Management of Blood Loss and Hypovolemic Shock Troy Phillips DO Assistant Professor VCOM Carolinas & Spartanburg Family Medicine Residency tphillips@srhs.com

Objectives Define shock Discuss physiology of shock Review the clinical presentation of shock Discuss normal blood volume of pediatric and adult patients Discuss the body’s compensatory responses to shock Review hemorrhage classification Describe appropriate IV access and initial fluid management in shock Discuss hemorrhage control

Definitions Shock Hypovolemic shock Hemorrhagic shock clinical syndrome that results from inadequate tissue perfusion an imbalance between tissue oxygen supply and demand Hypovolemic shock Shock resulting from the loss of either red blood cell mass or plasma volume alone Hemorrhagic shock Hypovolemic shock secondary to either internal or external hemorrhage

Meh

Physiology of Shock heart rate X stroke volume = cardiac output Know that if your stroke vol dec then your HR needs to inc You should prob know this….I mean, even I know this….and I hate all that is cardio

Physiology of Shock Meh

Physiology of Shock Shock at the Cellular Level Anaerobic metabolism > lactic acid & metabolic acidosis Loss of cell membrane integrity & electrical gradient Swelling of ER & mitochondrial damage, Lysosomal rupture & enzyme release, Fluid influx, cellular edema and death Meh

Physiology of Shock Shock at the Systemic Level Moderate hypoperfusion may be tolerated - compensation Prolonged /severe hypoperfusion leads to progressive cellular and organ dysfunction Aaaaaaaaaannnnnnnnnnd meh

Clinical Presentation Initial Findings Tachycardia Decreased peripheral perfusion (cool skin) Increased respiratory rate Mental status changes (anxiety) What finding is absent? Hypotension Know that with tachycardia, it is bc your HR increased to compensate = test question Hypotension is not an initial finding

By III  start to see bp drop bc lost 1.5 to 2 L blood So know that the level at which you see hypotension is level 3 Your pt is bad before they get to this pt

Do not wait for hypotension! An injured patient with tachycardia and cool skin is in shock until proven otherwise. Hypotension is a late finding in shock (Class III) Hypotension usually doesn’t present until a loss of 1/3 of total blood volume Normal MAP = 70 – 110 60 is our cut off where we start to see end organ perfusion issues Start to drop off at about 1.5L loss

Normal Blood Volume Normal blood volume in adult 70cc/kg Use ideal body weight, not actual Normal blood volume in child 80-90cc/kg About 5 L in adults

Compensatory Responses Microcirculation Systemic vascular resistance rises Maintain systemic pressure to perfuse heart and brain at expense of muscle, skin and GI tract 2/3 of circulating blood is contained in the venous system Cardiovascular Increased heart rate to maintain cardiac output in setting of decreased stroke volume Systemic vascular resistance rises Forces blood out of your venous system (which holds about 2/3 of your blood)

Compensatory Responses Neuroendocrine Increased adrenergic output and reduced vagal tone. Norepinephrine causes peripheral and splanchnic vasoconstriction Hypothalamic release of ACTH stimulating cortisol secretion Hepatic Increased gluconeogenesis further elevating blood glucose No neuroendocrine questions Elevated blood glucose is just a stress resp to shock (not because normally a DM pt)

Compensatory Responses Pulmonary Tachypnea in response to relative hypoxia. However, this eventually leads to respiratory alkalosis from increased dumping of CO2 Renal Conservation of salt and water by increased afferent arteriolar resistance leading to reduced urine formation

Know the (for the 1000th time) HR inc and the peripheral venous constriction occurs to keep MAP normal

Treatment Stop the bleeding. Replace fluids. Diagnosis and treatment occur simultaneously.

Treatment Airway and Breathing Circulation Provide high flow O2 for all patients in shock Circulation Find and control bleeding Obtain IV access Replace volume

Hemorrhage Control External Bleeding Direct Pressure (first!) Elevation Pressure points Immobilization (especially fractures) Hemostatic agents Tourniquet (expect limb loss) If you feel a pulse you can use that as a pressure pt Don’t use the carotid (or you’re an idiot)

Hemorrhage Control Internal bleeding Have to find it first Think chest, abdomen and retroperitoneum Surgical intervention or angiographic embolization “can’t do much about it until you find it”…This dude cracks me up

IV Access Establish adequate IV access 2 large bore peripheral IVs Central access (central line or IO) IO is intraosseous  drill a hole into the bone, like the tibia (cool stuff)

IV Fluids Give warmed NS or LR quickly Only 1/3 of crystalloid volume stays intravascular NS – normal saline LR – lactate ringers (surgeons like this better) He could give a crap Just know these are what you normally give, but normally only get about 1/3 into the intravasc space for what you give

meh

IV Fluids Adults Pediatrics Give 1-2L of NS or LR Repeat if needed No improvement after 3L, give blood Pediatrics 20cc/kg bolus Repeat if needed. If no relief, give blood. Know peds

Practice Questions What is the first sign of shock? Tachycardia (and cool skin, inc respiration, and axiety but NOT hypotension) What is an unreliable sign of early shock? Hypotension What is the blood volume in an adult with an ideal body weight of 70kg? 70cc/kg = about 5 L What is the blood volume in a child with a weight of 20kg? (take 80 – 90 cc/kg, they weigh 20Kg = 1600 – 1800 cc) What is the initial IV fluid of choice? NS or LR What is the initial bolus amount for a child? 20cc/kg bolus Test questions: One of the test questions are here verbatim HTN appears in class 3 Initial IV fluid and bolus amts  NS or LR, initial bolus amt for kids are 20cc/kg (see slide 24) What does the heart do to inc cardiac output in the setting of shock = inc heart rate (see like every other slide in the lecture) After given appropriate amt of NS or LR, your next IV fluid of choice = blood

Questions?

References UpToDate.com Shock in adults: Types, presentation, and diagnostic approach Hemorrhagic Shock lecture, Dr. Jim Powers 2/23/12 – VCOM Harrison’s Principle of Internal Medicine Kaplan Medical COMLEX Review – Pathology Emergency Care and Transportation of the Sick and Injured (6th edition)