Practical infant feeding

Preface

I HAVE tried to write a book on infant feeding which will be practical without being superficial, scientific without being tiresome. Its paramount purpose is to attempt to help the practitioner not only to treat but to understand feeding cases as they occur in his daily practice. It is absolutely essential, and not too much to ask, for the general practitioner, or anyone else who is feeding babies, to have a considerable knowledge of the chemistry of metabolism in normal and abnormal babies before they can feed them intelligently, and before they can be said to have a satisfactory working knowledge of infant feeding. This is what too many practitioners lack. They must know the processes that are going on in the digestive tract, and must understand what the difi'erent food elements do under various conditions, but so many conflicting views are held by various investigators in this country and abroad that it would be of little value in a text-book to attempt to give a review of the literature which forms the corner-stone of scientific infant feeding without setting any definite interpretation upon it. To my mind a text-book of infant feeding should consist of a clear presentation of what is generally believed on the subject, seen and interpreted through the eyes of the author, and largely supplemented by his own practical experience. It should serve at the same time as a working guide for the general man and as a reference book for the pediatrist.

I have tried in this book to effect a common-sense combination of science and practice, to apply scientific principles to practice as much as possible, to go into a good deal of detail concerning certain scientific investigations which are of practical importance, and to omit others which are not. It has not been my purpose to follow any one "school" of infant feeding,

12 PREFACE

but rather to amalgamate the best points taught in this country and abroad into what I hope is a homogeneous whole.

It is desirable, of course, to make any subject as simple and as easily understandable as possible, and infant feeding need not be made complicated, but, on the other hand, any presentation which does not explain underlying processes and the basis of symptoms is not enough for the thinking practitioner of today. As I heard an eminent Philadelphia pediatrist say not long ago, there is at present a tendency to try to make infant feeding so easy for the physician that there is a chance of forgetting whether or not the methods used may be suitable for the baby.

The general standard of infant feeding in America has, however, improved greatly in the last ten years owing to the increased interest that general practitioners have taken in it, which is shown by the continually increasing numbers coming for instruction to the large post-graduate schools, such as the Harvard Graduate School of Medicine and the New York Post-Graduate School.

To such men as this I respectfully offer this book, and sincerely hope that they may find it of value and interest.

I wish especially to thank Dr. W. W. Howell for so kindly consenting to write the chapter on Premature Infants; Dr. R. W. Lovett and other members of the staff for permitting me to use several pictures and Roentgen-ray plates taken from their cases in the Children's Hospital; Mr. J. V. Footman for kindly making the prints and taking many pictures, and the publishers for their many courtesies.

Lewis Webb Hill.

483 Beacon Street,

Boston, Mass.,

Chapter I Page

The Physiology and Pathology of Digestion and Nutrition 17

The Newborn Infant 17

The Physiology of the Digestive Tract 22

The Bacteriology of the Digestive Tract and the Relation of Bacteria

to Food 28

Fermentation and Putrefaction 32

The Metabolism of the Food Elements 34

Fat 38

The Vitamins 65

Energy Requirements 69

CHAPTER X Digestive and Nutritional Disturbances in the Bottle Fed .... 252

Underfeeding 256

Acute Fat Indigestion 258

Acute Sugar Indigestion 259

Acute Protein Indigestion 263

Acute Starch Indigestion 264

Chronic Fat Indigestion (Type 1) 268

Chronic Fat Indigestion (Type 2) 272

Chronic Sugar Indigestion 274

Marasmus 275

General Suggestions for Difficult Feeding Cases 286

Chapter I The Physiology And Pathology Of Digestion And Of Nutrition

THE NEWBORN INFANT

Von Reuss^ (Vienna) gives the average weight of the normal full term infant as 7 lbs. 2 oz. for boys and 6 lbs. 9 J oz. for girls. Ramsey and Alley^ (Minnesota) in a series of 300 newborn babies found that the average weight was 7| lbs. for boys and 7 lbs. 3 oz. for girls. In Curry's^ series of 521 cases (San Francisco) the average was 7 lbs. 3 oz. for females and 7 lbs. 11 oz. for males. Hecker of Munich (quoted by Von Reuss) in a large series of cases observed the following weights:

Every baby loses normally a certain amount of weight during the first few days of life. This loss, according to Talbot,^ is of two kinds: (1) mechanical, (2) physiologic. The mechanical loss is due to the passage of urine and meconium (70-90 gm.),

1 Die Krankheiten des Neugeboren, Berlin, 1914.

3 Quoted by Yerington, Jour. Amer. Med. Assoc, vol. 71, September 28, 1918.

2 17 the loss from the removal of vernix caseosa and other secretions, and possibly sometimes the vomiting of allantoic fluid, which the baby may have swallowed before birth. The "physiologic*' loss of weight is that caused by actual oxidation of body substance. For a few days, during the colostrum period, the baby is in a state of partial starvation, and the energy to supply his fuel needs has to come from oxidation of his body substance instead of from ingested food. The glycogen of the liver and tissues is first used, and when this is exhausted the body fat is burned. "Infants without a good layer of body fat should receive food at the earliest possible moment" (Talbot).

