Download Management of Blood Loss and Hypovolemic Shock

Management of Blood Loss and
Hypovolemic Shock
Troy Phillips DO
Assistant Professor
VCOM Carolinas &
Spartanburg Family Medicine Residency
[email protected]
Objectives
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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
– 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
Physiology of Shock
• heart rate X stroke volume = cardiac output
Physiology of Shock
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
Physiology of Shock
Shock at the Systemic
Level
Moderate hypoperfusion
may be tolerated compensation
Prolonged /severe
hypoperfusion leads to
progressive cellular and
organ dysfunction
Clinical Presentation
• Initial Findings
– Tachycardia
– Decreased peripheral perfusion (cool skin)
– Increased respiratory rate
– Mental status changes (anxiety)
– What finding is absent? Hypotension
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 Blood Volume
• Normal blood volume in adult
– 70cc/kg
– Use ideal body weight, not actual
• Normal blood volume in child
– 80-90cc/kg
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
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
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
Treatment
• Stop the bleeding. Replace fluids.
• Diagnosis and treatment occur
simultaneously.
Treatment
• Airway and Breathing
– 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)
Hemorrhage Control
• Internal bleeding
– Have to find it first
• Think chest, abdomen and
retroperitoneum
– Surgical intervention or
angiographic embolization
IV Access
• Establish adequate IV access
– 2 large bore peripheral IVs
– Central access (central line or IO)
IV Fluids
• Give warmed NS or LR quickly
• Only 1/3 of crystalloid volume stays
intravascular
IV Fluids
• Adults
– 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.
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
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)