A new machine learning algorithm to predict veno-arterial ECMO implantation after post-cardiotomy low cardiac output syndrome.

BACKGROUND: Post-cardiotomy low cardiac output syndrome (PC-LCOS) is a life-threatening complication after cardiac surgery involving a cardiopulmonary bypass (CPB). Mechanical circulatory support with veno-arterial membrane oxygenation (VA-ECMO) may be necessary in the case of refractory shock. The objective of the study was to develop a machine-learning algorithm to predict the need for VA-ECMO implantation in patients with PC-LCOS. PATIENTS AND METHODS: Patients were included in the study with moderate to severe PC-LCOS (defined by a vasoactive inotropic score (VIS) > 10 with clinical or biological markers of impaired organ perfusion or need for mechanical circulatory support after cardiac surgery) from two university hospitals in Paris, France. The Deep Super Learner, an ensemble machine learning algorithm, was trained to predict VA-ECMO implantation using features readily available at the end of a CPB. Feature importance was estimated using Shapley values. RESULTS: Between January 2016 and December 2019, 285 patients were included in the development dataset and 190 patients in the external validation dataset. The primary outcome, the need for VA-ECMO implantation, occurred respectively, in 16% (n = 46) and 10% (n = 19) in the development and the external validation datasets. The Deep Super Learner algorithm achieved a 0.863 (0.793-0.928) ROC AUC to predict the primary outcome in the external validation dataset. The most important features were the first postoperative arterial lactate value, intraoperative VIS, the absence of angiotensin-converting enzyme treatment, body mass index, and EuroSCORE II. CONCLUSIONS: We developed an explainable ensemble machine learning algorithm that could help clinicians predict the risk of deterioration and the need for VA-ECMO implantation in moderate to severe PC-LCOS patients.

Low Cardiac Output Syndrome After Cardiac Surgery: A Life-Threatening Condition from the Perspective of Pediatric Intensivists.

Low cardiac output syndrome is a clinical picture insourcing from insufficient oxygen sup- ply to tissues so as to meet the metabolic demand, myocardial dysfunction, and cardiovas- cular insufficiency. Low cardiac output syndrome is seen in nearly 25% of pediatric patients who underwent corrective or palliative surgery due to congenital heart defects. It is a clinical condition occurring typically 6-18 hours after surgery in pediatric patients undergoing cardiac surgery and causes organ failure, prolonged hospital and intensive care hospitalization time, increased resource utilization, and mortality. The identification and correct management of this serious complication in the early period is very important. However, there is no clear con- sensus or consensus report on the follow-up of this patient group and the definition of low cardiac output syndrome. Clinicians generally produced low cardiac output syndrome defini- tions according to their own approach. In this review, we aim to draw attention to low cardiac output syndrome and hope to summarize the pathophysiology, etiology, clinical definition, and treatment options of low cardiac output syndrome as a life-threatening condition in pediatric intensive care unit.

Risk factors, resource use, and cost of postoperative low cardiac output syndrome.

OBJECTIVE: Low cardiac output syndrome complicates recovery after cardiac surgery. We examined the incidence and risk factors for low cardiac output syndrome and its association with postoperative mortality, morbidity, resource use, and cost. METHODS: This cross-sectional retrospective observational study examined patients having cardiac surgery captured in the Premier Healthcare Database. Low cardiac output syndrome was defined as the requirement for postoperative mechanical circulatory support and/or hemodynamic instability requiring prolonged inotropic support. Incidence, risk factors, and association of low cardiac output syndrome with postoperative outcomes, including mortality, hospital and intensive care unit length of stay, hospital readmission, and cost at 30 days, 90 days, and 6 months, were examined. RESULTS: Among 59,810 patients from 164 hospitals having cardiac surgery between July 1, 2012, and June 30, 2014, low cardiac output syndrome developed in 6067 (10.1%) patients. Patients presenting in cardiogenic shock or systolic (± diastolic) heart failure were at greatest risk. Risk-adjusted in-hospital mortality was 12-fold greater with low cardiac output syndrome (odds ratio, 12.0; 95% confidence interval, 10.6-13.5). Risk-adjusted hospital costs (2019$; median [Q1, Q3]) were $64,041 [21,439] in patients who developed low cardiac output syndrome versus $48,086 [16,098] without; P < .001. Increased costs were driven by longer risk-adjusted hospital stay (10.1 [4.5] vs 8.5 [3.8] days); P < .001, intensive care unit (5.5 [2.5] vs 3.3 [1.5] days; P < .001) stay, and all-cause 30-day adjusted hospital readmission rates (mean [SD] 16.6 [8.2]% vs 13.9 [7.2]%; P < .001). CONCLUSIONS: Cardiac surgical patients who develop postoperative low cardiac output syndrome suffer greater mortality and have greater resource use, health care costs, and all-cause readmission, which informs perioperative decision making, and impacts hospital performance metrics and federal priority to reduce health care costs.

