TABLE
| Fat | Milk Sugar | Protein | |
| Whole milk | 4.00 | 4.50 | 3.50 |
| 7% cream | 7.00 | 4.45 | 3.40 |
| 10% cream | 10.00 | 4.40 | 2.25 |
| 16% cream | 16.00 | 4.20 | 3.05 |
| 32% cream | 32.00 | 3.40 | 2.50 |
| Skimmed milk | 1.00 | 5.00 | 3.55 |
| Separated milk (fat-free) | 0.25 | 5.00 | 3.65 |
| Whey | 0.25 | 5.00 | 0.90 |
Seven per cent. (7%) cream is obtained from the upper 16 ounces of a quart bottle of milk which has been allowed to stand undisturbed for six hours. The upper third of the bottle contains 10% fat, while the whole fat layer from the quart bottle, regardless of the number of ounces, contains about 16% of fat.
Methods of Artificial Feeding.—The use of whole milk, top milk, or skimmed milk, diluted with water, and either milk sugar, malt sugar, or sucrose (cane sugar) added, is the method of feeding most commonly used, and upon it are based the formulas universally advised by infant specialists. There are cases in which simple dilution is not advisable. In premature or very young infants, for example, the whey mixtures have been found to give the best results. In toxic diarrheas, where the putrefactive bacteria make the use of all but the minimum amount of protein inadvisable, the above method is contraindicated, as it is likewise in cases where vomiting of casein curd is a prominent feature.[68]
The Use of Alkalies.—There are many cases in which the physician deems it advisable to add an alkali to the milk mixture. The one generally selected is limewater. However, sodium citrate and sodium bicarbonate are also used. The reasons for adding alkalies to the milk mixtures are: (1) to check the coagulation of the casein, (2) to hasten the emptying of the stomach, or (3) to chemically change the formation of the curd. In certain cases it is only necessary to delay the coagulation of the casein in the stomach, in which case a certain amount of limewater is used. Its action is to swell the protein of the milk and in this way effect the precipitation of the casein. In other cases it is found advisable to prevent the formation of curd and hasten its departure from the stomach. Cannon[69] claims that milk before it coagulates leaves the stomach quickly like water in gushes. Hence, if an alkali like limewater, bicarbonate or citrate of soda is added to the milk this coagulation will be checked and the digestion be facilitated.
Amount and Type of Alkali Used.—The amount of alkali[70] necessary to bring about any change in the general effect of the formula must be determined by the amount of milk and cream in the mixture, since these constituents alone determine the acid content. However, it is impossible to judge exactly the amount of alkali to add, but an approximate estimate is made from the work done by the various investigators. It has been estimated that from 25 to 50% of limewater must be added to milk to change it to any marked degree. In using bicarbonate of soda, a much less quantity brings about the desired result, 1½ grains of bicarbonate of soda being equal to one ounce of limewater. The action of these two alkalies is different. The soda acting upon the milk causes the curds to be more porous, and therefore more easily acted upon in digestion.
Sodium citrate likewise tends to prevent the formation of tough curds. It is added in amounts of 1 to 2 grains to each ounce of milk or cream in the mixture whenever it is found necessary to use it at all.
The addition of any alkali to the formula is resorted to if the symptoms indicate the need for it, but the type and quantity is entirely within the province of the physician, not the nurse.
The Addition of Sugar.—Lactose is the form in which the carbohydrates are found in milk, and it has been a general rule to employ this sugar in making up the sugar content of a formula, using from 6 to 7% of the mixture in this form to cover the necessary energy requirements of the infant. Other sugars are used, however; and of late years malt sugar has been widely employed for this purpose. The form now generally accepted is known as dextri-maltose, which is a combination of dextrin and maltose, both of which are readily acted upon by the sugar-splitting enzymes of the digestive juices. In digestion, lactose or milk sugar is split to dextrose and galactose and utilized in the body, both as a source of energy and as a food for the lactic acid bacteria which are active in the small intestine.
