mechanical Ventilation Flashcards
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.
A COPD patient on BiPAP is found to have a pH of 7.50, PaCO₂ of 30 mmHg, and persistent tachypnea. What might be excessive?
A) IPAP setting
B) Oxygen flow rate
C) EPAP setting
D) Respiratory rate trigger
Answer: A
Rationale: Overventilation causing respiratory alkalosis suggests IPAP might be too high, blowing off CO₂ excessively.
A 62-year-old with ARDS is sedated and intubated. To avoid barotrauma, which ventilator strategy is recommended?
A) High tidal volume (10-12 mL/kg)
B) Low tidal volume (6 mL/kg) and PEEP
C) Zero PEEP
D) Mandatory RR of 30 breaths/min.
Answer: B
Rationale: Low tidal volume ventilation plus adequate PEEP is standard to reduce lung injury in ARDS
A patient on mechanical ventilation has a sudden drop in SpO₂ to 80% and high-pressure alarms. Which of the following emergency steps is most appropriate?
A) Remove the patient from the ventilator and bag with 100% O₂
B) Lower the PEEP setting
C) Administer diuretics
D) Increase sedation
Answer: A
Rationale: Disconnect from ventilator, bag-valve with 100% O₂ can quickly differentiate ventilator issue vs. patient problem.
Which of the following is a common complication of prolonged noninvasive ventilation (BiPAP/CPAP)?
A) Ventilator-associated pneumonia
B) Sinusitis and nasal skin breakdown
C) Pulmonary fibrosis
D) Tracheal stenosis
Answer: B
Rationale: Nasal mask pressure injuries, sinusitis, or dryness can occur with prolonged noninvasive ventilation use.
In a mechanically ventilated patient, what does an elevated plateau pressure (with normal peak pressure) typically indicate?
A) Increased airway resistance (bronchospasm)
B) Kinked ventilator tubing
C) Decreased chest wall compliance or stiff lungs
D) Patient coughing during inspiratory phase
Answer: C
Rationale: High plateau pressure suggests decreased lung/chest compliance, such as fibrosis, edema, or chest wall rigidity.
A patient with acute hypoxemic respiratory failure is started on CPAP at 5 cm H₂O. Oxygenation improves, but the patient complains of “air hunger.” Which adjustment may help?
A) Increase CPAP to 10 cm H₂O
B) Decrease CPAP to 2 cm H₂O
C) Discontinue CPAP and place on nasal cannula
D) Intubate immediately
Answer: A
Rationale: Increasing CPAP can improve alveolar recruitment and reduce the sensation of “air hunger” in hypoxemic respiratory failure.
A 68-year-old man on a ventilator has frequent “fighting the vent” episodes. Which strategy is best before escalating sedation?
A) Lower the respiratory rate drastically
B) Assess for pain, discomfort, or secretions
C) Increase mandatory tidal volume
D) Switch from volume control to pressure control
Answer: B
Rationale: Patients may “fight the vent” due to pain, anxiety, or airway secretions. Address these first before deeper sedation.
What is the primary reason for setting a backup respiratory rate in BiPAP?
A) Ensure mandatory breaths if the patient becomes apneic
B) Increase oxygenation
C) Reduce alveolar dead space
D) Improve sputum clearance
Answer: A
Rationale: The backup RR ensures ventilation if the patient stops triggering breaths spontaneously.
A patient on BiPAP is found to have a persistent leak around the mask. His respiratory rate is 35 breaths/min, and he’s struggling. Which factor might be contributing most?
A) Excessive sedation
B) Claustrophobia or poor mask fit
C) IPAP too low
D) Intolerance to PEEP
.
Answer: B
Rationale: Poor mask fit or patient distress causes air leak and high RR. A well-fitted mask and addressing comfort are critical
A 75-year-old man with hypercapnic respiratory failure on BiPAP has improved ABGs. Which step is most appropriate for potential weaning?
A) Stop BiPAP abruptly
B) Trial CPAP during daytime
C) Switch to 100% non-rebreather mask
D) Intubate and reduce ventilator settings
Answer: B
Rationale: Transitioning from BiPAP to a CPAP trial or lower IPAP/EPAP is a common weaning approach in stable patients.
Which of the following best describes the difference between IPAP and EPAP in BiPAP?
A) IPAP is for oxygenation; EPAP is for ventilation
B) IPAP controls inspiratory flow for ventilation; EPAP prevents alveolar collapse for oxygenation
C) IPAP and EPAP must always be identical
D) IPAP and EPAP have no influence on CO₂ removal
Answer: B
Rationale: IPAP (inspiratory) primarily affects ventilation (CO₂ removal); EPAP (expiratory) helps maintain alveolar patency (oxygenation).
- Noninvasive Ventilation (NIV)
is often first-line for hypercapnic respiratory failure in COPD or mild to moderate acute respiratory failure if the patient can protect their airway
BiPAP
= two pressures (IPAP & EPAP).
= one pressure throughout the respiratory cycle;
CPAP
inability to protect airway, altered mental status, severe acidosis, or hemodynamic instability.
Indications for Intubation include
A 55-year-old man with acute COPD exacerbation is placed on noninvasive positive pressure ventilation (NIV). After 2 hours, his PaCO₂ has not improved, and he is becoming lethargic. Which action is most appropriate?
A) Increase IPAP by 2 cm H₂O and reassess
B) Switch to high-flow nasal oxygen
C) Intubate and start invasive mechanical ventilation
D) Continue current BiPAP settings for 2 more hours
Answer: C
Rationale: Worsening hypercapnia (rising CO₂) and lethargy indicate respiratory failure despite NIV. Endotracheal intubation is needed to prevent further deterioration.
Preventing Complications (e.g., VAP, barotrauma, pressure injuries)
is crucial with both invasive and noninvasive ventilation.
Weaning Strategies (daily sedation breaks, spontaneous breathing trials)
help reduce duration on mechanical support.
A 62-year-old man in the ICU is on mechanical ventilation for pneumonia. He has a sudden rise in peak inspiratory pressure and the “high-pressure” alarm is activated. Which of the following is the most likely cause?
A) Ventilator circuit disconnection
B) Leaking endotracheal cuff
C) Excessive sedation
D) Mucous plug or kinked endotracheal tube
Answer: D
Rationale: A sudden increase in peak inspiratory pressure typically indicates an obstruction (secretions, kinks in tubing) or patient “fighting” the ventilator
A patient with CHF is on CPAP at 10 cm H₂O. Oxygen saturation is stable at 94%, but he complains of difficulty exhaling. Which strategy might help?
A) Increase CPAP to 14 cm H₂O
B) Switch to BiPAP with IPAP 12 cm H₂O, EPAP 5 cm H₂O
C) Place the patient on a T-piece trial
D) Lower the bed to flat position
Answer: B
Rationale: Transitioning to BiPAP provides lower expiratory pressure (EPAP) than CPAP, easing exhalation while still supporting inspiratory effort.
