Lecture 11: Altered Physiology and Shock Flashcards
Shock can be defined as systolic BP < _____ mmHg or a ↓ systolic BP ______ mmHg below baseline.
Shock can be defined as systolic BP < 80-90 mmHg or a ↓ systolic BP 40 mmHg below baseline.
Shock can be defined as a MAP
<60-65 mmHg
Levels of what are a reflection of tissue hypoxia?
Lactate
Which 3 categories of shock present with skin that is cool, clammy, cyanotic, pallor, and mottled (blotchy) distal extremities due to ↓ perfusion/vasoconstriction?
- Hypovolemic
- Cardiogenic
- Obstructive
Which type of shock will present with skin/extremities that are warm and pink due to vasodilation?
Distributive/dissociative shock (cyanide poisoning)
What is the HR like in shock and is useful why?
- Usually fast; occasionally slow
- Sensitive indicator of shock
Common renal manifestation of shock?
Oliguria
Which serum value associated with shock is related to an increase in mortality as levels get higher?
Lactate
What is responsible for the mental status changes associated with shock?
↓ cerebral perfusion –> confusion, restlessness, agitation, delirium, stupor, coma
What is the most common cause of hypovolemic shock?
Hemorrhagic shock
What are 3 non-hemorrhagic causes of hypovolemic shock?
- GI losses (vomiting, diarrhea)
- Skin losses (burns, heat strokes)
- DKA –> renal losses
What are 3 causes of distended neck veins?
- HF
- PE
- Tamponade
In shock what is the initial acid-base disturbance and then is followed by what?
Respiratory alkalosis —-> metabolic acidosis (think ↑ lactate)
Hypoaldosteronism, adrenal insufficiency, 3rd space loss, bowel obstruction, and systemic inflammation may all cause what type of shock?
HYPOvolemic
What is initial management for someone in hypovolemic shock, whether due to hemorrhagic or non-hemorrhagic cause?
- Fluids FAST - monitor BP and tissue perfusion
- Crystalloids —> NS useful in hypovol. from renal, GI, sweat, burns, hemorrhage
- Packed RBC for hemorrhage/function is erythrocyte
How does the pulse rate, BP, and pulse pressure change as you move from class I to class IV criteria of hemorrhagic shock?
- Pulse rate will ↑as the HR ↑
- BP will ↓
- Pulse pressure will ↓
What is the most common cause of non-cardiogenic shock?
Septic or Non-septic (vasodilation)=Distributive shock
What are 4 signs/sx’s of sepsis (distributive shock)?
- Fever (>38 C or <36 C)
- Tachycardia (>90/min)
- Tachypnea (>20 breaths/min)
- ↑ WBC (>12,000) or WBC (<4000)
What is the definition of septic shock?
Severe sepsis and dysfunction of organ system w/ hypotension (<90 systolic or >40 mmHg ↓ baseline) despite fluids
How does endothelial injury in distributive shock lead to a ↓ preload?
Becomes permeable and leaks fluid into tissue (lung, intestine, capillary leak) releases NO2 = potent vasodilator which ↓ preload
What are PE findings of the skin/extremities, HR, BP, and neck veins associated with distributive septic shock?
- Skin/extremities = warm, flushed (vasodilation)
- HR = fast (10-30% will have myocardial depression)
- BP = low (<90 systolic BP)
- Neck veins = flat = ↓ JVP
What are some of the common sources/underlying infections throughout each body system which may lead to sepsis (i.e., pulmonary, abdominal, GU, CNS, and skin..)
- Pneumonia, emphysema
- Peritonitis, cholangitis
- Pyelonephritis, abscess
- Meningitis
Cellulitis, necrotizing fascitis
If patient with septic shock doesn’t respond to IV fluids what should be given to maintain perfusion pressure; what is the 1st line agent and 2nd line agent?
- Norepinephrine = 1st line
- Dopamine = 2nd line –> can cause tachycardia
Other than fluids/pressors what else should be given as treatment for septic shock?
- Antibiotics –> vancomycin + piperacillin/tazobactam + aminoglycoside
- ± low dose steroids
What are some of the allergens which can lead to anaphylactic shock?
