Seminar On Shock

1. Good morning

2. Dept of Oral & Maxillofacial
Surgery
Presented by:
Dr.Abdul Qahar Qureshi
SHOCK
Presentation of Seminar
on

3. Contents
 Shock- What is it?
 Definitions
 Significance of Fluids &
Electrolytes
 Blood Components
 Fick Principle
 The Cardiovascular
System’s & it’s Role
 The Nervous System
& it’s Role
 Stages of shock
 Types of shock
 Management of
Shock
 Recent Advances in
Management
PART -1 PART -2

4. Shock & other terms
 Shock: “The body’s response to poor perfusion”
 synonyms:
 Hypoperfusion
 Acute circulatory collapse
 Perfusion: “The process by which oxygenated blood is
delivered to the body’s tissue and wastes are removed
from the tissue”
 Decreased perfusion leads to:
 Anaerobic metabolism
 Build up of toxins

5. Significance of Fluids and
Electrolytes
Fluids:
 Water
60%
Mixed with proteins and electrolytes
Sent to various compartments in the body
 Intracellular fluid - 75%
 Extracellular fluid - 25%
Interstitial fluid - 17.5%
Intravascular fluid - 7.5%

6. Electrolytes
 Substances that dissociate into electrically charged
particles when placed into water.
 “cations”
 Sodium Na+
 Potassium K+
 Calcium Ca++
 Magnesium Mg++
 “anions”
 Chloride Cl-
 Bicarbonate HCO3-
 Phosphate PO4-

7. “Next of Kin”
N
K
ext ra cellulara+
tra
cellular
in
+

8. Cations
 Sodium (Na+)
 Most prevalent cation in the extracellular fluid
 Plays a major role in regulating the distribution of water
 Potassium (K+)
 Most prevalent cation in the intracellular fluid
 Transmission of electrical impulses
 Calcium (Ca++)
 Muscle contraction
 Nervous impulse transmission
 Magnesium (Mg++)
 Several biochemical processes
 Closely associated with phosphate in many processes

9. Anions
 Chloride (Cl-)
 Most prevalent anion in the extracellular fluid
 Fluid balance and renal function
 Bicarbonate (HCO3-)
 Principle buffer of the body
 Neutralizes highly acidic hydrogen ion (H+)
 Phosphate (HPO4-)
 Major intracellular anion
 Important in body energy stores
 Helps maintain acid-base balance

10. Cellular Membranes
 Permeability
 The degree to which a substance is allowed to
pass through a cell membrane
 Semipermeable
 Cell membranes that allow only certain
substances to pass through them

11. Diffusion
Movement of
solutes from an
area of greater
solute
concentration to
an area of lower
solute
concentration

12. Osmosis
Movement of
water from an
area of lower
solute
concentration to
an area of higher
solute
concentration

13. Active Transport
 Movement of a substance across the cell
membrane against the osmotic gradient
 Faster than diffusion
 Requires energy
Example: Sodium-Potassium Pump

14. Facilitated Diffusion
 Requires the assistance of “helper proteins”
 Protein binds to molecule changing it’s
configuration
 May or may not require energy
Example: Insulin & Glucose

15. Isotonic Solutions
 State in which
solutions on opposite
sides of a semi-
permeable
membrane are equal
in concentration
 There is NO fluid
shift!

16. Hypotonic Solutions
 State in which a
solution has a lower
solute concentration
on one side than the
other
 There is a shift into
the intracellular
fluid!

17. Hypertonic Solutions
 State in which a
solution has a higher
solute concentration
on one side than the
other
 There is a fluid shift
into the interstitial
fluid!

