basai metabolic rates*

THE CANADIAN MEDICAL ASSOCIATION JOURNAL

A SIMPLE AND ACCURATE METHOD OF DETERMINI[NGBASAI METABOLIC RATES*

AN ELECTROMETRIC (KATHAROMETER) PROCEDURE

BY I. M. RABINOWITCH, M.D.,

Assistant Professor of Medicine and Lecturer in Biochemistry, McGill Univer.sity, Montreal

AND EiANOR V. BAZIN

Clinical Research Laboratory, Montreal General HospitalBASAL metabolic rate determination has be-

-come a comunon procedure in well establishedclinics. The possible applications of this lab-oratory test are becoming more generally recog-nized. The two great factors, however, whichtend to limit its usefulness are difficulties in theinterpretations of results and the necessarytechnical procedures. In a hospital with a fairlylarge routine, sufficient data accumulate in avery short time which demonstrate the numerousvagaries of basal metabolic rate determinations.The information sought by clinicians is the basalmetabolism, and there are many factors whichtend to make conditions other than basal. Thebasal character of metabolism is a very funda-mental phenomenon, and contrary to the viewgenerally held, not very readily obtained. Theprincipal pre-requisites are more than the ab-sence of fever, abstaining from food and a shortpreliminary rest period. Failure to recognizethese other pre-requisites, particularly those ap-pertaining to psychic and environmental condi-tions, makes this test more than useless; its re-sults may mislead. Since the information whichthe clinician seeks is the basal metabolic rate,and in view of the above observations, it may bestated that, contrary to the statement of makersof apparatus, this test is not yet, at least, in themajority of cases, an "office" procedure.Assuming fulfilment of all pre-requisites, the

necessary technical details are to be considered.It may be said, generally, that the degree ofusefulness of any laboratory test, clinically, isdirectly proportionate to the simplicity withwhich it can be carned out. The methods nowin use are generally known and require no de-tailed description.. For very accurate work, and

* From the Department of Metabolism, MontrealGeneral Hospital, Montreal, Canada.

conditions associated with marked alterations ofrespiratory quotients, a Tissot gasometer or aDouglas bag and meter, and gas analysis ap-paratus are required. As is well known themethod is "open". The subject inhales outsideair and the expired air passes into the gasometeror bag. For ordinary work, such as measuringthe progress of patients with hypeiloyroidism,and other conditions not associated with markedfluctuations of respiratory quotients, apparatuswhich determines the rate of oxygen consumptiononly, suffices. The apparatus for this purpose isusually built on the "closed- circuit" principle.From the patient's point of view-a very im-portant one-the "open" methods, at least inour experience are preferable. We have per-formed a large number of tests by both methodsin this hospital, and this statement is based uponthe observations of many patients who have beentested with both types of apparatus. Such sub-jective symptoms as "fullness in the head","headache", "difficulty of breathlag" are metwith less frequently when the patients receive"outside" air than when they receive pureoxygen. With our present knowledge, there maybe no apparent physiological basis for this dif-ference, but the fact remains that it exists. Thechief objections to the open methods, however,are that they are time consuming and demandhighly skilled gas analytical work.

Because of the foregoing facts, a more simpleprocedure, but one retaining the "open" prin-ciple, has been sought, and the purpose of thiscommunication is to record the results of anelectrometric method. It will be shown thatsimplicity has not been obtained by the sacrificeof accuracy. Basal metabolic rates, with thismethod, are calculated from the rates of carbondioxide production, determined by means of a

638

RABINOWITCH AND BAZIN: BASAL METABOLISM6

katharometer. A few brief remarks are neces-sary with reference to the use of the rate ofcarbon dioxide elimination as an index of therate of metabolism.

