Types of Shock

People in shock need to relax with some COVe SAND.

Cardiogenic
Obstructive
Volume(hypo)
e

-Septic
-Anaphylactic
-Neurogenic
Distributive

S, A, and N are all types of Distributive shock (where volume mobilized into the interstitial fluid because of infection or acute inflammation causes hypoperfusion.)
1. Cardiogenic: pump failure
2. Obstructive: mechanical impedance of blood flow
3. Volume(hypo): ↓ intravascular V
4. Distributive: ↓SVR, widespread vasodilation/vascular permeability
• Septic: bacterial Ag-induced inflammation
• Anaphylactic: hypersensitivity reaction
• Neurogenic/vasogenic: imbalance of PSNS & SNS
Clinical definitions for the progression of septic shock
Bacteremia “blood poisoning” -> SIRS -> sepsis -> severe sepsis -> septic shock
Associated with fever, chills, fatigue & malaise

Systemic inflammatory response syndrome (SIRS): 2+ of the following:
1. T > 38°C or <>
2. HR > 90
3. RR > 20 or PaCO2 <>
4. WBC >12, <4,>10% immature (band) forms

Sepsis: 2+ of the following as a result of a documented infection:
1. Rectal T > 38°C or <>
2. HR > 90
3. RR > 20
4. >1 of the following manifestations of inadequate organ function/perfusion also must be included:
a. Alteration in mental state
b. Hypoxemia (PaO2 <72>
i. (overt pulmonary disease not the direct cause of hypoxemia)
c. Elevated plasma lactate level
d. Oliguria (UOP <30>

Severe sepsis: This is sepsis & SIRS associated w/ hypotension, hypoperfusion and altered mental status
o Hypotension: SBP <90>40 from baseline
o End-organ hypoperfusion: cool or mottled extremities, weak or absent peripheral pulses; lactic acidosis; splanchnic vasoconstriction -> oliguria, bowel ischemia and hepatic dysfunction
o Altered mental status: ↓brain perfusion -> restless, agitated, confused, lethargic or comatose

Septic shock: severe sepsis complicated by persistent hypotension after fluid therapy.

References/Resources
CMDT 2006. (Hypotension & Shock, pp 477-80.)
McCance & Huether, Pathophysiology 5th ed. 2006.
eMedicine. Septic Shock. Accessed 11/26/06.