This document summarizes different types of shock: 1. Hypovolemic, cardiogenic, obstructive, distributive, and endocrine shock are classified. Obstructive shock involves reduced cardiac filling from mechanical obstruction. Distributive shock features vasodilation and hypotension from conditions like sepsis. 2. Specific causes of different shock types are outlined, such as tension pneumothorax in obstructive shock and anaphylaxis in distributive shock. 3. Features of early and late septic shock are compared, showing progression from warm to cold shock with worsening end-organ dysfunction over time.

1. Dr. Neeraj Kumar Jain
Dept. of General Surgery

2. In previous Lecture we discussed
 Shock is a systemic state of low tissue perfusion, which
is inadequate for normal cellular respiration.
 With insufficient delivery of oxygen and glucose, cells
switch from aerobic to anaerobic metabolism.
 If perfusion is not restored timely , it leads to cell
death .

3. Shock is
 Inadequate tissue perfusion to meet tissue demands.
Usually result of inadequate blood flow and/or oxygen
delivery.

4. Classification of shock
 ■ Hypovolaemic
 ■ Cardiogenic
 ■ Obstructive
 ■ Distributive
 ■ Endocrine

6. THE BLOOD
WHOLE
BLOOD
EXTERNAL
HG.
INTERNAL
HG.
PLASMA
GUT
*VOMITING
*NGT. DRAIN
*DIARRHOEA
* FISTULA
SKIN
•SWEAT
•* BURN
KIDNEY
*DM
*DI
*DIURETIC
3rd SPACE
* ASCITES

8. CARDIAC
CAUSESAFTERLOAD
PRELOAD
VALVES
MUSCLE POWER
RATE&
RHYTHEM

9.  Myocardial
 Infarction, contusion, myocarditis, cardiomyopathy,
pharmacologic, depressant factors
 Mechanical
 Valvular stenosis, regrurgitation
 Septal Defects
 Arrhythmogenic
Causes

10. In Todays lecture
 ■ Obstructive shock
 ■ Distributive shock
 ■ Endocrine shock

11. Obstructive shock
 In obstructive shock there is a reduction in preload because
of mechanical obstruction of cardiac filling.
 Common causes of obstructive shock include
 1. cardiac tamponade,
 2.tension pneumothorax,
 3.massive pulmonary embolus
 4. air embolus.
 There is reduced filling of the left and/or right sides of the
heart leading to reduced preload and a fall in cardiac
output.

12.  Extrinsic Vascular Compression
 tumors, fibrosis
 Increased Intrathoracic Pressure
 Tension pneumo; high autopeep in PPV
 Flow obstruction
 PE, Air embolism, tumors, Ao dissection, Ao
coarctation, acute pulmonary HTN, tamponade.
Shock -- Classification --
Obstructive

13. • 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
• X ray chest and general Investigation are done
• Rx: Needle decompression, chest tube insertion
Obstructive Shock

14. • 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
Obstructive Shock

15. • Pulmonary embolism
• Virscow triad: hypercoaguable, venous injury,
venostasis
• Signs: Tachypnea, tachycardia, hypoxia
• Low risk: D-dimer
• Higher risk: CT chest or VQ scan
• Rx: Heparin, consider thrombolytics
Obstructive Shock

16. Distributive shock
 It describes the pattern of cardiovascular responses
characterising a variety of conditions including
 A)septic shock,
 B) anaphylaxis and
 c)spinal cord injury.
 Inadequate organ perfusion is accompanied by vascular
dilatation with hypotension, low systemic vascular
resistance, inadequate afterload and a resulting
abnormally high cardiac output.

17. Distributive shock continue…
 In anaphylaxis, vasodilatation is caused by histamine
release, whereas in high spinal cord injury there is
failure of sympathetic outflow and adequate vascular
tone (neurogenic shock).
 The cause in sepsis is less clear but is related to the
release of bacterial products (endotoxins) and the
activation of cellular and humoral components of the
immune system.

18.  There is maldistribution of blood flow at a
microvascular level with arteriovenous shunting and
dysfunction of the cellular utilisation of oxygen.
 In the later phases of septic shock there is
hypovolaemia from fluid loss into the interstitial
spaces and there may be concomitant myocardial
depression, which complicates the clinical picture
Distributive shock continue…

19.  SIRS-related As sepsis (infectious); pancreatitis;
trauma; burns.
 Anaphylactic/anaphylactoid
 Spinal Trauma (low pulse, SVR low)
 Toxic, pharmacologic (B-blockers overdose)
Shock -- Classification --Distributive

20. Abnormal vessel tone
(decreased afterload)
Distributive Shock

21. Vasodilitation Venous Pooling
Decreased Afterload
Maldistribution of regional blood flow
Distributive Shock

22.  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
Distributive Shock

23. • 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
Anaphylactic Shock

24. • What are some symptoms of anaphylaxis?
Anaphylactic Shock
• 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

25. • 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
Anaphylactic Shock

26. • 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
Anaphylactic Shock

27. • 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
Anaphylactic Shock- Diagnosis

28. • 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)
Neurogenic Shock

29. • 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

30.  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
Septic Shock

31.  Components of Septic shock
 Decreased volume
 Decreased pump function
 Abnormal vessel tone
Septic Shock

32.  Therapy for Caridovascular Support
Preload Volume
Contractility Inotropes
Afterload Vasodilators
Septic Shock

33. Etiologies
 Inflammatory: too much, too little
 Coagulation pathway: DIC-bleeding, pro-coagulant,
microthombosis
 Multiple organ system failure
Septic Shock

34.  Early – warm shock – similar to neurogenic shock
 Late – Cold shock – similar to cardiogenic shock
Recognition of Septic Shock

35. 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

36. Endocrine shock
 Endocrine shock may present as a combination of
hypovolaemic, cardiogenic and distributive shock.
 Causes of endocrine shock include
 1.Hypo- and Hyperthyroidism and
 2. Adrenal insufficiency.

37. Endocrine shock Continue…
 Hypothyroidism causes a shock state similar to that of
neurogenic shock as a result of disordered vascular and
cardiac responsiveness to circulating catecholamines.
 Cardiac output falls because of low inotropy and
bradycardia.
 There may also be an associated cardiomyopathy.
 Thyrotoxicosis may cause a high-output cardiac
failure.

38. Endocrine shock Continue…
 Adrenal insufficiency leads to shock as a result of
hypovolaemia and a poor response to circulating and
exogenous catecholamines.
 Adrenal insufficiency may result from pre-existing
Addison’s disease or it may be a relative insufficiency
caused by a pathological disease state such as systemic
sepsis.

39. Type PAOP C.O. SVR
HYPOVOLEMIC   
CARDIOGENIC   
DISTRIBUTIVE  or N varies 
OBSTRUCTIVE   
Summary
Co Cardiac output,svr-systemic venous resistance,paop=pressure

40. Thank you

41. In the next lecture we will dicuss
 Severity of shock
 Compensated shock
 Decompensation
 Mild , moderate ,severe shock
 Consequences
 Unresuscitatable shock
 Multiple organ failure
 RESUSCITATION