18. Blood Components
 Plasma 54%
 Red Blood Cells
45%
 White Blood Cells
1%
 Platelets 1%

19.  Plasma
 Fluid portion of blood
 Contains proteins, carbohydrates, amino acids,
lipids, & mineral salts
 Erythrocytes
 Most numerous cells in blood
 Carry hemoglobin
 Leukocytes
 Fight infection
 Produce antibodies
 Platelets
 Essential for clot formation

20. The Fick Principle

21. Fick Principle
1. Adequate concentration of inspired oxygen
2. On-loading of oxygen to red blood cells at
lungs
3. Delivery of red blood cells to tissue cells
4. Off-loading of oxygen from red blood cells
to tissue cells

22. Fick Principle
1. Adequate concentration of inspired oxygen
requires:
 Adequate ventilation
 High concentration of inspired oxygen
 Unobstructed air passages

23. Fick Principle
2. On-loading of oxygen to red blood cells at
lungs requires:
 Minimal obstruction across alveolar-capillary
membrane and
 Appropriate binding of oxygen to
hemoglobin

24. Fick Principle
3. Delivery of red blood cells to tissue cells
requires:
 Normal hemoglobin levels
 Circulation of oxygenated cells to tissues
 Adequate cardiac function
 Adequate volume of blood flow
 Proper routing of blood through vasculature

25. Fick Principle
4. Off-loading of oxygen from red blood cells to
tissue cells requires:
 Close proximity of tissue cells to capillaries
 Ideal pH
 Ideal temperature

26. Remove any component
from the “Fick Principle”
and shock will follow!

27. Think in terms of Nutrition!!
 Cells require a continuous supply of
nutrients
 Ex: Glucose, Oxygen
 Workload demands determine the rate
of need
 The body automatically adjusts
 Breakdown of food into energy
 Aerobic
 Anaerobic

28. Aerobic Metabolism
 Required fuels
 Glucose
 Oxygen
 Waste products
 Pyruvic acid
 Carbon dioxide
 Method of excretion
 Respiration
 Urination

29. Anaerobic Metabolism
 Uses glucose only
 Almost 20 times less efficient than aerobic
 Causes dramatic increase in lactic acid
production, and therefore metabolic acidosis
 Vascular dilation follows, causing a further shift in
fluids out of the vascular space and into the
interstitial space
 Further, potassium shifts out of the cell, and
sodium in, which causes cell membrane instability

30. Death Cometh
 Brain and Lungs
Die within 4 to 6 minutes without
oxygen
 Organs
Die within 45 to 90 minutes without
oxygen
 Skin and muscle
Die within 4 to 6 hours without oxygen

31. The Pump, The Fluid, & The Container!
The Cardiovascular System’s Role

32. The Pump, The Fluid, & The
Container!

33. The Pump
Blood
Pressure
Cardiac
Output
Systemic
Vascular
Resistanc
e
Stroke
Volume
Heart
Rate
Preload
Myocardial
Contractilit
y
Afterload

34. Stroke Volume
 Amount of blood
ejected from the
heart with every
contraction
 Affected by:
 Preload
 Contractility
 Afterload
Stroke
Volume
Preload
Myocardial
Contractilit
y
Afterload

35.  Normal
60-100cc per beat for average adult
55 cc per beat for child
 Ejection Fraction
Percentage of blood in the ventricle
that is ejected during systole, > 50%,
or a way to measure the “efficiency” of
the “fuel pump”

36. Preload
 Heart muscle is stretched as
chambers fill with blood between
contractions.
 Stretching muscle fibers before
contraction increases strength of
contraction.

37.  Influenced by volume of blood returning
to heart.
 More blood returning increases preload; less
blood returning decreases preload.
 More stretch of muscles means more
forceful contraction.
 Frank Starling’s Law

38. Frank Starling’s Law
 More the heart is filled during
diastole, the greater the quantity of
blood that will be pumped during
systole
 Increase in volume stretches the
heart muscle and increases stroke
volume and thus increases cardiac
output

39. Contractility
 Contractility is extent and velocity of
muscle fiber shortening.
 Influenced by:
Oxygen supply and demand
Sympathetic stimulation
Electrolyte balance
Calcium

40. Afterload
 Pressure ventricular muscles must
generate to overcome higher
pressure in aorta.
 Greater afterload means harder
work for ventricles to eject blood
into arteries.
 Dictated to large degree by blood
pressure.

