Trends in Therapy and Outcomes Associated With Respiratory Failure in Patients Admitted to the Cardiac Intensive Care Unit

Extra-cardiac management of cardiogenic shock in the intensive care unit

Cardiogenic shock (CS) is a heterogeneous clinical syndrome characterized by low cardiac output leading to end-organ hypoperfusion. Organ dysoxia ranging from transient organ injury to irreversible organ failure and death occurs across all CS etiologies but differing by incidence and type. Herein, we review the recognition and management of respiratory, renal and hepatic failure complicating CS. We also discuss unmet needs in the CS care pathway and future research priorities for generating evidence-based best practices for the management of extra-cardiac sequelae. The complexity of CS admitted to the contemporary cardiac intensive care unit demands a workforce skilled to care for these extra-cardiac critical illness complications with an appreciation for how cardio-systemic interactions influence critical illness outcomes in afflicted patients.

Guide to Lung-Protective Ventilation in Cardiac Patients

The incidence of acute respiratory insufficiency has continued to increase among patients admitted to modern-day cardiovascular intensive care units. Positive pressure ventilation (PPV) remains the mainstay of treatment for these patients. Alterations in intrathoracic pressure during PPV has distinct effects on both the right and left ventricles, affecting cardiovascular performance. Lung-protective ventilation (LPV) minimizes the risk of further lung injury through ventilator-induced lung injury and, hence, an understanding of LPV and its cardiopulmonary interactions is beneficial for cardiologists.

Noninvasive Ventilation in the Cardiac Intensive Care Unit

Over the last several decades, the cardiac intensive care unit (CICU) has seen an increase in the complexity of the patient population and etiologies requiring CICU admission. Currently, respiratory failure is the most common reason for admission to the contemporary CICU. As a result, noninvasive ventilation (NIV), including noninvasive positive-pressure ventilation and high-flow nasal cannula, has been increasingly utilized in the management of patients admitted to the CICU. In this review, we detail the different NIV modalities and summarize the evidence supporting their use in conditions frequently encountered in the CICU. We describe the unique pathophysiologic interactions between positive pressure ventilation and left and/or right ventricular dysfunction. Additionally, we discuss the evidence and strategies for utilization of NIV as a method to reduce extubation failure in patients who required invasive mechanical ventilation. Lastly, we examine unique considerations for managing respiratory failure in certain, high-risk patient populations such as those with right ventricular failure, severe valvular disease, and adult congenital heart disease. Overall, it is critical for clinicians who practice in the CICU to be experts with the application, risks, benefits, and modalities of NIV in cardiac patients with respiratory failure.

Liberation From Mechanical Ventilation in the Cardiac Intensive Care Unit

The prevalence of respiratory failure is increasing in the contemporary cardiac intensive care unit (CICU) and is associated with a significant increase in morbidity and mortality. For patients that survive their initial respiratory decompensation, liberation from invasive mechanical ventilation (IMV) and the decision to extubate requires careful clinical assessment and planning. Therefore, it is essential for the CICU clinician to know how to assess and manage the various stages of IMV liberation, including ventilator weaning, evaluation of extubation readiness, and provide post-extubation care. In this review, we provide a comprehensive approach to liberation from IMV in the CICU, including cardiopulmonary interactions relative to withdrawal from positive pressure ventilation, evaluation of readiness for and assessment of spontaneous breathing trials, sedation management to optimize extubation, strategies for patients at a high risk for extubation failure, and tracheostomy in the cardiovascular patient.

Mechanical ventilation in patients with cardiogenic pulmonary edema: a sub-analysis of the LUNG SAFE study

BACKGROUND

Patients with acute respiratory failure caused by cardiogenic pulmonary edema (CPE) may require mechanical ventilation that can cause further lung damage. Our aim was to determine the impact of ventilatory settings on CPE mortality.

METHODS

Patients from the LUNG SAFE cohort, a multicenter prospective cohort study of patients undergoing mechanical ventilation, were studied. Relationships between ventilatory parameters and outcomes (ICU discharge/hospital mortality) were assessed using latent mixture analysis and a marginal structural model.

RESULTS

From 4499 patients, 391 meeting CPE criteria (median age 70 [interquartile range 59-78], 40% female) were included. ICU and hospital mortality were 34% and 40%, respectively. ICU survivors were younger (67 [57-77] vs 74 [64-80] years, p < 0.001) and had lower driving (12 [8-16] vs 15 [11-17] cmH2O, p < 0.001), plateau (20 [15-23] vs 22 [19-26] cmH2O, p < 0.001) and peak (21 [17-27] vs 26 [20-32] cmH2O, p < 0.001) pressures. Latent mixture analysis of patients receiving invasive mechanical ventilation on ICU day 1 revealed a subgroup ventilated with high pressures with lower probability of being discharged alive from the ICU (hazard ratio [HR] 0.79 [95% confidence interval 0.60-1.05], p = 0.103) and increased hospital mortality (HR 1.65 [1.16-2.36], p = 0.005). In a marginal structural model, driving pressures in the first week (HR 1.12 [1.06-1.18], p < 0.001) and tidal volume after day 7 (HR 0.69 [0.52-0.93], p = 0.015) were related to survival.

CONCLUSIONS

Higher airway pressures in invasively ventilated patients with CPE are related to mortality. These patients may be exposed to an increased risk of ventilator-induced lung injury. Trial registration Clinicaltrials.gov NCT02010073.

