Biomaterial Database

Cardiopulmonary readjustments during graded immersion in water at 35 degrees C. 1977

L E Farhi, and D Linnarsson

Six normal male volunteers, aged 25 to 34, suspended vertically in a harness that allowed them to completely relax their postural muscles, were studied in four randomly ordered conditions, namely in air at 28 degrees C, and immersed in water at 35 degrees C to the level of the hips, the xiphoid, or the chin. In each situation, several variables were measured by noninvasive techniques. Cardiac output rose from 5.11 min-1 (air) to 8.31-min-1 (chin), the increase in each of the three steps being significant at the 0.001 level. Heart rate dropped from 76 to 68 min-1 (P less than 0.001) from air to xiphoid immersion, but appeared to rise again (P less than 0.02) during chest immersion. Functional residual capacity decreased marginally during lower limb submergence, and considerably in each of the following stages. Pulmonary capillary blood volume rose significantly only during abdomen immersion. The arterial-endtidal PCO2 difference was minimally reduced as water reached hip level and then remained steady. Mixed venous PO2 increased during abdomen submergence, and PVCO2, was unaltered throughout. Analysis of the step-to-step changes demonstrates that some variables are set by a combination of processes which may counteract each other, and explains the difference between results obtained by previous investigators.

UI	MeSH Term	Description	Entries
D007101	Immersion	The placing of a body or a part thereof into a liquid.	Submersion,Immersions,Submersions
D008168	Lung	Either of the pair of organs occupying the cavity of the thorax that effect the aeration of the blood.	Lungs
D008297	Male		Males
D010100	Oxygen	An element with atomic symbol O, atomic number 8, and atomic weight [15.99903; 15.99977]. It is the most abundant element on earth and essential for respiration.	Dioxygen,Oxygen-16,Oxygen 16
D011311	Pressoreceptors	Receptors in the vascular system, particularly the aorta and carotid sinus, which are sensitive to stretch of the vessel walls.	Baroreceptors,Receptors, Stretch, Arterial,Receptors, Stretch, Vascular,Stretch Receptors, Arterial,Stretch Receptors, Vascular,Arterial Stretch Receptor,Arterial Stretch Receptors,Baroreceptor,Pressoreceptor,Receptor, Arterial Stretch,Receptor, Vascular Stretch,Receptors, Arterial Stretch,Receptors, Vascular Stretch,Stretch Receptor, Arterial,Stretch Receptor, Vascular,Vascular Stretch Receptor,Vascular Stretch Receptors
D001810	Blood Volume	Volume of circulating BLOOD. It is the sum of the PLASMA VOLUME and ERYTHROCYTE VOLUME.	Blood Volumes,Volume, Blood,Volumes, Blood
D002196	Capillaries	The minute vessels that connect arterioles and venules.	Capillary Beds,Sinusoidal Beds,Sinusoids,Bed, Sinusoidal,Beds, Sinusoidal,Capillary,Capillary Bed,Sinusoid,Sinusoidal Bed
D002245	Carbon Dioxide	A colorless, odorless gas that can be formed by the body and is necessary for the respiration cycle of plants and animals.	Carbonic Anhydride,Anhydride, Carbonic,Dioxide, Carbon
D002302	Cardiac Output	The volume of BLOOD passing through the HEART per unit of time. It is usually expressed as liters (volume) per minute so as not to be confused with STROKE VOLUME (volume per beat).	Cardiac Outputs,Output, Cardiac,Outputs, Cardiac
D005652	Functional Residual Capacity	The volume of air remaining in the LUNGS at the end of a normal, quiet expiration. It is the sum of the RESIDUAL VOLUME and the EXPIRATORY RESERVE VOLUME. Common abbreviation is FRC.	Capacities, Functional Residual,Capacity, Functional Residual,Functional Residual Capacities,Residual Capacities, Functional,Residual Capacity, Functional