CRIT CARE/RESPIRATORY FAILURE Flashcards
A 65-year-old patient with sepsis develops severe hypoxemia and a PaO2/FiO2 ratio of 150. A chest X-ray reveals diffuse infiltrates. What type of respiratory failure does this patient most likely have?
A) Type I: Acute hypoxemic respiratory failure
B) Type II: Hypercapnic respiratory failure
C) Type III: Lung atelectasis
D) Type IV: Respiratory failure due to shock
Type I: Acute hypoxemic respiratory failure
- Type I respiratory failure occurs in clinical settings such as sepsis, gastric aspiration, pneumonia, COVID-19, near-drowning, multiple blood transfusions, and pancreatitis
A 55-year-old male with chronic obstructive pulmonary disease (COPD) is admitted with acute respiratory failure. He is unable to eliminate carbon dioxide, and his PaCO2 level rises significantly. Which type of respiratory failure does this patient most likely have?
A) Type I: Acute hypoxemic respiratory failure
B) Type II: Hypercapnic respiratory failure
C) Type III: Lung atelectasis
D) Type IV: Respiratory failure due to shock
Type II: Hypercapnic respiratory failure
During a spontaneous breathing trial (SBT), a patient begins to exhibit a respiratory rate >35/min for over 5 minutes. What should be done next?
A) Continue the SBT for another 30 minutes
B) Increase the pressure support to facilitate breathing
C) Stop the SBT and reassess the patient’s readiness for extubation
D) Administer sedatives to decrease respiratory rate
Stop the SBT and reassess the patient’s readiness for extubation
- Spontaneous breathing trial is declared a failure and stopped if any of the following occur:
- 1) respiratory rate >35/min for >5 min
- (2) O2 saturation <90%
- (3) heart rate >140/min or a 20% increase or decrease from baseline
- (4) systolic blood pressure <90 mmHg or >180 mmHg,
- (5) increased anxiety or diaphoresis
A 45-year-old male in shock develops respiratory failure due to hypoperfusion of respiratory muscles. What is the primary factor contributing to his respiratory distress?
A) Increased cardiac output leading to pulmonary edema
B) Hypoperfusion of the respiratory muscles
C) Acute lung injury from mechanical ventilation
D) Severe anemia
Hypoperfusion of the respiratory muscles
- Normally, respiratory muscles consume <5% of total cardiac output and oxygen delivery
- Patients in shock often experience respiratory distress due to pulmonary edema (e.g., in cardiogenic shock), lactic acidosis, and anemia.
- up to 40% of cardiac output may be distributed to the respiratory muscles.
Which of the following is a primary cause of Type I (acute hypoxemic) respiratory failure?
A) Drug overdose
B) Guillain-Barré syndrome
C) Acute Respiratory Distress Syndrome (ARDS)
D) Myasthenia gravis
Answer: C) Acute Respiratory Distress Syndrome (ARDS)
Rationale: Type I respiratory failure results from ventilation-perfusion mismatch and intrapulmonary shunting, which are common in ARDS, pneumonia, and pulmonary edema. The other options primarily cause Type II respiratory failure.
What is the hallmark pathophysiologic mechanism in Type II (hypercapnic) respiratory failure?
A) Alveolar flooding
B) Ventilation-perfusion mismatch
C) Alveolar hypoventilation
D) High-altitude hypoxia
Answer: C) Alveolar hypoventilation
Rationale: Type II respiratory failure is due to inadequate alveolar ventilation, leading to CO₂ retention. Causes include CNS depression, neuromuscular disorders, and increased respiratory loads.
Which of the following conditions is NOT a typical cause of Type I respiratory failure?
A) Near-drowning
B) COVID-19 pneumonia
C) Drug overdose
D) Sepsis
Answer: C) Drug overdose
Rationale: Drug overdose causes respiratory depression and hypoventilation, leading to Type II respiratory failure, not Type I. Type I failure results from disorders causing alveolar flooding and V/Q mismatch.
