Acute Kidney Injury following Cardiac Surgery

The primary goal of this chapter is to provide the reader with an overview of basic renal physiology and function and to review the identification, pathogenesis, and treatment of acute kidney injury following cardiac surgery. Particular focus will be directed toward the diagnostic criteria for acute kidney injury, short- and long-term impacts on patient outcomes, role of novel biomarkers, mechanisms of acute renal injury, general management principles, preventative strategies, and the influence of anesthetic and surgical techniques on its development. The content of this chapter will serve to underscore a particularly harmful but likely underappreciated problem affecting patients in the cardiothoracic critical care setting.

Neurologic Complications in the Cardiac Surgery Patient

This chapter per the authors discusses the spectrum of complications that occur in the postoperative cardiac surgery patients. It evaluates the mechanistic role of cardiopulmonary bypass and the various cardiac surgical procedures in the development of cerebral injury. Furthermore, it evaluates the role of different intraoperative monitoring in early detection of cerebral injury in these patients. Finally, it provides evidence based practice guidelines for hemodynamic management as well as treatment of complications that are diagnosed in the cardiac surgical intensive care unit.

Vasodilating Agents

This chapter discusses the salient features of arterial and venous dilating agents commonplace in the management of the post-cardiotomy surgical patient. A keen understanding of the underlying cellular mechanism, pharmacology, indication, safety profile, and controversies of clinical utility of vasodilating agents is imperative for routine use. The evidenced-based examination of each therapeutic modality will strengthen the practitioner's fund of knowledge for management of each pathophysiological state.

Anticoagulation Options

There are multiple indications for anticoagulation in the cardiac surgery intensive care unit including cardiac valve replacement, mechanical circulatory pumps (ECMO and ventricular assist devices), deep vein thrombosis prophylaxis, treatment of heparin-induced thrombocytopenia, and treatment of other thrombotic conditions including pulmonary embolism. Anticoagulant medications broadly fall into two categories: antiplatelet drugs and inhibitors of protein clotting factors. In this chapter we will review anticoagulant medications, therapeutic drug monitoring, common indications for anticoagulation, and the risks associated with anticoagulation after cardiac surgery.

Organization and Structure of the Cardiothoracic Intensive Care Unit

The purpose of this chapter is to emphasize and describe the team nature of critical care medicine in the Cardiothoracic Intensive Care Unit. The chapter will review the importance of various team members and discuss various staffing models (open vs closed, high intensity vs low intensity, etc.) on patient outcomes and cost. The chapter will also examine the roles of nurse practitioners and physician assistants (NP/PAs) in critical care, and will briefly review the growing role of the tele-ICU. Most studies support the concept that a multi-disciplinary ICU team, led by an intensivist, improves patient outcomes and decreases overall cost of care. The role of the tele-ICU and 24 hour in-house intensivist staffing in improving outcomes is controversial, and more research is needed in this area. Finally, a brief discussion of billing for critical care will be discussed.

Physiologic Monitoring

This chapter will provide a review of modern concepts of cardiovascular monitoring with emphasis on essential hemodynamic variables in the early post cardiac surgery patient. When defining circulatory function, importance of the entire circulatory system is underscored. This includes the function and interaction of the heart, blood vessels and circulatory blood volume to deliver sufficient amount of oxygenated blood to tissue beds. In post cardiac surgery patients, the pulmonary artery catheter remains the most widely used technology to assess cardiac function. This chapter highlights the importance of validation of less invasive and noninvasive hemodynamic monitors for the management of critically ill patients and early post cardiac surgery patients. In addition, this chapter describes the evolution of monitoring of post cardiac surgery and critically ill patients, examines different monitoring technologies and address controversial questions in modern practice as well as future directions.

Heart Transplantation

Orthotopic heart transplantation (OHT) has evolved as the “gold standard” therapy for end stage cardiomyopathy, Advances in the fields of immunosuppression, infection prophylaxis and treatment, surgical techniques as well as intensice care management have transformed heart transplantation from what was once considered an experimental intervention into a standard therapy. This chapter focuses on the standard care for OHT including surgical techniques, perioperative management and management of common postoperative complications.

Surgical Management of Mitral Valve Disease

Surgery for the mitral valve has increased over the last decade, with a focus on an increasing number of valve repairs for degenerative mitral valve disease. This chapter discusses the surgical management of mitral valve disease with a focus on the pathology of mitral valve stenosis and regurgitation. With an examination into the pathophysiology of the lesions. Subsequently a discussion regarding the various surgical techniques for mitral valve surgery followed by the major and minor complications of surgery are reviewed to provide the Intensivist with an overview of possible complications. Finally a look at the future direction of the field is briefly examined.

Gastrointestinal Issues in the Cardiothoracic ICU

A thorough understanding of gastrointestinal issues in critical illness is necessary to optimize management of the cardiothoracic patient. Post-operatively, these patients are at increased risk of GI complications due a combination of underlying vascular disease, cardiopulmonary bypass, and low cardiac output, all of which lead to splanchnic hypoperfusion and subsequent damage to the gut mucosa. While GI complications are uncommon, they are associated with a disproportionately high rate of morbidity and mortality. Presence of unexplained fever, leukocytosis, bacteremia, hemodynamic compromise or abdominal pain or distention are concerning and require prompt assessment. Other GI management issues include delivery of adequate nutrition to counteract catabolism and promote wound healing and stress ulcer prophylaxis in patients with risk factors for upper gastrointestinal bleeding.

Perioperative Respiratory Care and Complications

Clinicians caring for patients with cardio-pulmonary disease invariably must manage the respiratory system. Doing so requires a basic understanding of physiology and the interaction of the heart and lung. The present chapter begins with rudimentary concepts of respiratory physiology, focusing on, gas exchange, pulmonary mechanics, and cardio-pulmonary interactions. These are used to develop an approach to mechanical ventilation and routine perioperative respiratory care of the patient having undergone a cardio-pulmonary procedure. The final section of this chapter addresses specific respiratory challenges encountered in caring for the critically ill cardiothoracic patient in addition to contemporary management strategies.