Pathophysiology of shock and its management by Dr. Bipul Borthakur

1. SHOCK AND THIS MANAGEMENT
DR. B. BORTHAKUR,
PROFESSOR,
DEPARTMENT OF ORTHOPAEDICS

2. DEFINITION
• clinical condition of organ dysfunction
resulting from an imbalance between cellular
oxygen supply and demand.

3. CLASSIFICATION OF SHOCK
DISTRIBUTIVE
• Septic shock
• Pancreatitis
• Severe burns
• Anaphylactic shock
• Neurogenic shock
• Endocrine shock
• Adrenal crisis

4. CARDIOGENIC
• Myocardial infarction
• Myocarditis
• Arrhythmia
• Valvular
i. Severe aortic valve insufficiency
ii. Severe mitral valve insufficiency

5. OBSTRUCTIVE
• Tension pneumothorax
• Cardiac tamponade
• Restrictive pericarditis
• Pulmonary embolism
• Aortic dissection

6. HYPOVOLEMIC
• Hemorrhagic
• GI losses
• Burns
• Polyuria
i. Diabetic ketoacidosis
ii. Diabetes insipidus

7. STAGES OF SHOCK
• Compensated shock (non progressive stage)
• Cardiac output :
(HR×SV) and Systemic Vascular Resistance
(peripheral vasoconstriction) work to keep BP
within normal by reflex compensatory
mechanism

8. ON EXAMINATION
• Tachycardia
• Decreased pulse and cool extremities in cold
shock
• Flushing and bounding pulse in warm shock
• Oliguria
• LAB FINDINGS
• Mild lactic acidosis

9. PROGRESSIVE (UNCOMPENSATED STAGE)
• Compensatory mechanism are overwhelmed
• Wide spread hypoxia
• Hypotensive shock
ON EXAMINATION
• Hypotensive
• Altered mental status
• Decreased urine output

10. • LABARATORY FINDINGS
• Increased lactic acidosis
• Quick progression to cardiac arrest
IRREVERSIBLE STAGE
• Wide spread cellular injury
• Release of lysosomal enzyme, worsens cardiac
contractility
• Irreversible organ injury

12. EVALUATION OF PATIENT WITH SHOCK
1. Recognize shock early
2. Assess for type of shock present
3. Initiate therapy simultaneous with the
evaluation into the etiology of shock
4. Restoration of oxygen delivery is the aim of
therapy
5. Identify etiologies of shock which require
additional lifesaving interventions

13. Diagnostic Testing
1. Lactate
2. Renal function tests
3. Liver function tests
4. Cardiac enzymes
5. Complete blood count (with differential)
6. PT, PTT, and INR
7. Urinalysis and urine sediment
8. Arterial blood gas
9. ECG

14. SEPSIS AND SEPTIC SHOCK

15. PATHOGENESIS

16. • The host response to sepsis involves
multiple mechanisms that lead to decreased
oxygen delivery (DO2) at the tissue level.
• The inflammatory response is typically
initiated by an interaction between
pathogen-associated molecular patterns
(PAMPs) expressed by pathogens and
pattern recognition receptors expressed by
innate immune cells on the cell surface (Toll-
like receptors [TLRs] and C-type lectin
receptors [CLRs]), in the endosome (TLRs) or
in the cytoplasm (retinoic acid inducible
gene 1–like receptors and nucleotide-
binding oligomerization domain–like

17. • The resulting tissue damage and necrotic
cell death lead to release of damage-
associated molecular patterns (DAMPs) such
as uric acid, high-mobility group protein B1,
S100 proteins, and extracellularRNA, DNA,
and histones.
• These molecules promote the activation of
leukocytes, leading to greater endothelial
dysfunction, expression of intercellular
adhesion molecule (ICAM) and vascular cell
adhesion molecule 1 (VCAM-1) on the
activated endothelium, coagulation

18. • This cascade is compounded by macrovascular
changes such as vasodilation and hypotension,
which are exacerbated by greater endothelial
leak tissue edema, and relative intravascular
hypovolemia.
• Subsequent alterations in cellular
bioenergetics lead to greater glycolysis (e.g.,
lactate production), mitochondrial injury,
release of reactive oxygen species, and greater
organ dysfunction.

