Chapter 3 Shock Flashcards
Define Shock
abnormality of the circulatory system that results in inadequate organ perfusion and tissue oxygenation
What is the most common type of shock in an injured trauma pt?
hemorrhagic
Define Cardiac output
Vol of blood pumped by the heart per minute
Define stroke vol
Amount of blood that leaves the heart w/ each cardiac contraction
What is stroke vol determined by?
Preload
Myocardial contractility
Afterload
Define preload
Volume of venous blood returned to the L and R side of the heart.
Define afterload
Also known as PVR
Amount of resistance to forward flow of blood leaving the heart
CO = ____ X _____
CO = Heart rate (BPM) X Stroke Vol (mL/beat)
Early physiologic response to blood loss is _____
Compensatory
What are the three main compensatory reactions to blood loss?
Vasoconstriction-Preserves blood flow to heart, kidney and brain
Catecholamine release- Increases PVR
Heart Rate Increase - to preserve C.O
What are the first signs of shock due to volume loss
Tachycardia
Cutaneous vasoconstriction
When does a decrease in systolic pressure occur?
Not until 30% vol loss occurs (SO THIS IS NOT A GOOD INDICATOR)
Define Tachycardia in an adult
HR > 100 BPM
Define Tachycardia in a pre-school age child
HR >140BPM
Define tachycardia in an infant
HR > 160 BPM
Define Tachycardia in a school age child-Puberty
HR >120 BPM
When looking for source of Hemorrhagic shock the term “The floor plus 4 more” refers to what?
Blood loss from Chest Abdomen Pelvis Retroperitoneum External bleeding
What sources of Non-hemorrhagic shock should be considered as well?
Cardiogenic shock Cardiac Tamponade Tension PTX Neurogenic shock Septic Shock
When should cardiogenic shock be considered possible?
Blunt cardiac injury when mech of injury is rapid deceleration
Also can be secondary to MI
What labs/tests should be done to detect and monitor possible cardiogenic shock?
ECG continuous monitor
Cardiac enzymes
When should Cardiac Tamponade as a cause of shock be considered?
Blunt/penetrating chest trauma Tachycardia Muffled heart sounds dilated engorged Neck veins Hypotension without response to fluid resusc.
What labs/tests should be done to detect and monitor possible cardiac tamponade in the case of shock?
ECG is not quick or that helpful although can detect
FAST US will identify pericardial fluid
What symptoms of Tension PTX differ from Cardiac tamponade
All of the symptoms of cardiac tamponade are present in T PTX except for muffled heart sounds, Breath sounds (which are absent in tPTX), and Hyperresonance (echoes in tPTX)
If patient has an isolated intracranial injury but appears to be in neurogenic shock what must be done?
Look for other cause!
Isolated intracranial injury does not cause neurogenic shock unless the brainstem is involved.
Classic presentation of neurogenic shock
Hypotension without tachycardia or cutaneous vasoconstriction
When should septic shock be considered in trauma pt?
Delayed presentation to ED.
Class I hemorrhage definition
and exam parameters
< 15% blood loss
All measurable parameters remain stable
Class II hemorrhage definition
and exam parameters
15-30% blood loss HR can remain same or increase Tachypnea Pulse pressure drops All other parameters remain stable
Class III hemorrhage definition
and exam parameters
31-40% blood loss
Marked tachycardia and tachypnea
Significant mental status change
Measurable systolic pressure drop
Class IV hemorrhage definition and exam parameters
> 40% blood loss
Tachycardia
marked systolic drop
Narrow pulse pressure or no traceable diastolic bp
Treat all shock as if it is _____ until proven otherwise
hemorrhagic
Steps to physical exam of shock pt
A and B- Establish airway and proper ventilation- provide supp O2, maintain O2 sat 95%
C- STOP THE BLEEDING, obtain IV access
D-Determine lvl of consciousness and assess cerebral perfusion
E-Expose to determine addl bleeding and keep warm!
Why is Gastric Decompression necessary in shock
To prevent aspiration
Why is urinary Cath helpful in shock?
To assess hematuria and measure urinary output
When is urinary cath contraindicated?
urethral injury
What is the proper protocol for initial fluid tx?
Initial warmed fluid bolus of isotonic fluid
Usual bolus is 1L in adults and 20mL/kg in children < 40kg.
bolus amount includes pre-hospital amount
Three different patient response schemes
Rapid response
Transient response
Minimal or No response
Rapid response to hemorrhage indicates which class of hemorrhage?
Class 1 <15% loss
What intervention should be given to pt with rapid response?
no further fluid management required after initial resusc.
Define transient response
Pt responds to initial bolus but return to unstable status once maintenance fluid is started
Transient response indicates what class of loss in shock?
Class II - III between 15-40%
indicates pt is still bleeding somewhere
What intervention should occur to pt that is a transient responder?
Blood product and blood should be started,
Re-eval for operative or angiographic control
consider activating MTP
What intervention should occur in pt w/ no response to fluid/blood resusc.
Immediate operative or angioembolization
Consider other types of shock (tamponade or PTX)
Initiate MTP
Define MTP
> 10u pRBCs w/ the first 24h of admission or
>4u in 1 hour