A 70-year-old post-operative patient has been on mechanical ventilation for 4 days. To reduce the risk of ventilator-associated pneumonia (VAP), which measure is most essential?
A) Administer prophylactic IV antibiotics
B) Maintain deep sedation for comfort
C) Elevate the head of the bed 30°–45°
D) Change the ventilator circuit daily
Answer: C
Rationale: Head-of-bed elevation (30°–45°) significantly reduces aspiration risk and is a key measure in preventing VAP.
Which of the following indicates the greatest urgency for endotracheal intubation rather than noninvasive ventilation?
A) Patient with COPD exacerbation, cooperative, pH 7.32
B) Patient with ARDS, awake, FiO₂ 0.4, SpO₂ 92%
C) Patient with severe pneumonia, altered mental status, and inability to protect airway
D) Patient with pulmonary edema, BP 150/90 mmHg
Answer: C
Rationale: Altered mental status and airway protection issues are absolute indications for invasive mechanical ventilation.
A 60-year-old man is intubated for hypoxemic respiratory failure. The peak inspiratory pressure is 24 cm H₂O, while the plateau pressure is only 18 cm H₂O. What does this difference most likely imply?
A) Chest wall stiffness
B) Increased airway resistance
C) Abdominal hypertension
D) Decreased lung compliance
Answer: B
Rationale: A large gap between peak pressure and plateau pressure usually indicates high airway resistance (bronchospasm, secretions) rather than lung/chest wall compliance issues.
A 48-year-old man on BiPAP complains of claustrophobia and pulls off the mask repeatedly. His respiratory rate is rising, and CO₂ is trending upward. What is the best next step?
A) Continue BiPAP despite distress
B) Switch to CPAP
C) Provide anxiolytic sedation if safe and reattempt BiPAP
D) Intubate immediately
Answer: C
Rationale: Anxiolytics or mild sedation can improve patient tolerance of BiPAP, preventing escalation to intubation if it’s otherwise appropriate.
A patient with ARDS is on low tidal volume ventilation. They have persistent hypoxemia (PaO₂ 50 mmHg) despite 80% FiO₂. Which adjunct measure often helps improve oxygenation?
A) Lower PEEP to 2 cm H₂O
B) Sedation vacation
C) Prone positioning
D) Bronchodilator nebulizers
Answer: C
Rationale: Prone positioning enhances gas exchange in ARDS by improving ventilation-perfusion matching and alveolar recruitment.
Which alarm condition on a mechanical ventilator is most suggestive of a potential circuit disconnection?
A) High-pressure alarm
B) Low-pressure or low-minute-volume alarm
C) High respiratory rate alarm
D) High PEEP alarm
Answer: B
Rationale: A low-pressure or low-minute-volume alarm often indicates a leak or disconnection in the system.
A COPD patient is on BiPAP (IPAP 14 cm H₂O, EPAP 5 cm H₂O) and has become tachycardic with new onset hypotension. Which phenomenon best explains this?
A) Hypervolemia
B) Excessive alveolar ventilation
C) Increased intrathoracic pressure decreasing venous return
D) Low oxygen saturation
Answer: C
Rationale: Positive pressure ventilation raises intrathoracic pressure, reducing venous return and possibly causing hypotension.
Noninvasive Ventilation (BiPAP/CPAP)
is beneficial for certain hypercapnic or mild to moderate hypoxemic failures if airway is protected.
Invasive Ventilation
is necessary for airway protection, severe acidosis, hemodynamic instability, or failure of NIV.
→ airway obstruction, secretions, patient-vent dyssynchrony.
o
High-pressure ventilator alarm
→ circuit disconnection or leak
Low-pressure/minute-volume
Optimizing Ventilation Settings
(IPAP, EPAP) can relieve work of breathing and hypercapnia or hypoxia.
A 60-year-old man with COPD is on BiPAP for acute hypercapnic respiratory failure. After 2 hours, his mental status is deteriorating, PaCO₂ has risen further, and he is no longer protecting his airway. What is the next best step?
A) Increase BiPAP IPAP
B) Transition to continuous positive airway pressure (CPAP)
C) Endotracheal intubation
D) Administer IV corticosteroids and continue BiPAP
Answer: C
Rationale: Rising PaCO₂, altered mental status, and inability to protect the airway indicate failure of noninvasive ventilation, necessitating invasive intubation.
Which of the following best indicates the need for advanced airway management in a patient with a severe facial fracture?
A) Patient is cooperative but has moderate hypoxia
B) Patient complains of mask discomfort on BiPAP
C) Significant orofacial injury with suspected airway compromise
D) Tachypnea with PaO₂/FiO₂ ratio of 250
Answer: C
Rationale: Facial fractures can lead to airway compromise; invasive airway management is critical to protect the airway.
A 72-year-old man in respiratory failure on BiPAP is requiring 25 cm H₂O of inspiratory pressure to maintain adequate ventilation. Which is most appropriate?
A) Decrease IPAP to 15 cm H₂O
B) Continue noninvasive ventilation if tolerated
C) Proceed with endotracheal intubation
D) Switch to nasal cannula
Answer: C
Rationale: Pressures >20 cm H₂O on BiPAP are generally poorly tolerated or ineffective; intubation is indicated.
Which of the following hemodynamic changes is most likely when a previously hypoxic, hypercapnic patient is intubated and placed on positive pressure ventilation?
A) Increased venous return and higher cardiac output
B) Decreased intrathoracic pressure and improved blood pressure
C) Drop in blood pressure due to decreased venous return
D) Massive sympathetic surge leading to hypertension
Answer: C
Rationale: Positive pressure ventilation decreases venous return, potentially causing hypotension post-intubation.
Which of the following medications is preferred for rapid sequence intubation in a patient with elevated intracranial pressure and hyperkalemia?
A) Succinylcholine + midazolam
B) Rocuronium + etomidate
C) Vecuronium + morphine
D) Succinylcholine + propofol
Answer: B
Rationale: Succinylcholine is contraindicated in elevated K⁺ and can raise intracranial pressure. Rocuronium and etomidate are safer in these scenarios.
A 52-year-old man with a severely compromised airway needs urgent intubation. He has a known difficult airway (Mallampati 4). What is the best approach?
A) Standard laryngoscopy in the emergency department
B) Fiberoptic or video-assisted intubation with expert airway team
C) Attempt nasotracheal intubation blindly
D) Administer high-dose opioids and place a laryngeal mask airway
Answer: B
Rationale: With difficult airway (Mallampati 4), a fiberoptic or video-assisted approach with experienced personnel is safer.
Which statement is true about orotracheal vs. nasotracheal intubation?
