Antoine G. Rochon

Innovative Approaches in the Perioperative Care of the Cardiac Surgical Patient in the Operating Room and Intensive Care Unit

Perioperative care for cardiac surgery is undergoing rapid evolution. Many of the changes involve the application of novel technologies to tackle common challenges in optimizing perioperative management. Herein, we illustrate recent advances in perioperative management by focusing on a number of novel components that we judge to be particularly important. These include: the introduction of brain and somatic oximetry; transesophageal echocardiographic hemodynamic monitoring and bedside focused ultrasound; ultrasound-guided vascular access; point-of-care coagulation surveillance; right ventricular pressure monitoring; novel inhaled treatment for right ventricular failure; new approaches for postoperative pain management; novel approaches in specialized care procedures to ensure quality control; and specific approaches to optimize the management for postoperative cardiac arrest. Herein, we discuss the reasons that each of these components are particularly important in improving perioperative care, describe how they can be addressed, and their impact in the care of patients who undergo cardiac surgery.

Reversal of decreases in cerebral saturation in high-risk cardiac surgery.

OBJECTIVES To measure the incidence of cerebral desaturation during high-risk cardiac surgery and to evaluate strategies to reverse cerebral desaturation. DESIGN Prospective observational study followed by a randomized controlled study with 1 intervention group and 1 control group. SETTING Tertiary care center specialized in cardiac surgery. PARTICIPANTS All patients were scheduled for high-risk cardiac surgery, 279 consecutive patients in the prospective study and 48 patients in the randomized study. INTERVENTIONS An algorithmic approach of strategies to reverse cerebral desaturation. In the control group, no attempts were made to reverse cerebral desaturation. MEASUREMENTS AND MAIN RESULTS Cerebral saturation was measured using near-infrared reflectance spectroscopy. A decrease of 20% from baseline for 15 seconds defined cerebral desaturation. The success or failure of the interventions was noted. Demographic data were collected. Models for predicting the probability and the reversal of cerebral desaturation were based on multiple logistic regressions. In the randomized study, 12 hours of measurements were continued in the intensive care unit without interventions. Differences in desaturation load (% desaturation × time) were compared between groups. Half of the high-risk patients had cerebral desaturation that could be reversed 88% of the time. Interventions resulted in smaller desaturation loads in the operating room and in the intensive care unit. CONCLUSIONS Cerebral desaturation in high-risk cardiac surgery is frequent but can be reversed most of the time resulting in a smaller desaturation load. A large randomized study will be needed to measure the impact of reversing cerebral desaturation on patients outcome.

The Endovascular Coronary Sinus Catheter in Minimally Invasive Mitral and Tricuspid Valve Surgery: A Case Series

OBJECTIVES To determine the safety and efficacy of a standardized approach to the use of an endovascular coronary sinus (CS) catheter during minimally invasive cardiac surgery. DESIGN Case series. SETTING University hospital. PARTICIPANTS Patients undergoing mitral and/or tricuspid valve surgery using a minimally invasive cardiac surgery approach. INTERVENTIONS An endovascular CS catheter was placed to enable the administration of retrograde cardioplegia using transesophageal echocardiography (TEE), fluoroscopy, and CS pressure measurements. MEASUREMENTS AND MAIN RESULTS Data were collected from 96 patient records. A total of 95 (99.0%) endovascular coronary sinus catheters were positioned. The mean time to insert the catheter into the sinus ostium under TEE guidance was 6.3 ± 8.4 minutes. Confirmation of adequate positioning with fluoroscopy took an average of 9.1 ± 10.6 minutes for a mean total procedure time of 16.1 ± 14.1 minutes. Successful positioning, as defined by the ability to generate a perfusion pressure in the CS greater than 30 mmHg during surgery, was achieved in 87.5% of cases. During positioning, ventricularization of the CS pressure curve was observed in 86.0% of cases. The presence of ventricularization was associated with an increase in positioning success (odds ratio = 15.8; 95% confidence interval, 3.713-67.239). One patient developed extravasation of contrast agent after CS catheter placement, without evidence of CS rupture. CONCLUSIONS Endovascular CS catheter insertion can be performed with a high rate of success for positioning and a low complication rate. During positioning, obtaining ventricularization is associated with an increased success rate.

Always consider left ventricular outflow tract obstruction in hemodynamically unstable patients.

Transesophageal echocardiography (TEE) plays a key role in the evaluation of hemodynamic instability, particularly in the diagnosis of left ventricular outflow tract obstruction (LVOTO) where it can completely alter patient management. The purpose of these rounds is to highlight how TEE can be instrumental in ensuring a timely diagnosis of this lesion by using examples from the recent archives of the Montreal Heart Institute of hemodynamic instability secondary to previously undiagnosed LVOTO. In some cases, TEE can also serve as an invaluable tool to evaluate the response to therapy in the perioperative and critical care settings. The Research Ethics Committee of the Montreal Heart Institute granted approval for use of the related images for research and publication purposes.