Malted Foods.—The addition of malted foods or malt sugar to the food of infants tends to bring about a more rapid gain, both in energy and in body weight, than is generally the case where other sugars are used. This sugar is used as a substitute for milk sugar in many formulas, especially in those cases in which the casein of cow’s milk needs to be made more digestible in form. Malt sugar is indicated in the following conditions:[71] (1) in severe atrophies, (2) in cases of fat indigestion before the atrophic stage is reached, (3) in cases where there is slight curd indigestion, indicated by some vomiting and slow gain in weight, (4) in cases where excessive intestinal fermentation is manifested by gas and colic.
Malt sugar (dextri-maltose) is contraindicated to a slight degree in cases “of simple acute diarrhea where lactose, by supplying fermentative media, more easily restores the normal bacterial balance.”
Diluents.—Barley and oatmeal water are used as diluents to the amount of one-fourth or more of the mixture. Oatmeal water or jelly is used more during the winter months than in the hot summer months. As the fat content of the oatmeal gives it a more laxative effect, it is undesirable to use it at the season in which the summer diarrheas are prevalent. Barley water has something of a colloidal action upon the casein, causing the curds to be finer and less tough in character. Both barley and oatmeal water are used in place of plain water for babies when this colloidal effect upon the curd of the milk is desired, also where the weight of the infant shows a disposition to remain stationary, especially where there are no other symptoms to account for the lack of gain.
Whey is used with babies who cannot digest the insoluble protein of cow’s milk. This is often the case in premature babies and is manifested by a persistent vomiting of curd. The energy requirements are obtained by the addition of cream and lactose to the whey.
Buttermilk Mixtures and “Eiweissmilch.”—It is often found desirable to use some other form of milk than whole, top, or even skimmed milk, and for this purpose lactic acid, milk and the albumen or “Eiweissmilch” are substituted. In the buttermilk mixtures the precipitation of the casein is brought about by lactic acid bacilli (Bulgarian culture). This prevents the coagulation of the casein into tough curds. Lactose buttermilk or lactic acid milk is used in the feeding of infants who have persistent green stools, and in cases of acute toxic diarrhea brought about through the action of gas bacillus.
Buttermilk is more difficult to administer to babies than formulas made from plain milk by reason of its flavor. However, the results are remarkable in the above-mentioned conditions.
“Eiweissmilch” is used in atrophic cases where there are bad green stools.
“Homogenized Milk.”—Dr. Ladd of the Children’s Hospital in Boston has presented many cases of infants who showed an intolerance for butter fat. These cases he has treated with formulas containing foreign fat, usually olive oil. This milk is subjected to a treatment which brings about a more complete emulsification of the fat than is possible in cow’s milk, causing it to resemble in character the quality of the mother’s milk. Homogenized milk has been used with success in cases where it was impossible to supply the infant with breast milk.
The process is accomplished by the use of an apparatus known as an “homogenizer”[72]; in this machine the fat globule is crushed and so finely divided as to prevent its re-formation. The greatest drawback to the use of this process lies in the scarcity of available machines. Cod liver oil is now used in many cases where the infant shows a failure to gain or is in possible danger of developing rickets, with the homogenizer it is possible to add the oil to the formula, thus facilitating its use.
Technique of Milk Modification.—The absolute necessity for cleanliness has already been dwelt upon in respect to milk, and in infant feeding the vigilance which must be observed in the preparation of the food cannot be too strongly emphasized. The milk itself must be of known purity. Where there is any uncertainty about its source, it must be sterilized or pasteurized according to the doctor’s orders. The bottles and nipples should be washed as soon as they are used, first with plain water to remove the milk, then with soapsuds and a bottle brush. The bottles should then be filled with boric acid or bicarbonate of soda solution until needed, when they should be emptied and placed in a deep pan filled with cold water and allowed to boil for a few minutes. They should not be taken from the water until they are to be filled with the milk mixture. The nipples are washed thoroughly and boiled once a day and dropped into a solution of boric acid or bicarbonate of soda when not in use. The plain black rubber nipples are best as they can easily be turned inside out and cleaned. If the milk drops too slowly from the bottle, the nipple may be pierced in one or two places with a darning needle.
