Re-Dosing del Nido cardioplegia in adult cardiac surgery: Perfusion characteristics and outcomes--Is there an optimal redosing strategy?

OBJECTIVES: del Nido cardioplegia is utilized for myocardial protection in adult patients undergoing cardiac surgery; however, no standardized re-dosing protocol exists. We describe perfusion characteristics and clinical outcomes in adult cardiac surgery patients who were re-dosed with del Nido cardioplegia. METHODS: Chart review was performed for adult patients undergoing cardiac surgery (specific inclusion/exclusion criteria below) who received exactly two doses of del Nido cardioplegia from 2012 to 2019; n = 542 patients. The main outcome was a composite endpoint comprised of operative mortality, myocardial infarction, post-operative cardiac support device (CSD), and postoperative decrease in ejection fraction (EF), which was analyzed via multivariable logistic regression (MVLR). A secondary analysis evaluated postoperative vasoactive-inotropic scores (VIS) via gamma log link regression (GLLR) as a more physiologic indication of myocardial recovery. RESULTS: MVLR demonstrated that increased total cardiopulmonary bypass (CPB) time was associated with a positive composite outcome (p < .001), whereas time between doses (p = .237) and the volume of each dose was not (p = .626). GLLR also demonstrated that prolonged CBP, decreased EF, congestive heart failure at time of surgery, and low hematocrit at the start of the surgery were all associated with higher VIS. CONCLUSIONS: In this retrospective study, variations in re-dosing strategy for del Nido cardioplegia do not affect postoperative outcomes and increased CPB time is associated with increased operative mortality, myocardial infarction, need for post-operative CSDs, and reduced postoperative EF, and increased VIS, irrespective of the re-dosing strategy. Further studies are warranted to to identify additional patient and operative characteristics that predispose to complications.

Effect of venoarterial extracorporeal membrane oxygenation initiation timing on tricuspid valve surgery outcomes.

Objectives: Tricuspid valve surgery is associated with high rates of shock and in-hospital mortality. Early initiation of venoarterial extracorporeal membrane oxygenation after surgery may provide right ventricular support and improve survival. We evaluated mortality in patients undergoing tricuspid valve surgery based on the timing of venoarterial extracorporeal membrane oxygenation. Methods: All consecutive adult patients undergoing isolated or combined surgical tricuspid valve repair or replacement from 2010 to 2022 requiring venoarterial extracorporeal membrane oxygenation use were stratified by initiation in the operating room (Early) versus outside of the operating room (Late). Variables associated with in-hospital mortality were explored using logistic regression. Results: There were 47 patients who required venoarterial extracorporeal membrane oxygenation: 31 Early and 16 Late. Mean age was 55.6 years (standard deviation, 16.8), 25 (54.3%) were in New York Heart Association class III/IV, 30 (60.8%) had left-sided valve disease, and 11 (23.4%) had undergone prior cardiac surgery. Median left ventricular ejection fraction was 60.0% (interquartile range, 45-65), right ventricular size was moderately to severely increased in 26 patients (60.5%), and right ventricular function was moderately to severely reduced in 24 patients (51.1%). Concomitant left-sided valve surgery was performed in 25 patients (53.2%). There were no differences in baseline characteristics or invasive measurements immediately before surgery between the Early and Late groups. Venoarterial extracorporeal membrane oxygenation was initiated 194 (23.0-840.0) minutes after cardiopulmonary bypass in the Late venoarterial extracorporeal membrane oxygenation group. In-hospital mortality was 35.5% (n = 11) in the Early group versus 68.8% (n = 11) in the Late group (P = .037). Late venoarterial extracorporeal membrane oxygenation was associated with in-hospital mortality (odds ratio, 4.00; 1.10-14.50; P = .035). Conclusions: Early postoperative initiation of venoarterial extracorporeal membrane oxygenation after tricuspid valve surgery in high-risk patients may be associated with improvement in postoperative hemodynamics and in-hospital mortality.

Assessing sex-based differences in postsurgical clinical outcomes after use of del Nido cardioplegia.

