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Alterations in the Specific Gravity of the Blood Plasma with Onset of Diuresis in Heart Failure

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Alterations in the Specific Gravity of the Blood Plasma with Onset of Diuresis in Heart Failure MECHANISM OF DIURESIS: ALTERATIONS IN THE SPECIFIC GRAVITY OF THE BLOOD PLASMA WITH ONSET OF DIURESIS IN HEART FAILURE Harold J. Stewart J Clin Invest. 1941;20(1):1-6. https://doi.org/10.1172/JCI101189. Research Article Find the latest version: https://jci.me/101189/pdf MECHANISM OF DIURESIS: ALTERATIONS IN THE SPECIFIC GRAVITY OF THE BLOOD PLASMA WITH ONSET OF DIURESIS IN HEART FAILURE By HAROLD J. STEWART (From the Department of Medicine of.the New York Hospital and Cornell University Medical College and the Hospital of the Rockefeller Institute for Medical Research, New York) (Received for publication July 3, 1940) There are divergent views concerning the Moreover, its duration may be brief before res- mechanism by which diuresis is initiated. Many toration is attempted, or it may be long enough of the observations on this subject relate to mer- and of such magnitude that it can be detected. curial drugs. Crawford and McIntosh (1) con- On the other hand, if diuresis is initiated at cluded that novasurol induced primary dilution, the tissue side of the system so that fluid enters followed by concentration of the blood in edema- the blood stream first, dilution of the blood would tous patients. Bryan, Evans, Fulton, and Stead occur. Equilibrium would be disturbed until the (2) thought that salyrgan resulted in concentra- kidneys began to excrete the surplus fluid. If di- tion of the blood, since sustained rise in its spe- lution of the blood was of sufficient duration and cific gravity occurred coincident with diuresis in magnitude, it might be detected. dogs made edematous by plasmapheresis. Schmitz It appeared that frequent observations of the (3) did not find evidence that salyrgan mobilized specific gravity of the blood would reflect changes fluid into the blood stream before the onset of in dilution and concentration of the blood and give diuresis. Blumgart, Gilligan, Levy, Brown, and data which would contribute to one or the other Volk (4) concluded from observations on normal of these points of view. Moore and Van Slyke subjects that diuresis following xanthine and mer- (7) demonstrated a linear relationship between curial drugs was not initiated by the kidneys in the observed specific gravity of the plasma of the response to measurable changes in specific gravity blood and the observed protein content of the or sodium or chloride contents of the blood. plasma of normal individuals and nephritic pa- Brown and Rowntree (5) found an increase in tients. They found also that when the specific blood volume with the onset of diuresis in cardiac gravity of the plasma was below 1.0223 in certain patients. On the other hand, using more accurate types of nephritis, edema was present, and that methods, Evans and Gibson (6) observed in dogs when the specific gravity was above this level, the a diminution of plasma volume during diuresis so-called edema zone, edema did not occur. induced by salyrgan. In cardiac patients, Moore and Stewart (8) For purposes of analysis the circulatory-renal also found that the specific gravity of the plasma system consists of the kidneys on the one hand and had a linear relationship to the protein content of the tissues which retain fluid on the other, the cir- the plasma and demonstrated that the plasma pro- culating blood connecting them. Tissue fluid to teins and specific gravity of cardiac patients were be excreted as urine must be carried by the blood above the edema level of nephritic patients. to the kidneys. The stimulus to inaugurate diu- Moore and Stewart's (8) observations relating to resis may be applied at different points in this the behavior of the specific gravity of the plasma system. If the mechanism is initiated in the kid- of normal individuals provided the background neys and increased secretion of urine is the first for turning Moore and Van Slyke's method to this step, concentration of the blood should occur on purpose. They found that the specific gravity of the withdrawal of fluid from it. How far this the blood plasma of normal individuals and of imbalance in the blood constituents can proceed cardiac patients in water equilibrium remained and how long it can be present before restoration constant to within 0.0004 from day to day. Di- occurs by the entrance of fluid from the edema- lution of blood by the injection of normal salt solu- tous tissues might vary with different diuretics. tion and following hemorrhage in dogs gave paral- 1 2 HAROLD J. STEWART Jan. Feb. 10270 6 . 