Which of the following ventilatory strategies has been shown to reduce mortality in ARDS patients?
A) High tidal volume (12 mL/kg) ventilation
B) Low tidal volume (6 mL/kg) ventilation
C) Routine neuromuscular blockade
D) Liberal fluid management
Answer: B) Low tidal volume (6 mL/kg) ventilation
Rationale: Low tidal volume ventilation reduces ventilator-induced lung injury (volutrauma) and has been shown to improve survival in ARDS patients.
Prone positioning is most beneficial in which group of patients?
A) Mild COVID-19 pneumonia
B) Severe ARDS
C) Postoperative atelectasis
D) Chronic obstructive pulmonary disease (COPD)
Answer: B) Severe ARDS
Rationale: Prone positioning improves oxygenation and reduces mortality in severe ARDS by optimizing lung recruitment and reducing ventilation-perfusion mismatch.
Which condition can lead to Type III (perioperative) respiratory failure?
A) Pulmonary embolism
B) Myasthenia gravis
C) Postoperative atelectasis
D) Opioid overdose
Answer: C) Postoperative atelectasis
Rationale: Type III respiratory failure occurs due to atelectasis, often seen in the perioperative period due to reduced functional residual capacity after anesthesia.
In patients with ARDS, what is the effect of excessive tidal volumes during mechanical ventilation?
A) Prevention of atelectasis
B) Increased alveolar recruitment
C) Ventilator-induced lung injury (volutrauma)
D) Improved oxygenation
Answer: C) Ventilator-induced lung injury (volutrauma)
Rationale: High tidal volumes overstretch alveoli, causing lung injury. A lung-protective strategy with low tidal volumes is recommended.
Which of the following patients is most at risk for developing Type II respiratory failure?
A) A patient with sepsis-induced ARDS
B) A patient with Guillain-Barré syndrome
C) A patient with massive pulmonary embolism
D) A patient with pulmonary edema
Answer: B) A patient with Guillain-Barré syndrome
Rationale: Guillain-Barré syndrome can cause respiratory muscle weakness, leading to hypoventilation and CO₂ retention characteristic of Type II respiratory failure.
Type IV respiratory failure is primarily associated with:
A) Alveolar collapse
B) Shock and metabolic acidosis
C) Ventilation-perfusion mismatch
D) Increased respiratory drive
Answer: B) Shock and metabolic acidosis
Rationale: Type IV respiratory failure results from inadequate oxygen delivery to respiratory muscles due to shock or severe metabolic acidosis.
Which of the following is the primary physiologic disturbance in distributive shock?
a) Increased systemic vascular resistance (SVR)
b) Reduced systemic vascular resistance (SVR)
c) Decreased cardiac output (CO)
d) Increased central venous pressure (CVP)
Answer: b) Reduced systemic vascular resistance (SVR)
Rationale: Distributive shock is characterized by a profound decrease in SVR, leading to inadequate tissue perfusion.
The most common cause of distributive shock is:
a) Anaphylaxis
b) Spinal cord injury
c) Sepsis
d) Adrenal insufficiency
Answer: c) Sepsis
Rationale: Sepsis is the leading cause of distributive shock due to the dysregulated host response to infection.
A hallmark of cardiogenic shock is:
a) Reduced pulmonary capillary wedge pressure (PCWP)
b) Elevated systemic vascular resistance (SVR)
c) Decreased systemic vascular resistance (SVR)
d) Increased venous pooling
Answer: b) Elevated systemic vascular resistance (SVR)
Rationale: Cardiogenic shock leads to compensatory vasoconstriction, increasing SVR.
What is the primary hemodynamic abnormality in hypovolemic shock?
a) Decreased cardiac output (CO)
b) Increased pulmonary capillary wedge pressure (PCWP)
c) Increased central venous pressure (CVP)
d) Decreased systemic vascular resistance (SVR)
Answer: a) Decreased cardiac output (CO)
Rationale: Hypovolemic shock results from reduced preload, leading to decreased cardiac output.