OBJECTIVES: del Nido cardioplegia is used to pharmacologically arrest the heart during cardiac surgery and decrease reperfusion- and ischaemia-related myocardial injury. Studies have demonstrated the physiological differences between male and female hearts, potentially related to cardiac size or myocyte calcium handling; we aimed to assess for between-sex differences in clinical outcomes after receipt of del Nido cardioplegia. METHODS: Patients who underwent coronary artery bypass or coronary artery bypass graft/valve surgery at our institution using del Nido cardioplegia (January 2014 to December 2019) were included (n = 2118). Clinical data were collected retrospectively. After the creation of a propensity-matched cohort (n = 1252), multivariable logistic regression was used to analyse binary postoperative outcomes, and a Gamma model was used for a continuous postoperative outcome. Our primary end-point was a composite end-point comprised of 30-day mortality and/or need for a post-bypass mechanical support device. RESULTS: The final cohort included 459 females and 793 males (matched up to 1:2, all standardized mean differences <0.1). Multivariable logistic regression showed that biological sex was not associated with the composite primary end-point (odds ratio = 0.898, P = 0.779). A Gamma model indicated that there were no sex-related differences in vasoactive-inotropic scores reflecting vasopressor and inotrope usage at the time of patient operating room exit (exp[est] = 1.394, P = 0.189). CONCLUSIONS: Our findings showed no significant between-sex differences in clinical outcomes after receiving del Nido cardioplegia, suggesting adequate myocardial protection as currently administered. Further research is warranted to elicit if there are sex-based differences between cardioplegic solutions. IRB APPROVAL DATE (PROTOCOL NUMBER): 26 May 2021 (AAAR8359).

Optimizing Perioperative Renal Replacement Therapy for Patients Undergoing Cardiac Surgical Procedures Requiring Cardiopulmonary Bypass.

Coronary artery disease is highly prevalent in patients with end-stage renal disease (ESRD), and cardiovascular complications remain the most common cause of death in this patient population. Accordingly, many cardiac surgical procedures requiring cardiopulmonary bypass support are performed on these patients each year, with morbidity and mortality rates far exceeding patients without ESRD. Anuric patients lack the normal renal homeostatic functions which typically allow for physiologic protection from challenges during the operation, such as volume overload, hyperkalemia, and acidemia. Careful preoperative planning and coordination to provide pre-, intra-, and postoperative renal replacement therapies for such patients are imperative. Many different strategies have been reported in the literature. Zero-balance ultrafiltration is a newer strategy which utilizes convective ultrafiltration much like pre-filter continuous renal replacement therapy and utilizes pre-existing connections on the cardiopulmonary bypass pump performed by the perfusion team. This allows for control of potassium concentration throughout the operation with existing personnel and minimal additional equipment. Here, we describe the unique challenges caring for patients receiving renal replacement therapy undergoing cardiac surgical procedures requiring cardiopulmonary bypass.

A novel dosing strategy of del Nido cardioplegia in aortic surgery.

Objective: While del Nido (DN) cardioplegia is increasingly used in cardiac surgery, knowledge is limited in its safety profile for operations with prolonged crossclamp time (CCT). We have introduced a unique redosing strategy for aortic surgery: all operations use DN with a 1000-mL initiation dose (750 mL antegrade, 250 mL retrograde) composed of 1:4 blood:DN crystalloid. At 90 minutes CCT and every 30 minutes thereafter, a 250-mL dose was introduced retrograde in a 4:1 ("reverse") ratio. Additionally, at 90 minutes CCT and every 90 minutes thereafter, a reverse ratio dose of approximately 100 to 400 mL was introduced via the right coronary artery. Here, we analyze the outcomes of our unique redosing strategy used. Methods: In total, 440 patients underwent aortic surgery between January 2015 and March 2021 under a single surgeon and received DN. Our primary end points were change in left ventricular ejection fraction (LVEF) and right ventricular systolic function based on echocardiography. Multivariable linear regression was used to analyze the relationship between CCT and outcomes. Results: The median was 61 years old (interquartile range, 51-69), and 23% were female. Indication was aneurysm in 65% and dissection in 24%. Median preoperative LVEF was 60% (55%-62%). Median CCT and cardiopulmonary bypass times were 135 minutes (93-165 minutes) and 181 minutes (142-218 minutes), respectively. In-hospital mortality occurred in 3%. Multivariable linear regression showed CCT was not associated with change in LVEF or change in right ventricular systolic function. Conclusions: Our unique method of redosing DN cardioplegia appears to provide safe and effective myocardial protection for aortic surgery.

Re-dosing of del Nido cardioplegia in adult cardiac surgery requiring prolonged aortic cross-clamp.