A) Nasotracheal intubation is easier and faster in emergencies
B) Orotracheal intubation has fewer complications in acute settings
C) Nasotracheal intubation reduces risk of sinusitis
D) Orotracheal tubes cannot be connected to ventilators
Answer: B
Rationale: Orotracheal intubation is generally faster, safer, and preferred for urgent/emergency intubations. Nasotracheal has higher complication rates (sinusitis, epistaxis).
A 68-year-old man is hypotensive and bradycardic immediately after receiving succinylcholine and etomidate for RSI. Which mechanism best explains this?
A) Persistent vagal stimulation
B) Allergy to succinylcholine
C) Normal response to sedation and loss of sympathetic tone
D) Hemorrhage from airway trauma
Answer: C
Rationale: Sedatives and neuromuscular blockers reduce sympathetic drive, causing hypotension/bradycardia (loss of compensatory catecholamines).
A patient is intubated but the end-tidal CO₂ detector remains at zero. You do not hear bilateral breath sounds, and the abdomen is distending. What is the most likely complication?
A) Right mainstem bronchus intubation
B) Esophageal intubation
C) Pneumothorax
D) Bronchospasm
Answer: B
Rationale: Zero end-tidal CO₂, absent breath sounds, abdominal distension → suggests esophageal (rather than tracheal) intubation.
A 70-year-old patient with chronic respiratory failure due to neuromuscular disease has been on mechanical ventilation for 3 weeks via endotracheal tube. The care team plans a more long-term airway. Which procedure is indicated?
A) Nasotracheal intubation
B) Cricothyrotomy
C) Tracheostomy
D) Orotracheal re-intubation with a larger tube
Answer: C
Rationale: Tracheostomy is preferred for prolonged mechanical ventilation, improving comfort and reducing airway complications.
Which of the following best explains why a patient’s blood pressure drops after intubation for status asthmaticus?
A) Excess IV fluids
B) Positive pressure ventilation decreasing venous return
C) Laryngospasm from the tube
D) Patient sedation reversal
Answer: B
Rationale: Positive intrathoracic pressure reduces venous return, leading to hypotension post-intubation.
A 55-year-old man with severe facial trauma and potential airway compromise needs urgent airway protection. Which approach is least appropriate?
A) Awake fiberoptic intubation
B) Video laryngoscopy with a skilled operator
C) Cricothyrotomy if standard approaches fail
D) Blind nasotracheal intubation
Answer: D
Rationale: Blind nasotracheal intubation is contraindicated in facial trauma due to risk of misplacement and hemorrhage.
A patient with acute stroke and compromised swallow reflex is at risk of aspiration. Which of the following best ensures airway protection?
A) BiPAP mask
B) High-flow nasal cannula
C) Endotracheal intubation
D) CPAP at 10 cm H₂O
Answer: C
Rationale: Definitive airway (endotracheal tube) is required for inability to protect airway (e.g., stroke with poor swallow).
A 70-year-old is intubated in the emergency department. After tube placement, you hear breath sounds only on the right side. Pulse oximetry is stable at 96%. What is the most likely explanation?
A) Bronchospasm in the left lung
B) Right mainstem bronchus intubation
C) Pneumothorax on the left side
D) Uncuffed endotracheal tube
Answer: B
Rationale: Right mainstem intubation is common because the right main bronchus is more vertical.
A 65-year-old on mechanical ventilation for respiratory failure needs sedation. Which combination is most appropriate to facilitate comfort but avoid significant hypotension?
A) Propofol at high dose + morphine
B) Midazolam + succinylcholine drip
C) Ketamine + fentanyl infusion
D) Haloperidol + intravenous beta-blockers
Answer: C
Rationale: Ketamine provides sedation, analgesia, with minimal hypotension; fentanyl for pain control. Propofol can drop BP, and succinylcholine drip is not used continuously.
A 60-year-old patient intubated for massive hemorrhagic stroke shows new subcutaneous emphysema and high ventilator pressures. Breath sounds are diminished bilaterally. Which complication should be ruled out first?
A) Tube malposition in the esophagus
B) Bilateral pneumothoraces
C) Right mainstem intubation
D) Ventilator circuit leak.
Answer: B
Rationale: Subcutaneous emphysema + increased airway pressures commonly indicates pneumothorax (particularly tension if bilateral)
A patient with a new tracheostomy tube placed 5 days ago is found with a sudden large-volume hemorrhage from the stoma site. What is the most concerning cause?
A) Tracheoinnominate artery fistula
B) Tracheoesophageal fistula
C) Pressure necrosis from the trach cuff
D) Tracheal stenosis
Answer: A
Rationale: Tracheoinnominate artery fistula can present with massive hemorrhage, a life-threatening complication.
Which of the following is a benefit of tracheostomy in a patient requiring prolonged mechanical ventilation?
A) Complete elimination of VAP risk
B) Improved communication and potential for speech
C) Decreased sedation requirement is rare
D) Immediate weaning off ventilator
Answer: B
Rationale: Tracheostomy can help patients better communicate (e.g., speaking valves) and is often better tolerated for long-term ventilation.
A 40-year-old man develops bradycardia and hyperkalemia after receiving succinylcholine for RSI. Which condition is most associated with this complication?
A) Acute coronary syndrome
B) Head trauma with increased ICP
C) Burn injury or crush injury
D) Hypothermia
Answer: C
Rationale: Succinylcholine can cause excessive hyperkalemia in burn or crush injuries, neuromuscular disease, or denervation injuries.
A 70-year-old patient is intubated for pulmonary edema. Post-intubation, you notice deep hypotension (BP 75/45). Which measure is most appropriate initially?
A) Reduce PEEP to zero
B) Start IV fluids and consider vasopressors
C) Increase sedation level
D) Extubate immediately
Answer: B
Rationale: Hypotension is common post-intubation; IV fluids and/or vasopressors help stabilize if the drop is significant.
A 65-year-old with ARDS is intubated. After sedation and paralysis, you notice sudden wheezing and difficulty ventilating. Which medication might relieve this bronchospasm?
A) Etomidate
B) Naloxone
C) Albuterol nebulizer
D) Succinylcholine bolus
Answer: C
Rationale: Bronchospasm in a ventilated patient may improve with beta-2 agonists (albuterol).
Which sign is most indicative of successful endotracheal intubation in the immediate setting (prior to chest X-ray)?
A) Bilateral breath sounds and positive color change on end-tidal CO₂ monitor
B) Chest X-ray showing tube 3 cm below the carina
C) Absent breath sounds on the left side
D) Gurgling heard over the epigastrium
Answer: A
Rationale: Bilateral breath sounds and end-tidal CO₂ detection confirm correct tracheal placement immediately.
What is the most direct method to confirm correct endotracheal tube depth after initial placement?
