Shock Flashcards
Define shock
state of inadequate tissue perfusion
6 categories of shock and common etiologies
Hypovolemic - hemorrhage, dehydration Distributive - sepsis, SIRS Obstructive - PE, cardiac tamponade, tension pneumo Cardiogenic -MI, CHF, valves Neurogenic - spinal injury
Pathophysiology of hypovolemic shock
low preload -> low SV -> low CO -> low BP
PVR increases to compensate
Pathophysiology of distributive shock
adequate preload but maldistribution of blood flow with open capillary beds
dilated vessels -> reduction in PVR -> low BP
Examples of distributive shock
Septic shock
Adrenal insufficiency
SIRS
Cardinal signs of SIRS
o Fever or hypothermia o Leukocytosis or leukopenia o Tachypnea o Tachycardia o Infectious or non-infectious (burns, pancreatitis, multiple trauma)
What spinal cord injuries cause neurogenic shock?
injury at or above thoracolumbar sympathetic roots leading to loss of sympathetically mediated vasomotor tone
- vascular tone is primarily mediated by sympathetic nervous system
Causative agents of sepsis
95% are microbes of normal flora that cause disease in immunocompromised
5% classic pathogens: strep pneumo, meningitis, enterobacteria, etc.
Renal complications of sepsis
Oliguria Azotemia Proteinuria ATN Lyte abnormalities
Issues with coagulation in sepsis
Liver produces less clotting factors
Thrombocytopenia
DIC
SIRS is defined by the presence of 2 or more of the following findings:
- Hypothermia or fever
- HR > 90
- RR > 20 or, on ABG, a PaCO2 less than 32 (tachypnea or hypocapnia due to hyperventilation)
- WBC count less than 4,000, or greater than 12,000, or greater than 10% band forms (leukopenia, leukocytosis, or bandemia)
Treatment of sepsis or septic shock
- Eliminate infection: abx, change catheters
- Hemodynamic support: increase intravascular volume with vasopressors (dopamine, norepinephrine)
- Respiratory support: supplement O2, ETT
- Renal support
- Metabolic support: nutrition, bicarb for severe metabolic acidosis, transfusion, control glucose, keep patient warm
- Misc: Steroids, anticoags, COX inhibitors
What is APACHE II Scores?
One of several ICU scoring systems, and arguably the best known “severity of disease classifications”
Patient “scored” on 12 physiologic parameters - BP, pulse, RR, temp, age, Hct, Na, K, creatinine etc.
Score 1-71; higher scores correlate with sicker patients
General pathophysiology of DIC
widespread intravascular fibrin formation in response to excess blood proteases
sustained coagulation results in using up coagulation factors and platelets which causes bleeding
Most sensitive indicator of DIC
fibrin degradation products (FDP)