Con: Artificial Intelligence-Derived Algorithms to Guide Perioperative Blood Management Decision Making.

Artificial intelligence has the potential to improve the care that is given to patients; however, the predictive models created are only as good as the base data used in their design. Perioperative blood management presents a complex clinical conundrum in which significant variability and the unstructured nature of the required data make it difficult to develop precise prediction models. There is a potential need for training clinicians to ensure they can interrogate the system and override when errors occur. Current systems created to predict perioperative blood transfusion are not generalizable across clinical settings, and there is a considerable cost implication required to research and develop artificial intelligence systems that would disadvantage resource-poor health systems. In addition, a lack of strong regulation currently means it is difficult to prevent bias.

Mechanisms of Acute Right Ventricular Injury in Cardiothoracic Surgical and Critical Care Settings: Part 2.

The right ventricle (RV) is intricately linked in the clinical presentation of critical illness; however, the basis of this is not well-understood and has not been studied as extensively as the left ventricle. There has been an increased awareness of the need to understand how the RV is affected in different critical illness states. In addition, the increased use of point-of-care echocardiography in the critical care setting has allowed for earlier identification and monitoring of the RV in a patient who is critically ill. The first part of this review describes and characterizes the RV in different perioperative states. This second part of the review discusses and analyzes the complex pathophysiologic relationships between the RV and different critical care states. There is a lack of a universal RV injury definition because it represents a range of abnormal RV biomechanics and phenotypes. The term "RV injury" (RVI) has been used to describe a spectrum of presentations, which includes diastolic dysfunction (early injury), when the RV retains the ability to compensate, to RV failure (late or advanced injury). Understanding the mechanisms leading to functional 'uncoupling' between the RV and the pulmonary circulation may enable perioperative physicians, intensivists, and researchers to identify clinical phenotypes of RVI. This, consequently, may provide the opportunity to test RV-centric hypotheses and potentially individualize therapies.

Thrombosis and coagulopathy in COVID-19 patients rceiving ECMO: A narrative review of current literature.

Extracorporeal membrane oxygenation (ECMO) is an established part of the treatment algorithm for coronavirus disease 2019 (COVID-19)-related acute respiratory distress syndrome. An intense inflammatory response may cause an imbalance in the coagulation cascade making both thrombosis and bleeding common and notable features of the clinical management of these patients. Large observational and retrospective studies provide a better understanding of the pathophysiology and management of bleeding and thrombosis in COVID-19 patients requiring ECMO. Clinically significant bleeding, including intracerebral hemorrhage, is an independent predictor of mortality, and thrombosis (particularly pulmonary embolism) is associated with mortality, especially if occurring with right ventricular dysfunction. The incidence of heparin-induced thrombocytopenia is higher than the general patient cohort with acute respiratory distress syndrome or other indications for ECMO. The use of laboratory parameters to predict bleeding or thrombosis has a limited role. In this review, the authors discuss the complex pathophysiology of bleeding and thrombosis observed in patients with COVID-19 during ECMO support, and their effects on outcomes.

The Effects of Escalation of Respiratory Support and Prolonged Invasive Ventilation on Outcomes of Cardiac Surgical Patients: A Retrospective Cohort Study.

OBJECTIVES: The aim of this study was to determine the effects of escalation of respiratory support and prolonged postoperative invasive ventilation on patient-centered outcomes, and identify perioperative factors associated with these 2 respiratory complications. DESIGN: A retrospective cohort analysis of cardiac surgical patients admitted to the cardiothoracic intensive care unit (ICU) between August 2015 and January 2018. Escalation of respiratory support was defined as "unplanned continuous positive airway pressure," "non-invasive ventilation," or "reintubation" after surgery; prolonged invasive ventilation was defined as "invasive ventilation beyond the first 12 hours following surgery." The primary endpoint was the composite of escalation of respiratory support and prolonged ventilation. SETTING: Tertiary cardiothoracic ICU. PARTICIPANTS: A total of 2,098 patients were included and analyzed. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: The composite of escalation of support or prolonged ventilation occurred in 509 patients (24.3%). Patients who met the composite had higher mortality (2.9% v 0.1%; p < 0.001) and longer median [interquartile range] length of ICU (2.1 [1.0-4.9] v 0.9 [0.8-1.0] days; p < 0.0001) and hospital (10.6 [8.0-16.0] v 7.2 [6.2-10.0] days; p < 0.0001) stay. Hypoxemia and anemia on admission to ICU were the only 2 factors independently associated with the need for escalation of respiratory support or prolonged invasive ventilation. CONCLUSIONS: Escalation of respiratory support or prolonged invasive ventilation is frequently seen in cardiac surgery patients and is highly associated with increased mortality and morbidity. Hypoxemia and anemia on admission to the ICU are potentially modifiable factors associated with escalation of respiratory support or prolonged invasive ventilation.

The Right Ventricle During Selective Lung Ventilation for Thoracic Surgery.

The right ventricle (RV) has been an area of evolving interest after decades of being ignored and considered less important than the left ventricle. Right ventricular dysfunction/failure is an independent predictor of mortality and morbidity in cardiac surgery; however, very little is known about the incidence or impact of RV dysfunction/failure in thoracic surgery. The pathophysiology of RV dysfunction/failure has been studied in the context of acute respiratory distress syndrome (ARDS), cardiac surgery, pulmonary hypertension, and left ventricular failure, but limited data exist in literature addressing the issue of RV dysfunction/failure in the context of thoracic surgery and one-lung ventilation (OLV). Thoracic surgery and OLV present as a unique situation where the RV is faced with sudden changes in afterload, preload, and contractility throughout the perioperative period. The authors discuss the possible pathophysiologic mechanisms that can affect adversely the RV during OLV and introduce the term RV injury to the myocardium that is affected adversely by the various intraoperative factors, which then makes it predisposed to acute dysfunction. The most important of these mechanisms seems to be the role of intraoperative mechanical ventilation, which potentially could cause both ventilator-induced lung injury leading to ARDS and RV injury. Identification of at-risk patients in the perioperative period using focused imaging, particularly echocardiography, is paramount. The authors also discuss the various RV-protective strategies required to prevent RV dysfunction and management of established RV failure.

Patients Discharged From the Intensive Care Unit on a Dopamine Infusion-A Retrospective, Observational Study.

OBJECTIVE: To assess the safety of discharging cardiac surgical patients from the intensive care unit (ICU) to wards while the patients are still receiving a dopamine infusion. DESIGN: Retrospective, observational study. SETTING: Cardiothoracic ICU of a tertiary academic hospital in the United Kingdom. PARTICIPANTS: The study comprised all cardiac surgical patients older than 18 years and admitted between September 1, 2015 and September 16, 2016 to the ICU and subsequently discharged to a surgical ward. Patients were divided in the following 2 groups: a dopamine group with patients discharged with a dopamine infusion and a control group with patients discharged without any dopamine infusion. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: The hospital mortality rate was comparable in both groups (0.7% in the dopamine group v 0.2% in the control group [p = 0.11]), despite that the median logistic EuroSCORE was significantly higher in the dopamine group (7.0 v 3.8 [p < 0.01]). The ICU readmission rate was higher in the dopamine group (6.6% v 2.4%; p < 0.01). ICU and hospital lengths of stay were longer in the dopamine group (1.7 v 0.9 days [p < 0.01] and 11.4 v 8.0 days [p < 0.01], respectively). CONCLUSIONS: Despite a higher ICU readmission rate, ICU discharge of patients on dopamine infusion was not associated with increased mortality.