A patient in acute respiratory failure is receiving ACV with a positive end-expiratory pressure (PEEP) of 10 cm H₂O. What sign alerts the nurse to undesirable effects of increased airway and thoracic pressure?

Immediately after endotracheal tube (ETT) insertion, the nurse must confirm correct tube placement to ensure ventilation and oxygenation. Assessing bilateral breath sounds and observing for symmetrical chest rise provides rapid, reliable evidence that the tube is in the trachea rather than the esophagus.

Rationale for Correct Answer

2. Assess bilateral breath sounds and observe for symmetrical chest rise: Auscultation of both lungs and observation of chest movement immediately confirm tracheal placement. Absence of breath sounds on one side may indicate mainstem bronchus intubation, and absent breath sounds bilaterally suggests esophageal placement, both of which require immediate correction.

Rationale for Incorrect Answers

1. Obtain a chest X-ray: A chest X-ray is the gold standard for confirming tube depth but is not immediate. Initial verification must be done at the bedside before ventilating.

3. Check the patient’s oxygen saturation after 10 minutes: Waiting 10 minutes delays recognition of malposition, risking hypoxia. Immediate assessment is required.

4. Inflate the cuff and secure the tube: While necessary for stabilizing the airway, cuff inflation alone does not confirm correct tracheal placement.

Take-Home Points

• Immediate confirmation of ETT placement is critical to prevent hypoxia or gastric insufflation.
• Bilateral breath sounds and chest rise are rapid bedside assessments for correct placement.
• Chest X-ray should follow to verify tube depth, but is not the first step.
• Always monitor oxygen saturation and ventilator parameters after securing the tube.

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.