TY - JOUR
T1 - Dependence of middle ear gas composition on pulmonary ventilation
AU - Mover-Lev, Haya
AU - Harell, Moshe
AU - Levy, Dalia
AU - Ar, Amos
AU - Luntz, Mlchal
AU - Sadé, Jacob
N1 - Funding Information:
From the Ear Research Laboratory, Department of Bioengineering (Mover-Lev, Levy, Luntz, Harell, Sade), the Department of Zoology (Ar), and The Sara and Felix Dumont Chair for Hearing Research Disorders (Sade), Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel. This research was supported by the Israel Foundation, administered by the Israel Academy of Science and Humanities. 4 1997 106 4 314 319 © 1997 SAGE Publications 1997 SAGE Publications
PY - 1997
Y1 - 1997
N2 - The middle ear (ME) steady state gas composition resembles that of mixed venous blood. We changed arterial and venous blood gases by artificially ventilating anesthetized guinea pigs and measured simultaneous ME gas changes during spontaneous breathing, hyperventilation, and hypoventilation. During hyperventilation, PaCO2 and PvCO2 (a = arterial, v = venous) decreased from 46.0 and 53.0 mm Hg to 17.9 and 37.5 mm Hg, respectively, while PaO2 and PvO2 (85.6 and 38.2 mm Hg) did not change. This was accompanied by an ME PCO2 decrease from 70.4 to 58.8 mm Hg and a PO2 decrease from 36.8 to 25.4 mm Hg. During hypoventilation, PaCO2 and PvCO2 increased to 56.8 and 66.4 mm Hg, while PvO2 decreased to 21.8 mm Hg. The ME PCO2 increased simultaneously to 88.8 mm Hg and the ME PO2 decreased to 25.4 mm Hg. The ME PO2 decrease during hyperventilation may be explained by a 33% decrease in ME mucosa perfusion, calculated from the ME ventilation-perfusion ratio. This study shows that ME gas composition follows fluctuations of blood gas levels and thus may affect total ME pressure.
AB - The middle ear (ME) steady state gas composition resembles that of mixed venous blood. We changed arterial and venous blood gases by artificially ventilating anesthetized guinea pigs and measured simultaneous ME gas changes during spontaneous breathing, hyperventilation, and hypoventilation. During hyperventilation, PaCO2 and PvCO2 (a = arterial, v = venous) decreased from 46.0 and 53.0 mm Hg to 17.9 and 37.5 mm Hg, respectively, while PaO2 and PvO2 (85.6 and 38.2 mm Hg) did not change. This was accompanied by an ME PCO2 decrease from 70.4 to 58.8 mm Hg and a PO2 decrease from 36.8 to 25.4 mm Hg. During hypoventilation, PaCO2 and PvCO2 increased to 56.8 and 66.4 mm Hg, while PvO2 decreased to 21.8 mm Hg. The ME PCO2 increased simultaneously to 88.8 mm Hg and the ME PO2 decreased to 25.4 mm Hg. The ME PO2 decrease during hyperventilation may be explained by a 33% decrease in ME mucosa perfusion, calculated from the ME ventilation-perfusion ratio. This study shows that ME gas composition follows fluctuations of blood gas levels and thus may affect total ME pressure.
KW - blood gases
KW - guinea pig
KW - hyperventilation
KW - hypoventilation
KW - middle ear gases
KW - middle ear pressure
KW - ventilation-perfusion ratio
UR - http://www.scopus.com/inward/record.url?scp=8244227978&partnerID=8YFLogxK
U2 - 10.1177/000348949710600410
DO - 10.1177/000348949710600410
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AN - SCOPUS:8244227978
SN - 0003-4894
VL - 106
SP - 314
EP - 319
JO - Annals of Otology, Rhinology and Laryngology
JF - Annals of Otology, Rhinology and Laryngology
IS - 4
ER -
