Shock:
More than just low blood pressure
Silver Cross EMSS CME
October 2011 3rd Trimester
Presented by Laurie Carroll, RN, ABMC
Questions?
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answer.
• If you are watching the pre-recorded version
of this presentation, please email questions to
Laurie at Laurie.Carroll@ahss.org, or Audrey
at Silver Cross EMSS at
afinkel@silvercross.org.
Definition of Shock
In 1852, shock was defined as “a rude
unhinging of the machinery of life.”
Probably no better definition exists to
describe the devastating effects of this process
on a patient, but a more recent definition calls
shock “the collapse and progressive failure of
the cardiovascular system.”
Shock left untreated may be fatal. It must be
recognized and treated immediately, or the
patient may die.
What is Shock?
Inadequate perfusion of body tissue
–begins at the cellular level
–if left untreated results in death of tissue,
organs, organ systems
–and ultimately the death of the entire
organism
•It is not (just) low blood
pressure
What is adequate perfusion?
• Constant and necessary passage of blood
through the body’s tissue
• •Delivery of nutrients and oxygen
• •Removal of CO2and the waste byproducts of
metabolism
Perfusion is dependent on a
functioning and intact circulatory
system
Fick Principle
•The movement and utilization of oxygen in the body is
dependent on the following conditions
–Adequate concentration of inspired oxygen
–Appropriate movement of oxygen across the alveolar/capillary
membrane into the arterial bloodstream
–Adequate number of red blood cells to carry oxygen
–Proper tissue perfusion
–Efficient off loading of oxygen at the tissue level
Goal of perfusion!
Result of hypoperfusion
Shock at the cellular level
•Causes vary, however the ultimate
outcome is impairment of cellular
metabolism
•Can be localized (AMI, CVA, compartment
syndrome) or generalized
Shock can result from :
•Trauma
•Fluid loss
•Cardiac
•Infection
•Allergic Reaction
•Spinal Cord Injury
•Other
Flow = Perfusion
Adequate Flow =
Adequate Perfusion
Inadequate Flow =
Indequate Perfusion
(Hypoperfusion)
Hypoperfusion =
Shock
10
Components of circulatory
system
•
The pump (heart)
•The fluid (blood)
•The container (blood vessels)
The Pump
 The heart is the pump of the cardiovascular system
 –Receives blood from the venous system (preload)
 –Pumps the blood to the lungs for oxygenation
 –Pressure causes the oxygenated blood to be
returned to the heart
 –Pumped out to the vital organs and peripheral
tissues (against afterload)
Inadequate Pump
Inadequate Pump
•cardiac contractile strength
•heart rate (too slow or too fast)
Cardiac Output
• Amount of blood pumped in one contraction
• Stroke Volume x Heart Rate = Cardiac Output
• Average person -70 bpm x 70 mL = 4,900 mL/min
Stroke Volume
• The amount of blood
ejected by the heart in
one contraction
Factors affecting SV
• –Preload
• –Force and Rate of
Contraction
• –Afterload
Preload
•Amount
of blood delivered to
the heart during ventricular
diastole
•Includes everything available
for next systole including
–Passive filling
–“Atrial kick”
Inotropy and Chronotropy
• It is affected by circulating hormones called
catecholamines
–epinepherine
–norepinepherine
• Chronotropy: rate per minute
• Inotropy: strength/force of cardiac contractions
Frank Starling Mechanism
•The
greater the stretch of the cardiac muscle, up to a
certain point, the greater the force of cardiac contraction
(ie: the rubber band effect)
Afterload
•Resistance
against which the ventricle must contract
•Determined by the degree of peripheral vascular
resistance
Peripheral Vascular Resistance
•Pressure against which the heart must
pump
•Blood Pressure = CO x PVR
Fluid
•Blood
is thicker and more adhesive than water
•Consist of plasma and formed elements:
Red cells, White cells, Platelets
•Transports oxygen, carbon dioxide, nutrients,
hormones, and metabolic waste
Inadequate Fluid
Hypovolemia (abnormally low
circulating blood volume)
–Not enough preload
Container
Blood vessels serve as the container
•Under control of the autonomic nervous system
•They can adjust size and selectively reroute blood
through microcirculation
•Microcirculation is comprised of the small vessels:
–Arterioles, Capillaries, and Venules
Container Problems
Dilated container without change in fluid
volume
•Normal container with low levels of fluid
•Leak in container
•Afterload too high –causes?
