What are the indications for zero Positive End-Expiratory Pressure (PEEP) ventilation?

Indications for Zero PEEP Ventilation

Zero PEEP (ZEEP) ventilation is generally not recommended in most clinical scenarios due to its association with atelectasis, decreased end-expiratory lung volume, and potential for lung injury. 1

Why ZEEP is Generally Avoided

ZEEP ventilation has been associated with several negative effects:

• Reduction in end-expiratory lung volume (EELV)
• Increased atelectasis formation
• Decreased respiratory system compliance
• Increased risk of atelectrauma from cyclic lung de-recruitment
• Potential for volutrauma in remaining aerated lung tissue 1

Limited Indications for ZEEP

Despite the general recommendation against ZEEP, there are specific clinical scenarios where it might be considered:

1. Severe Obstructive Disease with Air Trapping

• In patients with severe COPD or asthma experiencing dynamic hyperinflation
• When auto-PEEP (intrinsic PEEP) is already elevated
• To prevent further air trapping and associated hemodynamic compromise 2

2. Right Ventricular Dysfunction or Pulmonary Hypertension

• When any additional PEEP might worsen right ventricular afterload
• In cases where hemodynamic stability is precarious
• When continuous monitoring shows deterioration with even low PEEP levels 2

3. Bronchopleural Fistula

• To minimize air leak through the fistula
• When the goal is to promote fistula healing
• In conjunction with other strategies to manage the fistula

4. Specific Surgical Procedures

• During certain thoracic surgical procedures where surgeon preference dictates
• For brief periods during specific surgical maneuvers 3

Important Considerations When Using ZEEP

If ZEEP must be used:

• Limit duration as much as possible
• Closely monitor for development of atelectasis
• Consider recruitment maneuvers before and after ZEEP periods
• Maintain adequate FiO2 to prevent hypoxemia
• Monitor hemodynamics closely
• Avoid disconnection from the ventilator circuit 1, 2

Contraindications to ZEEP

ZEEP should be particularly avoided in:

• ARDS or acute lung injury patients
• Patients with atelectasis-prone conditions
• Post-surgical patients at risk for respiratory complications
• Patients with poor respiratory mechanics
• During emergence from anesthesia 1
• Before extubation (avoid apnea with ZEEP) 1

Expert Consensus Recommendations

Strong expert consensus (100%) recommends:

• Avoiding ZEEP during emergence from anesthesia
• Avoiding apnea with ZEEP before extubation 1

The ventilator should initially be set to deliver tidal volumes of 6-8 ml/kg predicted body weight with PEEP of at least 5 cm H2O. ZEEP is explicitly not recommended by multiple guidelines. 1, 2

Monitoring During Mechanical Ventilation

When mechanical ventilation is required, regardless of PEEP level:

• Monitor dynamic compliance, driving pressure, and plateau pressure
• Ensure continuous hemodynamic and oxygen saturation monitoring
• Adjust ventilator settings based on patient response
• Target SpO2 of 92-97% (or 88-92% in ARDS with PEEP ≥10 cmH2O) 2

Remember that the primary goal of mechanical ventilation is to optimize respiratory function while minimizing ventilator-induced lung injury, which is generally better achieved with some level of PEEP rather than ZEEP in most clinical scenarios.