Evaluation of Autonomic Reserves in Cardiac Surgery Patients

OBJECTIVE Autonomic nervous system dysfunction is a well-recognized but rarely evaluated risk factor for patients undergoing cardiac surgery. By measuring autonomic reserves in patients scheduled for cardiac surgery, the authors aimed to identify those with autonomic dysfunction and to evaluate their risk of perioperative complications. DESIGN This was a prospective, observational study. SETTING The study was conducted in a single academic center. PARTICIPANTS Sixty-seven patients completed the study. INTERVENTIONS Autonomic reserves were evaluated using analysis of heart rate variability (HRV) and blood pressure variability (BPV) after a Valsalva maneuver. MEASUREMENTS AND MAIN RESULTS The patients were divided into 2 groups depending on their response to the autonomic challenge, a group with autonomic reserves (AR, n = 38) and a group with negligible autonomic reserves (NAR, n = 29). The groups were compared for baseline psychologic distress, demographic and medical profiles, autonomic response to morphine premedication and the induction of anesthesia, hemodynamic instability, the occurrence of decreases in cerebral oxygen saturation, and postoperative complications. Patients in the NAR group had significantly higher psychologic distress scores (p < 0.001), a higher baseline parasympathetic tone (p = 0.003), were unable to increase parasympathetic tone with morphine premedication, had more severe hypotension at the induction of anesthesia (p < 0.001), more episodes of decreases in cerebral saturation (p = 0.0485), and a higher overall complication rate (p = 0.0388) independent of other variables studied. CONCLUSIONS Patients with diminished autonomic reserves can be identified before cardiac surgery using analysis of HRV and BPV of the response to the Valsalva maneuver, and some evidence suggests that they may be at increased risk of perioperative complications.

Intraoperative changes in regional wall motion: can postoperative coronary artery bypass graft failure be predicted?

OBJECTIVE To evaluate the accuracy of new intraoperative regional wall motions abnormalities (RWMAs) detected by transesophageal echocardiography (TEE) to predict early postoperative coronary artery graft failure. DESIGN A retrospective study. SETTING A tertiary care university hospital. PATIENTS Five thousand nine hundred ninety-eight patients who underwent coronary artery bypass graft (CABG) surgery. INTERVENTIONS An evaluation of RWMAs recorded with intraoperative TEE before and after cardiopulmonary bypass (CPB) in patients who had coronary angiography for suspected postoperative myocardial ischemia based on electrocardiogram (ECG), CK-MB, troponin T, hemodynamic compromise, low cardiac output, and malignant ventricular arrhythmia. Sensitivity, specificity, positive and negative predictive values, odds ratio, 95% confidence interval, and chi-square analysis were used. MEASUREMENTS AND MAIN RESULTS Thirty-nine patients (0.7%) underwent early coronary angiography for the suspicion of early graft dysfunction. Of the 32 patients with diagnosed early graft dysfunction, 5 patients (15.6%) had shown new intraoperative RWMAs as detected by TEE, 21 patients (65.6%) had no new RWMAs, no report was available in 5 patients (15.6%), and 1 examination (3.1%) was excluded because of poor imaging quality. The sensitivity of TEE to predict graft failure was 15.6%, the specificity was 57.1%, and the positive predictive and negative values were 62.5% and 12.9%, respectively. The odds ratio and 95% confidence interval was 0.1190 (0.0099-1.4257) when TEE was positive compared with coronary angiography. No association was found between new RWMAs detected with TEE and graft failure as documented with coronary angiography (p = 0.106). CONCLUSIONS In this retrospective study, RWMAs detected with TEE were of limited value to predict early postoperative CABG failure.

Transesophageal echocardiography training: looking forward to the next step

In this issue of the Journal, Jerath et al. describe how an interactive online transesophageal echocardiography (TEE) teaching module with a pretest/posttest design significantly improved the performance of multidisciplinary trainees. Why is such an initiative so important in 2011? Since the use of an esophageal echocardiographic probe was first described in 1976 there have been significant advances in both TEE and transthoracic echocardiography (TTE) in terms of equipment, indications, training requirements, certification, and continuous medical education. As echocardiography (TEE and, ultimately, goal-oriented TTE) becomes an integral part of the training not only of cardiac anesthesiologists but also of general anesthesiologists and critical care physicians, some issues need to be addressed.