41. Cardiac Output
 Amount of blood
ejected from the
heart each minute
 Affected by:
 Stroke Volume
 Heart Rate
Cardiac
Output
Stroke
Volume
Heart
Rate
Cardiac Output = Stroke Volume X Heart Rate

42. Blood Pressure
 Force that blood
exerts against
arterial walls
 Affected by:
 Cardiac Output
 Systemic Vascular
Resistance
BP
Cardiac
Output
Systemic
Vascular
Resistanc
e
BP = Cardiac Output X Systemic Vascular
Resistance

43. The Fluid
 Significant fluid loss
 Adult = 1 ½ liter
 Child = ½ liter
 Infant = 100 to 200 mL
 Decreased
 Hematocrit
 Hemoglobin

44. The Container
 Continuous, closed, pressurized pipeline
that moves blood through body.
 Elastic blood vessels adjust fluid volume
of container.
 Systemic Control
 Local Control
 Affects amount of blood returning to
heart and amount of tissue oxygenation.

45. The Nervous System & It’s Role!

46. Receptors
 Sensory nerve endings that sense
changes in blood pressure or carbon
dioxide
 Baroreceptors (pressure) located in:
 Aortic arch
 Walls of the atria
 Vena cava
 Carotid sinus
 Chemoreceptors (CO2) located in:
 Brain and spinal cord
 Notify the sympathetic nervous system

47. Sympathetic Nervous System
 “Fight or Flight” response
Increases heart rate
Stimulates the heart to beat more
forcefully
Respirations Increase
Release of norepinephrine
“Clamps down” on blood vessels
Kidneys decrease urinary output to
conserve water

48. PART -2

49. Contents
Stages of shock
Types of shock
Management of Shock
Recent Advances in
Management

50. The Stages of Shock
Compensated Shock
Also known as nonprogressive
Shock
Uncompensated Shock
Also known as progressive Shock
Irreversible Shock

51. Compensated Shock
 Earliest phase
 Up to 15-25% blood loss
 Body compensates
Activates the sympathetic nervous
system

52. Compensated Shock
 Signs / Symptoms
Altered Level of concious
Increased pulse rate
Increased respiratory rate
Pale, cool skin

53. Decompensated Shock
 Blood volume drop greater than 15-
25%
 Mechanisms no longer able to
maintain
Even more norepinephrine is released
 Cardiac output drops

54. Decompensated Shock
 Signs / Symptoms :
 Additional increase in pulse and breathing
 Cool, clammy skin
 Decreased capillary refill
 Narrowing of pulse pressure
 Sweating
 Increased anxiety and confusion
 Nausea and vomiting

55. Irreversible Shock
 Rapid deterioration of the
cardiovascular system
 Greater blood shunting to heart and
brain
 Cell death begins

56. Irreversible Shock
 Signs / Symptoms
Marked decrease in level of
responsiveness
Decreased respiratory rate
Profound hypotension
Decrease in pulse rate
Patient has feelings bad

57. Types of Shock
• Hypovolemic
• Septic
• Cardiogenic
• Anaphylactic
• Neurogenic
• Obstructive

58. Hypovolemic
Shock

59. Hypovolemic Shock
• Non-hemorrhagic
• Vomiting
• Diarrhea
• Bowel obstruction, pancreatitis
• Burns
• Dehydration
• Hemorrhagic
• GI bleed
• Trauma
• Massive hemoptysis
• Aneurysmal abdominal aortic rupture
• Post-partum bleeding
0
20
40
60
80
100
120
Normal 10% 25% 50%
BLOOD LOSS

60. Evaluation of Hypovolemic Shock
• CBC
• ABG/lactate
• Electrolytes
• BUN, Creatinine
• Coagulation studies
• As indicated
• Chest X-ray
• Pelvic X-ray
• Abd/pelvis CT
• Chest CT
• GI endoscopy
• Bronchoscopy
• Vascular radiology

61. Septic Shock

62. Sepsis
• Two or more of SIRS criteria
• Temp > 38 or < 36 C
• HR > 90
• RR > 20
• WBC > 12,000 or < 4,000
• Plus the presumed existence of infection
• Blood pressure can be normal!

