Hemodynamics & Shock PDF

Hemodynamics & Shock States CHELSEA KRUEGER, PHARMD, BCCCP Supplemental Materials 1. Hoffman EW. Basics of cardiovascular hemodynamic monitoring. Drug Intell Clin Pharm 1982;16(9):657- 64. 2. Moranville MP, Mieure KD, Santayana EM. Evaluation and management of shock states. J Pharm Pract 2011...

Hemodynamics & Shock States CHELSEA KRUEGER, PHARMD, BCCCP Supplemental Materials 1. Hoffman EW. Basics of cardiovascular hemodynamic monitoring. Drug Intell Clin Pharm 1982;16(9):657- 64. 2. Moranville MP, Mieure KD, Santayana EM. Evaluation and management of shock states. J Pharm Pract 2011;24(1):44-60. 3. MedCram 16-minute review of cardiogenic, hypovolemic, & distributive shock: https://youtu.be/CbM4UihE1TQ Note: uses PCWP in place of LVEDP and JVP in place of CVP 2 Hemodynamics WHAT IS NORMAL AND WHAT DOES IT MEAN? 3 Learning Objectives 1. Define the hemodynamic parameters that influence arterial blood pressure, cardiac output, and stroke volume. 2. Describe the relationships between hemodynamic parameters using Frank Starling Curves. 4  5 www.boxym.com/blog/what-is-blood-  1. Cardiac 2. Atrial systole, 3. Atrial diastole, diastole ventricular ventricular diastole Molnar C, Gair J. (2013). Concepts of Biology. Houston, TX: OpenStax CNX. systole 6  Arterial blood pressure (BP) Cardiac Systemic vascular output (CO) resistance (SVR) Heart rate Stroke volume (HR) (SV) Contractilit Preload Afterload y 7  Arterial blood pressure (BP) Cardiac Systemic vascular output (CO) resistance (SVR) Heart rate Stroke volume (HR) (SV) Contractilit Preload Afterload y 8  Cardiac Output (CO) Amount of blood ejected from the left ventricle in one minute Normal range = 4 - 7 L/min Cardiac Index (CI): CO normalized to body surface area Normal range = 2.8 - 3.6 L/min/m2 Hoffman EW. Drug Intell Clin Pharm 1982;16(9):657- 64. 9  If CO = 4.2 L/min… 27 yo M = 6’2” and 27 yo F = 5’2” and 85 kg 45 kg BSA = 2.11 BSA = 1.42 CI = 4.2/2.11 CI = 4.2/1.42 CI = 1.99 L/min/m2 CI = 2.96 L/min/m2 10  Arterial blood pressure (BP) Cardiac Systemic vascular output (CO) resistance (SVR) Heart rate Stroke volume (HR) (SV) Contractilit Preload Afterload y 11  Stroke Volume (SV) and Variation (SVV) SV: volume of blood ejected from the ventricle during each contraction Stroke volume index (SVI): SV/BSA Range 33-47 mL/beat/m2 SVV: indicates preload responsiveness (in mechanically ventilated patients in NSR!!) SVV10-15% = fluid responsive Berkenstadt et al. Anesth Analg 2001;92(4):984-9. 12  Contractility Intrinsic strength of myocardium during systole, i.e. inotropy Not directly measured Hoffman EW. Drug Intell Clin Pharm 1982;16(9):657- 64. 13 Molnar C, Gair J. (2013). Concepts of Biology. Houston, TX: OpenStax CNX.  Frank Starling Curve Contractili SV ty Sarcomere length Hoffman EW. Drug Intell Clin Pharm 1982;16(9):657- 64. 14  Preload Stretch of the myocardium prior to contraction Increases with total blood volume, venous return Decreases with poor ventricular or venous compliance, tachycardia, blood loss Represents a patient’s volume status Left ventricular end-diastolic pressure (LVEDP) ↑ preload = ↑ cardiac output Hoffman EW. Drug Intell Clin Pharm 1982;16(9):657- 64. 15 Molnar C, Gair J. (2013). Concepts of Biology. Houston, TX: OpenStax CNX.  Frank Starling Curve Contractili SV ty Preload Sarcomere (i.e.length LVEDP) Hoffman EW. Drug Intell Clin Pharm 1982;16(9):657- 64. 