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Critical Care

Noninvasive Ventilation

Noninvasive positive pressure ventilation is an intervention that delivers pressurized gas to the lungs via an external interface, augmenting alveolar ventilation and reducing the work of breathing without endotracheal intubation. Indications include acute and chronic respiratory failure, particularly cases with hypercapnic and cardiogenic etiologies. Contraindications include impaired airway protection, hemodynamic instability, and facial trauma. Advantages over intubation include reduced risk

v1 · Reviewed Nov 7, 2026 by Automated Clinical Reviewer (Strict Verbatim v1)
  • Arterial pH below 7.35 with elevated PaCO2 indicates acute or chronic hypercapnic respiratory failure requiring intensive care unit admission.
  • respiratory or cardiac arrest, in which immediate invasive support is required.
  • inability to protect the airway
  • hemodynamic instability
  • Determine indications for endotracheal intubation in patients receiving noninvasive positive pressure ventilation by assessing for clinical deterioration, ventilatory failure, or intolerance to therapy.
  • arterial blood gas abnormalities
  • Venous blood gas (VBG) or PaCO2 monitoring may be used instead.
  • Risk factors for NIV failure include PaO2/FiO2 less than 150 in acute respiratory distress syndrome
ROX index
The ROX index, calculated as peripheral oxygen saturation (SpO2) divided by the fraction of inspired oxygen (FiO2), then divided by respiratory rate (SpO2/FiO2 ÷ respiratory rate), is used to monitor HFNO, with a value below 4.88 at 12 hours indicating a high likelihood of failure.
  • Implement noninvasive positive pressure ventilation according to evidence-based protocols, ensuring proper initiation and equipment setup, titration, and ongoing assessment of patient response.
  • NIPPV should be initiated after careful selection of the patient, ventilator, and interface
  • BiPAP for acute or acute-on-chronic respiratory acidosis secondary to COPD exacerbation, with pH at or below 7.35
  • BiPAP or continuous positive airway pressure (CPAP) for CPE
  • CPAP or NIV if work of breathing is increased
EPAP
Not specified in source
Adult
5 cm H2O
Renal
Not specified in source
Duration
Not specified in source
Pressure support
Not specified in source
Adult
10 to 15 cm H2O
Renal
Not specified in source
Duration
Not specified in source
IPAP
Not specified in source
Adult
15 to 20 cm H2O
Renal
Not specified in source
Duration
Not specified in source
  • Absolute contraindications to NIV include conditions that prevent safe application or effective ventilation.
  • Relative contraindications encompass situations in which NIV may be attempted with caution or close monitoring, but the risk of failure or complications is elevated.
  • facial trauma or burns, which may impede mask fitting
  • fixed upper airway obstruction, which prevents airflow
  • active vomiting, which increases the risk of aspiration
  • life-threatening hypoxemia
  • HFNO now an acceptable alternative
  • Monitoring in the acute setting requires evaluation of both subjective and physiologic patient responses.
  • Patients likely to succeed with NIPPV exhibit a reduction in respiratory rate within 1 to 2 hours, decreased heart rate, and improved ventilator synchrony.
  • ABG analysis should be performed 1 hour after BiPAP initiation, as decreases in arterial carbon dioxide pressure (PaCO2) and increases in pH predict treatment success.
  • Tidal volume and air leak require close monitoring, as uncorrected abnormalities can contribute to NIPPV failure.
  • Hemodynamic parameters, including blood pressure and heart rate, must also be observed because increased intrathoracic pressure can elevate right ventricular afterload and reduce right ventricular preload.
  • The most common complication of NIPPV is mask discomfort.
  • Serious pressure-related complications include pneumothorax, pneumocephalus, and pneumomediastinum associated with NIPPV in the setting of SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) pneumonia.
  • Aspiration is a major complication, and careful patient selection is required to minimize aspiration risk during NIPPV use.
  • review
    Noninvasive Ventilation. StatPearls [Internet] — Abdulghani Sankari, Vaibhav Bora — StatPearls Publishing, 2026

Decision support only. Verify against local protocols and current labeling. Source: www.ncbi.nlm.nih.gov