King' has shown that basal metabolic rate de-termination, by measuring carbon dioxide elimin-ation, is a reliable procedure. Statistical andexperimental results agreed. The deductionmade by Raymond Pearl, from a statistical treat-ment of direct calorimetry data, was that there.sults of the measurement of oxygen intake werenot more highly correlated with the results ofdirect calorimetry than were those of carbondioxide elimination. One objection which maybe made to carbon dioxide measurements is thatin conditions associated with marked fluctua-tions of respiratory quotients, (such as in dia-betes), carbon dioxide production does notparallel heat elimination as closely as oxygenconsumption does. This objection is valid, andthe use of the method described here is for thisreason limited. Such conditions, however, repre-sent the minority in which basal metabolismstudies are usually made. The chief objectionwhich may be made, is the well known fact, thatindividuals may, temporarily, store carbondioxide, and wash it out during a period ofover ventilation while the test is proceeding. Itmight be recalled that under the conditions of abasal metabolism test, muscular activity is re-duced to a minimum. Respiration rate, ventila-tion rate, lactic acid formation, etc., thereforetend to be at a minimum also. King has shownthat the amount of carbon dioxide washed outduring the average test period is not of sufficientmagnitude to affect results. This observationhas been confirmed in our clinic in a large seriesof cases. Positive proof of the correctness ofthis view will, however, be shown presently,since by means of the katharometer, it is possibleto observe, accurately, the amount of carbondioxide eliminated, from minute to minute,throughout the entire period of a test. Anotherobservation by King, and worthy of note, is thatthe tendency to high results, that are not sup-ported by clinical evidence in cases of hyper-thyroidism, is considerably less with carbondioxide measurements than is indicated by thereports of work done by either the Tissot orclosed circuit oxygen methods. King's proced-ure is well known. Briefly, carbon dioxideeliminated is absorbed by soda lime and quan-

titatively determined by increase in the weightof the absorbing material.

PRINCIPLE OF NEW METHOD, THE KATHAROMETER

This apparatus makes use of the physicalproperty of heat conduction of different gases.The electrical system is arranged in a Wheat-stone bridge circuit, in the course of which thereis a galvanometer, G, as shown in the followingdiagram.

FIG. 1

The four branches, A, B. C., and D, are madeof platinum and so arranged that A, D, and B,C, are enclosed in separate chambers. Thechamber enclosing A and D contains air, and,through that enclosing B and C, the experi-mental gas, containing carbon dioxide, is madeto pass. Since the heat conductivity of carbondioxide is about forty per cent less than thatof air, the heats generated in the platinum wiresA and C, from the passing electric current, areconducted away at unequal rates, (more slowlyfrom A than from C). The resultant increasein temperature of branch A increases the resist-ance of the wire. The potentials at the connect-ing points p and p' of the galvanometer are thusaltered, and, other conditions being kept con-stant, the degree of deflection of the galvano-meter needle becomes a function of the concen-tration of carbon dioxide in the experimental gas.

This principle was first employed in 1915 byG. A. Shakespear of Birmingham, for the testingof the permeability of balloon fabrics* duringthe war and for the purity o fgases. It was thendeveloped by the Cambridge Instrument Com-pany of England, for the determination of CO2in flue gases.t A. V. Hill2 of Manchester then

* For the Board of Invention and Research of theBritish Admiralty.

t The instrument made use of in the present workwas made by the Cambridge Instrument Company, ofLondon, England.

639

THE CANADIAN MYEDICAL ASSOCIATION JOURNAL

applied it in his physiolog-ical researches on alveolarair. So far as could beascertained from the litera-ture no attempt has beenmade hitherto to apply itto basal metabolic rate de-termination.*The theory of the kath-

arometer is described indetail in the proceedingsof the Royal Society ofLondon (Series A, vol. 97,p. 273), by Dr. H. A.Daynes of the Universityof Birmingham. A morediagrammatic representa-of the general plan of suchapparatus was found in arecent number of the Chemical and Mletallurgi-cal Engineering Journal, (vol. 29, p. 248, 1923)in a description of a flue gas tester. This isshown in Fig. 2. It will be seen that the current

FIG. 2

from a battery, B, controlled by a rheostat, R,passes into a Wheatstone bridge circuit, theupper branch of which, A, passes through an

air chamber, and the lower, C, through thechamber containing the experimental gas. Atthe galvanometer connecting points, p and p',the continuations of these branches are so re-

versed as to allow the continuation of the upper

branch, B, to pass through the CO2 chamber,and that of the lower, D, through the airchamber. In addition there is a recording gal-vanometer, rG, for automatic readings.