OBJECTIVES: Few data exist on the use of del Nido cardioplegia in adults, specifically during operations requiring prolonged aortic cross-clamp. In this pilot study, we evaluate outcomes of patients undergoing surgery with cross-clamp time >3 h based on re-dosing strategy, using either full dose (FD; 1:4 blood to crystalloid ratio) or dilute (4:1 blood to crystalloid ratio) solution. METHODS: Consecutive adult patients (>18 years) undergoing cardiac surgery from 2012 to 2018 with cross-clamp time >3 h were reviewed. Patients were excluded if del Nido cardioplegia was not used. Patients were categorized into FD or dilute groups based on re-dosing solution. Propensity score matching was used to control for baseline differences between groups. The primary endpoint was in-hospital mortality. Other outcomes examined included: postoperative mechanical support, arrhythmia, stroke, dialysis and cardiac function. RESULTS: Included for analysis were 173 patients (115 male) with median age of 63.8 (interquartile range 53.9-73.1). Major comorbidities included diabetes (45), cerebrovascular disease (34), hypertension (131), atrial fibrillation (52) and previous cardiac surgery (83). There were 108 patients (62%) who received FD re-dosing, while 65 (38%) received dilute. A greater proportion of patients in the dilute group received retrograde delivery, for both induction (32/108 vs 39/65, P < 0.001) and re-dose (50/108 vs 53/65, P < 0.001). After propensity score matching, in-hospital mortality was not different between groups (6/48 vs 1/48, P = 0.131). There were no differences in rates of postoperative mechanical circulatory support, stroke, left ventricular ejection fraction or right ventricle dysfunction. CONCLUSIONS: Del Nido cardioplegia has been used in complex cardiac surgery requiring prolonged cross-clamp. Re-dosing can be performed with either FD or dilute del Nido solution with no statistical difference in outcomes.

Methylene Blue Does Not Improve Vasoplegia After Left Ventricular Assist Device Implantation.

BACKGROUND: Vasoplegia is a frequent complication of left ventricular assist device (LVAD) implantation. We investigated the effectiveness of methylene blue (MB) for vasoplegia in LVAD recipients. METHODS: Twenty-seven patients received MB for vasoplegia after LVAD implantation and met study criteria between March 2015 and May 2018. Propensity score inverse probability weighting identified 41 controls who did not receive MB for post-LVAD vasoplegia. Clinical outcomes were compared between control and MB groups and between patients who received doses during (n = 15) and after surgery (n = 12). Hemodynamics and vasopressor requirements were analyzed using analysis of covariance. RESULTS: Median total MB dose was 1.9 mg/kg (interquartile range, 1.2-2.2 mg/kg). Methylene blue recipients experienced a transient initial decline in norepinephrine requirement from 141 ng/kg per min (95% confidence interval [CI], 81-201 ng/kg per min) to 117 ng/kg per min (95% CI, 58-176 ng/kg per min; P = .022) and a delayed decline in vasopressin from 4.8 U/h (95% CI, 3.8-5.8 U/h) to 4.0 U/h (95% CI, 2.8-5.1 U/h) (P = .004). In-hospital mortality, postoperative complications, and end-organ dysfunction did not differ from those of controls. There were no observed differences in mean arterial pressure, vasopressor requirements, or outcomes between patients who received doses during or after surgery. Weighted overall mortality in the entire study cohort was 8.8%. CONCLUSIONS: Although MB may affect vasopressor requirements, clinical outcomes in vasoplegia after LVAD implantation did not improve and were not affected by the timing of administration.

Management of primary graft failure after heart transplantation: Preoperative risks, perioperative events, and postoperative decisions.

Primary graft failure (PGF) after heart transplantation (HT) is a devastating and unexpected event characterized by failure of the graft to adequately support recipient circulation necessitating high doses of vasopressors and inotropes and/or temporary mechanical circulatory support. Although it represents an increasingly common event in the current era, there remains a high degree of variability in prevalence, reported risk factors, and approach to this clinical entity. The purpose of the current review is to highlight preoperative considerations including known incidence and risk factors, perioperative issues involving the identification and management of PGF, and postoperative decisions related to weaning of mechanical circulatory support and titration of immunosuppressive therapy. Lastly, we highlight future directions in PGF research, involving basic and translational research, that have the potential to uncover novel strategies of risk stratification and treatment. CASE: Our patient is a 53-year-old man with end-stage non-ischemic dilated cardiomyopathy complicated by ventricular tachycardia (VT), post-capillary pulmonary hypertension, and renal insufficiency. After progressing to NYHA Class IV symptoms, he underwent implantation of a durable left ventricular assist device (LVAD) as bridge to transplant (BTT). On device support, he developed recurrent VT resulting in multiple defibrillator discharges and hospital admission for intravenous anti-arrhythmic therapy. He is subsequently upgraded to a higher status on the waiting list. A suitable donor is identified, with an appropriate predicted heart mass and an anticipated ischemic time of <4 hours. He is taken to the operating room, where at the time of anesthesia induction he develops vasodilatory shock, requiring high-dose vasopressors, and cardiopulmonary bypass (CPB) support for dissection. After surgical anastomosis, cross clamp removal and reperfusion, graft function is extremely poor, there is significant bradycardia requiring pacing, and the patient is unable to be weaned successfully from CPB. Venoarterial extracorporeal membrane oxygenation (VA-ECMO) is initiated, and the patient is transferred to the intensive care unit. Retrospective flow crossmatch is negative. This patient is suffering from severe primary graft failure.

