mechanical Ventilation Flashcards
(169 cards)
Which ventilatory strategy is recommended for ARDS to minimize ventilator-induced lung injury?
A) Low tidal volume (6 mL/kg) ventilation
B) High tidal volume (12 mL/kg) ventilation
C) No PEEP and high FiO2
D) CPAP only
Answer: A
Rationale: Low tidal volume ventilation reduces volutrauma and barotrauma in ARDS
You have a patient who is being mechanically ventilated. As the advanced practice registered nurse, you know there are different modes for managing respiratory failure. What mode would you want to use to have complete control of the patient’s breathing?
A. Pressure control
B. Pressure-regulated volume control
C. BiPAP
D. Synchronized intermittent mandatory ventilation
Correct Answer: A. Pressure control
Rationale:
In pressure control ventilation, the ventilator delivers breaths at a set pressure and fully controls the timing and volume of each breath when the patient is sedated or paralyzed. This mode is used when complete control of the patient’s breathing is necessary, ensuring that every breath is fully managed by the ventilator without any spontaneous effort interfering. Other modes, like pressure-regulated volume control, BiPAP, or SIMV, allow for patient-initiated breaths or spontaneous breathing efforts, which means they do not offer complete control over ventilation.
A patient with ARDS has a pH of 7.28 and a PaCO₂ of 60 mmHg. What is the best intervention?
A) Increase tidal volume
B) Increase respiratory rate
C) Decrease PEEP
D) Decrease FiO₂
Answer: B
Rationale: Increasing respiratory rate improves CO₂ clearance in ARDS patients with respiratory acidosis.
Which of the following is most important when initiating mechanical ventilation in ARDS?
A) High tidal volumes
B) High respiratory rate
C) Low tidal volumes with low plateau pressure
D) FiO₂ 100% at all times
Answer: C
Rationale: Low tidal volumes (6 mL/kg) reduce ventilator-induced lung injury.
A patient with severe ARDS is not improving despite lung-protective ventilation. What is the next step?
A) ECMO
B) High-dose steroids
C) Beta-blockers
D) CPAP
Answer: A
Rationale: Extracorporeal membrane oxygenation (ECMO) is used in refractory severe ARDS.
A 65-year-old man with COPD presents with hypercapnic respiratory failure (pH 7.31, PaCO₂ 65 mmHg). He is alert but in respiratory distress. Which intervention is most appropriate initially?
A) Intubate and start invasive mechanical ventilation
B) High-flow nasal oxygen
C) Noninvasive positive pressure ventilation (BiPAP)
D) IV corticosteroids alone
Answer: C
Rationale: BiPAP is often first-line for acute hypercapnic respiratory failure in a cooperative COPD patient to avoid intubation if possible.
A 58-year-old woman with cardiogenic pulmonary edema is experiencing severe dyspnea. She is conscious and hemodynamically stable but tachypneic. Which noninvasive ventilatory modality can most effectively reduce her work of breathing and improve oxygenation?
A) CPAP
B) High-flow nasal cannula
C) Mechanical ventilator with endotracheal tube
D) Nasal cannula at 6 L/min
Answer: A
Rationale: CPAP can significantly reduce preload and improve oxygenation in acute pulmonary edema by delivering continuous positive airway pressure and preventing alveolar collapse.
A 72-year-old with acute asthma exacerbation is in severe distress. He has accessory muscle use and can barely speak. Which of the following best indicates imminent need for invasive mechanical ventilation?
A) PaO₂ 60 mmHg on 2 L NC
B) Tachypnea with RR of 30 breaths/min
C) Altered mental status and rising PaCO₂
D) Bilateral wheezing on auscultation
Answer: C
Rationale: Altered mental status and rising PaCO₂ suggest impending respiratory fatigue; invasive mechanical ventilation is needed to prevent arrest.
A 55-year-old man with obstructive sleep apnea (OSA) uses a home device for nocturnal ventilation. Which setting is most typical for OSA management?
A) BiPAP with IPAP 15 cm H₂O, EPAP 5 cm H₂O
B) CPAP with fixed pressure of 8-10 cm H₂O
C) High-flow nasal oxygen at 40 L/min
D) Mechanical ventilator with tidal volume of 600 mL
Answer: B
Rationale: CPAP with a fixed continuous pressure is the standard first-line therapy for obstructive sleep apnea.
Which of the following statements best distinguishes CPAP from BiPAP?
A) CPAP provides a fixed positive pressure throughout the respiratory cycle; BiPAP provides different pressures for inspiration and expiration
B) CPAP is only used in acute settings; BiPAP is only used in chronic settings
C) CPAP is exclusively for COPD; BiPAP is exclusively for OSA
D) CPAP improves ventilation more effectively than BiPAP
Answer: A
Rationale: CPAP = one level of continuous pressure; BiPAP = two levels (IPAP for inspiration, EPAP for expiration).
A 48-year-old man with acute hypercapnic respiratory failure due to a COPD exacerbation is started on BiPAP. His initial settings are IPAP 10 cm H₂O and EPAP 5 cm H₂O. After 2 hours, his PaCO₂ has risen further. Which adjustment is most appropriate?
A) Increase EPAP from 5 to 10 cm H₂O only
B) Increase IPAP from 10 to 14 cm H₂O while slightly raising EPAP
C) Decrease IPAP to 8 cm H₂O
D) Discontinue BiPAP and switch to high-flow nasal cannula
Answer: B
Rationale: Rising PaCO₂ indicates inadequate ventilation; increasing IPAP improves ventilation (lower CO₂). Also raising EPAP slightly maintains alveolar recruitment and comfort.
A 75-year-old patient with severe pneumonia is placed on invasive mechanical ventilation. Which of the following is most crucial to prevent ventilator-associated pneumonia (VAP)?