19. DIAGNOSTIC CRITERIA

20. • Sequential Organ Failure Assessment (SOFA)
score ranges from 0 to 24 points, with up to 4
points accrued across six organ systems.
• The SOFA score is widely studied in the ICU
among patients with infection, sepsis, and
shock. With ≥2 new SOFA points, the infected
patient is considered septic and may be at
≥10% risk of in-hospital death.

21. • Quick SOFA (qSOFA) score was proposed as a
clinical prompt to identify patients at high risk
of sepsis outside the ICU
• qSOFA score ranges from 0 to 3 points, with 1
point each for systolic hypotension (≤100
mmHg), tachypnea (≥22breaths/min)or
altered mentation. A qSOFA score of ≥2 points
has a predictive value for sepsis similar to that
of more complicated measures of organ
dysfunction.

22. Elements of Care in Sepsis and Septic
Shock
• Resuscitation
• Sepsis and septic shock constitute an
emergency, and treatment should begin right
away.
• Resuscitation with IV crystalloid fluid (30 mL/kg)
should begin within the first 3 h.
• Saline or balanced crystalloids are suggested for
resuscitation.
• If the clinical examination does not clearly
identify the diagnosis, hemodynamic

23. • In patients with elevated serum lactate levels,
resuscitation should be guided towards
normalizing these levels when possible.
• In patients with septic shock requiring
vasopressors, the recommended target mean
arterial pressure is 65 mmHg.
• Hydroxyethyl starches and gelatins are not
recommended.
• Norepinephrine is recommended as the first-
choice vasopressor.

24. • Vasopressin should be used with the intent of
reducing the norepinephrine dose.
• The use of dopamine should be avoided except in
specific situations—e.g., in those patients at highest
risk of tachyarrhythmias or relative
• bradycardia.
• Dobutamine use is suggested when patients show
persistent evidence of hypoperfusion despite
adequate fluid loading and use of
• vasopressors.
• Red blood cell transfusion is recommended only
when the hemoglobin concentration decreases to
<7.0 g/dL in the absence of acute
• myocardial infarction, severe hypoxemia, or acute

25. • Infection Control
• So long as no substantial delay is incurred, appropriate
samples for microbiologic cultures should be obtained
before antimicrobial therapy is
• started.
• IV antibiotics should be initiated as soon as possible (within
1 h); specifically, empirical broad-spectrum therapy should
be used to cover all
• likely pathogens.
• Antibiotic therapy should be narrowed once pathogens are
identified and their sensitivities determined and/or once
clinical improvement is
• evident.
• If needed, source control should be undertaken as soon as
is medically and logistically possible.
• Daily assessment for de-esclation of antimicrobial therapy
should be conducted.

26. • Respiratory Support
• A target tidal volume of 6 mL/kg of predicted body weight
(compared with 12 mL/kg in adult patients) is recommended
in sepsis-induced
• ARDS.
• A higher PEEP rather than a lower PEEP is used in moderate
to severe sepsis-induced ARDS.
• In severe ARDS (PaO2
• /FIO2
• , <150 mmHg), prone positioning is recommended, and
recruitment maneuvers and/or neuromuscular blocking
• agents for ≤48 h are suggested.
• A conservative fluid strategy should be used in sepsis-induced
ARDS if there is no evidence of tissue hypoperfusion.
• Routine use of a pulmonary artery catheter is not
recommended.
• Spontaneous breathing trials should be used in mechanically
ventilated patients who are ready for weaning

27. • General Supportive Care
• Patients requiring a vasopressor should have an
arterial catheter placed as soon as is practical.
• Hydrocortisone is not suggested in septic shock if
adequate fluids and vasopressor therapy can
restore hemodynamic stability.
• Continuous or intermittent sedation should be
minimized in mechanically ventilated sepsis
patients, with titration targets used whenever
• possible.
• A protocol-based approach to blood glucose
management should be used in ICU patients with
sepsis, with insulin dosing initiated when two

28. • Consecutive blood glucose levels are >180 mg/dL.
• Continuous or intermittent renal replacement
therapy should be used in patients with sepsis
and acute kidney injury.
• Pharmacologic prophylaxis (unfractionated
heparin or low-molecular-weight heparin) against
venous thromboembolism should be used in the
• Absence of contraindications.
• Stress ulcer prophylaxis should be given to
patients with risk factors for gastrointestinal
bleeding.