Mechanical Aortic Valve Thrombus in Pregnancy: A Case Report.

Cardiac disease is one of the leading causes of maternal mortality in developed countries. The presence of a mechanical valve is a predictor of cardiac complications in obstetric patients, likely due to the challenges associated with pregnancy hypercoagulability and the imperative of meticulous management of anticoagulation throughout pregnancy, delivery, and the postpartum and to prevent the devastating event of a mechanical valve thrombosis. We report on the management of a pregnant woman with a mechanical aortic valve found to have a thrombus at 37 weeks gestation. It was decided to perform cesarean delivery to allow for a reoperative mechanical aortic valve replacement 24 hours thereafter.

Anesthetic management of the patient with a ventricular assist device.

The use of long- and short-term mechanical circulatory support in the form of ventricular assist device (VAD) has increased over the last decade. Although cardiothoracic anesthesiologists care for these patients during device placement, increasingly higher numbers of general anesthesiologists are involved in the management of VAD patients during noncardiac surgery and procedures. An understanding of devices, their indications, and complications is essential to the anesthesiologists caring for these patients. We review the anesthetic considerations for the implantation of these devices and concerns when caring for patients with durable and short-term devices already in place.

Anesthetic management of the patient with extracorporeal membrane oxygenator support.

The use of short-term mechanical circulatory support in the form of extracorporeal membrane oxygenation (ECMO) in adult patients has increased over the last decade. Cardiothoracic anesthesiologists may care for these patients during ECMO placement and for procedures while ECMO support is in place. An understanding of ECMO capabilities, indications, and complications is essential to the anesthesiologist caring for these patients. Below we review the anesthetic considerations for the implantation of ECMO and concerns when caring for patients on ECMO.

Designing and implementing the objective structured clinical examination in anesthesiology.

Since its description in 1974, the Objective Structured Clinical Examination (OSCE) has gained popularity as an objective assessment tool of medical students, residents, and trainees. With the development of the anesthesiology residents' milestones and the preparation for the Next Accreditation System, there is an increased interest in OSCE as an evaluation tool of the six core competencies and the corresponding milestones proposed by the Accreditation Council for Graduate Medical Education.In this article the authors review the history of OSCE and its current application in medical education and in different medical and surgical specialties. They also review the use of OSCE by anesthesiology programs and certification boards in the United States and internationally. In addition, they discuss the psychometrics of test design and implementation with emphasis on reliability and validity measures as they relate to OSCE.

Inadequate visualization and reporting of ventricular function from transthoracic echocardiography after cardiac surgery.

OBJECTIVES: The purpose of this study was to determine the incidence of and risk factors for inadequate reporting of ventricular function from transthoracic echocardiography after cardiac surgery. DESIGN AND SETTING: A retrospective study of cardiac surgical patients at 1 university hospital. PATIENTS: The first 300 consecutive patients who had transthoracic echocardiogram within the first 7 days after cardiac surgery. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: The primary outcomes for this study were inadequate visualization of the left ventricle, the right ventricle, or both ventricles. Analysis of data from 300 patients identified inadequate imaging of the left ventricle in 50 (17%) cases, inadequate imaging of the right ventricle in 112 (37%) cases, inadequate imaging of both ventricles in 37 (12%) cases, and inadequate imaging of either the left or right ventricle in 125 (42%) cases. Increasing age, earlier postoperative day, male sex, and median sternotomy were associated with inadequate imaging. CONCLUSIONS: Transthoracic imaging is often inadequate in patients who have undergone recent cardiac surgery. Patient and surgical characteristics influence reporting of right and left ventricular function.