The colostriun period usually lasts about three days, and it is not until about the fourth day in most cases that the milk secretion is established. Colostrum is a concentrated food, but there is very little of it. According to the analyses of Camerer and Soldner, very early colostrum contains fat 4.08 per cent., lactose 4.09 per cent., protein 5.80 per cent., ash 0.48 per cent; according to those of Bailey and Murlin,^ fat 2.9 per cent., lactose 7.1 per cent., protein 2.3 per cent. The amount of colostrum is usually estimated at about 20 c.c. on the first day, increasing somewhat on the second and third days.

Loss of water from the body is also of considera"ble importance, according to some authorities the most important factor in causing loss of weight. Birk and Edelstein^ found that the amount of water lost from the infant's body was 28.12 gm. per kilo for the first twelve hours, and 40.74 gm. and 53.6 gm. respectively for the next two twenty-four-hour periods. Von Reuss gave a considerable amount of water from the first day to a series of newborns, and noticed that there was much less loss of weight than in those babies to whom no water was given. The loss of weight continues for about three days, and on the third or fourth day the minimum is reached. The loss usually varies between 150 and 300 gm. (5-10 oz.), but occasionally may reach 400 to 500 gm. in babies who are apparently normal.

1 Amer. Jour. Obstet., vol. 1, 1915.

2 Monatschr. f. Kinderh.. vol. 60. 1910.

I

1>HYSI0L0GY AND PATHOLOGY OF DIGESTION AND NUTRITION 1 9

If the breast milk is late in coming in, or if it is lacking in quality or quantity, the initial loss of weight may be considerably more. The loss is proportional to the absolute body weight, and is usually about 6 to 9 per cent, of it. There is less likely to be a large loss of weight if the baby is nursed on the first day, and at frequent intervals; babies nursed or fed artifically at four-hour intervals almost always lose more weight than those fed at 2- or 2|-hour intervals. According to Benestad^ babies suffer a greater loss of weight, both relatively and absolutely, the greater the birth weight is. Most of the loss occurs during the first twenty-four hours, and according to various authors as much as 125 gm. may be lost in this time. Most authorities are agreed that nothing can stop the initial loss of weight, but Schick^ in 9 cases was able to prevent it by frequent forced feedings with a mixture of colostrum and breast milk. An excessive loss can be practically always prevented by proper feeding. According to Camerer the birth weight is regained by the eighth or tenth day, while according to Ramsey and Alley only about 25 per cent, of all cases regain the birth weight by the tenth day. Bergman,^ in a series of 1000 hospital cases, found that 11.4 per cent, regained their birth weight by the tenth day, 21.7 per cent, by the fourteenth day, and 24.1 per cent, had not regained it by the twenty-first day. All these babies were fed at four-hour intervals, however, and, moreover, were hospital cases. It is hardly fair, then, to accept these figures as a standard, and in most cases the average breast-fed baby in a private house, looked after carefully and fed at 2J- or 3-hour intervals will regain the birth weight by the fourteenth or fifteenth day. In the case of bottle-fed babies, however, the situation is far different, and many normal babies who have had to be fed entirely on the bottle from the day of birth may fail to regain their birth weights before the end of the third or fourth week.

Body Temperature. — ^At birth the body temperature is

1 Jahrhb. f. Kinderh., vol. 80, 1914.

2 Ztschr. f. Kinderh., vol. 13, 1916.

« Ibid., March. 1916.

relatively high (99,8°-100.8° F.), but during the first few hours of life a newborn baby loses a considerable amount of heat, and it is not unusual to record rectal temperatures of 95° F. in healthy full-term infants a few hours after birth. If the baby is kept warm the temperature soon comes up to normal, however. The first bath usually depresses the temperature from 1 to 1| degrees, and in the first week of life the daily variations are much greater than in older children (1° to 2° F.) (Von Reuss). The heat-regulating mechanism during the newborn period is very unstable, and newborn babies are likely to react differently than older babies to infection. Severe infections, such as erysipelas, may in some cases cause only a slight rise of temperature, while in other cases the temperature may be very high from relatively slight causes.