Rerouting (shunting) blood
•Capillaries have a pre-capillary sphincter between the arteriole and capillary
that responds to local tissue demands such as acidosis, hypoxia, and opens
as more blood is needed
•At the end of the capillary between the capillary and venule is a postcapillary sphincter that opens when blood is needed to be emptied into the
venous system
Compensated and
Decompensated shock
Usually the body is able to compensate
but when these mechanisms fail shock
develops and may progress
•
Compensation Mechanisms
•Catecholamine Release
–Faster
•Renin-Angiotensin
–Slower
•Anti-Diuretic Hormone
–Slowest
Stages of shock
Stages of shock
Types of shock commonly seen by EMS
•Hypovolemic shock (fluid)
•
• Cardiogenic shock (pump)
•Neurogenic shock
(container)
•Anaphylactic shock
(container and fluid)
•Septic shock (all three?)
Is This Patient in Shock?
• Patient looks ill
• Altered mental status
• Skin cool and mottled or
hot and flushed
• Weak or absent
peripheral pulses
• SBP <110
• Tachycardia
Yes!
These are all signs and
symptoms of shock
Shock:
Signs and Symptoms
• Restlessness, anxiety
• Decreasing level of
consciousness
• Dull eyes
• Rapid, shallow respirations
• Nausea, vomiting
• Thirst
• Diminished urine output
Why are these signs and symptoms present?
Hint: Think hypoperfusion
33
Shock:
Signs and Symptoms
• Hypovolemia will cause
– Weak, rapid pulse
– Pale, cool, clammy skin
• Cardiogenic shock may cause:
– Weak, rapid pulse or weak, slow
pulse
– Pale, cool, clammy skin
• Neurogenic shock will cause:
– Weak, slow pulse
– Dry, flushed skin
• Sepsis and anaphylaxis will
cause:
– Weak, rapid pulse
– Dry, flushed skin
Can you explain the differences in the signs
and symptoms?
34
Shock
Do you remember how to
quickly estimate blood
pressure by pulse?
60
70
80
90
Shock:
Signs and Symptoms
Shock is NOT the same thing
as a low blood pressure!
A falling blood pressure is
a LATE sign of shock!
36
Treatment
•
•
•
•
•
•
•
Secure, maintain airway
Apply high concentration oxygen
Assist ventilations as needed
Keep patient supine
Control obvious bleeding
Stabilize fractures
Prevent loss of body heat
37
What Type of Shock is This?
• 68 yo M with hx of HTN and DM
presents to the ER with abrupt
onset of diffuse abdominal pain
with radiation to his low back. The
pt is hypotensive, tachycardic,
afebrile, with cool but dry skin
Hypovolemic Shock
Hypovolemic Shock
•Trauma
•Long Bone Fx
•Internal or external hemorrhage
•Dehydration
•Plasma loss due to burns
•Excessive sweating
•Diabetic Ketoacidosis with resultant osmotic
diuresis
If a system that is supposed to be closed
leaks, what happens to the pressure in it?
Signs / Symptoms
Edema –wheezes and crackles are heard as
fluid levels increase
•Pulmonary
•Difficulty breathing
•Rarely -productive cough with white or pink-tinged foamy
sputum
•Cyanosis
•Altered mental status
•Oliguria (decreased urination –take a good history)
Infusion Rates
Access
18 g peripheral IV
16 g peripheral IV
14 g peripheral IV
8.5 Fr CV cordis
Gravity Pressure
50 mL/min 150 mL/min
100 mL/min
225 mL/min
150 mL/min
275 mL/min
200 mL/min 450 mL/min
Let’s take 5.
• Audrey will dig up a fun film for you to watch.
• Come back in 5 minutes or so and we will
continue with Cardiogenic shock.