* We are indebted to Professor A. V. Hill forhaving brought to our attention, in a personal com-munication, the only reference to the use of this;principle in physiological work.

c

FIG. 3

A photograph of the katharometer used in ourwork is shown in Fig. 3. Its dimensions are 13in. x 7in. x 51/2 in. and it weighs about f-ourteenpounds. The whole outfit is contained in aportable case with carrying handle.

MIETHOD OF DETERMINING CO2 CONTENTOF A GAS

The indicator on the galvanometer scale, G,is first set at the zero point by means of theadjusting screw, Z. The positive and negativeterminals of the battery, B, are then connectedwith their corresponding posts (+ and - asshown in the figure). The dial, K, is thenturned in the direction so that the arrow uponit is on the line marked "test". The circuit iscompleted by pressing the contact button E.This results in a deflection of the indicator onthe galvanometer, G, towards the end of thescale. The indicator is then set exactly on theline of the scale marked "10", by means of therheostat adjustor, R. Button E is then released.The indicator on the galvanometer, G, shouldreturn to zero. The arrow on the dial, K, isthen returned to the line marked "off". Theapparatus is now in order to receive the experi-mental gas.With the taps H and H' open, as shown in

Fig. 3, a sufflicient quantity of the gas to betested is allowed to pass through the chamber,in order to flush it of any air or gas remainingfrom the last determination. Taps H and H' areclosed. The arrow on the dial, K, is then set on

640


the line marked "'CO2,". After allowing threeor four minutes to elapse for the gas to diffuseinto the instrument, contact is made with buttonE.* The pointer on the galvanometer scale indi-cates the percentage of CO2. The present scaleis made to read from 0 to 10 per cent.

A few brief remarks are necessary with refer-ence to the source of electrical current. Thebattery consists of four "Fuller inert dry"cells, arranged in "series-parallel". These cellsare most applicable for this work because whenfirst received they are entirely "dead". It isonly after water has been added and allowed toabsorb that they bec6me "active". The objectof the "series-parallel" type of connection is toensure the necessary potential and utilize thecurrent capacity of the combination of cells tothe maximum.The cell is made by Fuller's United Electric

Works, Liinited, Essex, England. Directions forits use accompany each cell.

Since the expired air contains water vapour

and since the latter has a heat conductivity ofabout thirty per cent greater than air, it isnecessary to balance the effects of the expiredair vapour in the CO2 chamber by creating thesame vapour pressure in the air chamber. Inorder to do this, the metallic cap on the back ofthe katharometer is removed. The plug, con-

taining a washer, is then withdrawn and theabsorbent material in the plug is moistened withwater. The moisture keeps for a long time. Onesuch apparatus has been in operation for over

fourteen months, and has not required remoisten-ing. It is advisable however, to remLoisten every

three months.The first investigation necessary was to deter-

mine the limits of accuracy within which it was

possible to determine carbon dioxide contents ofalveolar air mixtures with the katharometer.For this purpose subjects were allowed tobreathe into a Tissot gasometer and the expiredgases were then analyzed, by means of a Haldanegas apparatus and a katharometer. In Table Iare shown twenty of the comparative results.Though a large series of analyses have beenmade, it serves no particular purpose to record

* Occasionally, after depressing the button E, thepointer on the galvanometer may deflect in the op-posite direction (to the left). This may be avoidedby depressing the button while the arrow on the dial,K, is either in the "off" or "test" position.