Interventions Associated With Treatment of Low Cardiac Output After Stage 1 Norwood Palliation.

BACKGROUND: Mortality after stage 1 palliation of hypoplastic left heart syndrome remains significant. Both cardiac output (CO) and systemic vascular resistance (SVR) contribute to hemodynamic vulnerability. Simultaneous measures of mean arterial pressure and somatic regional near infrared spectroscopy saturation can classify complex hemodynamics into 4 distinct states, with a low-CO state of higher risk. We sought to identify interventions associated with low-CO state occupancy and transition. METHODS: Perioperative data were prospectively collected in an institutional review board-approved database. Hemodynamic state was classified as high CO, high SVR, low SVR, and low CO using bivariate analysis. Associations of static and dynamic support levels and state classifications over 48 postoperative hours were tested between states and across transitions using mixed regression methods in a quasi-experimental design. RESULTS: Data from 10,272 hours in 214 patients were analyzed. A low-CO state was observed in 142 patients for 1107 hours. Both low CO and extracorporeal membrane oxygenation had increased mortality risk. The low-CO state was characterized by lower milrinone but higher catecholamine dose. Successful transition out of low CO was associated with increased milrinone dose and hemoglobin concentration. Increasing milrinone and hemoglobin levels predicted reduced risk of low CO in future states. CONCLUSIONS: Bivariate classification objectively defines hemodynamic states and transitions with distinct support profiles. Maintaining or increasing inodilator and hemoglobin levels were associated with improved hemodynamic conditions and were predictive of successful future transitions from the low-CO state.

Device Therapy and Arrhythmia Management in Left Ventricular Assist Device Recipients: A Scientific Statement From the American Heart Association.

Left ventricular assist devices (LVADs) are an increasingly used strategy for the management of patients with advanced heart failure with reduced ejection fraction. Although these devices effectively improve survival, atrial and ventricular arrhythmias are common, predispose these patients to additional risk, and complicate patient management. However, there is no consensus on best practices for the medical management of these arrhythmias or on the optimal timing for procedural interventions in patients with refractory arrhythmias. Although the vast majority of these patients have preexisting cardiovascular implantable electronic devices or cardiac resynchronization therapy, given the natural history of heart failure, it is common practice to maintain cardiovascular implantable electronic device detection and therapies after LVAD implantation. Available data, however, are conflicting on the efficacy of and optimal device programming after LVAD implantation. Therefore, the primary objective of this scientific statement is to review the available evidence and to provide guidance on the management of atrial and ventricular arrhythmias in this unique patient population, as well as procedural interventions and cardiovascular implantable electronic device and cardiac resynchronization therapy programming strategies, on the basis of a comprehensive literature review by electrophysiologists, heart failure cardiologists, cardiac surgeons, and cardiovascular nurse specialists with expertise in managing these patients. The structure and design of commercially available LVADs are briefly reviewed, as well as clinical indications for device implantation. The relevant physiological effects of long-term exposure to continuous-flow circulatory support are highlighted, as well as the mechanisms and clinical significance of arrhythmias in the setting of LVAD support.

A Multi-Institutional Simulation Boot Camp for Pediatric Cardiac Critical Care Nurse Practitioners.