A) End-tidal CO₂ waveform
B) Bilateral chest auscultation
C) Chest X-ray confirming tube tip 2–5 cm above carina
D) Pulse oximetry reading stabilizing at 96%
Answer: C
Rationale: Chest X-ray ensures the tube is at the correct depth (2–5 cm above carina). End-tidal CO₂ confirms location but not exact depth.
A patient with airway burns is predicted to have progressive edema. Which approach is best?
A) Wait until stridor develops
B) Early elective intubation
C) Noninvasive ventilation trial first
D) Cricothyrotomy only if complete obstruction occurs
Answer: B
Rationale: Airway burns often worsen with edema over time; early elective intubation secures airway proactively.
Which complication is commonly associated with prolonged endotracheal intubation (2–3 weeks) and suggests the need for tracheostomy?
A) Decreased sedation
B) Pressure ulcers on face
C) Risk of ventilator-associated pneumonia
D) Tracheal stenosis
Answer: D
Rationale: Prolonged intubation can lead to tracheal stenosis. Switching to tracheostomy can reduce such airway complications.
A nurse notices the pilot balloon on an endotracheal tube is flat. The ventilator low-pressure alarm sounds. The patient remains stable on pulse oximetry. Which is the best next step?
A) Attempt to reinflate the cuff
B) Remove the endotracheal tube immediately
C) Increase ventilator pressures
D) Draw an arterial blood gas
Answer: A
Rationale: A flat pilot balloon suggests a cuff leak. Reinflate the cuff to restore the seal and correct the alarm.
A 45-year-old man requires an emergent surgical airway in the ED for complete upper airway obstruction. Which procedure is fastest and safest in an emergency?
A) Elective tracheostomy in the operating room
B) Cricothyrotomy
C) Nasotracheal intubation
D) Retrograde intubation
Answer: B
Rationale: Cricothyrotomy is the preferred emergency surgical airway for acute obstruction.
A patient has undergone intubation with high sedation. He’s hypotensive. Which sedation agent is most likely contributing?
A) Ketamine
B) Fentanyl
C) Etomidate
D) Propofol
Answer: D
Rationale: Propofol commonly causes hypotension due to vasodilation and myocardial depression.
A 68-year-old man is intubated for sepsis. Two hours later, you notice absent breath sounds on the right side and oxygen saturation dropping to 84%. The tracheal tube marking is the same as before. Which complication is most likely?
A) Right pneumothorax
B) Esophageal intubation
C) Right mainstem intubation
D) Bronchospasm in the right lung
Answer: A
Rationale: Sudden loss of right-sided breath sounds and desaturation, with the tube marking unchanged, suggests a new right pneumothorax.
A patient has had a tracheostomy for several years. He presents with difficulty breathing. Imaging reveals erosion into the trachea near a major vessel. Which rare but life-threatening complication should be suspected?
A) Tracheoinnominate fistula
B) Tracheoesophageal fistula
C) Bronchopleural fistula
D) Tracheostomy tube displacement
Answer: A
Rationale: Tracheoinnominate artery fistula is a deadly complication of chronic tracheostomy with arterial erosion and massive hemorrhage risk.
Indications to switch from noninvasive to invasive ventilation
ventilation include worsening mental status, inability to protect airway, high inspiratory pressures, rising PaCO₂, and hypoxemia despite support
Rapid Sequence Intubation (RSI)
typically uses sedative + paralytic (e.g., etomidate + rocuronium)
Post-intubation hypotension can result from
from loss of sympathetic drive, positive pressure ventilation reducing venous return, and sedative-induced vasodilation
For Difficult airway (Mallampati 3-4, facial trauma, etc.)
consider fiberoptic or video-assisted intubation
Surgical airway (cricothyrotomy
is a life-saving measure in complete obstruction or impossible intubation scenarios
A 60-year-old man with acute respiratory failure is intubated. After stabilizing, the team decides on a volume-controlled mode that provides a fixed tidal volume whether the breath is machine- or patient-triggered. This mode does not synchronize with patient effort. Which mode is described?
A) Synchronized Intermittent Mandatory Ventilation (SIMV)
B) Assist Control (AC or CMV)
C) Pressure Control Ventilation (PCV)
D) Pressure Support Ventilation (PSV)
Answer: B
Rationale: Assist Control (AC) or Continuous Mandatory Ventilation (CMV) delivers a set tidal volume for each breath, not synchronized with patient effort.
. A 72-year-old with ARDS is placed on low tidal volume ventilation (6 mL/kg IBW). This strategy primarily aims to prevent which complication?
A) Oxygen toxicity
B) Stress ulcers
C) Volutrauma
D) Atelectasis
Answer: C
Rationale: Low tidal volume strategies reduce the risk of volutrauma in ARDS.
A patient on mechanical ventilation is receiving 70% FiO₂. You notice a PaO₂ of 195 mmHg on ABG. Which adjustment is most appropriate to avoid oxygen toxicity?
A) Increase tidal volume
B) Decrease FiO₂
C) Increase PEEP
D) Decrease respiratory rate
Answer: B
Rationale: If PaO₂ is >100 and stable, lowering FiO₂ helps reduce risk of oxygen toxicity.
Which of the following ventilator settings is primarily used to keep alveoli open at end-expiration and improve oxygenation?
A) Tidal volume
B) Respiratory rate
C) PEEP
D) FiO₂
Answer: C
Rationale: Positive End-Expiratory Pressure (PEEP) prevents alveolar collapse and improves oxygenation.
In volume-controlled ventilation (VCV), what parameter must clinicians closely monitor to avoid barotrauma?
A) Tidal volume
B) Peak and plateau pressures
C) FiO₂
D) Respiratory rate
Answer: B
Rationale: In VCV, pressure can rise unpredictably; peak and plateau pressures must be monitored to prevent barotrauma.
A 55-year-old woman is on pressure-controlled ventilation. Her tidal volumes fluctuate breath to breath. Which factor must be monitored to avoid hypoventilation or hyperventilation?
A) Inspiratory flow
B) Tidal volume
C) PEEP
D) Inspiratory time
Answer: B
Rationale: In pressure modes, volume varies, so monitoring tidal volume is crucial.
A patient with severe COVID pneumonia is placed on a pressure-regulated volume control mode, ensuring a target tidal volume while varying inspiratory pressures. Which advantage does this mode provide?
A) Completely fixed pressure with no volume variation
B) Patient control of respiratory rate only
C) Automatic adjustment of inspiratory pressure to maintain a set tidal volume
D) Complete weaning from sedation
Answer: C
Rationale: PRVC automatically adjusts inspiratory pressure to achieve the set tidal volume, enhancing patient comfort.