16  Afterload The “load” that the heart must eject blood against ↑ resistance to forward flow (i.e. afterload) = ↓ cardiac output Increased with ↑ systemic vascular resistance (SVR), ↑ aortic pressure, and aortic valve stenosis Afterload Hoffman EW. Drug Intell Clin Pharm 1982;16(9):657- 64. 17  Frank Starling Curve Contractili SV ↑ afterload ty Preload Sarcomere (i.e.length LVEDP) Hoffman EW. Drug Intell Clin Pharm 1982;16(9):657- 64. 18  Arterial blood pressure (BP) Cardiac Systemic vascular output (CO) resistance (SVR) Heart rate Stroke volume (HR) (SV) Contractilit Preload Afterload y 19  Systemic Vascular Resistance (SVR) Resistance to blood flow caused by the systemic vasculature Blood vessel diameter controlled by the autonomic nervous system ↑ SVR = ↓ cardiac output Normal range = 800 – 1200 dyne·sec/cm3 Skin temperature cooler with ↑ SVR Hoffman EW. Drug Intell Clin Pharm 1982;16(9):657- 64. 20  Arterial Blood Pressure Systolic pressure: maximal aortic pressure following ejection (i.e. systole) Diastolic pressure: lowest aortic pressure during relaxation (i.e. diastole) Reported in mmHg as Normal range Hoffman EW. Drug Intell Clin Pharm 1982;16(9):657- 64. 21 Klabunde, RE. (2016). Arterial Blood Pressure [Online image]. Retrieved from http://www.cvphysiology.com/Blood%20Pressure/BP002  Mean Arterial Pressure (MAP) Average arterial pressure during one cardiac cycle Normal range = 80 – 100 mmHg During shock, MAP neurogenic shock Most commonly encountered shock subset 48  Hypovolemi Cardiogeni Distributive Obstructive c c MAP ↓ ↓ ↓ SVR ↓ (afterload) ↑ ↑ HR ↑ ↑ or ↓ ↑ CO (or CI) ↓ ↓ ↑ LVEDP ↓ ↑ ↓ (preload) CVP ↓ ↑ ↓ Skin temp ↓ ↓ ↑ 49  Shock Hypovolemic Cardiogenic Distributive Obstructive Cardiac Blood loss Massive MI Septic shock tamponade Dehydration Aortic stenosis Anaphylaxis Massive PE ↓ ↓ CO ↓ SVR ↑ CVP LVEDP/preload 50  Obstructive Shock Extracardiac obstruction to flow 1. Impaired diastolic filling: cardiac tamponade 2. Impaired systolic contraction: massive pulmonary embolism Cardiac tamponade: ↓ CO and equalization of diastolic pressures between the left and right heart (↑CVP, ↑LVEDP) Massive pulmonary embolism: ↑ afterload and ↓ LVEDP Relatively uncommon shock subset CDC. (2014). Normal Heart [Online image]. Retrieved from https://www.cdc.gov/ncbddd/heartdefects/howtheheartworks.html 51  Hypovolemi Cardiogeni Distributive Obstructive c c MAP ↓ ↓ ↓ ↓ SVR ↑ (afterload) ↑ ↑ ↓ HR ↑ ↑ or ↓ ↑ ↑ CO (or CI) ↓ ↓ ↑ ↓ LVEDP ↓ ↑ ↓ ↑ or ↓ (preload) CVP ↓ ↑ ↓ ↑ Skin temp ↓ ↓ ↑ ↓ 52 53 Management of Shock HOW DO WE FIX WHAT IS WRONG? 54 Learning Objectives 1. Predict how a hemodynamic parameter will change with administration of isotonic crystalloids, inotropes, vasodilators, diuretics, and vasopressors 2. Design a therapeutic regimen for a patient based on their shock subset 55 Patient Case #1 28 yo M with GSW x3 to abdomen and chest Non-invasive Cold skin, vitals per EMS: 86/48, HR 140 FloTrac™ readings: CI 2.0, SVR 1350, MAP 60, SVV 17% What interventions can improve these hemodynamic derangements? 56  Hemorrhagic Hypovolemic Shock Leading cause of preventable trauma death and occurs rapidly Advances in management historically made during times of armed combat Focus is normalization of deranged physiology and correction of shock state 1-3% of patients Components require of massive damage transfusion control (e.g. ≥10u RBC in 24 hr) resuscitation Minimization of isotonic crystalloid Permissive hypotension Transfusion of a balanced ratio of blood products 2017;33(1):15-36. Chang R, Holcomb JB. Crit Care ClinGoal-directed correction of coagulopathy 57  Minimization of Crystalloids Historically, massive volumes used to ↑CO and oxygen delivery Supra-normal resuscitation ↑ abdominal compartment syndrome, multiple organ failure, dilutional coagulopathy, acute respiratory distress syndrome, and hyperchloremic metabolic acidosis American College of Surgeons (ACS) and Eastern Association for the Surgery of Trauma recommend the use of blood product resuscitation Isotonic crystalloids reserved for non-hemorrhagic hypovolemic shock Chang R, Holcomb JB. Crit Care Clin 2017;33(1):15-36. 