Critical Care: Treatment of Shock

Question 1

List four hemodynamic subsets of shock

Answer 1

1. Distributive or vasodilatory
2. Hypovolemic
3. Obstructive
4. Cardiogenic

Question 2

What three hemodynamic parameters are used in the diagnosis of shock

Answer 2

1. Cardiac index (CI)
2. Central Venous Pressure/Pulmonary Capillary Wedge Pressure
3. Systemic Vascular Resistance

Question 3

What are the diagnostic hemodynamic paramters for distributive or vasodilatory shock

Answer 3

1. High CI (early) and low CI (late)
2. Low CVP/PCWP (early) and normal to high CVP/PCWP (late)
3. Low SVR (early and late)

Question 4

Describe distributive or vasodilatory shock using hemodynamic parameters

Answer 4

1. Patients with distributive shock are typically hyperdynamic (high CI, due to increased HR) with
2. vasodilation (low SVR) and increased vascular permeability (“leaky capillaries”),
3. causing intravascular fluid shift into the interstitial spaces (thus, low PCWP.)
4. The vasodilation and vascular permeability are attributable to cytokines and inflammatory mediators.

Question 5

Describe hypovolemic shock using hemodynamic parameters

Answer 5

1. As illustrated with Starling curves, as intravascular volume is reduced, preload is reduced, causing decreased CI.
2. The reduced intravascular volume is indicated by a low PCWP.
3. There is a reflex increase in SVR to maintain tissue perfusion.

Question 6

What are the diagnostic hemodynamic parameters for hypovolemic shock?

Answer 6

1. Low CI
2. Low CVP/PCWP
3. High SVR

Question 7

What are the diagnostic hemodynamic parameters of obstructive shock?

Answer 7

1. Low CI
2. Low/High PCWP, i.e. LV preload.
3. High SVR

Question 8

Why can CVP be high or low in obstructive shock ?

Answer 8

1. Obstructive shock is a diagnosis of two disparate etiologies (i.e. pulmonary embolism and tamponade.)
2. Pulmonary embolism, tumors, acute worsening of pulmonary HTN, etc. cause right ventricular failure. This leads to decreased LV preload. (low PCWP)
3. In tamponade, there is an increased PCWP due to right atrial pressure from the tamponade compressing the atrium.

Question 9

What are the diagnostic hemodynamic parameters in cardiogenic shock?

Answer 9

1. Low CI
2. High CVP/PCWP
3. High SVR

Question 10

Describe cardiogenic shock in terms of hemodynamic parameters

Answer 10

1. Patients with cardiogenic shock have acute heart failure (low CI)
2. The insufficient forward blood flow causes venous congestion (high PCWP) and an underfilled arterial blood volume.
3. The subsequent reduced tissue perfusion causes a reflex vasoconstriction (high SVR.) and reduced renal excretion of sodium and water. Although it can improve blood flow to vital organs, can worsen heart function by increasing afterload.

Question 11

Treatment of hypovolemic shock focuses on what two aspects?

Answer 11

1. Restoring pressure

2. Restoring oxygen-carrying capacity

Question 12

What are two interventions in hypovolemic shock to restore pressure?

Answer 12

1. Volume resuscitation

2. Vasopressors

Question 13

When are blood products indicated in patients with hypovolemic shock in the general ICU?

Answer 13

Hgb less than 7 g/dL

Question 14

When might higher Hgb targets be permissible in patients with hypovolemic shock?

Answer 14

If they are indicated for other reasons, e.g. for patients with symptomatic cardiovascular disease needing a target greater than 10 g/dL

Question 15

When should blood products be given to patients with hypovolemic shock that are actively bleeding?

Answer 15

Actively bleeding patients should have blood products administered regardless of hemoglobin concentration in conjunction with interventions to stop the source of bleeding

Question 16

When should vasopressors be given to patients with hypovolemic shock?

Answer 16

Patients may need vasopressors if hypotension is not rapidly reversed with fluid resuscitation

Question 17

Two reasons why do you not give vasopressors to patients with intravascular volume depletion

Answer 17

1. The efficacy of vasopressors is reduced in patients who have not received adequate intravascular volume resuscitation
2. Adverse events associated with vasopressors (e.g. arrhythmias, ischemia) are greater in patients who have not received adequate fluid resuscitation.