The morning is the best time in which to prepare the baby’s food; the milk has not stood too long and it is easier to regulate the feedings if a fresh start is made each morning. Let the bottles and the rubber corks with which they must be stopped be boiled and cooled while the milk mixture is being prepared.
Preparation of Diluents.—If barley or oatmeal water is to be used as a diluent, let that be prepared first, that it may be cool before adding it to the milk. Cover the table with a clean cloth or oilcloth, upon this place the pitcher in which the milk is to be modified, have the funnel, milk dipper, and spoon which are to be used boiled with the bottles, cover the mouth of the pitcher with a clean square of gauze or cheesecloth, read the formula carefully and measure the sugar, dextri-maltose, lactose, Mellin’s Food, or cane sugar as directed and place it in a clean glass; now measure the diluent, water, oatmeal water, barley water, or whey; use part of this diluent to dissolve the sugar.
Measuring Milk according to Percentage of Fat.—Now dip off the required layer of top milk, that is, the layer containing the desired percentage of fat and protein. Mix this thoroughly and dip out the requisite number of ounces into the pitcher. If there is not sufficient cream in one quart bottle to fill the formula, the cream must be dipped from a second bottle and mixed with that of the first before it is measured into the pitcher. The dissolved sugar and rest of the diluent, together with the correct amount of limewater, are strained into the pitcher, mixed thoroughly, and strained through the absorbent cotton lining the funnel into the bottles, allowing the correct number of ounces for each feeding in every bottle.
Pasteurizing the Milk.—The corks are then adjusted, the bottles placed in the pasteurizer[73] and pasteurized for the desired number of minutes. The water in the pasteurizer must be cold in the beginning and the rise of temperature recorded on the thermometer, which is adjusted at a convenient place in the pasteurizer where the scale can be read easily. If the temperature of the water is too high, add cold water and lower the flame beneath the pasteurizer. When the desired number of minutes has elapsed, lift the bottle rack above the water for a few minutes and allow a stream of cold water to flow into the pasteurizer, taking care not to chill the bottles too suddenly or they will crack. Cool the bottles as quickly as possible and place on ice until needed, warming the bottle of milk as needed in warm water.
Amount Given at Each Feeding.—At birth a baby will usually take from one half to one ounce at each feeding, this amount is increased at the rate of a quarter of an ounce each week until the baby is receiving eight ounces at each feeding. Or the food is measured to allow of from one ounce to an ounce and a half more than the child’s age in months. For example a baby six months old would receive from seven to seven and a half ounces at each feeding. Some babies are bigger and stronger than others and require the maximum amount, while others are less vigorous and the amount of food which they can handle at a feeding may fall slightly short of the above amounts, but the quantities indicated above will serve as a guide in measuring the formula.
Method of Calculation of Formula.—The calculation of a formula consists in determining the amount (in grams or ounces), of the various constituents contained in the formula when the percentage of each is known. Or, in determining its percentage composition when the amount of fat, protein, carbohydrate and diluent is given. There are certain inaccuracies in all simple methods of calculation and the use of the Babcock tester to determine the fat content in the milk to be used, is advised in all milk or formula rooms. The following method of calculation has been found satisfactory, and the nurse must master it in order to intelligently carry out the directions of the pediatrist.