A patient is partially awake on mechanical ventilation. They can trigger extra breaths beyond the mandatory rate, but each triggered breath still delivers the set tidal volume. Which mode does this describe?
A) AC/CMV
B) SIMV
C) Pressure Control
D) Pressure Support
Answer: A
Rationale: In Assist Control, any patient-triggered breath still receives the set tidal volume.
In pressure-support ventilation, the patient fully controls the rate and timing of breaths. The ventilator provides a set inspiratory pressure once the patient initiates a breath. Which setting is not typically specified in PSV?
A) Tidal volume
B) Inspiratory pressure
C) FiO₂
D) PEEP
Answer: A
Rationale: Tidal volume is not fixed in pressure support; it depends on patient effort.
A 70-year-old on SIMV at 12 breaths/min, tidal volume 500 mL. He spontaneously takes 6 additional breaths, each receiving the same set volume. This scenario contradicts the usual concept of which mode?
A) CPAP
B) Assist Control
C) SIMV
D) Pressure Support
Answer: C
Rationale: In SIMV, only mandatory breaths are set volume. Extra breaths might be partially supported (or not) but typically not the full set volume unless combined with pressure support.
. An ICU patient with ARDS has persistent hypoxemia. The team increases PEEP from 8 to 12 cm H₂O. What is the main goal of raising PEEP?
A) Decrease minute ventilation
B) Prevent alveolar collapse and improve oxygenation
C) Increase tidal volume delivery
D) Reduce the need for sedation
Answer: B
Rationale: Higher PEEP helps keep alveoli open, improving oxygenation in ARDS.
A patient on Assist Control has a set tidal volume of 600 mL. The ABG shows hypercapnia (PaCO₂ 58 mmHg). Which initial ventilator change is most logical to reduce PaCO₂?
A) Decrease FiO₂
B) Increase PEEP
C) Increase respiratory rate or tidal volume
D) Lower respiratory rate
Answer: C
Rationale: To blow off CO₂, increasing minute ventilation (rate or volume) is the standard approach.
. On pressure-controlled ventilation, if the patient’s spontaneous inspiratory effort increases, what typically happens to the tidal volume?
A) Tidal volume remains fixed
B) Tidal volume increases
C) The ventilator prevents any additional volume
D) Tidal volume decreases to avoid barotrauma
Answer: B
Rationale: More inspiratory effort in pressure-control yields larger tidal volumes, as pressure is set but volume can vary.
A 50-year-old in shock is on mechanical ventilation. He develops hypotension after raising PEEP from 5 to 12 cm H₂O. Which mechanism best explains this?
A) Reduced alveolar recruitment
B) Decreased intrathoracic pressure
C) Lower venous return causing decreased cardiac output
D) Excess oxygenation leading to bradycardia
Answer: C
Rationale: Increased PEEP → increased intrathoracic pressure → reduced venous return → hypotension.
Which ventilation mode is most commonly used for weaning, allowing the patient to take spontaneous breaths at their own volume, with a small pressure boost for each breath?
A) Pressure Control Ventilation
B) SIMV with Pressure Support
C) Assist Control
D) APRV (Airway Pressure Release Ventilation)
Answer: B
Rationale: SIMV + Pressure Support is often used for gradual weaning, letting spontaneous breaths be partially supported.
A 65-year-old patient on volume-control ventilation is at risk for high plateau pressures. Which complication is most likely if these pressures remain high?
A) Alveolar hypoventilation
B) Barotrauma/pneumothorax
C) Increased venous return
D) Low oxygen saturation due to atelectasis
Answer: B
Rationale: High plateau pressures risk barotrauma (e.g., pneumothorax).
In pressure-support ventilation, the patient:
A) Receives a fixed mandatory tidal volume with every breath
B) Controls rate, inspiratory time, and volume, while ventilator provides a preset inspiratory pressure
C) Cannot initiate additional breaths
D) Is guaranteed a minimum respiratory rate set by the ventilator
Answer: B
Rationale: Pressure Support Ventilation only provides a certain pressure; the patient controls breath timing, volume, rate.
A 55-year-old’s ABG shows a PaO₂ of 52 mmHg on 60% FiO₂ and PEEP of 5 cm H₂O. To address hypoxemia without risking oxygen toxicity, which adjustment is preferable?
A) Increase FiO₂ to 80%
B) Increase PEEP to 10 cm H₂O
C) Decrease respiratory rate
D) Lower tidal volume
Answer: B
Rationale: Increasing PEEP helps improve oxygenation by recruiting alveoli, reducing the need for higher FiO₂.
If a patient on Assist Control frequently “fights the vent” and becomes tachypneic, receiving excessive volumes, which outcome is likely?
A) Hypoventilation
B) Respiratory alkalosis
C) Respiratory acidosis
D) Improved sedation
Answer: B
Rationale: Tachypnea + fixed tidal volume → excess ventilation → respiratory alkalosis.
A 72-year-old with ARDS is placed on a pressure-limited mode to protect against barotrauma. However, her tidal volumes are now quite low, causing hypercapnia. Which strategy addresses hypercapnia while maintaining lung-protective pressure?
A) Decrease PEEP
B) Increase respiratory rate
C) Switch to volume-control at 10 mL/kg
D) Increase FiO₂ significantly
Answer: B
Rationale: In a pressure-limited mode, increasing RR can help blow off CO₂ without raising plateau pressures.
A patient on AC/Volume Control with RR 12, tidal volume 500 mL, FiO₂ 40%, PEEP 5. ABG shows PaCO₂ 30 mmHg (alkalosis). Which is a reasonable next step?
A) Increase tidal volume
B) Decrease minute ventilation (RR or Vᵗ)
C) Increase PEEP to 10
D) Raise FiO₂
Answer: B
Rationale: Respiratory alkalosis indicates overventilation → reduce RR or tidal volume.
On SIMV of 8 breaths/min, the patient spontaneously takes 10 additional breaths with minimal volume. The ABG shows rising CO₂. Which addition might help?
A) Increase FiO₂
B) Increase sedation
C) Add pressure support to assist spontaneous breaths
D) Convert to CPAP only
Answer: C
Rationale: Pressure Support during spontaneous breaths can boost volume and reduce CO₂ retention.
A patient’s ventilator is set to Pressure Control. You notice tidal volumes are dropping over time due to decreased patient effort. The best intervention to maintain ventilation is:
A) Increase set inspiratory pressure
B) Reduce PEEP
C) Decrease inspiratory time
D) Switch to nasal cannula
Answer: A
Rationale: In PCV, raising inspiratory pressure can increase volume if the patient’s effort is waning.
In Pressure-Regulated Volume Control (PRVC), the ventilator:
A) Maintains a fixed pressure regardless of volume changes
B) Adjusts pressure breath-to-breath to deliver a target tidal volume
C) Only provides pressure support for spontaneous breaths
D) Delivers fixed volume and fixed pressure simultaneously
Answer: B
Rationale: PRVC auto-adjusts inspiratory pressure to achieve the target tidal volume each breath.
