What to do when plateau pressure is high in an intubated patient and tidal volume (TV) is not being delivered?

Management of High Plateau Pressure with Inadequate Tidal Volume Delivery

When plateau pressure is high and tidal volume is not being delivered in an intubated patient, immediately troubleshoot for endotracheal tube obstruction, then systematically reduce tidal volume to 4-6 mL/kg predicted body weight while accepting permissive hypercapnia to maintain plateau pressure below 30 cmH2O. 1, 2

Immediate Troubleshooting Steps

Rule Out Mechanical Obstruction First

• Check for endotracheal tube obstruction by inspecting for secretions or kinking, as progressive ETT occlusion can prevent tidal volume delivery even when pressures are elevated 3
• Pass a suction catheter through the ETT to confirm patency—if resistance is met, the tube may be occluded and require replacement 3
• In pressure-controlled modes specifically, ETT obstruction may not reduce delivered tidal volumes until occlusion is nearly complete, making this a critical first step 3

Assess Ventilator-Patient Synchrony

• Evaluate for patient-ventilator asynchrony, which can elevate peak pressures and prevent adequate tidal volume delivery 4
• Consider adjusting sedation if the patient is fighting the ventilator and contributing to elevated pressures 4

Ventilator Management Strategy

Primary Approach: Reduce Tidal Volume Aggressively

• Decrease tidal volume from 6 mL/kg predicted body weight down to 4 mL/kg predicted body weight if plateau pressure remains >30 cmH2O 1, 2
• This approach is supported by the landmark ARDS Network trial showing mortality reduction with tidal volumes of 6 mL/kg and plateau pressures ≤30 cmH2O compared to traditional higher volumes 5
• Calculate tidal volume based on predicted body weight, not actual body weight or ideal body weight, to avoid overventilation 1, 2

Accept Permissive Hypercapnia

• Allow hypercapnia to develop as long as pH remains >7.15-7.20 unless contraindicated by elevated intracranial pressure 1, 6
• Consider sodium bicarbonate or THAM infusion to facilitate tolerance of permissive hypercapnia if acidosis becomes severe 1

Optimize PEEP Strategy

• Maintain adequate PEEP to prevent alveolar collapse while being mindful that PEEP contributes to total end-inspiratory pressure 1, 2
• Calculate driving pressure (plateau pressure minus PEEP)—values exceeding 15 cmH2O are particularly concerning and predict worse outcomes 2, 4

Address Chest Wall Compliance Issues

Identify Reversible Causes

• Drain pleural effusions or ascites that restrict chest wall movement, as these decrease chest wall compliance and elevate plateau pressure even when lung stretch is not excessive 1, 4
• Large increases in chest wall stiffness may cause plateau pressure to exceed 30 cmH2O even when lung stretch is acceptable 1
• In such cases, the elevated plateau pressure may not reflect dangerous alveolar distension 1

Positioning Strategies

• Consider prone positioning for severe ARDS patients (PaO2/FiO2 ratio <100 mmHg), which can improve lung mechanics and reduce plateau pressures 1, 4
• Optimize patient positioning to maximize chest expansion 4

Ventilator Mode Considerations

Switching Modes

• Consider changing from volume-controlled to pressure-controlled ventilation to reduce peak airway pressures while maintaining similar tidal volumes 2, 4
• Be aware that pressure-controlled ventilation may result in variable tidal volumes if lung compliance changes, requiring close monitoring 4
• No single ventilation mode (pressure control vs. volume control) has proven superior when lung-protective principles are maintained 1

Adjust Inspiratory-Expiratory Ratio

• Shorten inspiratory time to allow more complete exhalation, reducing air trapping and auto-PEEP 4
• Auto-PEEP increases baseline pressure and adds to end-inspiratory stretch, worsening the plateau pressure problem 6

Critical Monitoring Parameters

Essential Measurements

• Measure plateau pressure by performing an inspiratory hold maneuver (0.5-second pause at end-inspiration) 5, 6
• Monitor delivered tidal volume continuously—in pressure-support modes, uncontrolled large tidal volumes can develop and cause barotrauma 7
• Calculate and track driving pressure as a strong predictor of outcomes 2, 4

Oxygenation Targets

• Maintain PaO2 between 70-90 mmHg or SaO2 between 92-97% to avoid both hypoxemia and hyperoxia 1, 2
• Hyperoxia increases lung inflammation and adversely affects microcirculation without providing benefit 1

Common Pitfalls to Avoid

• Do not delay addressing elevated plateau pressures—continuing high plateau pressure ventilation increases mortality risk 5, 8
• Younger age, higher body mass index, non-white race, and greater severity of illness are independently associated with elevated plateau pressure, so consider starting with lower initial tidal volumes (closer to 4-5 mL/kg) in these populations 8
• In pressure-support ventilation, tidal volumes must be closely monitored as patients may receive excessive volumes (>9.5 mL/kg predicted body weight), increasing risk of barotrauma 1, 7
• When plateau pressure exceeds 30 cmH2O despite tidal volume reduction to 6 mL/kg, do not hesitate to reduce further to 4 mL/kg rather than accepting the elevated pressure 1