positive end-expiratory pressure (PEEP)

Indications

• diffuse disease
• stiff lungs
• inability to oxygenate on a non-toxic fiO2 (<50%)
• acute respiratory distress syndrome (ARDS)

Contraindications

• no absolute contraindications
• caution: intracranial abnormalities, lung disease, hypotension

Mechanism of action

• opens up atelectic or fluid-filled alveoli
• decreases ventilation-perfusion mismatch
• improves oxygenation

Complications

• PEEP can decrease cardiac output by decreasing preload, thus worsen oxygen delivery to tissues
• auto PEEP

Management

• Goals
  • decrease FiO2 to non-toxic level (<50%)
  • maintaining cardiac output
• start 5 cm H20*
• > 5 cm of H20 is supraphysiologic
• increase PEEP to decrease FiO2
• indications for PEEP > 10 cm H20 not clear
• adjust PEEP to maintain end-expiratory pressure < 30-35 cm H20

* PEEP-FiO2 Table for Selecting PEEP for the Ventilation of Patients with ARDS

fiO2	PEEP
0.3	5
0.4	5
0.4	8
0.5	8
0.5	10
0.6	10
0.7	10
0.7	12
0.7	14
0.8	14
0.9	14
0.9	16
0.9	18
1.0	18-24

*Also see:

• permissive hypercapnia
• auto PEEP
• mechanical ventilation

More general terms

• alveolar pressure

More specific terms

• auto-PEEP

Additional terms

• lung protective ventilation; low tidal volume ventilation; permissive hypercapnia
• mechanical ventilation (assisted ventilation)