Transmission of pressure within the abdomen.
Tzelepis, George E., Louis Nasiff, F. Dennis McCool, and James
Hammond.
Departments of Medicine, Finch University of Health Sciences/The
Chicago Medical School and The Veterans Affairs Medical Center, North
Chicago, IL 60064, and Brown University, Pawtucket, RI 02860
APStracts 3:0265A, 1996.
The extent to which transmission of pressure within the abdomen is
accomplished in accordance with the laws of fluid mechanics, i.e.,
homogeneous transmission to all portions of the abdomen is
controversial. To examine the cranial to caudal as well as side to
side transmission of pressure within the abdomen in humans, we
measured intra-abdominal pressure at 4 sites in five subjects
undergoing colonoscopy. Liquid-filled catheters were inserted into
the colon and intracolonic pressure was measured in the rectum,
transverse, descending, and sigmoid colon. Differences in
intracolonic pressure were recorded during breaths to total lung
capacity and brief expulsive maneuvers. Measurements were taken in
the supine, right lateral and seated position. Comparison of pressure
swings at all sites showed that the pressure changes were nearly
equal during both inspiratory and expulsive maneuvers. The changes in
pressure were uniform in the cephalo-caudal axis as from side to
side. We conclude that transmission of abdominal pressure in humans
is nearly homogeneous. Our findings provide support for the hydraulic
model of abdominal mechanics.
Received 20 November 1995; accepted in final form 23 April 1996.
APS Manuscript Number A1215-5.
Article publication pending Journal of Applied Physiology.
ISSN 1080-4757 Copyright 1996 The American Physiological Society.
Published in APStracts on 17 June 96