Noninvasive Positive Pressure Ventilation: Physiological Foundations, Clinical Applications, and Contemporary Evidence

Noninvasive positive pressure ventilation (NIPPV) represents a cornerstone of modern respiratory support, offering a mechanistically sophisticated alternative to invasive mechanical ventilation across diverse clinical contexts. Since its rudimentary origins in the eighteenth century through the iron lung era and the pivotal polio epidemic innovations, NIPPV has evolved into a physiologically precise intervention grounded in respiratory mechanics and gas exchange physiology. This comprehensive review examines the anatomical and physiological principles underpinning NIPPV, including lung compliance dynamics, transpulmonary pressure relationships, and the threefold mechanisms by which positive pressure reduces work of breathing. Contemporary evidence from the American Thoracic Society and European Respiratory Journal establishes strong recommendations for NIPPV in chronic obstructive pulmonary disease exacerbations and cardiogenic pulmonary edema, with conditional support across additional acute respiratory failure etiologies. The landmark RENOVATE trial has further refined our understanding of high-flow nasal oxygen noninferiority across heterogeneous populations, reshaping clinical decision-making paradigms. This article delineates evidence-based indications and contraindications, equipment specifications including bilevel positive airway pressure and average volume-assured pressure support modalities, titration protocols for acute and chronic settings, complication profiles, and the critical importance of interprofessional collaboration. The clinical significance of early NIPPV initiation, systematic failure recognition, and timely escalation to intubation is emphasized to prevent patient self-inflicted lung injury. By synthesizing physiological theory with pragmatic clinical guidance, this review aims to equip healthcare professionals with the conceptual framework and technical knowledge necessary for optimal NIPPV utilization.