A 70-year-old with COPD on SIMV triggers extra breaths. Each spontaneous breath is unassisted. She tires easily. Which modification might help reduce fatigue?
A) Increase mandatory rate to 20
B) Add pressure support for spontaneous breaths
C) Switch to AC with
large tidal volume
D) Reduce sedation
Answer: B
Rationale: SIMV plus pressure support reduces the work of spontaneous breaths, preventing fatigue.
You note that your ARDS patient has a plateau pressure >30 cm H₂O on volume-control ventilation. Which measure helps reduce plateau pressure?
A) Increase tidal volume to 10 mL/kg
B) Decrease tidal volume and/or decrease inspiratory flow
C) Stop sedation to let patient breathe spontaneously
D) Increase mandatory rate
Answer: B
Rationale: Lowering tidal volume or adjusting flow can reduce plateau pressure, preventing barotrauma.
A patient is intubated and placed on BiVent/APRV (Airway Pressure Release Ventilation). This advanced mode typically helps with which aspect?
A) Guaranteed fixed tidal volume at each breath
B) Facilitating alveolar recruitment with intermittent release phases
C) Patient sedation requirements drastically reduced
D) Minimizing any pressure changes in the airway
Answer: B
Rationale: APRV (BiVent) uses prolonged high pressure phases to recruit alveoli, then short releases to remove CO₂.
Which factor is most critical in deciding between volume vs. pressure targeted ventilation?
A) Patient’s history of hypercoagulability
B) Risk of barotrauma vs. need to guarantee a minimum tidal volume
C) Whether the patient has a tracheostomy
D) Continuous sedation vs. daily sedation breaks
Answer: B
Rationale: The choice often hinges on protecting lungs from high pressure vs. guaranteeing a minimum tidal volume.
A patient on a volume-control mode complains of discomfort and feels breath-stacking. She’s triggering extra breaths out of sync with the mandatory cycle. Which alternative mode might improve patient-ventilator synchrony?
A) AC/CMV (Volume)
B) SIMV or Pressure-Regulated Volume Control
C) Keep the same settings, add sedation
D) Pressure control with no spontaneous triggers
Answer: B
Rationale: SIMV or PRVC can better synchronize with patient effort, potentially enhancing comfort.
In Pressure Support Ventilation, there is no backup rate provided. This is generally used in:
A) Heavily sedated patients with no spontaneous drive
B) Weaning trials to assess patient’s spontaneous effort
C) Complete alveolar hypoventilation
D) Apneic brain-dead patients
Answer: B
Rationale: PSV is a weaning or partial-support mode for patients who can initiate each breath.
On assist-control ventilation, your patient develops “auto-PEEP” or breath stacking. Which strategy may reduce auto-PEEP?
A) Increase respiratory rate
B) Decrease expiratory time
C) Decrease inspiratory time or tidal volume to prolong exhalation
D) Increase sedation to force slower breathing
Answer: C
Rationale: Increasing expiratory time (by reducing inspiratory time/volume) helps reduce auto-PEEP.
A patient is placed on AC/Volume Control at 8 mL/kg IBW. ABGs show improved O₂ but rising plateau pressures. The best immediate step to prevent barotrauma is:
A) Increase respiratory rate and reduce tidal volume
B) Lower PEEP and maintain tidal volume
C) Increase sedation to zero spontaneous breaths
D) Increase FiO₂ to 100%
Answer: A
Rationale: Reducing tidal volume decreases alveolar pressures, preventing barotrauma. Raising RR compensates for alveolar ventilation.
The ventilator alarm signals “high inspiratory pressure” repeatedly. On exam, the patient’s breathing sounds diminished bilaterally. Which initial action is correct?
A) Disconnect from ventilator and bag with 100% O₂
B) Increase sedation to reduce agitation
C) Suction the patient’s ETT
D) Check vital signs only
Answer: A
Rationale: Disconnect and manually bag helps quickly assess if it’s a ventilator/circuit issue or patient airway problem.
A patient on SIMV + Pressure Support has frequent spontaneous breaths. He complains of inadequate support. ABG shows mild hypercapnia. What’s a direct fix?
A) Increase mandatory breaths on SIMV
B) Increase pressure support level
C) Lower PEEP to 2 cm H₂O
D) Decrease inspiratory flow
Answer: B
Rationale: Increasing pressure support aids spontaneous breathing, improving ventilation and reducing CO₂.
A 50-year-old on pressure control sedation is lightened, and he spontaneously breathes more. Suddenly, tidal volumes jump from 400 mL to 700 mL. Risk of which complication increases?
A) Hypocapnia
B) Volutrauma from excessive volume
C) Hypoventilation
D) Cardiac arrest
Answer: B
Rationale: In PCV, increased effort can push volumes higher, risking volutrauma.
A patient with ARDS is set to low tidal volume (6 mL/kg) but remains severely hypoxemic on 60% FiO₂. The plateau pressure is 28 cm H₂O. Which next step helps better oxygenation without risking barotrauma?
A) Increase tidal volume to 10 mL/kg
B) Raise PEEP cautiously
C) Decrease respiratory rate to prolong expiration
D) Add pressure support
Answer: B
Rationale: Increasing PEEP can recruit more alveoli for oxygenation while keeping low tidal volume strategy intact.
A 78-year-old has a P/F ratio of 200 on SIMV, and ABGs show PaCO₂ 48 mmHg, pH 7.34, acceptable. The team tries to wean. Which weaning mode is typical?
A) Switch to AC with sedation
B) Pressure support ventilation
C) Increase mandatory RR to 20
D) Use volume-control with fixed rates
Answer: B
Rationale: Pressure support is often used for weaning to allow spontaneous breaths with minimal assistance.
. A COPD patient on mechanical ventilation experiences auto-PEEP. This can lead to:
A) Decreased work of breathing
B) Hypotension from decreased venous return
C) Higher sedation requirements
D) Lower alveolar pressures
Answer: B
Rationale: Auto-PEEP raises end-expiratory pressure, reducing venous return → can cause hypotension.
A patient is on PRVC. After sedation is reduced, the patient’s spontaneous effort improves. The ventilator lowers its applied pressure significantly. Why?
A) Tidal volume is pressure-limited
B) The ventilator senses less pressure needed to reach target volume
C) Machine is faulty
D) It’s preventing sedation-induced bradypnea
Answer: B
Rationale: PRVC automatically lowers inspiratory pressure if the patient’s effort helps achieve target volume.
