Physiology-Shock Flashcards Preview

Multisystems II > Physiology-Shock > Flashcards

Flashcards in Physiology-Shock Deck (20)
Loading flashcards...
1
Q

Definition of shock

A

State of inadequate tissue perfusion leading to tissue hypoxia and cell death

2
Q

A child presents with T: 38, RR > 20, HR > 90 and WBC > 12,000. CXR is shown below. Blood cultures and sputum cultures are positive for gram + bacteria. What is causing his condition?

A

Septic shock. This is caused by local infection that then becomes bacteremic leading to sepsis (SIRS: systemic inflammatory response to infection) and shock. Note that septic shock kills 1/5 people.

3
Q

Two most common nidus of infection that leads to septic shock?

A

Pneumonia and urinary tract infections.

4
Q

What physiologic changes happen in the body as it moves from localized immune reaction to systemic inflammatory response (SIRS)?

A

Endogenous mediators and exotoxins cause massive vasodilation, myocardial depression, acidosis and organ dysfunction that leads to hypoperfusion and multiple organ failure.

5
Q

Who gets septic shock?

A

Immunocompromised (diabetics, transplants, splenectomy, IV drug users, end-stage renal disease) and extremes of age.

6
Q

Tx of septic shock

A

Antibiotics as early as possible (broad-spectrum to start with). Early oxygen, early intubation and transfusion if necessary. Fluids to increased central venous pressure (CVP). Give vasoactive agents to increase mean arterial pressure (MAP).

7
Q

Why shouldn’t you rely on BP alone as a measure to see if someone has hemorrhagic shock?

A

People can lose up to 40% of blood volume before their blood pressure is decreased.

8
Q

Tx of hemorrhagic shock

A

Find the bleeding and stop the bleeding. Check 5 areas: chest, abdomen, pelvis, femurs and extremities. Reverse coagulopathies (warfarin, ASA), replace blood products.

9
Q

Why don’t you give crystalloid fluids to someone in hemorrhagic shock? When do you replace with crystalloid fluids?

A

You are going to dilute the remaining clotting factors they have if you do it. You always want to replace fluids with blood. You replace fluids in hypovolemic shock.

10
Q

Most common causes of death from anaphylactic shock?

A

1) Antibiotics (especially beta-lactams) 2) Insects 3) Food (shellfish and nuts)

11
Q

Physiology of anaphylaxis

A

Airway is compromised and hypotension induced by IgE-mediated degranulation mast cells and basophils. Degranulation and release of mediators causes diffuse urticaria, angioedema, abdominal pain, bronchospasm, rhinorrhea, conjunctivitis and hypotension.

12
Q

Non-IgE mediated reaction that has the same common pathway as anaphylaxis

A

Anaphylactoid reaction, no sensitizing exposure is required.

13
Q

Tx of anaphylaxis

A

Epinephrine (0.1mg IV or 0.3-0.5mg IM, give lower dose IV), there are no absolute contraindications. Airway intubation soon. Fluid resuscitation for hypotension. Steroids to halt inflammatory cascade (may take 6+ hours to work). Antihistamines (H1 & H2 blockers to control wheezing/rash). Albuterol (bronchospasms). Glucagon (to prevent inactivation of therapy if they are on beta-blockers)

14
Q

Physiology of neurogenic shock

A

Usually from c-spine blunt trauma that injures T1-L2 sympathetic nerve roots leading to unopposed VAGAL tone. This causes hypotension and bradycardia.

15
Q

How is neurogenic shock different from spinal shock?

A

In spinal shock you lose spinal reflex activity at or below the injury level. Neurogenic shock is referring to the systemic symptoms of unopposed vagal outflow.

16
Q

Tx for neurogenic shock

A

1) Assume hemorrhagic shock 2) Prevent secondary cord injury 3) Fluids 4) Vasopressors (phenylephrine)

17
Q

Most frequent cause of cardiogenic shock

A

MI that results in decreased cardiac output despite adequate volume leading to tissue hypoperfusion. Note that this can also happen with decompensated CHF, myocarditis, sepsis, chordae tendinae rupture and toxins.

18
Q

Diagnosing cardiogenic shock

A

EKG, Echo, CXR, labs and monitoring.

19
Q

Compare the central venous pressure, fluids and extremities in septic, hemorrhagic, anaphylactic, neurogenic and cardiogenic shock.

A

*

20
Q

How effective are pressors in treatment of shock?

A

They do not improve meaningful outcomes, except for with anaphylaxis.