthesiologists to tackle the difficulties of securing and maintaining the ventilation, cardiac surgeon who can swiftly establish cardiopulmonary bypass, an experienced surgeon for tracheal reconstruction are a prerequisite for managing these highly complex cases. The present paper describes three patients suffering from severe tracheal narrowing wherein spontaneous bag-mask ventilation was used for establishing cardiopulmonary bypass via mid-sternotomy as a rare life-saving procedure for urgent tracheal reconstructive surgery. A highly experienced team of anesthesiologists to tackle the difficulties of securing and maintaining the ventilation, cardiac surgeon who can swiftly establish CPB, and an experienced surgeon for tracheal reconstruction are a prerequisite for managing these highly complex cases. The present paper describes three patients suffering from severe tracheal narrowing wherein spontaneous bag-mask ventilation was used for establishing CPB via mid-sternotomy as a rare life-saving procedure for urgent tracheal reconstructive surgery.

Perioperative management of a patient with double orifice mitral valve with supramitral ring with subaortic membrane with ventricular septal defect and severe pulmonary hypertension: Report of a rare case.

Double-orifice mitral valve (DOMV) is an unusual congenital anomaly characterized by a mitral valve with a single fibrous annulus with two orifices or rarely two orifices with two separate mitral annuli opening into the left ventricle. We present a first report of a patient with a DOMV with supramitral ring (SMR), subaortic membrane (SAM), a large ventricular septal defect (VSD) with more than 50% aortic override, and severe pulmonary arterial hypertrophy (PAH). This patient underwent excision of the SAM, and SMR, with closure of the VSD together under cardiopulmonary bypass (CPB). However postoperatively, the patient developed an irreversible fatal pulmonary hypertensive crisis (PHC), immediately after transferring the patient to the cardiac intensive care unit from the operating room (OR). The PHC was refractory to intravenous and inhaled milrinone and nitroglycerine and intravenous adrenaline, dobutamine, norepinephrine, vasopressin, patent foramen oval (PFO), and CPB support. The management of DOMV and perioperative pulmonary hypertension is discussed.

Evaluation of different types of inferior vena cava cannulae placement by transesophageal echocardiography and its impact on hepatic dysfunction.

BACKGROUND: Postoperative hepatic dysfunction may occur in an otherwise uncomplicated open heart surgery. One of the reasons is malpositioning of the inferior vena cava (IVC) cannula in the hepatic vein (HV) or beyond. A straight cannula is considered more likely to be malpositioned compared to the angled cannula and a malpositioned cannula can lead to hepatic dysfunction. METHODS: In this prospective study, forty adult patients undergoing atrial septal defect repair were randomized into two groups as: straight cannula group (n=20) and angled cannula group (n=20). The cannula position was assessed by transesophageal echocardiography (TEE) (hepatic vein view). Alanine aminotransferase levels (ALT) and bilirubin levels were measured immediately, at 6 hours and on day 1, day 2 and day 7 after surgery as a marker of hepatic injury. RESULTS: TEE localization of the IVC cannula was achieved in all patients except one. Visualization was good in 85% of patients. A cannula in the HV or beyond the HV in the IVC was considered malpositioned. The number of cases of cannula malposition was 10 (50%) and 4 (20%) in the straight and angled cannula groups, respectively. The pattern of change in serum bilirubin and liver enzymes levels in the postoperative period was similar in both the groups (p>0.05). The mean distance between the right atrium (RA) - inferior vena cava (IVC) junction to the hepatic vein was 1.94±0.56 cm and the mean diameters of the IVC and HV were 1.95±0.5 and 1.31±0.33 cm, respectively. CONCLUSION: TEE can be used to monitor IVC cannula position. A higher frequency of cannula malposition was observed with the straight cannula compared to the angled cannula, but was not found to be associated with hepatic dysfunction.

Comparison of hemodynamic responses to laryngoscopy and intubation with Truview PCD™, McGrath® and Macintosh laryngoscope in patients undergoing coronary artery bypass grafting: A randomized prospective study.