An intubated patient has a persistent respiratory rate of 35/min on AC/Volume mode, receiving large volumes. She is at risk for:
A) Respiratory acidosis
B) Alkalosis due to overventilation
C) Improved sedation levels
D) Lower FiO₂ requirements
Answer: B
Rationale: Tachypnea + set volume → overventilation, leading to respiratory alkalosis
A patient is on the ventilator for 10 days and is stable with minimal sedation. The protocol calls for a spontaneous breathing trial on T-piece or low pressure support. Why is this done?
A) To test readiness for extubation
B) To increase sedation requirement
C) To reduce alveolar dead space
D) To maintain full support
Answer: A
Rationale: Spontaneous breathing trials gauge the patient’s readiness to be weaned and extubated.
An ICU patient meets weaning criteria: FiO₂ < 50%, PEEP 5, stable vitals. A 30-minute spontaneous breathing trial is started. Which outcome indicates success?
A) Tachypnea over 40/min
B) Maintaining SpO₂ > 90%, stable HR and BP
C) Marked accessory muscle use
D) Significant mental status change
Answer: B
Rationale: Stable vitals, acceptable SpO₂ during the trial suggests successful weaning potential.
A 65-year-old is weaned to pressure support of 5 cm H₂O and PEEP of 5. He tolerates 2 hours well. Next step if stable?
A) Increase sedation
B) Extubate if protective airway reflexes intact
C) Return to AC/Volume mode
D) Raise pressure support
Answer: B
Rationale: If the patient tolerates minimal support, the next step is extubation if airway protection is assured.
Which condition most impedes successful weaning from the ventilator?
A) Normal mental status
B) Adequate cough and minimal secretions
C) Severe malnutrition and neuromuscular weakness
D) FiO₂ requirement <40%
Answer: C
Rationale: Malnutrition, neuromuscular weakness hinder ventilator weaning by reducing respiratory muscle strength.
A 70-year-old has recurrent weaning failures. He remains on partial mechanical support. He also has difficulty clearing secretions. After 2 weeks, the team suggests a tracheostomy. Which advantage does a tracheostomy offer?
A) Guaranteed immediate extubation
B) Lower risk of pneumonia
C) Improved patient comfort and potential for easier weaning
D) Elimination of sedation use
Answer: C
Rationale: Tracheostomy can improve comfort, facilitate suctioning, and aid in prolonged weaning.
In a patient with ARDS, the team sets a low tidal volume and high PEEP approach. The main purpose of this combination is:
A) Maximize minute ventilation
B) Reduce sedation needs while increasing alveolar ventilation
C) Prevent barotrauma while keeping alveoli open
D) Achieve respiratory alkalosis intentionally
Answer: C
Rationale: Low Vᵗ prevents volutrauma; high PEEP prevents alveolar collapse.
A patient on mechanical ventilation for pneumonia is receiving sedation with propofol. The nurse reports a new BP of 80/50 mmHg. What sedation strategy might help maintain ventilation but reduce hypotension?
A) Increase propofol infusion
B) Switch to ketamine infusion
C) Discontinue sedation entirely
D) Add midazolam on top of propofol
Answer: B
Rationale: Ketamine generally preserves or increases BP, making it preferred in hypotensive patients needing sedation.
A patient on SIMV with pressure support is comfortable, RR 16, minimal sedation. ABG: pH 7.38, PaCO₂ 45, PaO₂ 80 on 40% FiO₂. Which is a sign of readiness for extubation?
A) Tachycardia and frequent PVCs
B) Multiple comorbidities precluding weaning
C) Stable ABG, normal RR, minimal sedation
D) Mandatory rate >20
Answer: C
Rationale: Stable ABGs, normal RR, minimal sedation → meets typical extubation readiness criteria.
In pressure support ventilation, if the patient’s spontaneous rate drops to 2 breaths/min, the ventilator does not deliver additional mandatory breaths. This can lead to:
A) Maintaining normocapnia
B) Apnea or hypoventilation
C) Higher plateau pressures
D) Automatic weaning
Answer: B
Rationale: PSV lacks a backup rate; inadequate spontaneous effort → risk of hypoventilation.
. A 74-year-old with septic shock requires mechanical ventilation. Over 5 days, his alveolar ventilation improves, but sedation level is deep. Which daily practice helps reduce time on the ventilator?
A) Continuous neuromuscular blockade
B) Full sedation to ease ventilator dyssynchrony
C) Daily sedation interruption (“sedation vacation”) and spontaneous breathing trial
D) Keeping the patient supine at all times
Answer: C
Rationale: Daily sedation breaks + spontaneous breathing trials shorten ventilation duration.
Modes of Mechanical Ventilation
fully controlled (AC) to partial support (SIMV, Pressure Support).
Volume-Targeted modes
guarantee tidal volume but risk high airway pressures
Pressure-Targeted modes
limit pressure but variable volume.
PEEP
enhances oxygenation by preventing alveolar collapse, but excessive PEEP or auto-PEEP can cause hypotension.
daily assessments, spontaneous breathing trials, and stepping down to partial support before extubation
ventilator Weaning involves
tidal volume, PEEP, and FiO₂ must be carefully set (lung-protective strategies).
To avoid barotrauma and oxygen toxicity,
- A 65-year-old with ARDS is on pressure control ventilation at 20 cm H₂O inspiratory pressure, PEEP 10 cm H₂O. Over time, you notice her tidal volumes are steadily decreasing. Her respiratory acidosis is worsening. What is the most appropriate ventilator adjustment?
- A) Increase FiO₂
B) Increase inspiratory pressure above 20 cm H₂O
C) Decrease the set respiratory rate
D) Lower PEEP to 5 cm H₂O
- Answer: B
Rationale: In pressure control, if tidal volumes drop and CO₂ rises, you often increase inspiratory pressure or RR to improve alveolar ventilation.
- Which situation is most likely to cause auto-PEEP (intrinsic PEEP) in a patient on volume-controlled ventilation?
- A) Setting a low respiratory rate
B) Prolonged inspiratory time with inadequate expiratory time
C) A large difference between IPAP and EPAP
D) Using minimal sedation
Answer: B
Rationale: Auto-PEEP frequently occurs when exhalation time is too short (e.g., prolonged I-time), leading to air trapping.
A patient with obstructive lung disease is on AC/Volume mode. To reduce risk of air trapping and auto-PEEP, which strategy is most appropriate?
A) Decrease inspiratory flow to slow breath delivery
B) Increase tidal volume to shorten inspiratory time
C) Increase the inspiratory-to-expiratory (I:E) ratio to 1:1
D) Shorten inspiratory time to allow a longer expiratory phase
- Answer: D
Rationale: Giving more time for exhalation helps obstructive patients avoid air trapping. Shortening I-time lengthens E-time.
- A 70-year-old with acute lung injury is on SIMV with 8 mandatory breaths/min. They spontaneously breathe an additional 15 breaths at low volumes. Their PaCO₂ is 58 mmHg. Which tweak is best to improve ventilation?