TABLE I

PERCENTAGE CO2 OF EXPIRED AiR DETERMINED BYHALDANE APPARATUS AND KATHAROMETER

Haldane (H) Katharometer (K) | ooHK

2.58 2.55 101.13.22 3.17 101.53.42 3.42 100.03.57 3.60 99.13.30 3.26 101.22.66 2.65 100.32.47 2.45 100.82.98 3.00 99.32.82 2.70 103.53.10 3.15 98.43.13 3.10 100.93.16 3.10 101.93.40 3.45 98.53.60 3.55 101.43.92 3.90 100.53.20 3.15 101.64.06 4.00 101.53.05 3.00 101.62.88 2.85 101.13.78 3.80 99.4

them all. Those recorded in this table weretaken consecutively without selection from therecords. In columns 1 and 2 are recorded thepercentages of carbon dioxide found by meansof the Haldane apparatus and katharometer re-spectively. In column 3 are recorded the ratiosof the Haldane to the katharometer values. Thearithmetical mean of the ratios of the wholeseries was 100.7, with a standard deviation of+ 1.25, and a coefficient of variation of 1.24.

Comparative data were then obtained to notethe possible effects of such variations on the finalresults, expressed in terms of basal metabolicrates. The expired air in each case was collectedby the usual Tissot method, and the basalmetabolic rates were then calculated from thecarbon dioxide values as found by the Haldaneapparatus and katharometer. King's' standardsfor carbon dioxide elimination were accepted forthe ages of twenty years and upwards for bothsexes. Carbon dioxide values for the ages offourteen to nineteen years were calculated fromthe Aub-DuBois calorie standards, assuming arespiratory quotient of 0.82. All values wererecalculated, on the basis of cubic centimetresof carbon dioxide eliminated per minute persquare meter of body surface. These standardvalues are recorded in Table II. In Table IIIare recorded the results of the above investiga-tion in twenty individuals, three of which hadhyperthyroidism and five had myxwedema. In

641


TABLE IISTANDARDS

CO2 ELIMINATION CC. PER MINUTE PER

SQUARE METER OF BODY SURFACE

Age Male Female

14-15 . 130.0 121.816-17 ............ 121.6 113.318-19 ............ 116.1 107.620-29 ............ 110.1 101.430-39 ............ 109.1 100.540-49 .... ... 106.2 99.650-59 ............ 103.6 96.56069 .100.6 93.770-80 ............. 97.8 90.9

the last two columns will be found the basalmetabolic rates as determined by the Haldaneand katharometer values respectively. Assum-ing effects of over ventilation to be inappreciable(to be proven presently) these results demon-strate the validity of the application of thekatharomete.r for the determination of basalmetabolic rates.

Since the katharometer makes possible carbondioxide readings at frequent intervals (minuteperiods or less) during an experiment, the nextstep was to determine how closely the arithmeti-cal mean value of frequent readings of the kath-arometer observed! during a test period wouldapproximate the Haldane reading, which would

represent the resultant mixture of the differentcompositions of the expired air. If the approxi-tnation was sufficiently close, one could dispensewith the Tissot gasometer or Douglas bag byhaving the patient breathe directly into a meter,and allowing the expired air to pass from themieter to the katharometer.For this purpose a gas meter was obtained*

and its efficiency was tested as follows. A setof flutter valves was so arranged as to allow thesubjects to breathe directly into the meter, andat the same time prevent rebreathing of expiredair. The meter was connected with a Tissotgasometer. The observed volumes of gas whichpassed through the meter were then comparedwith the volumes found in the gasometer. Hav-ing proven the efficiency of the meter, the follow-ing procedure was adopted.

Subjects were allowed to breathe directly intothe meter, from this the expired air was passedthrough the katharometer and then into theTissot gasometer, as shown in Fig. 4. By thisprocedure it was possible to (a) compare theventilation rates determined by means of themeter with those of the gasometer, (b) make

* We are indebted to the Montreal Light, Heat &Power Consolidated, for their co-operation and for thesupply of meters, gratis, during the period of thisinvestigation.

