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SHOCK

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Post-cardiac surgery. Complication of central line placement. Recognition. Tachycardia ... New' ' Therapies in Septic Shock. Activated Protein C (Xigris) ... – PowerPoint PPT presentation

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Title: SHOCK


1
SHOCK
  • NGA B. PHAM, MD, FAAP
  • CRITICAL CARE MEDICINE
  • CHILDRENS HEALTHCARE OF ATLANTA
  • EGLESTON
  • 2006

2
Objectives
  • Review basic physiologic aspects of shock
  • Define shock and its different categories
  • Describe management of shock

3
What is Shock?Pathophysiology of shock
  • Oxygen
  • Demand gt Supply

4
Definition of Shock
  • Inadequate tissue perfusion to meet tissue
    demands
  • Usually result of inadequate blood flow and/or
    oxygen delivery
  • Shock is not a blood pressure diagnosis

5
Determinants of Oxygen Delivery
  • Oxygen
  • Delivery Content x Cardiac output

6
Determinants of Oxygen Delivery
  • Oxygen content 1.34 (Hgb x SaO2) (PaO2 x
    0.003)
  • SaO2 Oxygen saturation
  • Hgb Hemoglobin concentration
  • PaO2 partial pressure Oxygen in plasma
  • To improve Oxygen content
  • Increase Hemoglobin concentration
  • Increase saturation

7
Determinants of Oxygen Delivery
  • Cardiac output
  • C.O. Heart rate x stroke volume
  • To improve Cardiac output
  • Increase Heart rate
  • Increase Stroke Volume
  • Preload volume of blood in the ventricle
  • Afterload resistance to contraction
  • Contractility force applied

8
Secondary Organ Dysfunction
  • Respiratory failure
  • Tachypnea
  • Decreased compliance
  • Pulm edema, pulm infiltrate, etc.
  • Increased resistance
  • Diaphragm fatigue
  • Central vs peripheral
  • Demand gtgt supply
  • Inadequate O2 delivery

9
Secondary Organ Dysfunction
  • CNS altered mental status
  • Renal insufficiency pre-renal
  • Coagulation abnormalities DIC
  • Hepatic/GI dysfunction bowel ischemia
  • Endocrine Calcium, hypo-adrenalism, vasopressin

10
Classification of Shock
  • Hypovolemic Shock (1 cause world wide)
  • Dehydration, hemorrhagic
  • Cardiogenic Shock
  • Pump failure, obstructive, L-R shunt
  • Distributive Shock
  • Neurogenic
  • Anaphylaxis
  • Septic Shock All of the above

11
Classification of Shock
  • Compensated
  • Organ perfusion is maintained
  • Uncompensated
  • Circulatory failure with end organ dysfunction
  • Irreverisble
  • Irreparable loss of essential organs

12
Mechanical Requirements for Adequate Tissue
Perfusion
  • Fluid
  • Pump
  • Vessels
  • Flow

13
Hypovolemic Shock
  • 1 cause of death world wide
  • Gastroenteritis
  • Hemorrhagic Trauma, GI bleed

14
Diagnosis of Hypovolemic Shock
  • Early
  • Increase HR
  • Decrease perfusion
  • Normal BP, decrease pulse pressure
  • Late
  • Sign increase HR
  • Sign decrease perfusion
  • Decrease BP
  • End organ dysfunction

15
Pathophysiology of Hypovolemic Shock
  • Decrease intravascular volume
  • Compensation increase endogenous catecholamines
  • Increase HR increase C.O., O2 delivery
  • Increase SVR increase BP (esp diastolic)
  • Compensation for lt15 dehydration

16
Cardiogenic Shock
  • Pump failure/malfunction
  • (decreased contractility)

17
Cardiogenic Shock
  • Electrical Failure
  • Arrhythmias
  • Mechanical failure
  • Cardiomyopathy
  • Metabolic acidosis
  • Anatomic
  • Hypoxia/ischemia
  • Obstruction

18
Cardiogenic ShockSymptoms
  • Tachycardia
  • Tachypnea
  • Respiratory distress
  • Mental status change
  • Cool extremities
  • Poor perfusion
  • Signs of dehydration

19
Cardiogenic ShockObstruction of Flow
  • Causes
  • Pericardial tamponade
  • Pulmonary embolism
  • Pulmonary hypertension

20
Cardiogenic ShockObstruction of Flow
  • Cardiac tamponade
  • Causes
  • Pericarditis
  • Post-traumatic
  • Post-cardiac surgery
  • Complication of central line placement
  • Recognition
  • Tachycardia
  • Low C.O., narrow pulse pressure (inc. diastole)
  • Inc. CVP, JVD
  • PULSUS PARADOXUS (gt10mmHg)
  • Muffled heart sounds (??rub)
  • NO RALES

21
Distributive Shock
  • Abnormal vessel tone
  • (decreased afterload)

22
Distributive Shock
  • Vasodilitation Venous Pooling
  • Decreased Afterload
  • Maldistribution of regional blood flow

23
Distributive Shock
  • Neurogenic or Anaphylactic Shock
  • Diminished or absent sympathetic tone
  • Reduce peripheral vascular tone
  • Peripheral pooling of blood volume
  • Inadequate venous return
  • Decreased perfusion, acidosis, hypotension

24
Septic Shock
  • Terminology in Sepsis
  • Infection response to micro organism
  • Bacteremia bug in blood
  • Systemic Inflammatory Response Syndrome (SIRS)
  • Tgt38, lt36
  • Increase HR
  • Increase RR, paCO2lt32
  • WBCgt12,000, lt4,000, gt10 bands

25
Septic Shock
  • Terminology in Sepsis
  • Sepsis SIRS as response to a known infection
  • Severe sepsis Sepsis organ dysfunction
  • Septic Shock Sepsis inadequate oxygen
    delivery
  • Multiple Organ Dysfunction Syndrome (MODS)
    organ dysfunction that requires intervention

26
Septic Shock
  • Components of Septic shock
  • Decreased volume
  • Decreased pump function
  • Abnormal vessel tone

27
Septic Shock
  • Therapy for Caridovascular Support
  • Preload Volume
  • Contractility Inotropes
  • Afterload Vasodilators

28
Septic Shock
  • Etiologies
  • Inflammatory too much, too little
  • Coagulation pathway DIC-bleeding, pro-coagulant,
    microthombosis
  • Multiple organ system failure

29
Recognition of Septic Shock
  • Early warm shock similar to neurogenic shock
  • Late Cold shock similar to cardiogenic shock

30
Diagnosis of Septic Shock
  • Establish presence of infection
  • Inc. HR, normal or dec. BP perfusion
  • Latic acidosis
  • Muti-organ dysfunction

31
Early vs Late Septic Shock
Early Late
Heart rate Tachycardia Tachycardia/ bradycardia
Blood pressure Normal decreased
Peripheral Perfusion Warm/cool Dec./inc. pulses Cool Dec. pulses
32
Early vs Late Septic Shock
Early Late
End-organ skin Dec. cap refill Very dec. cap Refill
Brain Irritable, restless Lethargic, unresponsive
Kidneys Oliguria Oliguria, anuria
33
Treatment Strategies in Shock
34
Principles of Resuscitation
  • Increase Oxygen Delivery\
  • Increase Oxygen content
  • Increase Cardiac output
  • Increase blood pressure
  • Decrease Demand
  • Sedation/analgesia
  • Intubation

35
Initial Treatment in Shock
  • Airway
  • Supplemental oxygen, intubation
  • Carefull with cardiovascular collapse post
    intubation due to positive thoracic pressure
    decrease venous return
  • Breathing
  • Circulation
  • Intravenous access go early, go IO
  • Volume expansion (40cc/kg NS, repeat prn)
  • Carefull with cardiogenic shock (5cc/kg then
    reassess)
  • Optimize cardiac function, oxygenation

36
Restoration of CirculationVolume
  • Fluids, fluids, fluids
  • Crystalloids vs Colloids

37
Restoration of CirculationVolume
  • Crystalloids
  • NS is the fluid of choice, availability
  • Rapid redistribution out of intravascular space
    capillary leak

38
Restoration of CirculationVolume
  • Colloids albumin, blood
  • Albumin
  • Worsening of edema due to cap leak in early
    sepsis
  • Blood
  • Great volume expanders
  • Side effects with massive transfusion gt1.5 blood
    volumes
  • Risk of infection
  • Dilutional thrombocytopenia and factors V VIII
  • Calcium binding hemodynamic instability (citrate)

39
Restoration of CirculationVolume Fluid Choices
  • Based on
  • Type of deficit
  • Urgency of repletion
  • Pathophysiology of shock

40
Restoration of CirculationVolume Fluid Choices
  • Crystalloids for initial resuscitation
  • Colloids/PRBCs to replace blood loss

41
Treatment of ShockCardiac Support
  • Alpha Dopamine Beta
  • Epinephrine
  • Norepinephrine Dobutamine
  • Neosynephrine

42
Inotropes
Agent Site of Action Dose Mcg/kg/min Effects
Dopamine Dopaminergic Beta Alpha gt Beta 1-3 5-10 11-20 Renal vasodilation Inotrope/vasoconstriction Increase perip. Vasc. resistance
Dobutamine Beta 1 2 1-20 Inotrope Vasodilation
Epineprhine Beta gt alpha 0.05 1.0 Inotrope, vasoconstriction Tachycardia
Norepinephrine Alpha gt beta 0.05 1.0 Profound vasoconstriction inotrope
Nitroprusside Vasodilator (art gt venous) 0.5 1.0 Vasodilation
Milranone Phosphodiesterase inhibitor 0.5 0.75 Inotrope vasodilation
43
New Therapies in Septic Shock
  • Vasopressin
  • Steroids
  • Activated protein C (Xigris) in Septic Shock

44
New Therapies in Septic ShockVasopressin
  • Unclear mechanism of action
  • Bridging vascular instability in high exogenous
    catecholamines requirement septic shock,
    therefore decrease side effects of toxic dosage
    of catecholamines
  • Also shows greater blood flow diversion from
    non-vital to vital organs

45
New Therapies in Septic ShockVasopressin
  • Dosage 0.01 0.04U/min up to 0.08U/min

46
New Therapies in Septic ShockSteroids
  • Hypo-adrenalism abnormal hypothalamus-pituitary-a
    drenal axis
  • At risk of adrenal insufficiency in the
    presence of catecholamine requirement
  • Fluid refractory shock
  • Normal BP, cold shock
  • Low BP, cold shock
  • Dosage stress dose
  • Hydrocortisone 150 mg/m2 ivp

47
New Therapies in Septic ShockSteroids
  • Glucocorticoid function immune response
  • Fall in circulating lymphocytes
  • Inhibits neutrophils migration to the
    inflammatory sites
  • Inhibits macrophages secretion
  • Promotes eosinophilic apoptosis
  • Modulates cytokines production

48
New Therapies in Septic ShockSteroids
  • Glucocorticoid function Cardiovascular
  • Modulate vascular reactivity to angiotensin II
    and to catecholamines -Not fully understood
    mechanism
  • Modulate vascular permeability and production of
    NO and other vasodilator factor
  • INCREASE IN BLOOD PRESSURE

49
New Therapies in Septic ShockSteroids
  • Glucocorticoid production in stress
  • Maintain homeostasis
  • Normalize vascular reactivity
  • Modulate inflammatory response

50
New Therapies in Septic ShockActivated
Protein C (Xigris)
  • Recombinant Human Activated Protein C
  • Prevent DIC cascade with antithrombotic activity
    by inhibiting factors Va VIIIa
  • May exerts anti-inflammatory effects by
    inhibiting TNF and by blocking leukocytes
    adhesions
  • Side effects
  • Bleeding
  • Pediatric trial terminated early (03/04) due to
    no benefit to known risk of bleeding
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