The Cardiovascular Dynamics of Bowel Function

A comparison of two bearing-down techniques during the second stage of labor

“…The research with nonpregnant subjects has also indicated that bearing‐down efforts performed without an initial full inspiration, with a partially closed glottis and slow exhalation, or with a slow increase up to 40 mm Hg strain, did not result in such pronounced circulatory changes as occurred when the Valsalva maneuver was performed after full inspiration and with breath‐holding 9, 10 . Multiple short bearing‐down efforts of less than 6 sec did not grossly effect circulation time (12‐50% delay) compared to more prolonged 10 sec bearing‐down efforts (100%) delay 11 . For these reasons, the Valsalva‐type bearing‐down technique, which is commonly encouraged in America, may not be the most advantageous method for mechanically or physiologically accomplishing expulsion for the mother or fetus.…”

Hazards of the Barium Enema Examination as Studied by Electrocardiographic Telemetry: Preliminary Report

“…Although the effects of straining during the barium enema examination have not been explored, there has been some investigation regarding the physiology of straining at stool. Halpern et al (12) measured the intrathoracic pressure during such straining by having the patient keep the glottis open and by using a manometer as a fixed resistance. It was found that in normal unconstipated subjects using a commode, 12 per cent of such strains were of sufficient magnitude to meet the criteria of the Valsalva maneuver.…”

“…However, consideration of comparable electrocardiographic phenomena indicates that the changes noted in our study should not be solely attributed to the effects of the Valsalva maneuver. It has been demonstrated (12) that approximately 20 per cent of normal persons show electrocardiographic changes consisting predominantly of T‐wave flattening following performance of the Valsalva test. In our study such alterations were not found during and after the barium enema in patients considered to be free of pre‐existing heart disease.…”

A New Laxative Preparation for the Rational Management of Geriatric Constipation

“…There is also the possibility of causing tachyphylaxis of the colonic musculature. The combining of guar gum with the concentrate of purified and standardized sennosides A and B [which have been established as safe and effective neuroperistaltic stimulants (20–36)] overcomes the factors that account for the lack of dependability and predictability of the action of bulk laxatives.…”