TABLE IIIBASAL METABOLIC RATES DETERMINED BY HALDANE APPARATUS AND KATHAROMETER

002 B. M. R.per cent per cent of normal

I~ ~ ~V . _

4033/26.. 27 F 167.5 50.6 1.56 52.3 10.0 3.18 3.25 105.1 107.44699/24.. 35 F 144.0 54.6 1.45 45.8 9.0 3.10 3.04 108.2 106.1Gross ..... 57 F 158.0 63.6 1.64 63.3 10.0 3.50 3.43 140.0 137.2Ward..... 47 F 167.5 81.2 1.90 46.2 10.0 * 4.06 4.00 99.1 97.62663/26.; 18 F 153.0 47.0 1.42 44.4 10.0 3.88 3.81 112.7 110.73336/26.. 23 F 159.0 76.2 1.79 57.1 10.0 3.92 3.90 123.3 122.73645/26.. 23 F 151.0 56.8 1.52 62.2 9.0 3.20 3.15 143.3 141.23001/26.. 30 F 149.0 45.2 1.36 53.9 10.0 2.76 2.74 108.8 108.05154/26.. 16 F 151.0 42.4 1.38 53.2 12.0 2.88 2.83 81.6 80.22959/26.. 40 F 150.0 47.0 1.40 54.2 12.0 3.05 3.02 98.8 97.115102/16.. 17 F 160.0 63.8 1.67 61.7 11.5 2.78 2.72 78.7 77.05068/26.. 17 F 163.0 50.0 1.52 54.7 11.0 2.65 2.65 76.4 76.45116/26.. 27 F 160.0 59.2 1.61 60.6 9.0 2.48 2.51 102.3 103.51896/18.. 70 M 154.0 58.4 1.56 54.5 12.25 2.80 2.89 81.7 84.2630/26.. 43 F 151.0 64.0 1.60 59.7 9.0 2.81 2.76 116.9 114.85456/26 55 F 160.5 68.2 1.71 51.7 .9.5 3.43 3.45 113.1 113.4.5465/26.. 36 F 161.0 66.4 1.70 51.8 9.5 2.61 2.68 83.3 85.3.5463/26- 24 F 156.0 45.0 1.41 49.7 10.0 3.14 3.25 109.1 112.9-4781/26.. 36 F 160.0 59.0 1.60 52.0 8.0 2.67 2.64 107.8 107.01257/22.. 40 F 158.0 76.2 1.78 46.1 8.0 3.02 3.00 98.1 97.5

642'

RABINOWITCH AND BAZIN: BASALI METABOLISM6

periodic readings of the carbon dioxide contentsof the expired air by means of the katharometer,

Haldane apparatus, and in column 8 the ratiosof the Haldane to katharometer values. Thearithmetical mean of all the ratios was 100.4,with a standard deviation of + 1.88, and a co-

efficient of variation of 1.87. These results againdemonstrate the accuracy of the katharometer,and also appear to justify the procedure ofsimply allowing the subjects to breathe directlyinto a gas meter, and obtaining periodically thepercentages of carbon dioxide in the expiredair by means of the katharometer, as shown inFig. 5. By means of such a procedure, basal

FIG. 4

and (c) collect the resultant gas mixtures fromthe Tissot gasometer for analysis by means ofthe Haldane gas apparatus. In Table IV are

shown the percentages of carbon dioxide foundin the Tissot gasometer with the Haldane ap-

paratus, and the periodic and average per-

centages of carbon dioxide determined by means

of the katharometer. In columns 1 to 5, are re-

corded the percentages of carbon dioxide, deter-mined at two minute intervals by means of thekatharometer. In column 6 are recorded thearithmetical mean values of these percenitages.In column 7 are shown the percentages of carbondioxide as found in the Tissot gasometer by the

FIG. 5

metabolic rate determination becomes a simpleprocedure.

It is of interest to note that the periodic fluc-tuations of carbon dioxide percentages duringthe test periods were remarkably small. Thisappears to offer reasonable proof that, as stated