Question 18

In obstructive shock, how can you temporarily improve symptoms without reversing the shock state?

Answer 18

1. Fluids
2. Vasopressors
3. can be used to temporarily improve end organ perfusion, but may not improve outcomes

Question 19

How to reverse shock state in patients with obstructive shock?

Answer 19

Treatment of the actual obstruction

Question 20

Obstructive shock: how to treat pulmonary embolism?

Answer 20

1. Thrombectomy

2. Administration of systemic or catheter-directed thrombolytics

Question 21

In what patients are thrombolytics used for treatment of pulmonary embolism?

Answer 21

Patients at high risk of death (due to risk of hemorrhage)

Question 22

Obstructive shock: how to treat pulmonary embolism?

Answer 22

Drainage or removal of fluid in the pericardial sac is the only definitive treatment

Question 23

What is the most common cause of vasodilatory shock?

Answer 23

Septic shock

Question 24

List 7 causes of distributive or vasodilatory shock

Answer 24

1. Septic shock
2. Anaphylaxis
3. vasoplegia
4. intoxication
5. pancreatitis
6. neurogenic
7. endorine

Question 25

Define sepsis

Answer 25

Life-threatening organ dysfunction caused by a dysregulated host response to infection

Question 26

Define septic shock

Answer 26

Septic shock is a subset of sepsis in which profound circulatory, cellular and metabolic abnormalities are associated with a greater risk of mortality than with sepsis alone

Question 27

Criteria for sepsis is split into two categories, which are

Answer 27

1. Outside the ICU | 2. Inside the ICU

Question 28

What is the definition of sepsis outside the ICU?

Answer 28

1. Infection PLUS | 2. Two or more qSOFA points

Question 29

What is the definition of sepsis inside the ICU?

Answer 29

1. Infection PLUS | 2. An acute change in total SOFA score greater than or equal to 2 points consequent to the infection

Question 30

What are the three items on the qSOFA?

Answer 30

1. Altered mental status (GCS score less than 15) 2. Increased respiratory rate (22 breaths/min or more) 3. SBP less than or equal to 100 mm Hg

Question 31

What is the criteria for septic shock?

Answer 31

1. Sepsis PLUS 2. Need for vasopressors to maintain MAP greater than or equal to 65 mm Hg 3. and lactate greater than 2 mmol/L.

Question 32

What is the hallmark treatment of septic shock?

Answer 32

Rapid antibiotic administration ideally within the first 1 hour of hypotension

Question 33

What is the surviving sepsis campaign (SSC)?

Answer 33

An initiative to reduce mortality from sepsis and septic shock

Question 34

What is the SSC bundle (in general)

Answer 34

A group of selected elements of care taken from evidence-based practice guidelines that when implemented as a group have a greater effect on outcomes than any individual element.

Question 35

List six components of the SSC 1-hour bundle

Answer 35

1. Measure lactate 2. Obtain blood cultures 4. Crystalloids 6. Reassess volume status and perfusion 3. Administer appropriate antibiotics 5. Vasopressors

Question 36

How much crystalloid should be administered to a patient with sepsis?

Answer 36

30 ml/kg rapidly infused (e.g. over an hour)

Question 37

What colloid is not recommended for fluid resuscitation because of an increased risk of acute kidney injury?

Answer 37

Hydroxyethyl starches (e.g. hetastarch)

Question 38

Administration of large volumes of chloride-rich solutions leads to metabolic ______ and acute kidney injury

Answer 38

1. Metabolic acidosis | 2. Acute kidney injury

Question 39

List two "balance crystalloids" which may protect the kidneys from injury compared to NS

Answer 39

1. lactated Ringer | 2. Plasmalyte

Question 40

When to reassess volume status and tissue perfusion in sepsis?

Answer 40

1. Persistent arterial hypotension despite volume resuscitation OR 2. Initial lactate 4 mmol/L or more

Question 41

What five items should be included on a repeated focused examination of volume status and tissue perfusion?

Answer 41

1. vital signs 2. cardiopulmonary examination 3. capillary refill 4. pulse 5. skin findings

Question 42

In the SSC bundle, what _ of the following should be performed to measure volume status and tissue perfusion

Answer 42

1. Two 2. CVP measurement 3. Scvo2 measurement 4. Bedside cardiovascular ultrasound 5. Dynamic assessment of fluid responsiveness with passive leg raise or fluid challenge