63. Septic Shock
• Plus refractory hypotension
• After bolus of 20-40 mL/Kg patient still has one of
the following:
• SBP < 90 mm Hg
• MAP < 65 mm Hg
• Decrease of 40 mm Hg from baseline

64. Sepsis

65. 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.

66. Septic Shock
• Clinical signs:
• Hyperthermia or hypothermia
• Tachycardia
• Wide pulse pressure
• Low blood pressure (SBP<90)
• Mental status changes
• Blood pressure may be “normal”

67. Ancillary Studies
• Cardiac monitor
• Pulse oximetry
• CBC, Chem 7, LFTs, Lipase
• ABG with lactate
• Blood culture , urine culture
• CXR
• Foley Cathetor

68. Examples of septic shock

69. Cardiogenic Shock

70. Cardiogenic Shock
• Signs:
• Cool, mottled skin
• Tachypnea
• Hypotension
• Altered mental status
• Narrowed pulse pressure
• Rales, murmur
• Defined as:
• SBP < 90 mmHg
• CI < 2.2 L/m/m2
• PCWP > 18 mmHg

71. Etiologies
• Causes of cardiogenic shock:
• AMI
• Sepsis
• Myocarditis
• Myocardial contusion
• Aortic or mitral stenosis,
• Acute aortic insufficiency

72. Pathophysiology of Cardiogenic Shock
• Often after ischemia, loss of LV function
• Lose 40% of LV clinical shock ensues
• CO reduction = lactic acidosis, hypoxia
• Stroke volume is reduced
• Tachycardia develops as compensation
• Ischemia and infarction worsens

73. Ancillary Tests
• CXR
• CBC, Cardiac enzymes, Coagulation studies
• Echocardiogram

74. Anaphylactic Shock

75. Anaphylactic Shock
• Anaphylaxis – a severe systemic
hypersensitivity reaction characterized by
multisystem involvement
• IgE mediated
• Anaphylactoid reaction – clinically
indistinguishable from anaphylaxis, do not
require a sensitizing exposure
• Not IgE mediated

76. Anaphylactic Shock
• 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

77. 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

78. Anaphylactic Shock
• Mild, localized urticaria can progress to full anaphylaxis
• Symptoms usually begin within 60 minutes of exposure
• Faster the onset of symptoms = more severe reaction
• Biphasic phenomenon occurs in up to 20% of patients
• Symptoms return 3-4 hours after initial reaction has cleared
• A “lump in my throat” and “hoarseness” heralds life-
threatening laryngeal edema

79. Anaphylactic Shock- Diagnosis
• Clinical diagnosis
• Defined by airway compromise, hypotension, or
involvement of cutaneous, respiratory, or GI
systems
• Look for exposure to drug, food, or insect
• Labs have no role

80.  Anaphylactic shock mechanism

81. Neurogenic Shock

82. Neurogenic Shock
• Occurs after acute spinal cord injury
• Sympathetic outflow is disrupted leaving
unopposed vagal tone
• Results in hypotension and bradycardia
• Spinal shock- temporary loss of spinal reflex
activity below a total or near total spinal cord
injury (not the same as neurogenic shock, the
terms are not interchangeable)

83. 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

84. Obstructive Shock

85. 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
• No tests needed!
• Rx: Needle decompression, chest tube
Needle chest tube

86. 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
• Diagnosis: large heart CXR
• Rx: Pericardiocentisis

87. Management of the Patient in Shock
 Work to maintain adequate blood
pressure and perfuse vital organs.
 Rapid assessment and immediate
transportation are essential for
patient survival.

88. Management of the Patient in Shock
 Evaluation directed at assessing
oxygenation and perfusion of body
organs
 Goals of pre-hospital care include:
Ensuring a patent airway
Providing adequate oxygenation and
ventilation
Restoring perfusion

89. Level of Consciousness
 Assessed throughout initial survey.
 Better indicator of tissue perfusion
than most other vital signs.
 Assume altered mental status is
due to decreased cerebral
perfusion.