TABLE IV

Periodic Katharometer readings (per cent C02)H

2 min. 4 min. 6 min. 8 min. 10 min. Average (K) Haldane (H) 100-K

2.85 2.80 2.75 2.70 2.70 2.76 2.76 100.03.00 2.80 2.80 2.80 -2.80 2.84 2.88 101.43.00 3.10 3.05 3.10 3.00 3.02 3.05 100.42.80 2.80 2.75 2.60 2.60 2.71 2.78 102.52.65 2.60 2.60 2.65 2.70 2.64 2.65 100.32.60 2.60 2.50 2.45 2.40 2.51 2.48 98.83.00 2.90 2.85 2.85 2.80 2.88 2.80 97.22.90 2.80 2.80 2.70 2.60 2.76 2.81 101.83.55 3.50 3.50 3.40 3.30 3.45 3.43 99.42.80 2.70 2.65 2.60 2.60 2.67 2.61 97.72.75 2.75 2.70 2.60 2.50 2.66 2.67 100.43.05 3.05 2.95 2.95 2.95 2.99 3.02 101.02.95 3.00 3.05 3.05 3.10 3.05 3.04 99.62.95 2.95 2.95 3.00 2.93 2.96 3.00 101.32.90 2.85 2.80 2.80 2.75 2.85 2.89 101.42.75 2.70 2.75 2.75 2.75 2.74 2.76 100.73.50 3.45 3.40 3.43 3.43 3.44 3.39 98.53.65 3.60 3.55 3.60 3.60 3.60 3.66 101.64.05 4.00 3.95 4.00 4.00 4.00 4.06 101.53.20 3.05 3.05 3.05 3.09 3.09 3.16 102.3

Average. . . . 100.4

643


above, overventilation, resulting in washing outexcesses of carbon dioxide during the averageperiod of an experiment, and under basal meetab-olism conditions, is not of sufficient mlagnitudeto affect the results of metabolic rates deter-mined by carbon dioxide elimination.

Positive proof that overventilation is a verysmall factor, under the set of conditions for thletest, appears to be found in analyses of the dif-ferent rates of carbon dioxide eliminationthroughout observation periods, and also in com-parison of results of preliminary period testswith those of subsequent periods. Such com-parative data were obtained in the followingmanner.The galvanometer was made to record con-

tinuously throughout a period of observation bykeeping the contact points at E in the katharo-meter together. It was thus possible to makereadings every thirty seconds throughout a test.In each case, about twenty litres of air wereallowed to pass through the meter and katharo-meter, as shown in Fig. 5, before records weremade. In Chart I, are graphically recorded theresults of two such tests. Alany such curveswere obtained. Since the results were practi-cally identical, it serves no particular purposeto record all of them. The continuous linesrepresent the results of the preliminary periods,and the dotted lines, those of the subsequent

CIIART IPorod..iO 9 2 3 4 5 6 7 e 9 10 II 12 13 14 15

p-4 --.# ao-m.s)

ft 3.50It>%W)410tlIDvk13(k

5 4bjic 1.

i l3

2.50i..ti 2

tests. In Table V, are shown the value of allthe readings. It will be seen that if the r-esultsof the first few minutes of a test are discarded,the compositions of expired air at the differenittimes are remarkably constant, and the data ofpreliminary periods differ very little from thoseof the subsequent tests.

It is obvious that these data should be corre-lated with the ventilation rates, in order todemonstrate quantitatively the rate of elimina-tion of carbon dioxide. If the first threee min-utes of the tests are discarded the ventilationrates of preliminary and second tests agree suf-ficiently to affect inappreciably the final results,

TABLE VPERIODIC OBSERVATIONS OF CO2 COMIPOSITIONS OF EXPIRED AIR BY MEANS OF KATHAROMETER

SUBJECT 1

*Period

1 .~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

1............2............3............4............5............6............7............8............9............10............11............12............13............14............15............16............

CO2 percentage comnposition Period_

Prelimiinary period

3.303.253.203.103.103.103.103.053.053.103.103.103.103.153.153.15

Second period

3.002.982.982.952.982.952.983.003.053.103.103.103.103. 153.153.15

*Each period represents thirty seconds.

1ISUBJECT 2

Prelins

CO2 percentage composition

rtinary period Second period

1.....2.3.4.5.6.7.8.9.10.11.12.13.14.

16.