CONTEXT: We hypothesized that reduced oropharyngolaryngeal stimulation with video laryngoscopes would attenuate hemodynamic response to laryngoscopy and intubation. AIM: Comparison of hemodynamic response to laryngoscopy and intubation with video laryngoscopes and Macintosh (MC) laryngoscope. SETTING AND DESIGN: Superspecialty tertiary care public hospital; prospective, randomized control study. METHODS: Sixty adult patients undergoing elective coronary artery bypass grafting (CABG) were randomly allocated to three groups of 20 each: MC, McGrath (MG), and Truview™. Hemodynamic parameters were serially recorded before and after intubation. Laryngoscopic grade, laryngoscopy, and tracheal intubation time, ST segment changes, and intra-/post-operative complications were also recorded and compared between groups. STATISTICAL ANALYSIS: SPSS version 17 was used, and appropriate tests applied. P < 0.05 was considered significant. RESULTS: Heart rate and diastolic arterial pressure increased at 0 and 1 min of intubation in all the three groups (P < 0.05) while mean arterial pressure increased at 0 min in the MG and TV groups and at 1 min in all three groups (P < 0.05). A significant increase in systolic arterial pressure was only observed in TV group at 1 min (P < 0.05). These hemodynamic parameters returned to baseline by 3 min of intubation in all the groups. The intergroup comparisons of all hemodynamic parameters were not significant at any time of observation. Highest intubation difficulty score was observed with MC (2.16 ± 1.86) as compared with MG (0.55 ± 0.88) and TV (0.42 ± 0.83) groups (P = 0.003 and P = 0.001, respectively). However, duration of laryngoscopy and intubation was significantly less in MC (36.68 ± 16.15 s) as compared with MG (75.25 ± 30.94 s) and TV (60.47 ± 27.45 s) groups (P = 0.000 and 0.003, respectively). CONCLUSIONS: Video laryngoscopes did not demonstrate any advantage in terms of hemodynamic response in patients with normal airway undergoing CABG.

Where does the pulmonary artery catheter float: transesophageal echocardiography evaluation.

BACKGROUND: Pulmonary artery (PA) catheter provides a variety of cardiac and hemodynamic parameters. In majority of the patients, the catheter tends to float in the right pulmonary artery (RPA) than the left pulmonary artery (LPA). We evaluated the location of PA catheter with the help of transesophageal echocardiography (TEE) to know the incidence of its localization. Three views were utilized for this purpose; midesophageal ascending aorta (AA) short-axis view, modified mid esophageal aortic valve long-axis view, and modified bicaval view. METHODS: We enrolled 135 patients undergoing elective cardiac surgery where both the PA catheter and TEE were to be used; for this prospective observational study. PA catheter was visualized by TEE in the above mentioned views and the degree of clarity of visualization by three views was also noted. Position of the PA catheter was further confirmed by a postoperative chest radiograph. RESULTS: One patient was excluded from the data analysis. PA catheter was visualized in RPA in 129 patients (96%) and in LPA in 4 patients (3%). In 1 patient, the catheter was visualized in main PA in the chest radiograph. The midesophageal AA short-axis, modified aortic valve long-axis, and modified bicaval view provided good visualization in 51.45%, 57.4%, and 62.3% patients respectively. Taken together, PA catheter visualization was good in 128 (95.5%) patients. CONCLUSION: We conclude that the PA catheter has a high probability of entering the RPA as compared to LPA (96% vs. 3%) and TEE provides good visualization of the catheter in RPA.

Healed perivalvular abscess: Incidental finding on transesophageal echocardiography [corrected].

A 36-year-old male patient presented with the complaints of palpitations and breathlessness. Preoperative transthoracic echocardiography (TTE) revealed a bicuspid aortic valve; severe aortic regurgitation with dilated left ventricle (LV) and mild LV systolic dysfunction (ejection fraction 50%). He was scheduled to undergo aortic valve replacement. History was not suggestive of infective endocarditis (IE). Preoperative TTE did not demonstrate any aortic perivalvular abscess. Intraoperative transesophageal echocardiography (TEE) examination using the mid-esophageal (ME) long-axis view, showed an abscess cavity affecting the aortic valve, which initially was assumed to be a dissection flap, but later confirmed to be an abscess cavity by color Doppler examination. The ME aortic valve short-axis view showed two abscesses; one was at the junction of the non-coronary and left coronary commissure and the other one above the right coronary cusp. Intraoperatively, these findings were confirmed by the surgeons. The case report demonstrates the superiority of TEE over TTE in diagnosing perivalvular abscesses.

Incidence and implications of coronary artery disease in patients undergoing valvular heart surgery: the Indian scenario.

AIMS AND OBJECTIVES: We evaluated the incidence and implications of coronary artery disease (CAD) in patients above 40 years presenting for valve surgery. MATERIALS AND METHODS: Between January 2009 and December 2010, coronary angiography (CAG) was performed in all such patients ( n = 140). RESULTS: Coronaries were normal in 119 (Group I), and diseased in 21 (Group II). In Group II, 11 patients were < 50 years, 3 were between 51 and 60 years and 7 were > 61 years. In 8 of these, only valve replacement was performed. Coronary artery bypass grafting (CABG) and aortic valve replacement was performed in 10, CABG and mitral valve replacement in 2 and CABG with mitral and aortic valve replacement in one. The number of vessels grafted in these 13 patients was 1.54 ± 0.66. Hypertension and diabetes were significant ( P < 0.05) in this group. The mortality was significant in Group II (11 vs. 6, P < 0.05). Six patients died in Group II, 5 had severe aortic stenosis and severe left ventricular hypertrophy; the sixth patient had severe mitral stenosis and was in CHF. The predominant cause of death was congestive heart failure (CHF). CONCLUSIONS: Fifteen percentage of these patients had CAD. CAG should be performed routinely in these patients while presenting for valve surgery. Combined CABG and valve replacement carries high mortality (28.5%), especially in patients with aortic stenosis. The study suggests that the cardio-protective measures should be applied more rigorously in this subset of patients.

