Use the following case study to answer the next 2 questions

Case Study

A 55-year-old male is admitted to the ICU with increasing shortness of breath, cough, and fever. He has a history of COPD and was recently diagnosed with COVID-19. His vital signs are: BP 90/60 mmHg. HR 120 bpm, RR 32 breaths/min, SpO2 88% on 6L/min oxygen via nasal cannula, Temp 38.9°C (102°F). ABG results show: pH 7.26, PaO2 58 mmHg. PaCO2 55 mmHg. HCO3 25 mEq/L.

Which of the following interventions should the nurse prioritize for this patient?

A. Synchronized Intermittent Mandatory Ventilation (SIMV): SIMV delivers a preset number of mandatory breaths with a fixed tidal volume but allows the patient to breathe spontaneously between ventilator-delivered breaths. However, those spontaneous breaths are not assisted by the ventilator.

B. Pressure Support Ventilation (PSV): PSV is used for spontaneous breathing where each patient-initiated breath is supported by a preset inspiratory pressure. It does not deliver mandatory breaths or a fixed tidal volume.

C. Assist-Control (AC) Ventilation: AC mode delivers a preset tidal volume at a preset rate but also assists with every patient-initiated breath by delivering the same preset tidal volume. This ensures consistent ventilation while allowing the patient to initiate breaths, reducing the work of breathing in acute respiratory failure.

D. Continuous Positive Airway Pressure (CPAP): CPAP provides constant pressure throughout the respiratory cycle to keep airways open but does not deliver preset breaths or tidal volumes. It is primarily used for patients who can breathe spontaneously but need support to maintain oxygenation.

A. Hyperventilation: In assist-control (AC) ventilation, every patient-initiated breath is supported with a preset tidal volume. If the patient breathes rapidly, the ventilator will deliver the same volume for each breath, which can result in excessive minute ventilation and respiratory alkalosis due to hyperventilation.

B. Hypercapnia: Hypercapnia is unlikely in AC mode if the ventilator is set correctly, as the preset tidal volume ensures adequate CO2 elimination. Hypercapnia usually occurs if ventilation is inadequate or there is severe underlying lung pathology.

C. Tachycardia: Tachycardia is not a direct complication of AC ventilation; it may occur secondary to hypoxemia, anxiety, or underlying illness but is not caused by the ventilator mode itself.

D. Fever: Fever is unrelated to ventilator mode. It may indicate infection or inflammation but is not a complication of assist-control ventilation.