03. Noninvasive Positive Pressure Ventilation (NIPPV) BiPAP or CPAP

Clinical Indications for NIPPV

  • Moderate-severe COPD  exacerbation (PaCO2 >45 mmHg or pH <7.3): BiPAP is first-line treatment.
    • Decreased mortality, intubation rate, treatment failure, hospital length of stay and complications related to treatment.
  • Cardiogenic pulmonary edema: CPAP and BiPAP decrease afterload, decrease wall stress, improve oxygenation, and improve dyspnea.
    • Shown to lower in-hospital mortality.
  • Hypoxemic respiratory failure (consider HFNC as well):
    • Decreased ICU mortality and intubation in patients with community-acquired pneumonia WITHOUT significant secretions.
    • Decreased ICU mortality, intubation rate, and ICU length of stay in immunosuppressed patients with pulmonary infiltrates and fever (likely due to decreased ventilator-associated pneumonia in these vulnerable patients).
  • Immediately post-extubation (planned NIPPV)
    • Decreased all-cause mortality, ICU length of stay, hospital length of stay, and rates of VAP. No increased rate of extubation failure or reintubation. Benefits greatest in COPD patients.
  • Severe asthma exacerbation:
    • Data inconclusive, though suggest decreased rate of hospitalization.

When NIPPV is not indicated

  • Severe ARDS: data limited and inconclusive, though recent evidence suggest BiPAP (or HFNC) in conjunction with awake proning may avert some intubations for mild or moderate ARDS. This strategy appears to work reasonably well for ARDS due to COVID-19 pneumonia even when moderate to severe.
  • Post-extubation respiratory failure: unplanned post-extubation NIPPV may increase mortality by delaying re-intubation. If someone is in respiratory distress post-extubation, re-intubation may be necessary!

Contraindications to NIPPV

  • Impending circulatory collapse or respiratory arrest.
  • Altered mental status / inability to protect airway and manage secretions (although a short trial (1-2 hours) with close monitoring may improve COPD with CO2 narcosis).
  • Excessive secretions or upper GI bleeding.
  • Upper airway obstruction.
  • Recent facial trauma or surgery (due to risk of worse face trauma/abrasion).
  • Recent upper airway or gastrointestinal surgery (due to gastric distention).
  • Inability to get good fit with mask (facial hair, facial deformity).
  • Inability to adequately monitor patient (patient should be in the ED or ICU; use with extreme caution in step-down or transitional units).

Predictors of failing NIPPV

  • Very low pH (<7.25) on initial ABG (<7.1 for COPD exacerbation).
  • Severely altered mental status (GCS<10).
  • Rapid respiratory rate (>30 breaths/minute).
  • Advanced age and higher number of comorbidities.

Modes and Settings

  • CPAP (Continuous Positive Airway Pressure): usually at 5-10 cm H20. For OSA and CHF.
  • BiPAP (Bi-level Positive Airway Pressure): usually can start at around 10/5 cm H2O and titrate accordingly with RT. Provides higher set pressure during inspiration than during expiration (PEEP).
  • AVAPS (Average Volume-Assured Pressure Support): special mode that combines BiPAP with a backup rate for non-spontaneous breaths to guarantee a minimum minute ventilation. Not used very commonly but can be helpful for severe obesity hypoventilation, central apnea, and neuromuscular weakness.

Tips for Use

  1. MOST IMPORTANT:  Assess the patient’s clinical status within 30 minutes and with an ABG after 1-2 hours of therapy.  Failure of ABG to improve with therapy is highly predictive of subsequent failure, and intubation should be considered before the patient deteriorates further.
  2. If available use helmet masks as rates of intubation and mortality are lower than for face masks.
  3. Use face mask for at least the first few hours to minimize air leaks and nasal resistance.
  4. If patient improves and is not a “mouth breather,” a nasal mask/pillows may be tried for comfort.

Keywords: noninvasive ventilation, CPAP, BiPAP

Burns KEA, Meade MO, Premji A, Adhikari NKJ. Noninvasive positive-pressure ventilation as a weaning strategy for intubated adults with respiratory failure. Cochrane Database of Systematic Reviews 2013, Issue 12. 

Demoule A, Girou E, Richard JC, et al. Benefits and risks of success or failure of noninvasive ventilation. Intensive Care Med. 2006;32(11):1756. 

Ding, L., Wang, L., Ma, W. et al. Efficacy and safety of early prone positioning combined with HFNC or NIV in moderate to severe ARDS: a multi-center prospective cohort study. Crit Care 24, 28 (2020). 

Ferreyro BL, Angriman F, Munshi L, et al. Association of Noninvasive Oxygenation Strategies With All-Cause Mortality in Adults With Acute Hypoxemic Respiratory Failure: A Systematic Review and Meta-analysis. JAMA. 2020;324(1):57–67. 

Girou E, Schortgen F, Delclaux C et al. Association of noninvasive ventilation with nosocomial infections and survival in critically ill patients. JAMA. 2000 Nov 8;284(18):2361-7. 

Peter JV, Moran JL, Phillips-Hughes J, Warn D. Noninvasive ventilation in acute respiratory failure--a meta-analysis update. Crit Care Med. 2002;30(3):555. 

Ram FS, Picot J, Lightowler J, Wedzicha JA. Non-invasive positive pressure ventilation for treatment of respiratory failure due to exacerbations of chronic obstructive pulmonary disease. Cochrane Database Syst Rev. 2004; 

Vital FM, Ladeira MT, Atallah AN. Non-invasive positive pressure ventilation (CPAP or bilevel NPPV) for cardiogenic pulmonary oedema. Cochrane Database Syst Rev. 2013; Issue 5. 

Weng CL, Zhao YT, Liu QH, et al. Meta-analysis: Noninvasive ventilation in acute cardiogenic pulmonary edema. Ann Intern Med. 2010;152(9):590.