The success rate and safety of internal jugular vein cannulation using anatomical landmark technique in patients undergoing cardiothoracic surgery.

AIMS AND OBJECTIVES: Landmark-guided internal jugular vein (IJV) cannulation is a basic procedure, which every anesthetist is expected to acquire. A successful first attempt is desirable as each attempt increases the risk of complications. The present study is an analysis of 976 IJV cannulations performed in adults undergoing cardiothoracic surgery. MATERIALS AND METHODS: The IJV was cannulated with a triple lumen catheter using the anatomical landmarks. The following data were recorded: Patient demographics, age, sex, body mass index, diagnosis, operative procedure, operator (resident/consultant), site of cannulation (central approach, right IJV, left IJV, external jugular vein), number of attempts and duration of cannulation, length of insertion of the catheter, number of correct placements on X-ray and any complications. RESULTS: The success rate of IJV cannulation was 100%. In 809 (82.9%) patients, cannulation was performed in the first attempt. Residents performed 792 cannulations and the consultants performed 184 cannulations. In 767 patients, the residents were successful in inserting the catheter and in 25 they failed after 5 attempts, hence, they were cannulated by the consultant. The time taken for insertion of the catheter was 6.89 ± 3.2 minutes. Carotid artery puncture was the most common complication, it occurred in 22 (2.3%) patients. CONCLUSION: IJV cannulation with landmark technique is highly successful with minimal complications in the adult patients undergoing cardiothoracic surgery. Basic training of cannulating the IJV by landmark technique should be imparted to all the traines as ultrasound may not be available in all locations.

Anesthetic management of a child with nephrotic syndrome undergoing open heart surgery: report of a rare case.

The congenital nephrotic syndrome (NS) in infancy and childhood is an important entity but combination with acyanotic congenital heart disease is uncommon. Anesthesia in such cases is challenging because of associated problems like hypo-protienemia, anti-thrombin III deficiency, edema, hyperlipidemia, coagulopathy, cardiomyopathy, immunodeficiency, increased lung water etc. We describe anesthetic management of a patient with childhood NS and sinus venosus atrial septal defect (ASD) undergoing open heart surgery. We also suggest guidelines for safe conduct of anesthesia and CPB in such patients.

Successful double lumen tube insertion in a patient with unanticipated laryngeal and tracheal web.

A 45-year-old female patient admitted for surgical management of carcinoma esophagus, presented with difficulty in insertion of left-sided 37 F and 35 F double lumen tube (Mallinckrodt® Broncho-Cath). Fiberoptic bronchoscopy revealed a subglottic web in the larynx just below the vocal cords and a tracheal web just above the carina. Differential lung ventilation could be achieved with a 35 F internal diameter double lumen tube (Portex® Blueline® Endobronchial tube).

Myocardial protection with isoflurane during off-pump coronary artery bypass grafting: a randomized trial.

OBJECTIVES: To analyze the hemodynamic effects and myocardial injury using troponin-T and creatine phosphokinase (CPK-MB) with isoflurane and compare it with a control group in patients undergoing off-pump coronary artery bypass (OPCAB) surgery. DESIGN: This prospective, randomized study was performed in patients scheduled for elective OPCAB surgery during February 2007 to February 2009. SETTING: Tertiary care, university teaching hospital. PARTICIPANTS: Forty-five patients undergoing elective OPCAB surgery. INTERVENTIONS: Patients were randomly allotted to receive either isoflurane (inspired concentration between 1.0% and 2.5%) or propofol (1.5 to 3.5 mg/kg/h) during OPCAB surgery. The concentration of these agents was titrated such that the BIS value was maintained between 50 and 60. MEASUREMENTS AND MAIN RESULTS: The hemodynamic data were measured and recorded after induction of anesthesia (baseline), during the distal anastomosis of each coronary artery, and 5 and 30 minutes after giving protamine. In addition, blood samples for troponin-T and CPK-MB were obtained after induction (baseline), after 6 hours and 24 hours postoperatively. The cardiac index was significantly higher in the isoflurane group at all stages, except during distal anastomosis of the diagonal branch of the left anterior descending artery (p < 0.05). There was a significant increase in troponin-T levels at 6 and 24 hours after surgery in the propofol group (from 0.037 ± 0.013 ng/mL to 0.098 ± 0.045 ng/mL and 0.081 ± 0.025 ng/mL, respectively, p < 0.05). Significant increases in the troponin-T levels were observed at 6 hours (from 0.033 ± 0.011 ng/mL to 0.052 ± 0.025 ng/mL, (p < 0.05) in the isoflurane group, and the levels in the propofol group were significantly higher than the isoflurane group at 6 and 24 hours after surgery (p < 0.05). The CPK-MB levels increased in both groups, but were not statistically different. CONCLUSIONS: Isoflurane provides protection against myocardial damage in a clinically used dosage as documented by lower levels of troponin-T in patients undergoing OPCAB surgery.