OBJECTIVES: Assess the effect of a simulation "boot camp" on the ability of pediatric nurse practitioners to identify and treat a low cardiac output state in postoperative patients with congenital heart disease. Additionally, assess the pediatric nurse practitioners' confidence and satisfaction with simulation training. DESIGN: Prospective pre/post interventional pilot study. SETTING: University simulation center. SUBJECTS: Thirty acute care pediatric nurse practitioners from 13 academic medical centers in North America. INTERVENTIONS: We conducted an expert opinion survey to guide curriculum development. The curriculum included didactic sessions, case studies, and high-fidelity simulation, based on high-complexity cases, congenital heart disease benchmark procedures, and a mix of lesion-specific postoperative complications. To cover multiple, high-complexity cases, we implemented Rapid Cycle Deliberate Practice method of teaching for selected simulation scenarios using an expert driven checklist. MEASUREMENTS AND MAIN RESULTS: Knowledge was assessed with a pre-/posttest format (maximum score, 100%). A paired-sample t test showed a statistically significant increase in the posttest scores (mean [SD], pre test, 36.8% [14.3%] vs post test, 56.0% [15.8%]; p < 0.001). Time to recognize and treat an acute deterioration was evaluated through the use of selected high-fidelity simulation. Median time improved overall "time to task" across these scenarios. There was a significant increase in the proportion of clinically time-sensitive tasks completed within 5 minutes (pre, 60% [30/50] vs post, 86% [43/50]; p = 0.003] Confidence and satisfaction were evaluated with a validated tool ("Student Satisfaction and Self-Confidence in Learning"). Using a five-point Likert scale, the participants reported a high level of satisfaction (4.7 ± 0.30) and performance confidence (4.8 ± 0.31) with the simulation experience. CONCLUSIONS: Although simulation boot camps have been used effectively for training physicians and educating critical care providers, this was a novel approach to educating pediatric nurse practitioners from multiple academic centers. The course improved overall knowledge, and the pediatric nurse practitioners reported satisfaction and confidence in the simulation experience.

[Perioperative Care of Low Cardiac Output Syndrome].

Low cardiac syndrome( LOS) is the imbalance of the oxygen supply and demand at the tissue due to reduced oxygen supply by decreased cardiac function. The causes of the cardiac dysfunction are insufficient cardioplegia, elongation of aortic clamp or cardiopulmonary bypass (CPB) duration, incomplete revascularization, and so on. The preventions of LOS are myocardial protections intraoperatively. The most important myocardial protection is to accomplish more quickly, accurately and safety to operation. And today, cardioplegia is essential for surgery requiring CPB. The integrated myocardia protection is likely to be effective to the patients who suffer low cardiac function. LOS is commonly defined the decreased cardiac index (CI)[<2.0~2.2 l/min/m2], systolic blood pressure (<80~90 mmHg) and the signs of tissue malperfusion, in the absence of hypovolemia. The treatment of LOS is, at first, the correction of hypovolemia, then rhythm control, adjustment of preload and afterload. When it does not recover from LOS despite adequate treatment, the mechanical circulatory assist devices should be introduced without hesitation.

[Telemetric follow-up of implantable electronic cardiac devices : Optimisation of care in clinical practice]. / Telemetrische Nachsorge von implantierbaren kardialen Aggregaten : Optimierung der Betreuung in der Praxis.

Remote follow-up of patients with implantable electronic cardiac devices (IECD) is a scientifically well-evaluated and technically mature method. Advantages over conventional follow-up include rapid detection of clinically relevant events (i. e. arrhythmias) and of technical problems. Additionally, telemetric follow-up of IECDs has a high degree of acceptance among both patients as well as health care professionals and carries the potential to reduce health care costs. The implementation of a remote follow-up programme is associated with organisational, infrastructural and legal aspects, which are reviewed.

[Low-flow low-gradient aortic valve stenosis : Current evidence]. / "Low-flow-low-gradient"-Aortenklappenstenose : Aktuelle Evidenz.

Many patients with severe aortic stenosis have a "low-flow, low-gradient" aortic stenosis. The management of these patients can be quite difficult, as these patients often show impairment of the left ventricle, which can lead to false measurements of the severity of stenosis and also leads to a higher risk during aortic valve replacement. More diagnostic tools than only standard echocardiography are needed to correctly differentiate true severe aortic stenosis from pseudo severe aortic stenosis.

Update on surgical sepsis syndrome.

