Transcript Bleeding and Shock - Dr. Mehdi Hasan Mumtaz

SHOCK
Prof.M.H.MUMTAZ
1
SHOCK
Inadequate perfusion
(blood flow) leading to
inadequate oxygen delivery to
tissues
2
Physiology


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Basic unit of life = cell
Cells get energy needed to stay
alive by reacting oxygen with
fuel (usually glucose)
No oxygen, no energy
No energy, no life
3
Aerobic Metabolism
6 CO2
6 O2
METABOLISM
GLUCOSE
6 H2O
36 ATP
HEAT (417 kcal)
4
Anaerobic Metabolism
2 LACTIC ACID
GLUCOSE
METABOLISM
2 ATP
HEAT (32 kcal)
5
Anaerobic? So What?
Inadequate
Cellular
Oxygenation
Inadequate
Energy
Production
Metabolic
Failure
Anaerobic
Metabolism
Lactic Acid
Production
Cell Death!
Metabolic
Acidosis
6
Homeostasis is
maintenance of balance

Requires proper functioning
systems
• Cardiovascular
• Respiratory
• Renal
7
Cardiovascular System


Transports oxygen, fuel to cells
Removes carbon dioxide, waste
products for elimination from body
Cardiovascular system must be able to
maintain sufficient flow through
capillary beds to meet cell’s oxygen and
fuel needs
8
Flow = Perfusion
Adequate Flow =
Adequate Perfusion
Inadequate Flow =
Indequate Perfusion
(Hypoperfusion)
Hypoperfusion =
Shock
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What is needed to maintain
perfusion?

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Pump Heart
Pipes Blood Vessels
Fluid Blood
10
How can perfusion fail?
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Pump Failure
Pipe Failure
Loss of Volume
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Factors Affecting The
Pump
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Preload
Contractile force
• Frank-starling mechanism

Afterload
Muscle Anatomy
13
Contraction: Sliding
Filaments
image from: http://www.accessexcellence.com/AB/GG/muscle_Contract.html
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What Is Blood Pressure?
BP = COxSVR
CO = Stroke Volume
X Heart Rate
SVR= B.vessel calibre +viscosity
What Affects Blood
Pressure?


ANS balance
Contractility
• Preload
• Starling’s law

Afterload
16
Types of Shock and
Their Causes
CARDIOGENIC
HYPOVOLAEMIC
SEPTIC
NEUROGENIC
PSYCHOGENic
obstructive
ANAPHYLACTIC
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Cardiogenic Shock


Pump failure
Heart’s output depends on
• How often it beats (heart rate)
• How hard it beats (contractility)

Rate or contractility problems
cause pump failure
18
Cardiogenic Shock

Causes
• Acute myocardial infarction
• Very low heart rates (bradycardias)
• Very high heart rates (tachycardias)
Why would a high heart rate caused decreased output?
Hint: Think about when the heart fills.
19
Neurogenic Shock
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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?
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Hypovolemic Shock

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Loss of volume
Causes
• Blood loss: trauma
• Plasma loss: burns
• Water loss: Vomiting, diarrhea, sweating,
increased urine, increased respiratory loss
If a system that is supposed to be closed
leaks, what happens to the pressure in it?
21
Psychogenic Shock
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Simple fainting (syncope)
Caused by stress, pain, fright
Heart rate slows, vessels dilate
Brain becomes hypoperfused
Loss of consciousness occurs
What two problems combine to produce
hypoperfusion in psychogenic shock?
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Septic Shock


Results from body’s response to
bacteria in bloodstream
Vessels dilate, become “leaky”
What two problems combine to produce
hypoperfusion in septic shock?
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Anaphylactic Shock
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Results from severe allergic reaction
Body responds to allergen by
releasing histamine
Histamine causes vessels to dilate
and become “leaky”
What two problems combine to produce
hypoperfusion in anaphylaxis?
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OBSTRUCTIVE SHOCK
PUMONARY EMBOLISM ?
CRDIAC TEMPONADE ?
PNEUMOTHORAX ?
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Shock:
Signs and Symptoms
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Restlessness,
anxiety
Decreasing level of
consciousness
Dull eyes
Rapid, shallow
respirations
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Nausea, vomiting
Thirst
Diminished urine
output
Why are these signs and symptoms present?
Hint: Think hypoperfusion
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Shock:
Signs and Symptoms
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
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
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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?
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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?
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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!
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Treatment
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Secure, maintain airway
Apply high concentration oxygen
Assist ventilations as needed
Keep patient supine
Control obvious bleeding
Stabilize fractures
Prevent loss of body heat
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Treatment
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Elevate lower extremities 8 to 12
inches in hypovolemic shock
Do NOT elevate the lower
extremities in cardiogenic shock
Why the difference in
management?
31
Management of Shock
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Shock begins when DO2 to the
cells is inadequate to meet
metabolic demand
The major therapeutic goals in
shock therefore are sufficient
tissue perfusion and
oxygenation
Early diagnosis remains a major
problem
32
Treatment

