Learning Objectives: 1) Explain the rationale for noninvasive ventilation. 2) Describe the effects, indications, advantages, disadvantages, & complications associated with negative pressure ventilation. 3) Describe the operation of specific negative pressure ventilators 4) Describe the modes, effects, complications, indications, & contraindications associated with noninvasive positive-pressure ventilation (NPPV). 5) Describe the evidence basis for NPPV for selected conditions. 6) Compare the interfaces used in NPPV with respect to their indications, advantages, & limitations. 7) Describe the issues pertaining to types of NPPV circuits & humidification systems. 8) Compare the ventilator types and modes applied to NPPV with respect to their advantages and disadvantages. 9) Describe techniques for ventilator control adjustments for NPPV. 10) Discuss clinical issues pertaining to NPPV, including aerosol delivery, heliox, clinical sites, and end-of-life care.