Cardiogenic Shock
What Type of Shock is This?
• A 55 yo M with hx of HTN, DM
presents with “crushing”
substernal CP, diaphoresis,
hypotension, tachycardia and
cool, clammy extremities
Cardiogenic
Cardiogenic Shock
•Pump
fails to act as an effective forward
pump
•Usually the result of left ventricular failure
secondary to acute MI or CHF
Signs / Symptoms
Edema –wheezes and crackles are heard as
fluid levels increase
•Pulmonary
•Difficulty breathing
•Rarely -productive cough with white or pink-tinged foamy
sputum
•Cyanosis
•Altered mental status
•Oliguria (decreased urination –take a good history)
Obstructive Shock
What Type of Shock is This?
• A 24 yo M presents to the ED after
an MVC c/o chest pain and
difficulty breathing. On PE, you
note the pt to be tachycardic,
hypotensive, hypoxic, and with
decreased breath sounds on left
Obstructive
Obstructive Shock
• Tension pneumothorax
• Air trapped in pleural space with 1 way valve,
air/pressure builds up
• Mediastinum shifted impeding venous return
• Chest pain, SOB, decreased breath sounds
• Rx: Needle decompression, chest tube
• Pulmonary embolism
• Signs: Tachypnea, tachycardia, hypoxia
Obstructive Shock
• Cardiac tamponade
• Blood in pericardial sac prevents venous return to
and contraction of heart
• Related to trauma, pericarditis, MI
• Beck’s triad: hypotension, muffled heart sounds,
JVD
• Diagnosis: large heart CXR, echo
• Rx: Pericardiocentisis
Neurogenic Shock
What Type of Shock is This?
• A 41 yo M presents to the ER after
an MVC complaining of decreased
sensation below his waist and is
now hypotensive, bradycardic, with
warm extremities
Neurogenic
Neurogenic Shock
•Results from injury to brain or spinal cord causing interruption
of nerve impulses to arteries
•Arteries lose tone and dilate causing hypovolemia
•Sympathetic nerve impulses to the adrenal glands are lost,
which prevents the release of catecholamines and their
compensatory effects
•Neurogenic shock is commonly due to severe injury to spinal
cord or total transection of cord (spinal shock)
Neurogenic Shock
• Loss of sympathetic tone results in warm and
dry skin
• Shock usually lasts from 1 to 3 weeks
• Any injury above T1 can disrupt the entire
sympathetic system
• Higher injuries = worse paralysis
Neurogenic Shock
• Loss of peripheral resistance
• Spinal cord injured
• Vessels below injury dilate
What happens to the pressure in a
closed system if you increase its size?
61
Signs / Symptoms
•Warm Skin (no cyanosis or pallor, no diaphoresis)
•Low Blood Pressure
•Slow Pulse
Anaphalactic Shock
What Type of Shock is This?
• A 34 yo F presents to the ER after dining
at a restaurant where shortly after
eating the first few bites of her meal,
became anxious, diaphoretic, began
wheezing, noted diffuse pruritic rash,
nausea, and a sensation of her “throat
closing off”. She is currently
hypotensive, tachycardic and ill
appearing.
Anaphalactic
Anaphylatic Shock
•Severe immune response to foreign substance
•Most signs and symptoms occur within minutes but can
take up to hours to occur
•The faster the reaction develops the more severe it is
likely to be
•Death will occur if not treated promptly
Anaphylactic Shock
• What are some symptoms of anaphylaxis?
• First- Pruritus, flushing, urticaria appear
•Next- Throat fullness, anxiety, chest tightness,
shortness of breath and lightheadedness
•Finally- Altered mental status, respiratory
distress and circulatory collapse
Shock: Signs and Symptoms
• Patients with anaphylaxis will:
– Develop hives (urticaria)
– Itch
– Develop wheezing and difficulty breathing
(bronchospasm)
What chemical released from the body during an
allergic reaction accounts for these effects?