Cardiovascular Critical Care Training: A Collaboration between Intensivists and Cardiologists

With growing patient complexity, the cardiovascular intensive care unit (CICU) of today has evolved substantially from the coronary care unit (CCU) of decades ago. The growing burden of noncardiac critical illness and highly specialized acute cardiovascular disease requires a degree of expertise beyond that afforded through a general cardiology training program. Therefore, the American Heart Association (AHA) has proposed a CICU staffing model to include dedicated cardiac intensivists; in the present day, "dual-trained" physicians are extremely sparse. Guidance on designing critical care fellowships for cardiologists is limited but will require collaboration between cardiologists and medical intensivists. Here, we review the evolution of the CICU, describe training pathways, and offer guidance on creating a cardiology critical care training program.

Relation of Ischemic Heart Disease to Outcomes in Patients With Acute Respiratory Distress Syndrome

Patients with ischemic heart disease (IHD) are often excluded from acute respiratory distress syndrome (ARDS) clinical trials. As a result, little is known about the impact of IHD in this population. We sought to assess the association between IHD and clinical outcomes in patients with ARDS. Participants from 4 ARDS randomized controlled trials with shared study criteria, definitions, and end points were included. Using multivariable logistic regression, we assessed for the association between IHD and a primary outcome of 60-day mortality. Secondary outcomes included 90-day mortality, 28-day ventilator-free days, and 28-day organ failure. Among 1,909 patients, 102 had a history of IHD (5.4%). Patients with IHD were more likely to be older and male (p <0.05). Noncardiac co-morbidities, severity of illness, and other markers of ARDS severity were not statistically different (all, p >0.05). Patients with IHD had a higher 60-day (39.2% vs 23.3%, p <0.001) and 90-day (40.2% vs 24.0%, p <0.001) mortality, and experienced more frequent renal (45.1% vs 32.0%, p = 0.006) and hepatic (35.3% vs 25.2%, p = 0.023) failure. After multivariable adjustment, 60-day (odds ratio [OR] 1.76; 95% confidence interval [CI]: 1.07 to 2.89, p = 0.025) and 90-day (OR 1.74; 95% CI: 1.06 to 2.85, p = 0.028) mortality remained higher. IHD was associated with 10% fewer ventilator-free days (incidence rate ratio 0.90; 95% CI: 0.85 to 0.96, p = 0.001). In conclusion, co-morbid IHD was associated with higher mortality and fewer ventilator-free days in patients with ARDS. Future studies are needed to identify predictors of mortality and improve treatment paradigms in this critically ill subgroup of patients.

Oxygen Supplementation and Hyperoxia in Critically Ill Cardiac Patients: From Pathophysiology to Clinical Practice

Oxygen supplementation has been a mainstay in the management of patients with acute cardiac disease. While hypoxia is known to be detrimental, the adverse effects of artificially high oxygen levels (hyperoxia) have only recently been recognized. Hyperoxia may induce harmful hemodynamic effects, including peripheral and coronary vasoconstriction, and direct cellular toxicity through the production of reactive oxygen species. In addition, emerging evidence has shown that hyperoxia is associated with adverse clinical outcomes. Thus, it is essential for the cardiac intensive care unit (CICU) clinician to understand the available evidence and titrate oxygen therapies to specific goals. This review summarizes the pathophysiology of oxygen within the cardiovascular system and the association between supplemental oxygen and hyperoxia in patients with common CICU diagnoses, including acute myocardial infarction, heart failure, shock, cardiac arrest, pulmonary hypertension, and respiratory failure. Finally, we highlight lessons learned from available trials, gaps in knowledge, and future directions.

Heart Failure-Related Cardiogenic Shock: Pathophysiology, Evaluation and Management Considerations: Review of Heart Failure-Related Cardiogenic Shock

Despite increasing prevalence in critical care units, cardiogenic shock related to HF (HF-CS) is incompletely understood and distinct from acute myocardial infarction related CS. This review highlights the pathophysiology, evaluation, and contemporary management of HF-CS.

Quality of Heart Failure Care in the Intensive Care Unit

Patients with heart failure (HF) who are seen in an intensive care unit (ICU) manifest the highest-risk, most complex and most resource-intensive disease states. These patients account for a large relative proportion of days spent in an ICU. The paradigms by which critical care is provided to patients with HF are being reconsidered, including consideration of various multidisciplinary ICU staffing models and the development of acute-response teams. Traditional HF quality initiatives have centered on the peri- and postdischarge period in attempts to improve adherence to guideline-directed therapies and reduce readmissions. There is a compelling rationale for expanding high-quality efforts in treating patients with HF who are receiving critical care so we can improve outcomes, reduce preventable harm, improve teamwork and resource use, and achieve high health-system performance. Our goal is to answer the following question: For a patient with HF in the ICU, what is required for the provision of high-quality care? Herein, we first review the epidemiology of HF syndromes in the ICU and identify relevant critical care and quality stakeholders in HF. We next discuss the tenets of high-quality care for patients with HF in the ICU that will optimize critical care outcomes, such as ICU staffing models and evidence-based management of cardiac and noncardiac disease. We discuss strategies to mitigate preventable harm, improve ICU culture and conduct outcomes review, and we conclude with our summative vision of high-quality of ICU care for patients with HF; our vision includes clinical excellence, teamwork and ICU culture.