Determining the Composition of Formula.[74]—Gravity cream and skimmed milk are used in this method, the cream is estimated as containing 16% fat, and consists of the entire cream layer from a quart bottle of milk which has been allowed to stand without being disturbed for six hours or longer. The cream must be dipped off with a cream dipper, or poured off. If there is not a sufficient number of ounces in one bottle of milk, a second must be used, the entire cream layer taken, then mixed with that obtained from first bottle, before the required number of ounces are measured off. Skimmed milk is estimated as being fat-free (although this is not entirely accurate). Both gravity cream and skimmed milk are estimated as containing 3.2% protein, and 4.5% sugar. In this method, one rounded tablespoonful of milk sugar is estimated as weighing one half ounce (dextri-maltose may be estimated in the same way). With this brief explanation of the terms used we will proceed with the method itself.
It is always essential before beginning the calculation of the formula, to know what percentages of fat, sugar, and protein it is to contain, and the amount to be given in twenty-four hours; it is also necessary to know how much lime water is to be added if this substance is to form a part of the formula.
Suppose a thirty-two-ounce mixture is to be made containing 3% of fat, 6% of sugar, 2% of protein, and lime water sufficient to equal 25% of the cream and skimmed milk in the mixture. The fat in the food must be derived from cream, since it is the only substance containing fat to be used in the formula. If the food was composed entirely of gravity cream it would contain 16% of fat. Since it is to contain but 3% of fat it is evident that only 3/16 of the mixture must be gravity cream, 3/16 of thirty-two ounces is six ounces. Six ounces of gravity cream will, therefore, provide the 3% of fat desired in the mixture. The gravity cream contains protein as well as fat. There are six ounces of gravity cream in the thirty-two-ounce mixture. The protein content of gravity cream is 3.2%. The protein content of a thirty-two-ounce mixture containing six ounces of gravity cream is evidently 6/32 of 3.2% or 0.60%. Two per cent protein is, however, desired in the mixture. The gravity cream has provided only 0.60%. One and forty hundredths per cent of protein, the difference between the percentage of protein desired and that furnished by the gravity cream, must be obtained in some other way. It must be obtained, moreover, from some substance which does not contain fat. Skimmed milk is such a substance. Skimmed milk contains 3.2% protein. In order to get 1.40 per cent in the mixture by the use of skimmed milk, it is evident that 140/320 of the mixture must be skimmed milk. 140/320 of thirty-two ounces is fourteen ounces. Fourteen ounces of skimmed milk will, therefore, provide the additional 1.40% of protein desired.
Both gravity cream and skimmed milk contain 4.50% milk sugar. Twenty ounces of gravity and skimmed milk are required to furnish the desired percentages of fat and protein. These twenty ounces in a thirty-two-ounce mixture must add 20/32 or 4.50% of sugar to the mixture. Twenty thirty-seconds of 4½ or 20/32 of 9/2 = 180/64, or practically 3% of milk sugar. It is, however, desired to have 6% of milk sugar in the mixture. That is, 3% more of milk sugar is required. This additional sugar must be added in the form of dry milk sugar. Three per cent of thirty-two ounces is 3/100 of thirty-two. This will give the amount of sugar desired in ounces. The sugar is to be measured in rounded tablespoonfuls, or half ounces. If the figures given above are multiplied by two, the result will be the number of rounded tablespoonfuls needed. That is, 3/100 of 32 × 2 = 192/100 rounded tablespoonfuls, or for all practical purposes, two rounded tablespoonfuls.
It is also desired to have the amount of lime water in the mixture equal to 25% of the cream and milk in the mixture. There are twenty ounces of cream and milk in the mixture. Twenty-five per cent of twenty ounces is five ounces. Five ounces of lime water must therefore be added. The total quantity of the mixture is to be thirty-two ounces. The milk sugar goes into solution and, therefore, does not add to this quantity. The difference between thirty-two and twenty-five ounces is seven ounces. Seven ounces of water must, therefore, be added to make up the quantity desired.