3.002.952.852.852.802.802.802.852.852.852.852.902.852.852.852.80

2.802.802.802.752.702.702.702.752.802.802.802.802.802.802.802.80

644

t


expressed in terms of basal metabolic rates, asthe following, demonstrates:

In calculating the basal mletabolic r.ates withthe assumed respir.atory qutotient of 0.82, it was

Average ventilation r.ate Average percentage carbon Average output CO2(litres per n-in.) dioxide per min. (c.c.)

Preliminary Second Preliminary Second Preliminary Secondtest test test test test test

Casel1 6.82 6.88 3.12 3.04 212.7 209.1Case 2 6.08 6.30 2.85 2.77 173.2 174.5

In view of the above findings, a series of indi- assumed that the oxygen consumption valuies asviduals, knowvn to be normal by their basal found by the Tissot method, would have beenmetabolic rates, previously determined, were the samte, had a Bene.dict "portable" o. Bene-observed by m.eans of the new method, (simply dict-Roth apparatus been employed. The com-breathing into a meter and making periodic ob- bined results are shown in Table VI.servations with the katharometer). In order All the data necessary for. the different cal-however to test the accuracy of this procedure culations are recorded. In the last three columnnsstill further, the expired air was allowed to pass are shown the different basal metabolic rates. Itinto a Tissot gasometer as shown above, Fig 4. will be noted that these subjects, all known toIt was thus possible to obtain the following be normal, had basal metabolic rates within thevalues: normal limits of variation. In four eases the

1. Basal metabolic rate by actual respiratory rates determined by CO, were between +11 andquotient. +14. (Nos. 7, 9, 11 and 13). This incidencee

2. Basal metabolic rate by assumed quotient was not, however, greater than those found byof 0.82. the other methods. (See Nos. 9, 10, 11, 13, with

3. Basal metabolic rate by katharometer. the actual R.Q., and Nos. 9, 10, 11, 13, and 16method. with the assumed R.Q.). The arithmetical miean,

TABLE VIBASAL MIETABOLIc RATES BY THREE DIFFERENT METHODS

1 .. .

2 .. .

3 .. .

4. ..

5 . ..

6 ...

7 .. .

89 ...

10 ...

11 ...12. ..

13 ...

14..15.. .

16...*17.*18..*19.20.. .

4742554253424060601836232730515151515145

R

FFmmmmmmmmmFmFmmmmmM

Haldane

4.3423.3123.8402.9693.5243.2153.3094.1503.0984.1102.7423.5083.7843.3784.5284.7912.9333.1272.8494.477

*Same subject.

ql.) ;.%> q)

'iQ

q)c P...R. cq

c (zC

I- I ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~I*I-~~~~~~~~~~~~~~~~~~~~~~~~3.3452.7372.9882.3972.9702.7592.7523.3002.4203.0102.0903.0543.0792.7563.4843.4612.2612.3772.2903.300

0.7690.8270.7780.8070.8430.8580.8120.7960.7830.7320.7620.8700.8130.8160.7670.7210.771l0.7600.8040.735

3.362.773.022.362.952.712.743.332.463.082.123.003.132.763.543.532.292.412.303.38

40.0056.9958.2566.6757.4670.3040.11.54 .2653.4472.4374.8239.1064.0969.3955.6456.9955.3957.8961.8755.13

8.010.010.010.010.09.06.010.07.010.06.07.09.09.510.010.07.08.08.010.0

157.0151.5155.0169.0158.0174.0157.0174.0168.0181 .0175.0162.0170.0162.0165.0165.0170.0170.0170.0174.0

66.053.061.456.551.086.052.081.057.062.0104.048.566.087.080.279.067.467.467.466.0

1 .671.481 .601.641 .502.011.511 .961.641 .792.181 .501.771.911.881.861 .781.781 .781.80

B.M.R.

per cent o*f normal

1-

103.1102.0106.890.4104.795.3110.090.7113.4114.5113.2103.4111.2104.0100.4110.399.296.595.0100.6

101.2101.0107.990.7104:294.4110.391.1114.5117.2114.6102.1111.5103.8101.8113.297.99'8.795.4103.4

101.0107.1106.190.3109.199.1114.291.6113.8107.3111.1110.2114.3105.0.97.0104.498.395.997.197.4

1

645

-.il ;::.le... P.z.t .

c., Cd;Z. CO

qb)c t75 b

S-.1-1

646 THE CANADIAN MEDICAL ASSOCIATION JOURNAL

standard deviation and coefficient of variationwere calculated with each method. These wereas follows.

