• Hypoxemia is generally attributed to one of four processes: hypoventilation, shunt (right to left), diffusion limitation, and ventilation/perfusion (VA/Q) inequality. (wikipedia.org)
  • The significant increase in wasted ventilation (alveolar dead space) in the R group only may be secondary to the higher carbon dioxide tension, perhaps related to bronchodilatation. (atsjournals.org)
  • Altogether, synchronized respiratory muscle contraction generates a breath which ultimately drives alveolar ventilation and blood gas regulation ( Figure 2.1 ) [7] . (veteriankey.com)
  • Because there is no blood flow, no gas exchange is possible, and the region functions as alveolar dead space, or wasted ventilation. (clinicalgate.com)
  • Since then, Sassoon and colleagues ( 8 ) have supported this finding, whereas Dunn and colleagues ( 6 ) have found more evidence for a reduction in respiratory drive to ventilation. (atsjournals.org)
  • During ventilation, respiratory mechanics and arterial oxygen and carbon dioxide levels change as conditions are altered, thus providing further sensory feedback to brainstem respiratory areas which imparts the respiratory continuum. (veteriankey.com)
  • The first section reviews the normal (gravity-determined) distribution of perfusion and ventilation, the major nongravitational determinants of resistance to perfusion and ventilation, transport of respiratory gases, and the pulmonary reflexes and special functions of the lung. (clinicalgate.com)
  • The data produced by the MIGET is an approximation of the distribution of V A / Q {\displaystyle V_{A}/Q} ratios across the entire lung. (wikipedia.org)
  • Ventilation, cardiac output, and the distribution of ventilation-perfusion (V˙ a /Q˙ ) ratios were measured using the multiple inert gas elimination technique breathing air and then 100% oxygen through a nose mask. (atsjournals.org)
  • The other 10 patients showed a change in Pa CO 2 of − 1.3 ± 2.2 mm Hg breathing oxygen and were classified as nonretainers (NR). Ventilation fell significantly from 9.0 ± 1.5 to 7.2 ± 1.2 L/min in the R group breathing oxygen (p = 0.007), whereas there was no change in ventilation in the NR group (9.8 ± 1.8 to 9.9 ± 1.8 L/min). (atsjournals.org)
  • This study suggests that an overall reduction in ventilation characterizes oxygen-induced hypercapnia, as an increased dispersion of blood flow from release of hypoxic vasoconstriction occurred to a significant and similar degree in both groups. (atsjournals.org)
  • High flow oxygen was shown to result in worsening ventilation-perfusion mismatch due to absorption atelectasis and inhibition of reflex pulmonary vasoconstriction. (bmj.com)
  • 19 This effect is likely to be due to maldistribution of blood flow, with functional shunting to protect the vital organs from non-physiological effects of high oxygen tension. (bmj.com)
  • Moreover, a similar understanding exists for the relationship between the distribution of blood flow and the distribution of ventilation. (wikipedia.org)
  • The technique quantifies true shunt, physiological dead space ventilation, ventilation versus blood flow (VA/Q) ratios, and diffusion limitation. (wikipedia.org)
  • In this model, retention (R) is measured from the ratio P A / P v {\displaystyle P_{A}/P_{v}} . Stated mathematically: R = λ λ + V A / Q {\displaystyle R={\frac {\lambda }{\lambda +V_{A}/Q}}} From this equation, we can measure the levels of each inert gas retained in the blood. (wikipedia.org)
  • The former is associated with control of ventilation or muscle function, whereas the latter is associated with the intrapulmonary control of ventilation-perfusion matching. (atsjournals.org)
  • The relative importance of a reduction in total ventilation and an increase in Bohr dead space (V d/Vt) in causing hyperoxic hypercapnia remains controversial. (atsjournals.org)
  • The technique quantifies true shunt, physiological dead space ventilation, ventilation versus blood flow (VA/Q) ratios, and diffusion limitation. (wikipedia.org)
  • Hypoxemia is generally attributed to one of four processes: hypoventilation, shunt (right to left), diffusion limitation, and ventilation/perfusion (VA/Q) inequality. (wikipedia.org)
  • After treatment, cardiac output, Pa o 2 , and o 2 increased and distribution returned to normal excepted for the persistence of a slightly increased shunt. (comprehensivephysiology.com)
  • Moreover, a similar understanding exists for the relationship between the distribution of blood flow and the distribution of ventilation. (wikipedia.org)