Principles of Positive Pressure Mechanical Ventilatory Support

Duke University Medicai Center, Durham, North Caroiina, U.S.A. 

Positive pressure mechanical ventilation (PPMV) uses positive pressure tidal breaths to either totally or partially affect O2 and CO2 transport between the environment and the alveolar spaces. Positive pressure is also used to maintain alveolar patency during expiration. The desired effect of PPMV is to maintain appropriate levels of P02 and PCO2 in arterial blood while properly unloading the ventilatory muscles. Although a life-support technology, PPMV can also be harmful if used inappropriately. The discussion that follows, describes the principles of PPMV, its physiologic effects, the complications that can occur, and recent innovations. 

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Principles of Positive Pressure Mechanical Ventilatory Support... 

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