A) Daily sedation vacations and weaning assessments
B) Routine use of broad-spectrum antibiotics
C) Maintaining supine position at 0°
D) Intermittent circuit disconnection to air-dry tubing
Answer: A
Rationale: Daily sedation vacations and spontaneous breathing trials reduce ventilation duration, lowering VAP risk. Head-of-bed elevation also helps.
An obese patient is extubated post-operatively but remains hypoventilating with hypercapnia. Which noninvasive option can help prevent re-intubation?
A) BiPAP for ventilatory support
B) High-dose intravenous diuretics
C) Low-flow nasal cannula at 2 L/min
D) T-piece weaning circuit
Answer: A
Rationale: BiPAP supports ventilation in obese patients prone to hypoventilation, often preventing re-intubation.
A 60-year-old patient with COPD on BiPAP complains of difficulty exhaling. Which parameter should be adjusted to ease expiration?
A) Increase IPAP
B) Decrease IPAP while increasing EPAP
C) Lower EPAP level
D) Increase respiratory rate setting
Answer: C
Rationale: If exhalation is difficult, EPAP may be too high. Lowering EPAP reduces resistance during expiration.
Which clinical scenario most clearly indicates the need for endotracheal intubation rather than noninvasive ventilation?
A) COPD exacerbation with mild acidosis (pH 7.33) but alert patient
B) Acute pulmonary edema with BP 190/100 mmHg
C) Severe respiratory distress with altered mental status and inability to protect airway
D) Obstructive sleep apnea patient with moderate hypercapnia
Answer: C
Rationale: Airway protection is a key indication for invasive mechanical ventilation. Altered mental status → risk of aspiration.
A 50-year-old man is being considered for mechanical ventilation due to severe pneumonia. Which factor suggests attempting noninvasive ventilation first?
A) Hemodynamic instability (BP 80/50)
B) Profound altered mental status
C) PaCO₂ of 70 mmHg, pH 7.10, GCS 6
D) Alert, cooperative, mild acidosis, rapidly rising PaCO₂
Answer: D
Rationale: Alert, cooperative patients with only mild to moderate acidosis can often benefit from a trial of noninvasive ventilation.
A nurse notes that a patient on BiPAP has a large air leak around the mask. The patient’s respiratory distress is not improving. What is the best next step?
A) Discontinue BiPAP and intubate immediately
B) Check mask fit and headgear tension; readjust as needed
C) Increase IPAP to compensate for leak
D) Switch to nasal cannula
Answer: B
Rationale: Large air leak → ineffective BiPAP. Reassessing mask fit is crucial to ensure adequate ventilation and patient comfort
A 66-year-old man has been on mechanical ventilation for 7 days due to ARDS. Which of the following is essential to prevent complications?
A) Keep sedation as deep as possible
B) Early initiation of parenteral nutrition only
C) Head-of-bed elevation to 30°–45°
D) Avoid daily weaning attempts
Answer: C
Rationale: Head-of-bed elevation helps prevent aspiration and reduces VAP risk. Minimizing sedation and daily weaning trials also improve outcomes.
A patient on BiPAP for COPD exacerbation is persistently hypercapnic with a pH of 7.20 and rising PaCO₂ after several hours. What is the most appropriate next intervention?
A) Continue BiPAP; no change
B) Increase IPAP by 2–3 cm H₂O and reassess
C) Transition to CPAP
D) Proceed with endotracheal intubation and invasive ventilation
Answer: D
Rationale: If BiPAP fails to improve ventilation, endotracheal intubation is typically required to prevent respiratory arrest.
A 30-year-old woman with acute severe asthma is noncompliant with BiPAP and remains in distress. She refuses intubation. Which approach is most appropriate?
A) Respect her refusal; continue BiPAP if tolerated
B) Sedate the patient to facilitate BiPAP compliance
C) Attempt CPAP alone
D) Arrange urgent psychiatric evaluation
Answer: A
Rationale: Patient autonomy must be respected. If the patient refuses intubation, continuing less invasive measures is appropriate unless she cannot protect her airway
A patient is on CPAP of 10 cm H₂O. He finds exhalation difficult and complains of “air hunger.” Which setting might be better?
A) Switch to BiPAP with IPAP 10 cm H₂O, EPAP 5 cm H₂O
B) Increase CPAP to 20 cm H₂O
C) Intubate for mechanical ventilation
D) Reduce CPAP to 5 cm H₂O
Answer: A
Rationale: Transitioning to BiPAP allows lower expiratory pressure than inspiratory, making exhalation easier.
Which of the following is the greatest risk when using noninvasive ventilation (BiPAP/CPAP) in a patient with severe respiratory distress?
A) Pressure ulcers on the nose
B) Ventilator-associated pneumonia
C) Claustrophobia
D) Delayed intubation leading to worse outcomes
Answer: D
Rationale: Delayed intubation is a major concern if noninvasive ventilation fails, potentially causing life-threatening compromise.
A 70-year-old with acute decompensated heart failure is placed on CPAP of 8 cm H₂O. What is the primary physiologic benefit of CPAP in this scenario?
A) Increased tidal volume delivery
B) Reduced fluid retention
C) Decreased afterload on the right ventricle
D) Reduced preload and improved alveolar recruitment
Answer: D
Rationale: CPAP reduces preload by increasing intrathoracic pressure and prevents alveolar collapse, improving oxygenation.
A nurse notices the pressure alarm on a ventilator frequently going off for high peak pressures. Which potential problem should be investigated first?
A) Ventilator circuit disconnection
B) Secretions causing increased airway resistance
C) Extubation readiness
D) Lower respiratory rate setting
Answer: B
Rationale: High peak pressures often indicate increased airway resistance, e.g., from secretions, biting the tube, or kinks in the tubing.