58 Balogh Z, McKinley BA, Cocanour CS, et al. Arch Surg 2003;138(6):637-642. Vasopressors and Inotropes Vasopressor: a drug that augments SVR by promoting vasoconstriction Indication: hypotension refractory to IV fluids Patients in hypovolemic shock already have a ↑↑ SVR Inotrope: a drug that augments CO by increasing contractility Contraindicated in the initial management of hypovolemic shock. The patient must always be resuscitated first. 59  Resuscitation Goals MAP ↓ SVR MAP >65 or SBP>90 (afterload) ↑ mmHg HR ↑ CO (or CI) ↓ UOP >0.5 mL/kg/hr LVEDP (preload) ↓ Resolution of altered CVP ↓ mental status Skin temp ↓ Carmazine MN, et al. J Trauma Acute Care Surg 2015;78(6):S48-53. 60 Patient Case #1 28 yo M with GSW x3 to abdomen and chest Non-invasive Cold skin, vitals per EMS: 86/48, HR 140 FloTrac™ readings: CI 2.0, SVR 1350, MAP 60, SVV 17% Restore plasma volume with blood products in preference to IV crystalloids Defer vasopressors; monitor FloTrac™ 61  Non-Hemorrhagic Hypovolemic Shock Multifactorial plasma loss: burns, pancreatitis, peritonitis, vomiting, diarrhea IV fluids indicated if altered mental status or hypotension Isotonic crystalloids (Lactated Ringer’s, Plasmalyte, NaCl 0.9%) first line Resuscitation recommendations vary Pancreatitis: 20-30 mL/kg Lactated Ringer’s, then 250 mL/hr (~3 mL/kg/hr) Burns: 4 mL/kg/% total BSA burned; 50% over 8 hr, 50% over 16 hr Resuscitate to goal MAP >65 mmHg and urine output >0.5 mL/kg/hr Aggarwal A, et al. World J Gastroenterol 2014;20(48):18092-18103. 62 Mitchell KB, et al. J Burn Care Res 2014;34(1):196-202. Fluid Compartments 2/3 Intracellular Fluid Total Body Extravascul Water 3/4 ar (TBW) 1/3 (Interstitial) ECF Fluid 1/4 Intravascula ~8% r Fluid 63  Osmolar Fluid Tonicity Na Cl K Ca Mg Buffers ity Bicarbon Plasma Isotonic 140 103 4 5 2 290 ate D5W Hypotonic - - - - - - 250 0.45% NaCl Hypotonic 77 77 - - - - 154 0.9% NaCl Isotonic 154 154 - - - - 308 Lactated Isotonic 130 110 4 3 - Lactate 275 Ringer’s Plasma-Lyte Isotonic 140 98 5 - 3 Acetate 295 130 - 130 - < Albumin 5% Isotonic - - - 308 160 160 1 3% NaCl Hypertonic 513 513 - - - - 1027 64  Osmolar Fluid Tonicity Na Cl K Ca Mg Buffers ity Bicarbon Plasma Isotonic 140 103 4 5 2 290 ate D5W Hypotonic - - - - - - 250 0.45% NaCl Hypotonic 77 77 - - - - 154 0.9% NaCl Isotonic 154 154 - - - - 308 Lactated Isotonic 130 110 4 3 - Lactate 275 Ringer’s Plasma-Lyte Isotonic 140 98 5 - 3 Acetate 295 130 - 130 - < Albumin 5% Isotonic - - - 308 160 160 1 3% NaCl Hypertonic 513 513 - - - - 1027 **Isotonic crystalloids are first-line IVF for resuscitation** 65  Practice 2/3 Intracellular 667 mL Fluid 1000 Total mL Body NS D5W Extravascul Water 3/4 ar 750 mL 250 (TBW) 1/3 (Interstitial) ECF Fluid 1/4 Intravascula 83 mL 250 mL r Fluid 66 Patient Case #2 62 yo F with dizziness; reports diet and medication non-compliance Physical Exam 1. +3 edema, rales, “Cold and wet” 8 5 Non-invasive MAP 60, HR 90, SBP 18, CI >2.2) IV diuretics ± IV vasodilators (venous) Subset III: Cold and dry (hypoperfusion; PCWP 15-18, CI