BACKGROUND: Sepsis is a serious complication in surgical patients, and is associated with prolonged hospital stay and high mortality rates. The definitions of sepsis have been revisited recently. This article reviews how definitions have changed over the years, and provides an update on basic pathobiology and essential aspects of treatment. METHODS: PubMed was searched for reports published in English before October 2016, using the search terms 'surgical sepsis' AND 'surgical ICU'. The reference lists of articles identified in the search were also checked. Other relevant literature was selected based on personal knowledge of developments in the field of sepsis. RESULTS: Sepsis is defined as the presence of infection plus associated organ dysfunction. It occurs as the result of a dysregulated host response to the infection. Prevention of infection is an important means of limiting the development of sepsis. Treatment relies on source control, appropriate antibiotics and organ support. Research continues in an attempt to identify effective immunomodulatory therapies. CONCLUSION: Sepsis is an important and serious complication of surgery, and precautions must be taken to try to prevent infection in surgical patients. If sepsis develops, rapid diagnosis is crucial so that appropriate source control, antimicrobial therapy and organ support can be started early in the course of disease. New techniques enabling a better classification of a patient's particular sepsis profile will enable more personalized therapy.

The use of neonatal extracorporeal life support in pediatric cardiac intensive care unit.

AIM: The aim of the study is to evaluate extracorporeal life support system (ECLS) employed in neonates in pediatric cardiac intensive care unit. MATERIAL AND METHODS: Twenty-five neonates that required ECLS in between November 2010 and November 2015 were evaluated. RESULTS: The median age was 12 days (range 3-28 days) and the median body weight was 3 kg (range 2.5-5 kg). Venoarterial ECLS was performed in all of the cases. Ascendan aorta-right atrial cannulation in 22 patients and neck cannulation in three patients were performed. The reason for ECLS was E-CPR in two patients, inability to wean from cardiopulmonary bypass (CPB) in seven patients, respiratory insufficiency and hypoxia in nine patients, low cardiac output (LCOS) in seven patients. Median duration of ECLS was four days (range 1-15). Hemorrhagic complications developed in 15, renal complications in 13, pulmonary complications in 12, infectious complications in 11, neurologic complications in three and mechanical complications in two of the patients. Weaning was successful in 15 of the patients. Eleven patients were successfully discharged. CONCLUSION: ECLS is an important treatment option that is performed successfully in many centers around the world to maintain life support in patients unresponsive to medical treatment. The utilization of this modality especially in newborns with congenital heart disease should be taken into consideration.

Outcome analysis for prediction of early and long-term survival in patients receiving intra-aortic balloon pumping after cardiac surgery.

BACKGROUND: Patients requiring an intra-aortic balloon pump (IABP) after cardiac surgery are critically ill and need a prolonged ICU stay. Considering limited health care resources, the early identification of patients with an extremely poor prognosis is important as a solid base for the decision whether further aggressive continuation or cessation of the therapy is recommendable. METHODS: From 2001 to 2007, 552 patients with low-output syndrome after open-heart surgery and IABP implantation in OR or within 24 h thereafter on ICU were retrospectively analyzed. RESULTS: The overall mortality at 30 and 180-day were 31 and 40 %, respectively. According to multivariate analyses, following factors were used to generate an IABP score: female gender, age ≥70 years, simultaneous coronary and valve surgery, aortic cross-clamp time >120 min., need of norepinephrin more than 0.4 µg kg(-1) min(-1), postoperative dialysis, and maximal serum creatinine kinase >3000 mg mL(-1). The 30-day mortality continuously increased along the score (10.1 % for score = 0, n = 98; 11.8 % for score = 1, n = 144; 27.5 % for score = 2, n = 153; 40.4 % score = 3, n = 89; 65.2 % for score = 4, n = 46; 77.8 % for score = 5, n = 27) and reached 100 % for all patients with a score of 6 (n = 4). CONCLUSIONS: Prediction of 30 days mortality was possible with our scoring system based on multivariate analysis, and patients with scores of 4 or greater had remarkably worse early and late survival.

A randomized controlled trial of levosimendan to reduce mortality in high-risk cardiac surgery patients (CHEETAH): Rationale and design.