68
Signs / Symptoms
•Skin
–Flushing
–Itching
–Hives
–Swelling
–Cyanosis
•Respiratory System
–Breathing difficulty
–Sneezing, Coughing
–Wheezing, Stridor
–Laryngeal edema
–Laryngospasm
•Cardiovascular System
–Vasodilation
–Increased heart rate
–Decreased blood pressure
•Gastrointestinal System
–Nausea, vomiting
–Abdominal cramping
–Diarrhea
Anaphylactic Shock
• Risk factors for fatal anaphylaxis
• Poorly controlled asthma
• Previous anaphylaxis
• Reoccurrence rates
• 40-60% for insect stings
• 20-40% for radiocontrast agents
• 10-20% for penicillin
• Most common causes
• Antibiotics
• Insects
• Food
Septic Shock
What Type of Shock is This?
• An 81 yo F resident of a nursing
home presents to the ED with
altered mental status. She is febrile
to 101.2, hypotensive with a
widened pulse pressure, tachycardic,
with warm extremities
Septic
Sepsis
•Symptoms
of sepsis usually are nonspecific
and include fever, chills, and constitutional
symptoms of fatigue, malaise, anxiety, or
confusion
Sepsis –what is it?
Febrile, tachycardic, elevated RR -> presume sepsis
Septic Shock
•An
infection enters bloodstream and is carried
throughout body
•Toxins released overcome compensatory
mechanisms
•Can cause dysfunction of one organ system or
cause multiple organ dysfunction
Pathogenesis of Sepsis
Nguyen H et al. Severe Sepsis and Septic-Shock: Review of the Literature and Emergency Department Management Guidelines. Ann Emerg Med. 2006;42:28-54.
Signs / Symptoms
•Signs
and symptoms of sepsis with persistent
hypotension / hypoperfusion
TX of Septic Shock
•IMC
•Treat per protocol for primary complaint
•Syncope (IV fluid challenges)
•Dysrhythmia (brady or tachycardia)
•Cardiogenic shock (IV fluid challenges –fill the tank)
FYI
All patients with sepsis require supplemental fluids. Assessment of the patient's
volume and cardiovascular status guides the amount and rate of infusion. For
adult patients who are hypotensive, administer an isotonic crystalloid solution
(sodium chloride 0.9%) in boluses of 200 mL (20 mL/kg in children), with repeat
clinical assessments after each bolus.
Administer repeat boluses until signs of adequate perfusion is restored.
Monitor patients for signs of volume overload, such as dyspnea, pulmonary
crackles, and pulmonary edema. Improvement, stabilization, and
normalization of the patient's mental status, heart rate, BP, capillary refill,
and urine output indicate adequate volume resuscitation.
Shock “combo”
Multiple Organ Dysfunction
Syndrome
•MODS
is the progressive impairment of two or more
systems from and uncontrolled inflammatory response
to a severe illness or injury
Multiorgan Dysfunction
Syndrome (MODS)
• Progression of physiologic effects as shock
ensues
•
•
•
•
Cardiac depression
Respiratory distress
Renal failure
DIC
• Result is end organ failure
Progression To MODS
•Infection
•Sepsis
•Septic shock
•MODS
•Death (if uncorrected early in cascade
FYI –MODS timeline
•24 hours
–Low grade fever
–Tachycardia
–Dyspnea
–Altered mental status
•14-21 days
–Renal and Hepatic failure
intensify
–Gastrointestinal collapse
–Immune system collapse
•24-72 hours
•After 21 days
–Pulmonary failure begins –Hematologic failure begins
–Myocardial failure begins
•7-10 days
–Altered Mental status
–Hepatic failure begins
resulting from
–Intestinal failure begins
encephalopathy
–Renal failure begins
–Death
Dopamine
•A naturally
occurring substance that acts as a
neurotransmitter
•At low doses it causes dilation of renal, mesenteric and
renal arteries which can stimulate urine output
•At moderate doses it causes positive chronotropicand
inotropiceffects on the heart
•At high doses it acts as a vasopressor, causing
vasoconstriction and increased peripheral vascular
resistance
Primary Use
•Cardiogenic shock
–At 5-10 mcgm/kg/min, positive inotropic (stroke
volume) and chronotropic (heart rate) effects can
cause increased cardiac output (CO = HR x SV)
–At > 10 mcgm/kg/min, vasopressor effect can raise
blood pressure to increase perfusion of coronary
arteries and improve inotropic function
Desired Dopamine Effect
•+ inotropic effect
•↑ mean arterial pressure
•↑ coronary artery perfusion
•↑ stroke volume
•↑ forward pumping action of heart
Caution
•Intravenous
fluids should be provided to maintain
adequate preload (ie: fill the tank). Use caution to
prevent fluid overload and worsen the pump failure
(pulmonary edema or a decrease in BP are your
warning signs)
•Extreme heart rates should be avoided because they
may increase myocardial oxygen consumption,
increase infarct size, and further impair the pumping
ability of the heart. With higher doses, (the positive
chronotropic effect of) dopamine has the disadvantage
of increasing the heart rate and myocardial oxygen
consumption.
