Humidification insights in mechanical ventilation and respiratory support. A narrative review

INTRODUCTION: Adequate airway humidification is important in respiratory care, significantly affecting patient comfort, airway function, and clinical outcomes. Adequate humidification helps prevent airway dryness, mucosal damage, and respiratory complications, making its understanding crucial for effective patient management. AREAS COVERED: The bibliographic database PubMed and search engine Google Scholar was searched for systematic reviews and metanalyses, clinical trials and observational studies on humidification practices in adult spontaneously breathing tracheostomized patients and those receiving invasive mechanical ventilation, noninvasive ventilation (acute and long term), and oxygen therapy (low and high flow). The physiological principles of airway humidification, the characteristics and applications of various active and passive humidification devices, impact of ventilator settings, interfaces, and patient-specific factors on humidification efficacy were reviewed. EXPERT OPINION: There is no doubt that humidification plays a crucial role in maintaining airway mucosal integrity. A comprehensive knowledge of humidification strategies is must for their proper implementation in clinical practice. Even when upper airways are intact, as in NIV or oxygen therapy, humidification may still be necessary to prevent discomfort and maintain mucosal integrity. Future research should focus on refining humidification strategies to maximize efficacy, minimize complications and developing improved methods for monitoring airway humidity at the patient interface.