Actual R.Q. R.Q. = .82 CO2 method

Mean. 103.0 104.0 103.5S.D.. +6.7 +7.6 +7.4C. of V.. 6.5 7.3 7.1

In view of the above finidings the procedureof simuply breathing into a meter, allowing theair to pass from the meter into the katharo-meter, (Fig. 5), and recordingo, readings at fre-quent intervals was finally adopted. The basalmetabolic rate is obtained by correlating thegalvanometer with the meter readinigs, and con-sulting tables for automatic calculations. Inci-dentally, it is economical, requiring neitheroxygen nor soda lime. The method is simple,requires a minimum of technical skill, maintainsthe "open" principle, dispenses with gas analy-sis, and sinmplicity was not obtained by thesacrifice of accuracy. As a matter of fact, itis our opinion that owing to the attitude of thepatients toward the "open" method, accuracyhas not only not been sacrificed, but has beenenhanced. The comfort of the individual withthe "open" method is reflected in the remark-ably constant values of the percentages of CO2observed at intervals of thirty seconds. Themethod is not applicable to those few conditionsassociated with marked fluctuations of respira-tory quotients (such as diabetes, etc.).In order to make the apparatus more practical,

an attempt is being made to combine the meter,the katharometer and the arm which supportsthe mouth piece into one apparatus. The arm-

piece will be miade collapsible. Since CO2 valuesunder the conditions of the test do not exceedfive per cenit, the galvanometer scale is also beingso modified as to read within this value. Withthe same scale length this will, therefore, resultin more simple and still more accurate readings.A recording galvaanometer is also being included.The purpose of the recording, galvanometer isfor studies involving continuous observations ofCO, output duriing a respiration experiment.No apparatus has, hitherto, inade such a studypossible with the same degree of accuracy.

Notes on case of katlharoimeter.-The makersof the apparatus supp)ly a list of inistructions forits care. For the l)resent purposes two are ofparticular note.

It is necessary that the platinum wires in theconitrol chamber be continually exposed to water.The latter is conitained in a small brass tubefitted in the bottoml of the case. It will seldomneed attentioni. Wlhen it does it may be re-moved by taking out the plate (with the ba-yonetjoint) uniderneath the case and filling out thesmall tube which then p)rojects.The moisture condenses rather rapidly in the

mietal fitting on the top plate, and this shouldbe cleared frequently. A tube is provided inthis fitting to prevent water from getting downinto the holes in the brass block of the katharo-meter. These holes may be inspected by un-screwing the two nickel nuts and removing thereetangular block from the top plate, care beingtaken on replacing it to nmake a good gas tightjoint with the rubber washer.

REFERENCES(1) KING, J. T., JR., J. H. Bulletin, 1921, vol. xxxii,

277, Basal metabolism (Williams and WVilkiins), 1924.(2) HILL, A. V., Proc. Soc. J. Pliys., 1922, vol. ]vi, p.xx.

Gallstones in Children.-J. D. Carey, FortCollins, Colo., relates the case of a girl, aged9 years and 3 months, who was referred foroperation for appendicitis. Two years pre-viously, she. began to have attacks of abdominalpain of such character and severity that shewas compelled to be absent from school on anaverage of four days each month. The painvas located in the right side, associated withvomiting, slight fever and a small degree ofrigidity. Attacks would come on suddenly and

confine her to bed for a period lastinig frontwo to four days. The appendix was removedand showed signs of slight chronic inflammationi,though not sufficient to cause the amount oftrouble that the girl was having. The pelviswas normal on examination; the gallbladder wasgreatly distended, and an oval stone 1 inch(2.5 em.) in diameter, was lodged in the commonduct. The gallbladder was removed and thewound closed. The recovery was uninterrupted.-Jour. Am. MIed. Ass., April 6, 1926.

basai metabolic rates*

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