title: Lower body positive pressure by anti-G garment inflation: a suitable method to increase pulmonary capillary wedge pressure in healthy elderly subjects.
abstract: In a study on non-invasive assessment of pulmonary capillary wedge pressure (PCWP), we sought a method to increase PCWP non-invasively. We hypothesized that inflation of an anti-G garment was suitable to increase PCWP non-invasively in healthy elderly subjects. In 20 subjects, aged 70 +/- 4 years (mean +/- SD), before, immediately after, and 4 min after anti-G garment inflation to 52 mmHg, PCWP and mean pulmonary artery pressure (MPAP) were measured with a Swan-Ganz catheter, and mean arterial blood pressure (MAP) with Finapres, in supine and semi-recumbent position. Supine, PCWP (mmHg, mean +/- SD) increased from 9.9 +/- 2.1 to 15.5 +/- 3.9** immediately after inflation and 13.4 +/- 3.7** at 4 min; semi-recumbent from 8.9 +/- 2.0 to 17.5 +/- 3.3** and 14.7 +/- 2.9** (*P<0.05, **P< 0.001 versus before inflation). MPAP (mmHg) increased after inflation: supine 16.9 +/- 2.3 to 22.3 +/- 4.6** and 20.6 +/- 3.9** and semi-recumbent 15.7 +/- 2.8 to 24.3 +/- 5.1** and 22.5 +/- 3.5**, suggesting that increased preload was the primary effect of anti-G garment inflation. Supine MAP (mmHg) increased from 96.0 +/- 11.3 to 101.4 +/- 13.4** and 100.5 +/- 12.7* and semi-recumbent from 102.0 +/- 8.9 to 108.3 +/- 11.4** and 106.0 +/- 11.3*, suggesting an effect of increased afterload as well. The latter was supported by an increase in total peripheral resistance (d s cm(-5)) from 1346 +/- 299 to 1441 +/- 384 after 4 min (P = 0.057) and from 1461 +/- 341 to 1532 +/- 406 (P = 0.054), supine and semi-recumbent respectively, while cardiac output remained unchanged. Complications did not occur. We conclude that in healthy elderly subjects, anti-G garment inflation is a safe, non-invasive, method to induce a significant increase in PCWP. Our findings justify its application in future studies in which non-invasive temporary increase in PCWP is required.
authors.affiliation: Department of Geriatric Medicine, University Medical Center Nijmegen, Nijmegen, the Netherlands. j.remmen@cardio.umcn.nl
authors.forename: J J
authors.initials: JJ
authors.lastname: Remmen
authors.forename: W R M
authors.initials: WR
authors.lastname: Aengevaeren
authors.forename: F W A
authors.initials: FW
authors.lastname: Verheugt
authors.forename: A
authors.initials: A
authors.lastname: Bos
authors.forename: R W M M
authors.initials: RW
authors.lastname: Jansen
mesh_terms: D000368:Aged; D000704:Analysis of Variance; D001794:Blood Pressure / Q000502:physiology; D002302:Cardiac Output / Q000502:physiology; D005260:Female; D005676:Gravity Suits; D006801:Humans; D008297:Male; D011187:Posture / Q000502:physiology; D011312:Pressure; D011669:Pulmonary Wedge Pressure / Q000502:physiology*; D012016:Reference Values; D013997:Time Factors; D014655:Vascular Resistance / Q000502:physiology