29. Antimicrobial Therapy for Severe Sepsis with No
Obvious Source in Adults with Normal Renal
Function

30. CARDIOGENIC SHOCK
• CS is a low cardiac output state resulting in life-
threatening end-organ hypoperfusion and
hypoxia.
• The clinical presentation is typicallycharacterized
by persistent hypotension (<90 mmHg systolic
blood pressure [BP]) unresponsive to volume
replacement and is accompanied byclinical
features of peripheral hypoperfusion, such as
elevated arterial lactate (>2 mmol/L).

31. PATHOPHYSIOLOGY

32. Etiologies of Cardiogenic Shock
Acute myocardial infarction/ischemia
• Left ventricular failure
• Ventricular septal rupture
• Papillary muscle/chordal rupture–severe mitral
regurgitation
• Ventricular free wall rupture
• Other conditions complicating large myocardial infarctions
• Excess negative inotropic or vasodilator medications
• Post-cardiac arrest
• Post-cardiotomy
• Refractory sustained supra or ventricular tachyarrhythmias
• Refractory sustained bradyarrhythmias
• Acute fulminant myocarditis

33. • End-stage cardiomyopathy
• Takotsubo syndrome/Apical ballooning syndrome
• Hypertrophic cardiomyopathy with severe outflow
obstruction
• Aortic dissection with aortic insufficiency or tamponade
• Severe valvular heart disease
• Critical aortic or mitral stenosis
• Acute severe aortic regurgitation or mitral regurgitation
• Toxic/metabolic
• β-blocker or calcium channel antagonist overdose
• Hypertensive crisis
• Post-cardiac arrest stunning
• Myocardial depression in setting of septic shock or SIRS
• Myocardial contusion

34. Hemodynamic Patterns

35. Cardiogenic SHOCK Mangement

36. HYPOVOLEMIC SHOCK
• Hypovolemic shock encompasses disease
processes that reduce CO (and oxygen delivery)
via a reduction in preload. In addition to the
reduced CO this shock type is characterized by
an elevated SVR and low CVP and PCWP related
to decreased intravascular volume.
• Any process causing a reduction in intravascular
volume can cause shock of this type.
• Hypovolemic shock most commonly is related
to hemorrhage, that may be external
(secondary to trauma) or internal (most
commonly upperor lower gastrointestinal [GI])

37. Classification of hypovolumic shock

38. Management of hypovolumic shock

39. Neurogenic shock
• Results in spinal cord trauma (usually T5 or
above)or spinal anaesthesia
• Injury results in major vasodilation without
compensation due to loss of sympathetic
nervous system vasoconstrictor tone
• Major vasodilation leads to pooling of blood in
blood vessel, tissue hypoperfusion and
impaired cellular metabolism

40. • Spinal anaesthesiacan block transmission of
impulse from SNS result in neurogenic shock
• CLINICAL FEATURES
• Hypotension
• Bradycardia
• Inability to maintain temperature

41. TREATMENT
• High dose steroid to reduce inflammation
• Elevate and maintain HOB 30 degree
• Support cardiovascular and neurologic
function
• Prevent pooling of blood in lower extremity

42. Anaphylactic shock
• Acute and life threatening allergic reaction to
sensitizing substance
• Immediate response causing massive
vasodilation release of vasodilator mediator
and increase capillary permeability
• Can lead to respiratory distress due to
laryngeal edema or severe bronchospasm and
circulatory failure due to vasodilation

43. SYMPTOMS
• Cheat pain
• Dizziness
• Incontinence
• Swelling of lips and tongue
• Wheezing ans stridor
• Angioedema
• Anxious and confused
• Utricaria, Flushing, pruritis

44. Treatment
• Airway management
• Epinephrine.0.3 sq or im to vastus lateralis
• BLS /ACTS
• Asses for allergies

45. THANK YOU
“nāsti buddhirayuktasya na cāyuktasya bhāvanā
na cābhāvayataḥ śāntiraśāntasya kutaḥ sukham”
“For the unsteady there is no wisdom, and there is
no meditation for the unsteady man.
And for an un-meditated man, there is no peace.
How can there be happiness for one without
peace?”