Non-invasive ventilation (NIV) is an advanced respiratory support technique that assists breathing without the need for endotracheal intubation. It delivers pressurized air and oxygen through a tightly fitted mask over the nose, mouth, or both, helping patients maintain adequate ventilation while preserving natural airway defenses. NIV plays a critical role in ICU and high-dependency units, particularly in patients with reversible respiratory conditions.

The most common indications for NIV include acute exacerbations of chronic obstructive pulmonary disease (COPD), cardiogenic pulmonary edema, obesity hypoventilation syndrome, neuromuscular weakness, and selected cases of pneumonia or respiratory distress. NIV is also widely used to prevent respiratory failure after surgery or to support patients during weaning from invasive ventilation.

NIV works by delivering positive airway pressure in two main forms: continuous positive airway pressure (CPAP) and bilevel positive airway pressure (BiPAP). CPAP provides a constant pressure throughout the breathing cycle, keeping airways open and improving oxygenation. BiPAP delivers different pressures during inhalation and exhalation, assisting both oxygenation and carbon dioxide removal.

One of the major advantages of NIV is avoidance of intubation-related complications such as ventilator-associated pneumonia, airway injury, and heavy sedation. Patients remain conscious, can communicate, cough, and swallow, which contributes to comfort and faster recovery. However, patient cooperation is essential, and NIV is not suitable for individuals who are unconscious, severely agitated, vomiting, or unable to protect their airway.

Close ICU monitoring is mandatory during NIV therapy. Vital signs, blood gases, respiratory effort, and mask fit are continuously assessed. Failure to improve within a defined time frame requires prompt escalation to invasive mechanical ventilation to avoid deterioration.

When used in appropriately selected patients, NIV significantly reduces ICU length of stay, complications, and mortality. Its success depends on timely initiation, expert supervision, and clear criteria for escalation.