Non-invasive ventilation
Introduction
Non-invasive ventilation (NIV) is a method of providing ventilatory support to patients who are unable to breathe adequately on their own. This method of ventilation is characterized by the use of a mask or other interface, rather than an endotracheal tube, to deliver a mixture of oxygen and air to the patient. NIV has been shown to reduce the need for invasive mechanical ventilation, decrease hospital length of stay, and improve survival in certain patient populations.
Indications and Contraindications
NIV is indicated in a variety of clinical scenarios, including acute respiratory failure, chronic obstructive pulmonary disease (COPD), and congestive heart failure. It is also used in the management of sleep-disordered breathing, such as obstructive sleep apnea (OSA), and in certain neuromuscular diseases.
However, NIV is not suitable for all patients. Contraindications include facial trauma or deformity, inability to protect the airway, high risk of aspiration, severe hemodynamic instability, and uncooperative or agitated patients.
Techniques
There are two primary techniques of NIV: continuous positive airway pressure (CPAP) and bilevel positive airway pressure (BiPAP).
CPAP provides a constant level of pressure throughout the respiratory cycle, which helps to keep the airways open, while BiPAP provides a higher pressure during inspiration and a lower pressure during expiration, which can make it easier for the patient to exhale.
Complications
While NIV is generally well-tolerated, complications can occur. These include skin breakdown from the mask, dryness of the nose and throat, eye irritation, gastric distension, and aspiration. More serious complications, such as pneumothorax, are rare.
Future Directions
As technology advances, NIV is likely to become more sophisticated and more widely used. Future research is likely to focus on improving patient comfort and adherence, optimizing ventilator settings, and expanding the indications for NIV.