- Drugs (antibiotics, chemo, hormones, NSAIDs)
- Insect bites
- Foods
- Latex
- Contrast agents
What occurs to SVR in distributive shock (i.e., anaphylactic and septic shock) vs. hypovolemic shock vs. cardiogenic shock?
- Distributive (septic and anaphylactic) = ↓ SVR (vasodilation)
- Hypovolemic = ↑ SVR (due to vasoconstriction)
- Cardiogenic = ↑ SVR (compensating for ↓BP and ↓CO)
Cardiogenic shock is due to a decrease in systemic oxygen delivery caused by what?
Deterioration of cardiac function due to myocardial, valvular, structural, toxic or infectious causes = PUMP FAILURE
What is the BP, CO, and urine output like in cardiogenic shock?
- ↓ BP (<90 or >30 mmHg below baseline)
- ↓ CO –> ↓ urine output
What are the 3 classifications of cardiogenic shock?
- Cardiomyopathic
- Arrhythmogenic
- Mechanical
What are the clinical signs of cardiogenic shock (BP, UO, skin, neck veins, and lungs.)
- ↓ BP and ↓UO
- Cool, mottled extremities
- Distended neck veins (↑ CVP >12 mmHg)
- Pulmonary edema
What is the most common cause of cardiogenic shock?
LV failure due to AMI
RV infarction assoc. w/ inferior MI leading to cardiogenic shock should be treated how?
IV fluids = preload sensitive (do not give nitrates)
What are some complications arising after an MI which can lead to Cardiogenic Shock?
- Acute mitral regurgitation
- VSD
- RV infarction
- Ventricular free wall rupture —> tamponade
Which drugs are given for cardiogenic shock?
- Norepinephrine = preferred = alpha-1, beta-1, beta-2 agonist
- Dopmaine
- Inotropes = dobutamine and milrinone
Which drug can be given in cardiogenic shock to decrease the pulmonary edema?
Furosemide (loop diuretic - Lasix)
What are some of the causes of extracardiac obstructive shock?
- Obstructed RV output = massive PE air embolus
- Impaired diastolic filling = SVC syndrome
- Cardiac tamponade
- Constrictive pericarditis
- Severe HTN
Any patient with pleuritic chest pain and dyspnea should make you think of what cause?
Pulmonary embolism
Any patient with chronic dyspnea and ↑ P2 (pulmonic valve sound) should make you think of what cause?
Pulmonary HTN
Common cause of chest pain, SOB, tracheal deviation (away from affected side), ↓ unilateral breath sounds?
Tension Pneumothorax
Distended neck veins, muffled heart sounds, pulsus paradoxus dilated IVC are features of what?
Cardiac Tamponade
Emergent tx for tension pneumothorax?
- 14-16 gauge IV catheter in 2nd, 3rd ICS, MCL followed by thoracostomy
OR
- Emergent tube thoracostomy in 5th ICS, MCL
When using echocardiogram to diagnose pericardial tamponade what highly sensitive sign are you look for and what other common findings?
RA collapse (sensitive); RV collapse; IVC dilation
Tx for Pericardial Tamponade?
Echo/ultrasound to guide pericardialcentesis
What occurs to HR, JVD, extremities, lungs, and SVR in extracardiac obstructive shock?
- ↑HR
- ↑JVP (w/o volume overload)
- Extremities = cool
- Lungs = dry
- SVR = ↑
Which imaging is preferred for pulmonary embolism (extracardiac obstructive shock)?
Computer Tomography Pulmonary Angiography (CTPA)
When would a V/Q scan be preferred over CTPA for diagnosing PE?
- Pt is allergic to contrast agents used in CTPA
- Renal insufficiency
- Women <40 y/o to ↓ radiation
- Pregnancy
Which degradation product of fibrin is an indirect index of clotting and has high sensitivty, but low specificity, for PE?
D-dimer
What are ECG and Echocardiogram findings associated with PE/extracardiac obstructive shock?
- ECG = S1 Q3 T3 + sinus tachycardia (most common sign)
- Echo = RV dilation w/ tricuspid regurgitation