OBJECTIVE: Patients undergoing cardiac surgery are at risk of perioperative low cardiac output syndrome due to postoperative myocardial dysfunction. Myocardial dysfunction in patients undergoing cardiac surgery is a potential indication for the use of levosimendan, a calcium sensitizer with 3 beneficial cardiovascular effects (inotropic, vasodilatory, and anti-inflammatory), which appears effective in improving clinically relevant outcomes. DESIGN: Double-blind, placebo-controlled, multicenter randomized trial. SETTING: Tertiary care hospitals. INTERVENTIONS: Cardiac surgery patients (n = 1,000) with postoperative myocardial dysfunction (defined as patients with intraaortic balloon pump and/or high-dose standard inotropic support) will be randomized to receive a continuous infusion of either levosimendan (0.05-0.2 µg/[kg min]) or placebo for 24-48 hours. MEASUREMENTS AND MAIN RESULTS: The primary end point will be 30-day mortality. Secondary end points will be mortality at 1 year, time on mechanical ventilation, acute kidney injury, decision to stop the study drug due to adverse events or to start open-label levosimendan, and length of intensive care unit and hospital stay. We will test the hypothesis that levosimendan reduces 30-day mortality in cardiac surgery patients with postoperative myocardial dysfunction. CONCLUSIONS: This trial is planned to determine whether levosimendan could improve survival in patients with postoperative low cardiac output syndrome. The results of this double-blind, placebo-controlled randomized trial may provide important insights into the management of low cardiac output in cardiac surgery.

Shoshin Beriberi With Low Cardiac Output and Hemodynamic Deterioration Treated Dramatically by Thiamine Administration.

"Shoshin beriberi", which is a fulminant form of cardiovascular beriberi accompanied by hemodynamic deterioration with high cardiac output and decreased systemic blood pressure, caused by thiamine deficiency due to alcoholic abuse or malnutrition, is often difficult to address because of its rarity and non-specific symptoms. We here present a patient with a history of alcoholic abuse who had suffered hemodynamic deterioration with extremely low cardiac output refractory to extracorporeal membrane oxygenation and intravenous catecholamine support, which was improved dramatically by bolus intravenous thiamine administration. Such a type with low cardiac output would be the most severe form of Shoshin beriberi, and cannot be rescued without diagnostic administration of thiamine.

Predictors of low cardiac output syndrome after isolated coronary artery bypass grafting.

Low cardiac output syndrome (LCOS) is one of the most important complications following coronary artery bypass grafting (CABG) and results in higher morbidity and mortality. However, few reports have focused on the predictors of LCOS following CABG. This study aimed to evaluate the predictors of LCOS following isolated CABG through the review of 1524 consecutive well-documented patients in a single center, retrospective trial.The relevant preoperative and intraoperative data of patients with complete information from medical records undergoing isolated CABG from January 2010 to December 2013 in our center were investigated and retrospectively analyzed. LCOS was considered when the following criteria were met: signs of impairment of body perfusion and need for inotropic support with vasoactive drugs or mechanical circulatory support with an intra-aortic balloon pump to maintain systolic blood pressure greater than 90 mmHg.LCOS developed in 205 patients following CABG, accounting for 13.5% of the total population. The in-hospital mortality in the LCOS group was significantly higher than that in the non-LCOS group (25.4% versus 1.8%, P < 0.0001). In addition to the length of ICU stay and postoperative hospital stay, LCOS was correlated with negative cerebral, respiratory and renal outcomes. Through univariate analysis and then logistic regression analysis, the predictors of LCOS following CABG included older age (age > 65 years) (OR = 1.85, 95%CI 1.27-3.76), impaired left ventricular function (OR = 2.05, 95%CI 1.53-4.54), on-pump CABG (OR = 2.16, 95%CI 1.53-4.86), emergent CPB (OR = 9.15, 95%CI 3.84-16.49), and incomplete revascularization (OR = 2.62, 95%CI 1.79-5.15).LCOS following isolated CABG caused higher mortality, higher rates of morbidity, and longer ICU and postoperative hospital stays. Older age, impaired left ventricular function, on-pump CABG, emergent CPB, and incomplete revascularization were identified as 5 predictors of LCOS following isolated CABG surgery.