Pericardial Constriction Caused by a Giant Lipoma

We report the case of a 52-year-old woman who was referred to our center for an unusually large constrictive pericardial mass. Her medical and surgical history included obstructive sleep apnea, reduction mammoplasty, breast cancer, obesity (body mass index = 44.63 kg/m2), and latex allergy. She complained of exercise intolerance and progressive dyspnea (New York Heart Association class III) for 6 months. Physical examination revealed low heart sounds without paradoxal pulse. Her chest x-ray showed an enlarged cardiac silhouette (Figure 1A), and her ECG was in sinus rhythm with low QRS voltage in leads aVL and III (Figure 1C). On cardiac CT scan, we observed a very large, well-delimited, noninvasive lipidic mass (20×17×15 cm) surrounding a normal-size heart (Figure 2A). No additional anomaly was found. Transthoracic echocardiography was challenging, with obesity and the fatty mass limiting echocardiographic windows. Therefore we performed a cardiac MRI, which showed normal biventricular size and function and no significant valvular disease. Cardiac MRI depicted a well-delimited intrapericardial mass with high signal intensity on T1-weighted images (Figure 3). The mass signal was fully nulled with application of fat saturation, confirming a diagnosis of giant intrapericardial lipoma. There was no gadolinium enhancement in the myocardium, …

Subaortic stenosis after atrioventricular septal defect repair.

A 43-year-old woman was referred to our institution for surgical resection of a subaortic stenosis. Her medical history included the repair of a transitional atrioventricular (AV) septal defect (AVSD) at the age of 14 years, consisting of an ostium primum AVSD and a restrictive muscular ventricular septal defect (VSD), associated with a cleft anterior mitral leaflet. After her surgery, she remained asymptomatic until she was 34 years old, when she experienced progressive fatigue. A transthoracic echocardiography showed no residual shunt, mild tricuspid and aortic regurgitation, moderate mitral regurgitation, and subaortic stenosis with a fixed left ventricular outflow tract (LVOT) peak gradient of 52 mm Hg. The subaortic stenosis worsened over the years, reaching a systolic peak gradient of 100 mm Hg. She remained active, but experienced more frequent diaphoretic episodes with mild activity. After induction of general anesthesia, a transesophageal echocardiography (TEE) was performed. In the midesophageal long-axis view, remnants of mitral valve chordae originating from the base of the thickened anterior mitral leaflet and attached to the interventricular septum were seen (Fig. 1) (Video 1, see Supplemental Digital Content 1, http://links.lww.com/AA/A283; see Appendix for video legends), and a distinct subvalvular membrane (Fig. 2), both causing deformation and narrowing of the LVOT, and associated with turbulent flow (Video 2, see Supplemental Digital Content 2, http://links.lww.com/AA/A284; see Appendix for video legends). A common AV junction (same septal insertion of the AV valves), mild regurgitations of both AV valves, and hypertrophy of the interventricular septum were also visualized. Intraoperative findings correlated well with the structures seen with TEE. A subvalvular membrane and mitral valve chordae inserted into the LVOT were resected in addition to a septal myectomy. Postoperative TEE showed no significant residual obstruction in the LVOT with a systolic peak gradient reduced to 14 mm Hg and the mitral regurgitation decreased to trivial. The mild aortic regurgitation was still present. No shunt at the ventricular level was found after the septal myomectomy.

Myocardial Protection in Mitral Valve Surgery: Comparison Between Minimally Invasive Approach and Standard Sternotomy

OBJECTIVE To compare antegrade and retrograde cardioplegia administration in minimally invasive mitral valve surgery (MIMS) and open mitral valve surgery (OMS) for myocardial protection. DESIGN Retrospective study. SETTING Tertiary care university hospital. PARTICIPANTS The study comprised 118 patients undergoing MIMS and 118 patients undergoing OMS. INTERVENTIONS The data of patients admitted for MIMS from 2006 to 2010 were reviewed. Patients undergoing isolated elective OMS from 2004 to 2006 were used as a control group. Cardioplegia in the MIMS group was delivered via the distal port of the endoaortic clamp and an endovascular coronary sinus catheter positioned using echographic and fluoroscopic guidance. Antegrade and retrograde cardioplegia were used in OMS. Data regarding myocardial infarction (MI) (creatine kinase [CK]-MB, troponin T, electrocardiography); myocardial function; and hemodynamic stability were collected. MEASUREMENTS AND MAIN RESULTS There was no difference in the perioperative MI incidence between both groups (1 in each group, p = 0.96). No statistically significant difference was found for maximal CK-MB (35.9 µg/L [25.1-50.1] v 37.9 µg/L [28.6-50.9]; p = 0.31) or the number of patients with CK-MB levels >50 µg/L (29 v 33; p = 0.55) or CK-MB >100 µg/L (3 v 4; p = 0.70) between the OMS and MIMS groups. However, maximum troponin T levels in the MIMS group were significantly lower (0.47 µg/L [0.32-0.79] v 0.65 µg/L [0.45-0.94]; p = 0.0007). No difference in the incidence of difficult weaning from bypass and intra-aortic balloon pump use between the MIMS and OMS groups was found. CONCLUSIONS Antegrade and retrograde cardioplegia administration during MIMS and OMS provided comparable myocardial protection.