Inhalation heterogeneity from subresidual volumes in elite divers.
Punctate reopening of the lung from subresidual volumes (sub-RV) is commonly observed in excised lung preparations, either degassed or collapsed to zero transpulmonary pressure, and in the course of reinflation of human lungs when the chest is open, secondary to traumatic or surgical pneumothoraxes. In the course of physiological studies on two elite breath-hold divers, who are able to achieve lung volumes well below traditional RV with glossopharyngeal exsufflation, we used MRI lung imaging with inhaled hyperpolarized (129)Xe to visualize ventilatory patterns. We observed strikingly inhomogeneous inhalation patterns with small inhalation volumes from sub-RV, consistent with reopening of frankly closed airways. On the other hand, two age-matched and two older controls, inhaling from just above RV, showed a much more homogeneous pattern. Our results demonstrate the concept of frank airway closure below RV in young healthy adults with an intact chest wall.
Muradyan
Iga
I
Department of Radiology, Brigham and Women's Hospital, LMRC, 221 Longwood Ave., Boston, MA 02115, USA. muradian@bwh.harvard.edu
Loring
Stephen H
SH
Ferrigno
Massimo
M
Lindholm
Peter
P
Topulos
George P
GP
Patz
Samuel
S
Butler
James P
JP
D000328:Adult; D016022:Case-Control Studies; D004242:Diving; D005930:Glossopharyngeal Nerve / Q000502:physiology*; D006801:Humans; D001239:Inhalation; D007327:Insufflation; D008168:Lung / Q000502:physiology*; D008176:Lung Volume Measurements; D008279:Magnetic Resonance Imaging; D008875:Middle Aged; D012123:Pulmonary Ventilation; D013997:Time Factors; D014979:Xenon Isotopes / Q000008:administration & dosage
D014979:Xenon Isotopes