- A) Lower FiO₂
B) Increase mandatory RR or add pressure support
C) Increase sedation to decrease spontaneous breaths
D) Decrease PEEP to 0 cm H₂O
- Answer: B
Rationale: If spontaneous breaths are low volume and CO₂ is high, either increase the mandatory rate or provide pressure support to augment spontaneous breaths.
- Which complication is most associated with high levels of PEEP in a hemodynamically unstable patient?
- A) Cardiac arrhythmias
B) Excessive sedation requirements
C) Decreased venous return and hypotension
D) Hyperventilation leading to respiratory alkalosis
- Answer: C
Rationale: Elevated PEEP → raised intrathoracic pressure → decreased venous return → potential hypotension.
- A 55-year-old is recovering from sepsis on pressure support ventilation (PSV). They suddenly become tachypneic and anxious, with rising CO₂. You note minimal inspiratory pressure support at 5 cm H₂O. Which ventilator setting change might help the patient?
- A) Lower FiO₂
B) Increase the pressure support level
C) Decrease PEEP
D) Switch to high-flow nasal cannula
- Answer: B
Rationale: If the patient is under-ventilating on PSV, increasing the pressure support can reduce their work of breathing and better blow off CO₂.
- A patient on volume-control ventilation (tidal volume 500 mL, RR 14, FiO₂ 50%, PEEP 5) shows new onset respiratory alkalosis (PaCO₂ 28, pH 7.52). Which immediate change helps normalize PaCO₂?
- A) Decrease the respiratory rate
B) Increase PEEP
C) Decrease FiO₂
D) Increase tidal volume
Answer: A
Rationale: Respiratory alkalosis indicates overventilation. Decreasing RR (or tidal volume) lowers minute ventilation, raising PaCO₂.
- On pressure-control ventilation, if the patient’s inspiratory demand rises, the ventilator will:
- A) Still deliver the same volume each breath
B) Potentially allow a higher tidal volume if the patient can draw more air
C) Automatically switch to volume control
D) Immediately alarm for high pressure
- Answer: B
Rationale: In PCV, volume can increase if the patient exerts more inspiratory effort, so tidal volume may rise.
- Which ventilator mode provides a targeted tidal volume while automatically adjusting pressure breath-to-breath to achieve that volume?
- A) SIMV with pressure support
B) Pressure Control Ventilation (PCV)
C) Pressure-Regulated Volume Control (PRVC)
D) Noninvasive CPAP
- Answer: C
Rationale: PRVC sets a target tidal volume and adjusts pressure as needed to deliver that volume each breath.
- In a weaning trial, a patient is switched to T-piece for 30 minutes. Their respiratory rate remains 22–24, HR stable, SpO₂ 94%. They remain comfortable. The next best step is:
- A) Return to AC mode for 12 hours
B) Increase sedation to promote rest
C) Remove the endotracheal tube if airway reflexes are intact
D) Add pressure support ventilation for a prolonged period
Answer: C
Rationale: Tolerating a T-piece trial with stable vitals suggests readiness for extubation, assuming protective airway reflexes are present.
Volume-Controlled Modes:
Tidal volume is fixed; watch pressures to avoid barotrauma.
- Pressure-Controlled Modes:
Pressure is fixed; volume varies with patient effort, requiring close monitoring of tidal volume.
Critical for improving oxygenation but can cause hemodynamic changes and risk of barotrauma.
- PEEP Adjustments:
- Weaning:
Often involves T-piece trials or pressure support to assess readiness for extubation.
Common in obstructive lung disease if inadequate expiratory time → leads to air trapping and hypotension
Auto-PEEP:
Which ventilator setting error most likely causes barotrauma in a patient with acute respiratory failure?
A. Using low tidal volumes
B. Excessively high peak pressures/large tidal volumes
C. Sufficient PEEP for alveolar recruitment
D. Minimal sedation
Correct Answer: B. Excessively high peak pressures/large tidal volumes
Rationale:
Barotrauma in ventilated patients most commonly occurs when there is excessive pressure or volume delivered to the lungs, leading to alveolar overdistension and rupture. Using excessively high peak pressures or large tidal volumes can cause such overdistension, thereby increasing the risk of barotrauma. The other options—using low tidal volumes, sufficient PEEP for alveolar recruitment, or minimal sedation—are either protective or unrelated to causing barotrauma.
- (Mechanical Ventilation / Common)
Which intervention is commonly performed to reduce ventilator-associated pneumonia (VAP) in intubated patients?
A. Prone positioning only
B. Elevating the head of the bed and daily sedation interruptions
C. Very high tidal volumes
D. Avoiding spontaneous breathing trials
B. Elevating the head of the bed and daily sedation interruptions
Rationale:
Elevating the head of the bed (typically to 30–45 degrees) helps reduce the risk of aspiration, while daily sedation interruptions allow for regular assessments of the patient’s readiness for extubation. Both practices have been shown to reduce the incidence of ventilator-associated pneumonia in intubated patients.
- Which of the following best describes the purpose of mechanical ventilation?
A. To replace lung function entirely
B. To support patients with respiratory failure by ensuring adequate gas exchange
C. To cure underlying pulmonary pathology
D. To prevent the need for supplemental oxygen
o Answer: B
o Rationale: Mechanical ventilation provides life-sustaining support in patients who cannot maintain adequate gas exchange on their own.
- Which complication “will kill your patient” if mechanical ventilation settings are not properly managed?
A. Improved oxygenation
B. Ventilator-associated lung injury (barotrauma, volutrauma)
C. Increased patient comfort
D. Enhanced secretion clearance
o Answer: B
o Rationale: Improper ventilator settings can cause ventilator-induced lung injury, which may be fatal.
- What is “common” regarding the use of positive end-expiratory pressure (PEEP) in mechanical ventilation?
A. It is always harmful
B. It improves oxygenation by preventing alveolar collapse
C. It is used to decrease intrathoracic pressure
D. It has no effect on oxygenation
o Answer: B
o Rationale: PEEP is routinely used to keep alveoli open, thereby improving oxygenation.
- Which parameter is critical to monitor on a ventilator to prevent lung injury?
A. Tidal volume
B. Body temperature
C. Heart rate
D. Urine output
o Answer: A
o Rationale: Monitoring tidal volume is essential to avoid volutrauma from overdistension of the lungs.
- In mechanically ventilated patients, what is a common complication that “will harm your patient” if not prevented?
A. Improved respiratory function
B. Ventilator-associated pneumonia (VAP)
C. Enhanced alveolar recruitment
D. Increased spontaneous breathing
o Answer: B
o Rationale: VAP is a frequent and serious complication in ventilated patients, increasing morbidity and mortality.
