The efffect of sustained +Gz acceleration on extravascular lung water content in domestic fowl.

In order to examine the effects of sustained acceleration on pulmonary fluid balance, chickens were centrifuged at low sustained +G acceleration (LSG) intensities of +3Gz or +4Gz or high sustained +G acceleration (HSG) at +6Gz for varying periods. Animals were exposed to acceleration on a hydraulic-driven centrifuge. Controls (Group I) were not centrifuged. The vascular lungs were rapidly excised after centrifugation, and the extravascular lung water content (EVLW) was measured. EVLW in Group I animals = 2.19 +/- 0.38 g/g. Results indicate that positive acceleration elevated in animals exposed to +4Gz for 60 min (Group III). In this group, EVLW = 3.01 +/- 1.07 g/g. This increase is largely attributable to an elevated EVLW in those animals which died as a result of centrifugation, in which EVLW = 3.90 +/- 1.04 g/g. Exposure to +3Gz for 120 min (Group II) or +6Gz for periods up to 50 min (Group IV) did not produce significant elevations in EVLW in either group as a whole, but EVLW in those Group II animals which died as a result of centrifugation was significantly elevated. EVLW in these animals = 2.87 +/- 0.21 g/g. We conclude that pulmonary edema caused by centrifugation is dependent on both magnitude and duration of G force.