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Pharmacologic Management of Acute Circulatory Failure: Vasoactive Medications Thank you Suanne Daves, MD Slide 2 What you will hear today A short review of Shock A look at how the intrinsic sympathetic nervous system & various drugs that can accelerate/enhance the excitation- contraction coupling phenomenon in myocytes (improve cardiac output). Slide 3 Circulatory Failure / Shock What is it? Metabolic demand outstrips supply or the ability to extract The anaerobic state leads to accumulation of lactic acid. Energy dependent cellular processes cease Cellular edema, cellular disruption, cell death.. Organ failure Slide 4 Slide 5 Slide 6 A digression to cell biology Cardiac Output and SVR are all about Calcium are all about Calcium Slide 7 PDE all about Calcium Slide 8 Back to something more familiar: Starling Slide 9 The Bodys Neuronal Defense System Slide 10 121121 22 DA 1-2 Vasopressin 1 2 Vasopressin Slide 11 Slide 12 Slide 13 Slide 14 Slide 15 Bohn (2006). Inotropic Agents in Heart Failure. Heart Failure in Children and Young Adults. Chang & Towbin. Slide 16 PDE Slide 17 When you need to intervene: Vasoactive Medications: Goals of treatment Provide adequate tissue oxygenation. Maintain vital organ function. Restore systemic blood pressure. Tailor drugs to minimize adverse side effects. Slide 18 Slide 19 Vasoactive Medications Catacholamines Vasopressin Phosphodiesterase inhibitors Calcium sensitizers Slide 20 Catacholamines with inotropic properties Epinephrine Norepinephrine Isoproterenol Dopamine Dobutamine Slide 21 Bohn (2006). Inotropic Agents in Heart Failure. Heart Failure in Children and Young Adults. Chang & Towbin. Slide 22 Bohn (2006). Inotropic Agents in Heart Failure. Heart Failure in Children and Young Adults. Chang & Towbin. Slide 23 Bohn (2006). Inotropic Agents in Heart Failure. Heart Failure in Children and Young Adults. Chang & Towbin. Slide 24 Bohn (2006). Inotropic Agents in Heart Failure. Heart Failure in Children and Young Adults. Chang & Towbin. Slide 25 Bohn (2006). Inotropic Agents in Heart Failure. Heart Failure in Children and Young Adults. Chang & Towbin. Slide 26 Starling again Improved inotropy CO Slide 27 Catacholamines with pressor properties Phenylephrine Epinephrine Norepinephrine Dopamine Slide 28 More Starling more preload = more CO Remember: too much afterload = CO Slide 29 Other Vasoactive Options Milrinone PDE inhibitor Vasopressin Vasoconstriction Improves sensitivity to catachols Levosimendan Calcium sensitizing agent Slide 30 Starling again Reduced afterload improved CO Slide 31 The Downside of Vasoactive Agents (mostly true for catachols) Increased myocardial O2 demand Myocardial injury/cell death Tolerance/tachyphylaxis Arrhythmogenesis Peripheral vasoconstriction Elevates SVR Compromises splanchnic blood flow Slide 32 A 4-mos-old infant presents to the ER with irritability, poor po intake, and tachypnea. The ER doc says the baby looks shocky. They have started an IV & given 20mL/kg NS. Bedside Reality Slide 33 The infant is awake & quiet. HR: 170s-180s (sinus) RR: 70s BP: 90/68 He is cool peripherally. His pulses are thready pH 7.29/pCO 2 38/pO 2 82/HCO 3 18 Lactate 4.0 Would you begin an inotrope/pressor? Which one? Slide 34 Same infant. HR: 180s (sinus) RR: 70s BP: 52/44 Slide 35 Key Concepts The predominant -AR in the heart is the 1 -AR (