MAXIMUM INTRA-THORACIC PRESSURE WITH ANTI-G STRAINING MANEUVERS AND POSITIVE PRESSURE BREATHING DURING +Gz

PDF

Authors
  1. Buick, F.
  2. Hartley, J.
  3. Pecaric, M.
Corporate Authors
Defence and Civil Inst of Environmental Medicine, Downsview ONT (CAN)
Abstract
Positive pressure breathing during + 1 Gz (PBG) and anti-G straining maneuvers (AGSM) each improve + 1 Gz tolerance by increasing blood pressure through increases in intra-thoracic pressure, but the maximal intra-thoracic pressure from their combined effect is not known. Six subjects performed the following: (1) maximal AGSM at + 1 Gz; (2) assisted PBG (constant 60 mm Hg) at +Gz; (3) submaximal AGSM at +Gz (enough to maintain peripheral vision); (4) maximal AGSM at +Gz; and (5) combined PBG and maximal AGSM at +Gz. They wore TLSS mask/helmet ensemble, CSU-15/P G-suit, and TLSS-style jerkin. Intra-thoracic pressure was measured with a catheter-tip pressure transducer in the esophagus (Pes). The change in gastric pressure was also measured (DELTA Pga). For both Pes and DELTA Pga, there were no significant differences among experimental conditions ((1), (4) and (5), as above. Group mean Pes and DELTA Pga in these three conditions were 139 and 197 mm Hg, respectively. TRUNCATED
Report Number
DCIEM-91-43 — Reprint; See also DSIS 92-00990
Date of publication
15 Aug 1992
Number of Pages
11
Reprinted from
Aviation Space and Environment Medicine, vol 63, 1992, p 670-677
DSTKIM No
92-03583
CANDIS No
126944
Format(s):
Hardcopy;Originator's fiche received by DSIS;Document Image stored on Optical Disk

Permanent link

Document 1 of 1

Date modified: