What are the recommended tidal volume and plateau pressure settings for mechanical ventilation?

Recommended Tidal Volume and Plateau Pressure Settings for Mechanical Ventilation

For mechanical ventilation, use a tidal volume of 6 mL/kg predicted body weight (PBW) with plateau pressures maintained below 30 cmH2O for patients with ARDS, while patients without ARDS should receive 6-10 mL/kg PBW with plateau pressures below 25 cmH2O. 1

Tidal Volume Recommendations

For Patients with ARDS:

• Use low tidal volume ventilation of 6 mL/kg PBW as this has been shown to improve mortality in critical care settings 1, 2
• This lung-protective strategy decreases the risk of systemic cytokine-mediated nonpulmonary organ dysfunction 1
• Lower tidal volumes minimize alveolar barotrauma and have beneficial effects on hemodynamic status by reducing negative effects of positive pressure ventilation on preload 1

For Patients without ARDS:

• For patients requiring mechanical ventilation for reasons other than ARDS, tidal volumes between 6-10 mL/kg PBW are appropriate 1
• The PREVENT trial compared 6 mL/kg PBW with 10 mL/kg PBW in non-ARDS patients and found no significant difference in outcomes 1
• Even in non-ARDS patients, lung-protective ventilation with lower plateau pressures helps prevent ventilator-induced lung injury 1

Plateau Pressure Targets

For Patients with ARDS:

• Maintain plateau pressure below 30 cmH2O to prevent ventilator-induced lung injury 1, 2
• Driving pressure (ΔP = Plateau pressure – PEEP) predicts outcomes better than other ventilatory parameters, with values exceeding 15 cmH2O being particularly concerning 1
• Despite tidal volume and plateau pressure limitation, patients with larger non-aerated lung compartments may still experience tidal hyperinflation 3

For Patients without ARDS:

• Aim for plateau pressures below 25 cmH2O in patients without ARDS 1, 4
• Regularly measure both peak and plateau pressures to assess the effectiveness of ventilation interventions 4

Strategies to Optimize Ventilation

• Calculate driving pressure (plateau pressure - PEEP) as it's a strong predictor of outcomes in ARDS patients 1, 4
• Consider switching from volume-controlled to pressure-controlled ventilation to reduce peak airway pressures while maintaining the same tidal volume 4
• Address factors that decrease chest wall compliance, such as draining pleural effusions or ascites that may restrict chest wall movement 4
• Position the patient optimally to maximize chest expansion; consider prone positioning in severe ARDS cases 4
• Adjust I:E ratio to allow for more complete exhalation, which can reduce air trapping and auto-PEEP 4

Common Pitfalls and Caveats

• Females are more likely to receive non-lung-protective ventilation with tidal volumes ≥8 mL/kg compared to males (56% vs 9%) 5
• Always calculate tidal volumes based on predicted body weight rather than actual body weight to avoid overventilation 1
• Delaying intubation in patients with progressive respiratory failure can increase mortality, but premature intubation exposes patients to unnecessary risks 1
• Changing to pressure-controlled ventilation may result in variable tidal volumes if lung compliance changes 4
• Large increases in chest wall stiffness may cause plateau pressure to exceed the recommended upper limit of 30 cmH2O, even when lung stretch is not excessive 1

Monitoring Parameters

• Maintain PaO2 within normal range (70-90 mmHg) or SaO2 between 92-97% 1
• Avoid hyperoxia as it may increase lung inflammation and adversely affect the microcirculation 1
• Monitor for patient-ventilator asynchrony and adjust flow patterns to match patient demand 4
• Calculate driving pressure regularly as it provides information about the functional size of the lung 1