Changing the Formula.—It is often found necessary to change the formula when using artificial feeding for infants, and under these circumstances it is necessary to know the percentages of the food constituents contained in the formula already in use. For this purpose the following method, quoted from “Diseases of Nutrition and Infant Feeding,”[75] is included:
Morse and Talbot’s Method.—Suppose that a baby is taking a food made up of—
| Gravity cream | 12 ounces |
| Skimmed milk | 18 ounces |
| Limewater | 6 ounces |
| Barley water | 12 ounces |
| Milk sugar | 4 rounded tablespoonfuls |
“The barley water is made with two teaspoonfuls of barley flour in a pint of water. The total quantity of the mixture is 48 ounces. Gravity cream contains 16% fat. Twelve ounces of gravity cream in a 48-ounce mixture will give, therefore, 12/48 of 16% of fat, or 4% fat. Both gravity cream and skimmed milk contain 3.20% protein. There are 30 ounces of gravity cream and skimmed milk in the mixture; 30 ounces in a 48-ounce mixture will give 30/48 of 3.20% of protein, or 2.00% of protein. Both gravity cream and skimmed milk also contain 4.50% of sugar. Thirty ounces of gravity cream and skimmed milk in a 48-ounce mixture will therefore furnish 30/48 of 4½ which is the same as 30/48 of 9/2 or almost 3.00% of milk sugar. Four rounded tablespoonfuls of milk sugar are equal to two ounces. Two ounces of sugar in a 48-ounce mixture is equal to 2/48 of 100% or 4%. The total percentage of sugar is, therefore, 7%. Two teaspoonfuls of barley flour in a pint of water makes a 1.50% decoction of starch. Twelve ounces of barley water of this strength in a 48-ounce mixture will give 12/48 of 1.50% or about 0.35% starch. There are six ounces of limewater in the mixture and 30 ounces of gravity cream and skimmed milk. 6/30 of 100% is 20%. The limewater is, therefore, 20% of the milk and cream. The mixture thus contains 4% fat, 7% sugar, 2% protein, and 0.35% starch, while the limewater is in the proportion of 20% of the cream and milk.”
If, therefore, the nurse will follow out the plan suggested by Drs. Morse and Talbot, it should be a simple matter to change the percentage of any of the food constituents in any formula.
The following schemes for feeding well babies are included to facilitate the work in the home. A nurse may teach the mother the manner in which these schemes are used, keeping in mind that there can be no iron clad rule for feeding all babies. No nurse should recommend a formula without directions from a physician. And no formula should be changed without his permission.
The following milk formulas are used in the Nathan Straus Pasteurized Milk Laboratories of New York:
Formula No. 1.—Infants from 1st to 4th week, by A. R. Green.
24 ounces of mixture divided into 8 feedings of three ounces each, fed at intervals of 2½ hours:
¾ oz. 16% cream
3 oz. full milk
19 oz. water
1¼ oz. limewater
1½ oz. milk sugar
Formula No. 2.—Infants 1st to 3d month, by Dr. R. G. Freeman.
1½ oz. 16% cream
3 oz. full milk
13 oz. water
½ oz. limewater
1 oz. milk sugar
Divided into 6 feedings of 3 oz. each, fed 3 hours apart.
Formula No. 3.—Infants 2d to 6th month, by Dr. R. G. Freeman.
18 oz. full milk
16½ oz. water
1½ oz. limewater
1½ oz. milk sugar
Divided into 6 feedings of 6 ounces each, fed at intervals of 3 hours.
Formula No. 4.—Infants 3d to 7th month, by Dr. A. Jacobi.
18 oz. full milk
18 oz. barley water
1 oz. cane sugar
20 grains salt (less than ¼ tsp.)
Divided into 6 feedings of 6 ounces each, fed at intervals of 3 hours.
Formula No. 5.—Infants 7th to 9th month, by Dr. A. Jacobi.
2½ oz. full milk
7½ oz. oat or barley water
1½ oz. cane sugar
30 grains (about ¼ tsp.) table salt
Divided into 5 feedings of 6 ounces each, fed at intervals of 3½ hours.