90. Level of Consciousness
 Restlessness or agitation
 Disorientation
 Confusion
 Inability to respond
 Combative behavior
 Unresponsive

91. Airway
 Opening the airway
 Head-tilt, chin-lift
 Modified jaw thrust
 Sounds that may indicate airway
obstruction include:
 Snoring (tongue)
 Gurgling (liquids such as blood or vomitus)
 Stridor (foreign body/swelling)

92. Airway
 Use airway adjuncts if necessary.
 Endotracheal intubation is preferred
to prevent aspiration of blood.
 Clear blood or fluids with suction.
 Remove large foreign objects with
finger sweep.

93. Breathing & Oxygenation
 LOOK, LISTEN & FEEL, for air
exchange.
 RATE, QUALITY & DEPTH of
respirations.

94. Breathing & Oxygenation
 Provide 100% oxygen with non-
rebreather mask at 10 to 15 L/min.
 Ensure reservoir remains inflated at end of
each inspiration.
 For assisted ventilations, supply 100%
oxygen via bag-valve-mask.

95. Circulation
 Look for and control obvious external
bleeding.
 Assess RATE, RHYTHM, & QUALITY of
pulse.
 Palpable pulse location may provide
estimate of systolic pressure.
 Note color, appearance, and
temperature of skin.

96. Circulation
 A fast, weak, or thready pulse suggests
decreased circulatory volume
 Color, appearance, and temperature of the
skin
 Pale
 Mottled
 Cyanotic

97. Circulation
 Control any obvious external
bleeding
Direct pressure
Pressure points
Tourniquet
PASG

98. Circulation
 Elevate patient's legs.
 Apply, and if necessary inflate the
pneumatic anti-shock garment.
 Place 2 large bore IV lines.

99. Pneumatic Anti-Shock Garment
 Tool to care for hypotension and
shock.
 Helps control bleeding by applying
pressure to blood vessels.

100. PASG Indications
 Hypovolemic shock from any
cause.
 Hypotension secondary to
decreased cardiac output.
 Fracture stabilization.
 Criteria for PASG include systolic
blood pressure below 90 mm Hg
with obvious signs and symptoms
of shock.

101. PASG Contraindications
 Pulmonary edema (absolute
contraindication).
 Abdominal compartment inflation is
contraindicated in:
 Pregnancy
 Respiratory distress of any nature
 Evisceration
 Cases of impaled objects in abdomen

102. PASG Complications
 Use in presence of chest injuries.
 May increase bleeding in
intrathoracic cavity leading to
tension hemopneumothorax.
 Will increase breathing difficulty in
patient with flail segment.

103. PASG Pneumatic Anti-Shock Garment
BP to 100 mmHg, or velcro crackles

104. Fluid Replacement
 IV lines are used to counter blood
loss by introducing fluid into
intravascular space.
 Fluids help restore circulating
volume until body can manufacture
more blood.
 Patient in hypovolemic shock needs
at least two IV lines.

105. Maintain Body Temperature
 Maintain body temperature as close
to normal as possible.
 Pay attention to:
Environmental / Weather Conditions
Temperature of oxygen and IV fluids
Location of patient
 Protect patient from elements.

106. Maintain Body Temperature
 Remove wet clothing.
 Cover patient to prevent heat loss.
 Too much heat produces
vasodilation, counteracting body's
vasoconstrictive compensatory
efforts.

107. DRUGS
 Sedatives- Morphine, Barbiturates
andLargactil
 Chronotropic Agents-Atropine
 Inotropic Agents-Dopamine and Dobutamine
 Vasodilators-Nitroprusside and Nitroglycerin
 Vasocontrictor
 Beta-blockers
 Diuretics

108. References:
Shwartz:Principles of Surgery,
Guyton & Hall: Medical Physiology,
Sembulingam: Medical Physiology,
Davidson’s :Textbook of Medicine,
Harrison’s :Textbook of Medicine,
Manipal:text book of general surgery.

109. HAVE A NICE DAY