The Cardiorenal Syndrome is commonly encountered, and frequently misunderstood. Join the CardioNerds team as we discuss the complex interplay between the heart and kidneys with Dr. Elliott Miller (Assistant Professor of Medicine at Yale University School of Medicine and Associate Medical Director of the Cardiac Intensive Care Unit of Yale New Haven Hospital), and Dr. Nayan Arora (Clinical Assistant Professor of Medicine and Nephrologist at the University of Washington Medical Center). We are hosted by FIT lead Dr. Matthew Delfiner (Cardiology Fellow at Temple University), Cardiac Critical Care Series Co-Chairs Dr. Mark Belkin (AHFTC faculty at University of Chicago) and Dr. Karan Desai (Cardiologist at Johns Hopkins Hospital), and CardioNerds Co-Found Dr. Dan Ambinder. In this episode we discuss the definition and pathophysiology of the cardiorenal syndrome, explore strategies for initial diuresis and diuretic resistance, and management of the common heart failure medications in this setting. Show notes were developed by Dr. Matthew Delfiner. Audio editing by CardioNerds Academy Intern, student doctor Akiva Rosenzveig. The CardioNerds Cardiac Critical Care Series is a multi-institutional collaboration made possible by contributions of stellar fellow leads and expert faculty from several programs, led by series co-chairs, Dr. Mark Belkin, Dr. Eunice Dugan, Dr. Karan Desai, and Dr. Yoav Karpenshif. Pearls • Notes • References • Production Team CardioNerds Cardiac Critical Care PageCardioNerds Episode PageCardioNerds AcademyCardionerds Healy Honor Roll CardioNerds Journal ClubSubscribe to The Heartbeat Newsletter!Check out CardioNerds SWAG!Become a CardioNerds Patron! Pearls and Quotes - Management of Cardiorenal Syndrome in the CICU Cardiorenal syndrome (CRS) represents a range of clinical entities in which there is both heart and kidney dysfunction, and can be driven by one, or both, of the organs. CRS is caused by reduced renal perfusion, elevated renal congestion, or a combination of the two. Treatment therefore focuses on increasing perfusion, by optimizing cardiac output and mean arterial pressure, and reducing congestion through diuresis. Patients should be monitored for an adequate response to the initial diuretic dose within 2 hours of administration. If the response is inadequate, the loop diuretic dose should be doubled. Diuretic resistance can be managed via sequential nephron blockade, most commonly with thiazide diuretics, but also with amiloride, high-dose spironolactone, or acetazolamide, as these target different regions of the nephron. In cases of refractory diuretic resistance, hypertonic saline can be considered with the help of an experienced clinician. Continuation or cessation of renin-angiotensin-aldosterone system (RAAS) inhibitors in the setting of CRS should be made on a case-by-case basis. Show notes - Management of Cardiorenal Syndrome in the CICU 1. Cardiorenal syndrome (CRS) is a collection of signs/symptoms that indicate injury to both the heart and kidneys. Organ dysfunction in one can drive dysfunction in the other. Cardiorenal syndrome can be categorized as: Type 1 - Acute heart failure causing acute kidney injury Type 2 - Chronic heart failure causing chronic kidney injury Type 3 - Acute kidney injury causing acute heart failure Type 4 - Chronic kidney injury causing chronic heart failure Type 5 - Co-development of heart and kidney injury by another systemic process. These categories can be helpful for education, discussion, and research purposes, but they do not usually enter clinical practice on a regular basis since different categories of cardiorenal syndrome are not necessarily treated differently. 2. CRS is caused by either reduced renal perfusion, elevated renal congestion, or a combination of the two. When dealing with CRS, note that: CRS can be caused by poor kidney perfusion,