Techniques of Ventilation Using Constant Flow
The traditional concept of gas exchange in the lung during spontaneous breathing or conventional mechanical ventilation (MV) predicts that to achieve adequate gas exchange, the tidal volume (VT) must exceed the dead space (VD). This model is based on the concept that gas transport in the lung takes place in two distinct zones: the conducting airways where gas transport occurs by convection, and the alveolar zone where transport occurs by molecular diffusion. This concept forms the basis for the design of most mechanical ventilators that have been used very successfully over the last fifty years . However, because VT must be relatively large to exceed VD, relatively large pressures are produced in the lung and this is associated with a number of complications including pulmonary barotrauma and hemodynamic compromise.
KeywordsCatheter Dioxide Convection Respiration Washout
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- 3.Hooke R (1667) Account of an experiment, made by R. Hooke, of preserving animals alive by blowing through their lungs with bellows. Philos Trans R Soc Lond 2:539–540Google Scholar
- 8.Holmdahl MH (1956) Pulmonary uptake of oxygen, acid-base metabolism and circulation during prolonged apnea. Acta Chir Scand (Suppl) 212:1–128Google Scholar
- 15.Joels N, Samueloff M (1956) The activity of the medullary centres in diffusion respiration. J Physiol (London) 133:360–372Google Scholar
- 26.Bergosfsky EH, Hurewitz AN (1989) Airway insufflation: Physiological effects on acute and chronic gas exchange in humans. Am Rev Respir Dis 140:885–890Google Scholar
- 39.Vetterman J, Brusasco V, Rehder K (1988) Gas exchange and intrapulmonary distribution of ventilation during continuous-flow ventilation. J Appl Physiol 64:1864–1869Google Scholar
- 47.Fukuchi Y, Ishida K, Yano K, Kayama S, So K, Harasawa H (1984) Significance of cardiogenic gas mixing in constant flow ventilation. Am Rev Respir Dis (abstract) 129:A230Google Scholar
- 51.Shykoff B, Naqvi SSJ, Menon AS, Slutsky AS (1990) Respiratory sinus arrhythmia (RSA) in dogs: effects of phasic afferents and chemostimulation. J Clin Invest (In press)Google Scholar
- 53.Naqvi SSJ, Menon AS, Shykoff B, Rebuck AS, Slutsky AS (1990) Phrenic neural output during hypoxia in dogs: constant flow ventilation (CFV) vs spontaneous breathing. J Appl Physiol (In press)Google Scholar