Ventilated Patient With Rising Airway Pressures
Mr. Haddad, 47, is day 3 of mechanical ventilation for severe pneumonia. Settings: volume control, tidal volume 450 mL, PEEP 8 cm H2O, FiO2 0.50. Over 30 minutes the peak airway pressure rose from 28 to 44 cm H2O while plateau pressure rose from 20 to 32 cm H2O. Respiratory rate is 30/min, SpO2 88%, heart rate 128/min, blood pressure 96/58 mmHg. Breath sounds are diminished on the right with crackles on the left. He is restless and the ventilator alarms repeatedly. Sedation is light; he is triggering some breaths.
1. Differentiate the cause of the pressure change and state your immediate actions.
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Differentiation: Both peak and plateau pressures rose, which points to a problem with compliance rather than purely resistance. A resistance problem (secretions, bronchospasm, kinked tube) raises peak pressure but leaves plateau near normal. Here the rising plateau suggests worsening alveolar filling or stiff lungs - consistent with pneumonia progression, atelectasis, or early ARDS - or a pneumothorax, especially with diminished right breath sounds and hypotension.
Immediate actions:
- Call for help and manually ventilate with a bag-valve to assess compliance and confirm the problem; listen for breath sounds.
- Check tube position and patency, suction if secretions are suspected, and verify the circuit is not kinked.
- Obtain an urgent chest radiograph and prepare for possible needle decompression if tension pneumothorax is suspected (tracheal deviation, worsening hypotension, absent sounds).
- Increase FiO2 temporarily to maintain SpO2, and notify the provider of the pressure trend.
- Check sedation and synchrony; ensure the patient is not fighting the ventilator.
- Monitor blood pressure closely; the rising intrathoracic pressure can impair venous return.
Document pressures, interventions, and response.
2. How do you adjust ventilation and monitor for ventilator-induced lung injury once the cause is addressed?
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Ventilation adjustment (per order/protocol): Use lung-protective principles - target tidal volume around 6 mL/kg predicted body weight, keep plateau pressure at or below 30 cm H2O, and use the lowest PEEP that maintains oxygenation. Mr. Haddad's tidal volume of 450 mL and plateau of 32 cm H2O exceed protective targets; clarify with the provider to reduce tidal volume and adjust PEEP. Consider permissive hypercapnia if ordered and tolerated.
Monitoring for injury:
- Track peak and plateau pressures every shift and after any change; calculate driving pressure.
- Monitor SpO2, ABGs, and end-tidal CO2.
- Watch for barotrauma signs: sudden desaturation, asymmetric breath sounds, subcutaneous emphysema, hypotension.
- Assess for auto-PEEP in an obstructive component.
- Maintain sedation and analgesia to promote synchrony, and use lung-protective suctioning.
Communication: Update the team on pressure trends and document changes. Educate the family briefly on the plan.