Which mode of ventilation is used with critically ill patients and allows the patient to self-regulate the rate and depth of spontaneous respirations but may also deliver a preset volume and frequency of breaths?
Assist-control ventilation (ACV)
Pressure support ventilation (PSV)
Pressure-controlled inverse ratio ventilation (PC-IRV)
Synchronized intermittent mandatory ventilation (SIMV)
The Correct Answer is D
Synchronized Intermittent Mandatory Ventilation (SIMV) is a mode commonly used for critically ill patients that combines mandatory ventilator breaths with spontaneous breaths. This allows the patient to self-regulate the rate and depth of their breathing while still receiving preset volume and frequency support as needed.
Rationale for Correct Answer
4. Synchronized intermittent mandatory ventilation (SIMV): In SIMV, the ventilator delivers a set number of mandatory breaths at a preset volume or pressure, synchronized with the patient’s spontaneous efforts. Between mandatory breaths, the patient can breathe spontaneously, controlling rate and tidal volume, which promotes respiratory muscle use and supports gradual weaning.
Rationale for Incorrect Answers
1. Assist-control ventilation (ACV): Delivers a full ventilator-assisted breath for every patient-initiated or timed breath, minimizing spontaneous effort. The patient has less control over rate and depth.
2. Pressure support ventilation (PSV): Only provides pressure assistance for patient-initiated breaths. There are no mandatory breaths; it cannot deliver preset volume or frequency.
3. Pressure-controlled inverse ratio ventilation (PC-IRV): Used in severe ARDS to improve oxygenation by prolonging inspiratory time. It is a fully controlled mode, not allowing spontaneous regulation of rate and depth.
Take-Home Points
- SIMV allows combination of ventilator support and spontaneous breathing, promoting muscle strength and weaning.
- ACV provides maximum support, minimizing patient effort.
- PSV assists spontaneous breaths but does not provide mandatory support.
- Selecting the appropriate mode balances oxygenation, ventilation, and respiratory muscle preservation in critically ill patients.
Nursing Test Bank
Naxlex Comprehensive Predictor Exams
Related Questions
Correct Answer is A
Explanation
Respiratory alkalosis in a patient receiving assist-control ventilation (ACV) usually results from hyperventilation, which causes excessive CO₂ elimination. The primary intervention is to reduce the ventilator rate to allow CO₂ to accumulate to normal levels, restoring acid-base balance.
Rationale for Correct Answer
1. Decrease the ventilator rate: Lowering the respiratory rate reduces minute ventilation, allowing PaCO₂ to rise and correcting respiratory alkalosis. This adjustment directly targets the cause of excessive alveolar ventilation.
Rationale for Incorrect Answers
2. Increase the FiO₂ level: FiO₂ affects oxygenation, not CO₂ elimination. Increasing FiO₂ does not correct alkalosis caused by hyperventilation.
3. Increase the tidal volume: Increasing tidal volume would further increase CO₂ elimination, worsening respiratory alkalosis rather than correcting it.
4. Add positive end-expiratory pressure (PEEP): PEEP improves oxygenation and alveolar recruitment, but it does not correct PaCO₂ or respiratory alkalosis.
Take-Home Points
- Respiratory alkalosis in mechanically ventilated patients is usually caused by hyperventilation.
- Decreasing the ventilator rate is the primary adjustment to normalize PaCO₂.
- Monitor ABGs after ventilator adjustments to ensure correction without compromising oxygenation.
- Always assess patient comfort, anxiety, and pain, as these can contribute to hyperventilation.
Correct Answer is C
Explanation
A mechanically ventilated, orally intubated patient who is restless and anxious is at risk for accidental extubation, even if oxygen saturation is adequate. The first priority is to reduce agitation safely through sedation and continuous presence of a caregiver or nurse, addressing both comfort and safety before considering restraints.
Rationale for Correct Answer
3. Administer sedatives and have a caregiver stay with the patient: Sedation decreases anxiety and restlessness, reducing the likelihood of self-extubation or tube displacement. A caregiver or nurse provides constant supervision, ensuring rapid intervention if the patient attempts to pull at the tube. This approach addresses the root cause of agitation while maintaining patient safety.
Rationale for Incorrect Answers
1. Obtain an order and apply soft wrist restraints: Restraints should be a last resort after sedation and close monitoring fail. Applying restraints first does not address anxiety, may increase agitation, and carries ethical considerations.
2. Remind the patient that he needs the tube inserted to breathe: Verbal reassurance alone is insufficient for a patient who is physiologically and psychologically distressed and may not fully comprehend due to sedation or confusion.
4. Move the patient to an area close to the nurses’ station for closer observation: While closer observation may help, it does not reduce agitation or prevent self-extubation by itself; sedation and continuous presence are more effective first-line interventions.
Take-Home Points
- Sedation and constant supervision are first-line measures to prevent accidental extubation in anxious, intubated patients.
- Restraints are a secondary measure and should be used only if sedation and monitoring are insufficient.
- Always assess agitation, pain, and discomfort in ventilated patients to guide safe interventions.
- Preventing self-extubation reduces risk of hypoxia, airway trauma, and ventilator complications.
Whether you are a student looking to ace your exams or a practicing nurse seeking to enhance your expertise , our nursing education contents will empower you with the confidence and competence to make a difference in the lives of patients and become a respected leader in the healthcare field.
Visit Naxlex, invest in your future and unlock endless possibilities with our unparalleled nursing education contents today
Report Wrong Answer on the Current Question
Do you disagree with the answer? If yes, what is your expected answer? Explain.
Kindly be descriptive with the issue you are facing.