EM E1: Shock

What is shock?

circulatory insufficiency that creates imbalance btwn tissue O2 supply and O2 demand → hypoperfusion, dec venous oxygen, metabolic (lactic) acidosis

What is hypovolemic shock?

loss of blood volume or fluids from the blood

What is dissociative shock?

dec ability to carry O2 to the tissues

What is distributive -neurogenic shock?

loss of control over the dilation and contraction of blood vessels which lead to dec BP

What is distributive -anaphylactic shock?

massive release of histamine and redistribution of blood/fluid from core to surface

What is distributive -septic shock?

dec volume and/or inability of blood to carry oxygen to the tissue secondary to infection and/or toxins

What is distributive -psychogenic shock?

temporary dec of circulating blood to the brain

What is mechanical -cardiogenic shock?

impaired function of the heart preventing effective circulation

What is mechanical -obstructive shock?

physical obstruction within the heart or great vessels

Do you use bicarbonate in the tx of acidosis from shock?

No -may worsen the acidosis

What is the primary treatment of acidosis in shock?

reverse the underlying cause

How might significant acute hemorrhage induced hypovolemia present?

tachycardia, hypotension, narrow pulse pressure, AMS, signs of poor peripheral perfusion (cool, pale, clammy extremities w/ weak pulses and prolonged cap refill)

What are the 3 goals of hypovolemic/hemorrhagic shock tx?

maximize oxygen delivery, control further blood loss, fluid resuscitation

What blood transfusion is given in an acute setting?

1-2 units type O Rh-

What transfusion is given for massive hemorrhage?

FFP + plt transfusion to reverse coagulopathy

What will pts receiving > 8-10 units of blood also require?

replacement clotting factors w/ infusion of FFP + plt transfusion

What is the presence of infection associated with meeting SIRS criteria?

Sepsis

What is the presence of infection in association with SIRS criteria + evidence of end-organ dysfunction?

(AMS, hypotension, inc cr, DIC)

Severe sepsis

What is persistent hypotension despite adequate fluid resuscitation or tissue hypoperfusion manifested by a lactate > 4 mg/dL?

Septic shock

SIRS criteria:

(need 2 or more)

Temp: < 36C (96.8F) or > 38C (100.4F)

HR: >90 bpm

RR: >20 breaths/min

PaCO2: <32 mmHg

WBC: >12,000 or <4,000 or >10% bands

What criteria helps identify sepsis but is falling out of favor bc many non septic pts meet the criteria?

SIRS

Does an inc in WBC = infectious process?

NO -can be d/t steroids, trauma, idiopathic, stress, pregnancy, medications, leukemias, allergies, etc

What are the 2 most commonly used classifications for identification of early sepsis?

qSOFA & NEWS2

qSOFA criteria:

(> 2 = high risk of poor outcome)

AMS: GCS < 15

RR: > 22

SBP: < 100 mmHg

Review NEWS scoring system

*slide 29

0-4 low risk

5-6 medium risk

7+ high risk

What is the most frequent cause of sepsis?

respiratory tract infections & UTIs

*followed by abd infxn and soft tissue infxn

What typically causes nosocomial-acquired sepsis?

use of intravascular devices

What disease states predispose you to sepsis?

malignancies, DM, chronic liver disease, chronic renal failure, immunosuppression

What pts are at a high risk for polymicrobial sepsis*?

*becoming more prevalent

pts w/ neutropenia

How does sepsis present?

fever, tachycardia, inc RR, AMS

What is a very common presentation of sepsis in the elderly?

AMS

What are the 4 steps in tx of sepsis?

1. Blood cultures before Abx

2. Lactate

3. IV Abx before 60 minutes

4. 30 mL/kg of IV fluids before 180 minutes

• re-eval pt and document

What is the MC initiating event of cardiogenic shock?

AMI

How does cardiogenic shock present?

sustained hypotension, hypoperfusion, AMS, JVD, cardiac gallop, pulm edema, tachycardia

What are signs of acute cardiac ischemia?

CP, SOB, diaphoresis, N/V, ± syncope

In children, what is cardiogenic shock more likely d/t?

preceding viral infection > myocarditis

What is the role of ED care in cardiogenic shock tx?

making dx, preventing further ischemia, tx underlying cause

How soon should PCI should be administered?

w/in 90 minutes of cardiogenic shock presentation

What should be initiated for cardiogenic shock tx if PCI/CABG are not available?

thrombolytics

*NOT 1st line

What is the MCC of anaphylaxis in children?

food

What is anaphylaxis?

severe systemic hypersensitivity reaction

What agents commonly cause anaphylaxis?

abx (PCN, sulfa), NSAIDs, IV contast, stings, foods (nuts, shellfish)

How does the "classic" anaphylaxis pathway work?

requires 2 separate exposures to either an antigen or a hapten-protein antigenic complex

-sensitization; CANNOT be allergic the 1st time you try something

What is an anaphylactoid rxn?

exposure to inciting substance causes direct release of mediators

*NOT IgE mediated

Which is mediated by IgE: Anaphylaxis or Anaphylactoid reaction

Anaphylaxis

What is the classic presentation of anaphylaxis?

pruritis, cutaneous flushing, urticaria, sense of fullness in throat, anxiety, chest tightness, SOB, lightheaded

What is the MCC of death in anaphylaxis?

complete airway obstruction

What is the most important part anaphylaxis tx?

maintain a patent airway

What pts may be resistant to the effects of epi in the tx of anaphylaxis?

pts on BBs → give larger doses or give Glucagon

What is neurogenic shock characterized by?

hypotension and bradycardia

What is hypovolemic/hemorrhagic shock characterized by?

hypotension and tachycardia

What causes neurogenic shock?

acute spinal cord injury that disrupts sympathetic outflow; usually above T6

What helps differentiate neurogenic shock from other forms of shock?

skin remains warm & dry

The (higher/lower) the injury, the more likely or more severe the resulting neurogenic shock

Higher

An injury at what level is capable of disrupting the spinal tracts that control the entire sympathetic system?

above T1

What is the tx of neurogenic shock?

ABCDEs

correct hypotension & bradycardia

neuro consult

Why should you be careful when tx neurogenic shock?

careful d/t danger of excessive fluid (can cause HF/pulm edema)

Atropine can be used for bradycardia