1.0260 10240 A FIG. 1. RELATIONSHIP BETWEEN ONSET OF DIGITALIs, THEOCALCIN, AND SPONTANEOUS DiuREsis To SPECIFIC GRAvrTY OF THE BLOOD PLASMA In this figure is shown the relation of onset of diuresis to the level of specific gravity of the blood plasma. In B. McL., 58 years (Figure 1A), in whom heart failure was a consequence of hypertension, diuresis re- sulted from giving digitan 12 grams in 24 hours. In L. C., 64 years (Figure 1B), in whom heart failure resulted from hypertension, the administration of theocalcin 4.5 grams on April 14, and daily thereafter, re- sulted in marked diuresis. In J. McM., 44 years (Figure 1C), in whom heart failure resulted from arteriosclerotic heart disease, diuresis occurred spontaneously. SPECIFIC GRAVITY OF PLASMA IN DIURESIS 3 £ 53 1.0270 e 1.0260 c0- O u,, [0250 ta o E. -5 1.0270-_ n Zn 10240 1.0260 1.0230 ° 8 1.0250 1.0220 H Q s 1.0240C B C FIG. 1 (conttintued) lel decreases in specific gravity of the plasma and gestive heart failure was estimated by the method of plasma proteins. The oral administration of 1000 Moore and Van Slyke (7). Duplicate samples were cc. of water did not alter specific gravity of the checked to within 0.00002. The daily fluid and salt in- plasma; during the urine concentration test, how- takes of the patients were 1200 cc. and 5 grams, respec- tively. Patients remained in bed. There was a control ever, the specific gravity and the plasma proteins period before giving diuretics. Since samples of blood increased, indicating concentration of the blood. were taken frequently before and after the administration In short, when concentration of the blood occurs, of diuretics, it was not expedient to keep the subjects in the specific gravity rises and when dilution occurs, the basal or postabsorptive state. The patients ate break- it decreases. fast at 7:30 a.m., after which they received no fluid 1 It appeared from these observations that during until samples of blood were taken without stasis at 10:30 a.m. The was a time in which nothing was done to deplete the diuretic then given. A rubber stopper was plasma proteins, the specific gravity of the plasma used to eliminate evaporation. Clotting was prevented by use of heparin. could be used to indicate dilution or concentration of the blood. METHODS AND PLAN OF OBSERVATIONS 1 It is recalled, however, that Moore and Stewart (8) The specific gravity of the plasma of the blood of found that drinking 1000 cc. water did not alter the cardiac patients exhibiting signs and symptoms of con- specific gravity of the blood. 4 HAROLD J. STEWART OM PATIEMr S *:DURIS fAILURE SP. GR. OF bLOOD PLASMA CAROIAC OaRECOVIRED C RELATIOM OF OCCURREnCE Of DIURES3S TO SP. OR. OF bLOOD PLASMA 5 1o*%v*@|DIU%v] *" |RI1l o RELAT1on or IfITIATIOMfOFOIURESIS TO SP. CR. Of BLOOD PLASMA A l'l~.Ia?I?D¶?uII''IIi'eI~I,~I4 LA 1468 IUR4ST~'0'- .,,t, iL A & 16"1"8' o 2 "'8"o2 I 4,Wo"l4 % I'''~~~9IAl& o,4I8w - o & 6 ao u0 o ' O X, O. Ot a #4 - - w - #4 0 4 #4 o4 0 0. 0t ~ FIG. 2. RELATION OF INITIATION AND OCCURRENCE OF DiuREsis TO, SPECIFIC GRAVITY OF THE BLOOD PLASMA In Figure 2A are plotted specific gravity estimations of the plasma to show the level at which diuresis was initiated. Closed circles indicate that diuresis was initiated at the level shown. In Figure 2B are plotted data to show the relation of occurrence and persistence of diuresis to specific gravity of the blood plasma. Closed circles in- dicate occurrence of diuresis and open ones that diuresis was not taking place. In Figure 2C are plotted specific gravity estimations of patients during (closed circles) and recovered (open circles) from heart failure. OBSERVATIONS diuresis. Similar patterns were recorded in one other patient with auricular fibrillation and 3 patients with Specific gravity of the blood plasma was observed in instances of diuresis occurring spontaneously without the normal sinus mechanism. The case of J. McM. (Figure 1C) illustrates the re- use patients), in diuresis resulting from of drugs (8 auricular fibrillation and 5 patients digitalis (9 patients), and, finally, in diuresis following sults in 3 patients with with normal sinus rhythm in whom diuresis occurred the use of theocalcin (Merck) (5 patients). Patients spontaneously with rest in bed and limitation of fluid having auricular fibrillation, as well as those with normal intake. There was a fall in specific gravity when diuresis sinus rhythm, were subjects. when the first Patient B. McL. (Figure 1A) illustrates the effect of occurred; or, if diuresis had been initiated sample was taken, the specific gravity was low, rose with digitalis. Rest in bed and restriction of fluids did not the continuance of diuresis, and had risen to a normal result in diuresis. When digitan 1.2 grams (Merck) 2 level when excess fluid had been eliminated. were given in 24 hours, diuresis with loss in weight For all the level of specific gravity of the occurred promptly.
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