Effects of hypergravity and anti-G suit pressure on intraregional ventilation distribution during VC breaths
2001 (English)In: Journal of applied physiology, ISSN 8750-7587, E-ISSN 1522-1601, Vol. 91, no 2, 637-644 p.Article in journal (Refereed) Published
The effects of increased gravity in the head-to-foot direction (+G(z)) and pressurization of an anti-G suit (AGS) on total and intraregional intra-acinar ventilation inhomogeneity were explored in 10 healthy male subjects. They performed vital capacity (VC) single-breath washin/washouts of SF(6) and He in +1, +2, or +3 G(z) in a human centrifuge, with an AGS pressurized to 0, 6, or 12 kPa. The phase III slopes for SF(6) and He over 25-75% of the expired VC were used as markers of total ventilation inhomogeneity, and the (SF(6) -- He) slopes were used as indicators of intraregional intra-acinar inhomogeneity. SF(6) and He phase III slopes increased proportionally with increasing gravity, but the (SF(6) -- He) slopes remained unchanged. AGS pressurization did not change SF(6) or He slopes significantly but resulted in increased (SF(6) -- He) slope differences at 12 kPa. In conclusion, hypergravity increases overall but not intraregional intra-acinar inhomogeneity during VC breaths. AGS pressurization provokes increased intraregional intra-acinar ventilation inhomogeneity, presumably reflecting the consequences of basilar pulmonary vessel engorgement in combination with compression of the basilar lung regions.
Place, publisher, year, edition, pages
2001. Vol. 91, no 2, 637-644 p.
gravity, He, SF6, single-breath washout, ventilation inhomogeneity, vital capacity
IdentifiersURN: urn:nbn:se:kth:diva-44608ISI: 000169950900013PubMedID: 11457775OAI: oai:DiVA.org:kth-44608DiVA: diva2:451656
QC 201111022011-10-262011-10-252011-11-02Bibliographically approved