Which type of shock is primarily due to mechanical obstruction impairing cardiac output?
a) Hypovolemic shock
b) Distributive shock
c) Cardiogenic shock
d) Obstructive shock
Answer: d) Obstructive shock
Rationale: Obstructive shock occurs due to external factors like tension pneumothorax, cardiac tamponade, or pulmonary embolism.
Which of the following is a key feature differentiating septic shock from hypovolemic shock?
a) Decreased cardiac output
b) Increased pulmonary capillary wedge pressure
c) Decreased systemic vascular resistance
d) Increased central venous pressure
Answer: c) Decreased systemic vascular resistance
Rationale: Septic shock is characterized by profound vasodilation, leading to decreased SVR.
In hypovolemic shock, which parameter is typically decreased?
a) Systemic vascular resistance
b) Pulmonary capillary wedge pressure
c) Heart rate
d) Hematocrit
Answer: b) Pulmonary capillary wedge pressure
Rationale: Hypovolemic shock results from reduced preload, leading to decreased PCWP.
Which type of shock is characterized by decreased central venous pressure (CVP), decreased pulmonary capillary wedge pressure (PCWP), and increased cardiac output?
a) Hypovolemic shock
b) Cardiogenic shock
c) Distributive shock
d) Obstructive shock
Answer: c) Distributive shock
Rationale: Distributive shock is the only type characterized by a compensatory increase in cardiac output along with decreased CVP and PCWP due to systemic vasodilation.
A patient in cardiogenic shock would most likely exhibit which of the following hemodynamic patterns?
a) Decreased CVP, decreased PCWP, increased cardiac output, increased SVR
b) Increased CVP, increased PCWP, decreased cardiac output, increased SVR
c) Increased CVP, decreased PCWP, increased cardiac output, decreased SVR
d) Decreased CVP, decreased PCWP, decreased cardiac output, increased SVR
Answer: b) Increased CVP, increased PCWP, decreased cardiac output, increased SVR
Rationale: Cardiogenic shock results from heart failure, leading to increased pressures in the heart (CVP and PCWP) with a compensatory rise in SVR to maintain perfusion.
Which of the following shock types is associated with increased central venous pressure (CVP) and increased pulmonary capillary wedge pressure (PCWP)?
a) Distributive shock
b) Hypovolemic shock
c) Obstructive shock
d) Cardiogenic shock
Answer: d) Cardiogenic shock
Rationale: In cardiogenic shock, the failing heart leads to congestion and increased filling pressures, reflected by elevated CVP and PCWP.
A patient with obstructive shock due to a massive pulmonary embolism is most likely to exhibit which hemodynamic changes?
a) Increased CVP, increased PCWP, decreased cardiac output, increased SVR
b) Increased CVP, normal or increased PCWP, decreased cardiac output, increased SVR
c) Decreased CVP, decreased PCWP, increased cardiac output, decreased SVR
d) Decreased CVP, decreased PCWP, decreased cardiac output, increased SVR
Answer: b) Increased CVP, normal or increased PCWP, decreased cardiac output, increased SVR
Rationale: Pulmonary embolism obstructs right heart outflow, leading to increased CVP, variable PCWP (depending on right versus left heart involvement), decreased cardiac output, and compensatory SVR elevation.
Which type of shock is distinguished by both decreased central venous pressure (CVP) and decreased pulmonary capillary wedge pressure (PCWP), along with decreased cardiac output?
a) Cardiogenic shock
b) Distributive shock
c) Hypovolemic shock
d) Obstructive shock
Answer: c) Hypovolemic shock
Rationale: Hypovolemic shock results from decreased intravascular volume, leading to lower preload, reflected in decreased CVP and PCWP, along with a decrease in cardiac output.