Desired Outcome
•Used properly, at the right dose and with the
right patient (adequate preload):
↑ Heart Rate
+
↑ Stroke Volume
=
↑ Cardiac Output
Secondary Use
•Bradycardia refractory to other therapy
Dopamine may be considered in the treatment of
symptomatic bradycardia unresponsive to atropine,
as a temporizing measure while awaiting availability of a
pacemaker, or if pacing is ineffective
Silver Cross EMS Strip O’ the Month
Atrial Fibrillation (AFib)
Mosby items and derived
items © 2011, 2006 by
Mosby, Inc., an affiliate of
Atrial Fibrillation—
How Do I Recognize It?
• Irregularly irregular with wiggles, squiggles or
bumps instead of p-waves.
Mosby items and derived
items © 2011, 2006 by
Mosby, Inc., an affiliate of
Atrial Fibrillation—
How Do I Recognize It?
Rate
Atrial rate usually 400–600 bpm;
ventricular rate variable
Rhythm
Ventricular rhythm usually irregularly irregular
P Waves
No identifiable P waves, fibrillatory waves present;
erratic, wavy baseline
PR Interval
Not measurable
QRS
0.10 sec or less but may be widened if an
intraventricular conduction delay exists
Mosby items and derived
items © 2011, 2006 by
Mosby, Inc., an affiliate of
Atrial Fibrillation—
What Causes It?
• Can occur in patients with or without
detectable heart disease or related symptoms
• Common rhythm in patients with
CHF/Pulmonary Edema
• Increased stroke risk
– Atria do not contract effectively
– Blood pools within the atria, forming clots
– Clot dislodges and moves to artery in the brain
Mosby items and derived
items © 2011, 2006 by
Mosby, Inc., an affiliate of
Atrial Fibrillation—
What Do I Do About It?
• If rate is not too fast or too slow, patient may
have no associated complaints.
• If new-onset Afib, patient may complain of
dizziness, weakness, syncope, etc.
• If rapid ventricular rate and serious signs and
symptoms, synchronized cardioversion
needed.
Mosby items and derived
items © 2011, 2006 by
Mosby, Inc., an affiliate of
Silver Cross EMS Drug O’ the Month
Synchronized Cardioversion
• Delivery of an electrical shock to the heart
timed to occur during QRS
Mosby items and derived
items © 2011, 2006 by
Mosby, Inc., an affiliate of
Cardioversion—Indications
• Tachycardias with a ventricular rate greater
than 150 bpm that have a clearly identifiable
QRS complex
• SVT’s including rapid afib, atrial tachycardia,
junctional tachycardia, abberant v-tach.
• Cardioversion is for unstable patients. Stable
patients with SVT get vagal maneuvers and
adenocard.
Mosby items and derived
items © 2011, 2006 by
Mosby, Inc., an affiliate of
Cardioversion - tips
• Cardioversion hurts.
– Versed reduces patient discomfort.
• Set monitor at manufacturer-recommended level.
– Biphasic approx 100-120J
– Monophasic approx 100-200J
• Re-sync before every shock.
– Monitors default to non-sync after shock in case you need
immediate defibrillation.
Thank you!
• Next month… documentation!
• And EMS coordinators, holler if you need help
with training your personnel on any new SMO
skills! We love to help!