Definition Stages of Shock Mechanism of Progressive & Irreversible shock Types of Shock & Causes Treatment for shock

1. Shock
Pandian M
Dept of Physiology
DYPMCKOP

2. SLO
•Definition
•Stages of Shock
•Mechanism of Progressive & Irreversible
shock
•Types of Shock & Causes
•Treatment for shock

3. Definition
• Shock is a condition in which is a disparity between
circulating blood volume & capacity of vascular tree.
Stages of Shock
i. Non progressive stage
ii. Progressive stage
iii.Irreversible stage

4. i. Non progressive stage
• Its also called as compensated stage
• Initial stage of shock occurs when there is a moderate reduction in cardiac
output
• When blood loss is less than 10% of total volume, the BP decreases only
moderately.
• the regulatory mechanisms in the body operate successfully to reestablish
normal BP and normal blood flow throughout the body.
• the shock becomes nonprogressive and the person recovers
• During this stage various compensatory mechanism (short term)
• Regulatory mechanisms involve negative feedback control.
• Those are:
i. Baroreceptor mechanism, ii. Renal mechanism, iii. ADH mechanism.

8. Progressive Stage
• Second stage of the circulatory shock is progressive stage which
occurs after 15–25% loss of total blood volume.
• In this stage, the compensatory mechanisms are not able to stop the
progression of the shock.
• Second stage is also called decompensated stage.
• In progressive shock, the structures of circulatory system begin to
deteriorate and various types of positive feedback mechanisms
develop
• Timely therapeutic interventions are essential in this stage
• In this stage, all therapeutic interventions are usually ineffective and
• eventually the patient dies. Its called refractory shock

9. Effect on body tissues in progressive shock
•In progressive shock, there occurs widespread
cellular degeneration in the body tissues.
•Generalized cellular damage usually occurs first
in highly metabolic tissues, such as liver, lung
and heart.

10. • 1. Cardiac failure.
• 2. Vasomotor failure.
• 3. Peripheral circulatory failure.
• 4. Septicaemia and toxicaemia.

12. Progressive stage of circulatory shock

15. Irreversible stage
• Third stage is the last stage prior to the collapse.
• It is also called refractory stage.
• Irreversible stage leads to death regardless of type of
treatment offered to the patient.
• It is because the brain fails to function due to severe cerebral
ischemia.
• The blood pressure falls drastically.
• Even the infusion of blood fails to restore blood pressure.
• Finally, cardiac failure occurs due to decrease in the
myocardial activity and reduced arteriolar tone resulting in
death of the affected person

18. Types of shock
1.Circulatory shock
2.Hypovolemic Shock
3.Septic shock
4.Anaphylactic shock
5.Neurogenic shock

19. TYPES AND CAUSES OF CIRCULATORY SHOCK
•Circulatory shock is primarily classified into four
types
A. Shock due to decreased blood volume
B. Shock due to increased vascular capacity
C. Shock due to cardiac disease
D. Shock due to obstruction of blood flow.

21. Cardiogenic or circulatory shock
•serious reduction of tissue perfusion with a relatively or
absolutely inadequate cardiac output
•This is due to decrease in pumping efficiency of heart
•Bcoz brain doesn’t receive adequate blood flow to get
metabolic needs
• e.g MI
•VR decreases followed by CO also decreases.
•Decrease vascular tone
•Decreased diminished blood flow
• E.g. Arrhythmia, Congestive heart failure

22. Hypovolaemic shock also known as cold shock,
•Major factor is decreased blood volume due to
•Hemorrhagic shock
•Traumatic shock
•Surgery
•Burns
•Fluid loss in vomiting & diarrhea

23. Action
• The brain suffers Ischemia due to inadequate blood flow
• Sympathetic reflex causes powerful reflex were decrease pressure in
pulmonary arteries & venus.
• Baroreceptor vascular stretch receptor.
• Systemic Vas.Constrictors
• Arterioles constrict inmost part of the systemic circulation increases
Total PR
• Venous, veins constriction helped to maintain adequate VR
• Increased HR from normal to 160-180

24. Neurogenic Shock
• This developed due to sudden loss of vasomotor tone
throughout the body
• Causing MASSIVE DILATION of the resistance &
capacitance of the vessels like arterioles & veins

25. Causes
• Deep general anesthesia - this often depress VMC
causing loss of VM tone
• Spinal anesthesia – it blocks sympathetic outflow
with resulting loss of VM tone
• Brain damage – injury to the brain can cause the
damage to the VMC with resulting loss of VM tone
• Venous pooling leads to decrease in CO with
resultant fall in BP

26. Anaphylactic shock
•Anaphylaxis is an allergic condition in which
cardiac output & arterial pressure often decreases
•Ag-Ab rxn rapidly occurs after Ag enter to the
circulation
•Peripheral effect is to cause the basophils in the
blood & mast cell in the pericapillary tissues to
release Histamine or Histamine like substanecs.

27. Causes of histamine
1. Increase in vascular capacity
- B’coz vasodilation and decrease VR
2. Dilation of arterioles
- reduction in arterial pressure
3. Increase capillary permeability
rapid loss protein & loss of fluid
4. Large amount of histamine causes “Histamine
shock”

28. Septic shock
• It is due to septicemia
• Bacterial toxins produced vasodilation which
increased capillary permeability causing a leakage of
plasma into the tissue
• Result Blood volume decreased
• Toxins depress the myocardium & causes decreased
Cardiac output
•

29. Causes
• Peritonitis caused by infection from uterus, fallopian tubes in
females
• Mostly instrumental abortion performed with unsterile
condition one of the factor for septic shock
• Peritonitis result rupture of GIT system caused by intestinal
disease & by wound
• Skin infection caused by streptococcal or staphylococcal
infection
• Liver tissue damage by gangrene bacilli
• Blood from kidney or urinary tract caused by colon bacilli

30. Treatment for the shock
a. Transfusion of compatible whole blood or blood substitute.
- This will improve the blood volume & BP.
- Dextran solution as plasma expander is highly useful
b. Vasoconstriction agent – Adrenaline, Noradrenaline,
Dopamine used for traumatic, cardiogenic shock not in
hemorrhagic shock.
c. Subject Head down and leg up position to improve the
cerebral flow as well maintain the CO

31. d. Inotrophic agent used for congestive heart failure
e. 100% O2 administrate to improve O2 supply to tissue
f. Antihistamine, hydrocortisone along with antibodies
for anaphylaxis & septicemia.
g. NaHCo3 associated with metabolic acidosis
h. Room temperature maintain in lower level

32. Referred :-
• Text book of Medical Physiology
• Guyton, 12th edition,
• Text book of Medical Physiology
• Indu khurana,
• Text book of Medical Physiology
• Vander’s
• Text book of Medical Physiology
• Sembulingam &
• LPR

33. THANK YOU . . .