Administer nothing by mouth,
even if the patient complains of
thirst
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Hemodynamic Characteristics in
Different Types of Shock
Type
Preload
Hemmorrhagic
LOW
Anaphylactic
LOW
Cardiogenic
HIGH
Septic
(Hyperdynamic
)
LOW
Septic
(Hypodynamic)
LOW
CO
PVR
SVR
/
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Inotropic Agents and
Vasodilators
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Vasoactive drugs are an important
pharmacologic defense in the
treatment of shock.
May be required to support BP in the
early stages of shock.
These agents may be needed to:
• Enhance CO through the use of inotropic
agents
• Increase SVR through the use of
vasopressors
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Effects of Inotropic
Agents and Vasodilators
Drug
Receptor
Epinephrin a1 ,b1, (b2)
e
Norepinep a1, b1
hrine
Dopamine b2, DR, (a)
Dobutamin b1, b2
e
Dopexamin b1, b2, DR
e
CO
SVR
Dose Range
0.02 – 0.5
0-
0.05 – 0.5
2 -12
2 - 12
0-
0-
0.9 - 5
(mg/kg/min)
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1
Effects of Inotropic
Agents and Vasodilators
Drug
CO
SVR
Dose Range
Nifedipine
0-
0.5 - 10
Nitroglycerin
0-
3-5
Nitroprusside
0-
0.5 - 5
Prostacyclin
10 - 40
(mg/kg/min)
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2
Dopamine
An endogenous precursor of norepinephrine with
multiple dose-related effects

Low Dose (0.5 - 3 mg/kg/min)
 b2 and dopaminergic (DR) effects
• Enhanced blood flow to renal and
splanchnic beds

Moderate Dose (5 -10
mg/kg/min)
• Positive inotropic effects

High Dose (>20 mg/kg/min)
 a-actions (vasoconstriction)
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MANAGEMENT GUIDE

1,Haemodynamic monitoring
Blood pressure/HR
SV,HR,CI,CO
SVR,SVRI
TOOLS ; SWAN GANZ
TEMPERATURE
LIDCO
CENTRAL VENOUS PRESSURE
2,
OXYGENATION STATUS
FIO2/PAO2/PaO2/DO2/VO2/ Lactate
3, ACID BASE STATUS
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HAEMODYNAMIC TRUTHS
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1,TACHYCARDIA IS NEVER AGOOD THING.
2,HYPOTENSION IS ALWAYS PATHOLOGIC
3,THERE IS NO SUCH THING AS NORMAL
CARDIAC OUTPUT.
4,CENTRAL VENOUS PRESSURE IS ONLY
ELEVATED IN DISEASE.
5,PERIPHERA EDEMA IS OF COSMETIC
CONCERN.
PINKSY..Chest.2007; 132;2020-2029
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Bleeding
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Bleeding Significance

If uncontrolled, can cause
shock and death
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Identification of External
Bleeding

Arterial Bleed
• Bright red
• Spurting

Venous Bleed
• Dark red
• Steady flow

What is the
physiology that
explains the
differences?
Capillary Bleed
• Dark red
• Oozing
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Control of External
Bleeding
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Direct Pressure
• gloved hand
• dressing/bandage
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Elevation
Arterial pressure points
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Arterial Pressure Points
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Upper extremity: Brachial
Lower extramity: Femoral
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Control of External
Bleeding
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Splinting
• Air splint
• Pneumatic antishock garment
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Control of External
Bleeding
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Tourniquets
•
•
•
•
Final resort when all else fails
Used for amputations
3-4” wide
write “TK” and time of application
on forehead of patient
• Notify other personnel
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Control of External
Bleeding

Tourniquets
• Do not loosen or remove until
definitive care is available
• Do not cover with sheets,
blankets, etc.
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Epistaxis
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Nosebleed
Common problem
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Epistaxis
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Causes
•
•
•
•
•
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Fractured skull
Facial injuries
Sinusitis, other URIs
High BP
Clotting disorders
Digital insertion (nose picking)
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Epistaxis
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Management
•
•
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•
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Sit up, lean forward
Pinch nostrils together
Keep in sitting position
Keep quiet
Apply ice over nose
15 min adequate
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Epistaxis
Epistaxis can result in lifethreatening blood loss
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Internal Bleeding

Can occur due to:
•
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•
•
Trauma
Clotting disorders
Rupture of blood vessels
Fractures (injury to nearby vessels)
53
Internal Bleeding
Can result in rapid progression
to hypovolemic shock and death
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Internal Bleeding

Assessment
• Mechanism?
• Signs and symptoms of
hypovolemia without obvious
external bleeding
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Internal Bleeding

Signs and Symptoms
• Pain, tenderness, swelling,
discoloration at injury site
• Bleeding from any body orifice
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Internal Bleeding

Signs and Symptoms
• Vomiting bright red blood or coffee
ground material
• Dark, tarry stools (melena)
• Tender, rigid, or distended
abdomen
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Internal Bleeding
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Management
•
•
•
•
•
•
Open airway
High concentration oxygen
Assist ventilations
Control external bleeding
Stabilize fractures
Transport rapidly to appropriate
facility
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