Transitory Fever of the Newborn. — Not a few normal infants show a rise of temperature to 101° or 102° F., most commonly on the third, fourth, or fifth days. In many cases it is not accompanied by symptoms, while in others the baby may be restless and irritable, with mild toxic symptoms. Marked toxic symptoms are unusual, but may occur. The temperature usually lasts from twenty-four to forty-eight hours, and then rapidly subsides. It is difficult to estimate how frequently this transitory fever occurs, as it is undoubtedly often overlooked. CrandalP found at the Sloane Maternity Hospital in New York that it occurred in 135 of 500 consecutive newborns, a rather high percentage, while at the Nursery and Child's Hospital only 20 babies out of 200 showed it. Heimann^ found that if the baby was not put to the breast until twenty-four hours after delivery, from 2.3 to 4.2 per cent, had transitory fever, while if the nursing was begun 12 hours after delivery only 0.6 to 1.3 per cent, showed it. Von Jaschke^ in 1000 newborns found only 31 with transitory fever. The etiology of the condition is not well understood. It has been usually called "inani-

2 Monatschr. f. Geburtsh. u. Gynakol., Bd. 51, 1920.

3 Ztschr. f. Geburtsh. u. Gynakol., 78, 119, 1915.

tion" or "exsiccation" fever, and has been supposed to be due to the desiccation of the tissues during the first few days of the newborn period, when but little fluid has been taken. It has also been supposed to occur especially in babies who lose an excessive amount of weight, which is somewhat borne out by the fact that it is seen most commonly on the third to fifth day, when the weight has usually reached its lowest point. These views have, however, been recently disproved by Grulee and Bonar,^ who found that there was no regular relationship between the occurrence of fever and the amount of fluid taken, or the weight loss. They believe that it is best explained by the absorption of some protein products, bacterial or otherwise, from the intestine, probably from putrefaction of the meconium, which is relatively high in protein and low in sugar. As soon as the breast milk comes in, and the high protein meconium is replaced by the high lactose breast milk, putrefaction stops, and the fever subsides. It is probable, however, that many factors are operative, and an excellent summary of them is given by Von Reuss^:

"The replacement of meconium flora by milk flora in the intestine; the irritant effect of bacterial products of decomposition or toxins, and of nutritive ingredients on the intestinal cells, the presence of products of the breaking down of tissue such as occurs during the fiirst days of life; the deficiency of water, due partly to an inadequate external supply of fluid, and partly to internal causes, and the resulting concentration of tissue fluids and restriction of diuresis; and finally, the backwardness of the mechanism of heat regulation."

Diagnosis. — This is not ordinarily difficult, but it must be remembered that there are other causes of temperature in the first few days. Sepsis does not ordinarily have to be considered, as it occurs very rarely before the fifth day. "Transitory" fever practically always occurs before the fifth day. Furthermore, if sepsis is present, the focus can be found. Naso-

1 Amer. Jour. Dis. Chil., vol. 22, No. 1, July, 1921.

2 Diseases of the Newborn, London, 1920, p. 475.

pharyngitis, otitis media, and pyelitis occur occasionally in newborns, and must be ruled out. I have recently seen a baby of three days with an otitis media which gave rise to a high temperature, and subsided as soon as the ear drmn was incised, and a considerable amount of bloody serum was evacuated. The ears should always, therefore, be examined in any newborn baby with an imexplained fever. With otitis media the baby is usually a good deal sicker than is the case with "transitory" fever.

Pyelitis is very rare in the newborn, but has been reported. The diagnosis is made by an examination of a catheter specimen of the urine.

Treatment. — One-half teaspoonful of castor oil should be given at once, and fluid and food forced. If the breast milk is late in coming in, as it very frequently is, a few ounces of breast milk should be secured from some other woman, and should be given In small, frequent feedings. If breast milk is not available, a weak cow^s milk modification is given, with a very low fat and protein and relatively high sugar. Water should be given frequently in as large amounts as possible between the feedings. The condition is not a dangerous one, and the fever practically always subsides in a day or two, without further symptoms. Its chief importance in most cases is that a good deal of alarm is unnecessarily experienced. In a few cases, however, toxic symptoms are marked, but usually subside after catharsis and free fluid and sugar intake.

THE PHYSIOLOGY OF THE DIGESTIVE TRACT The Mouth. — ^Mouth digestion is relatively unimportant until the baby possesses ten or twelve teeth. Even then it is not as important as in adults, as babies ordinarily chew very little. The habit that many babies have of holding food in their mouths for some time before swallowing probably aids somewhat in the digestion of the starches, even if only a few teeth are present. The quantity of saliva in the first week of life is very small, but it has been shown to contain ptyalin. When the teeth begin to appear the secretion of saliva becomes more abundant. The weight of the saHvary glands at three months is double that at birth, and at a year is quadrupled.^

The stomach of the infant is placed more vertically than that of the adult, which accounts partly for the ease with which babies regurgitate. The pylorus lies slightly to the right of the midline between the umbilicus and the xiphoid. The average anatomic capacity of the stomach in newborn babies, according to Scammon and Doyle,^ is 25 c.c. The anatomic capacity, or size of the stomach, is however, not a good index of the physiologic capacity, or amount of food that may be taken at one time, as a good part of it passes out through the pylorus before the last part has entered the stomach. The stomach increases rapidly in size during the first few days of life. According to Scammon and Doyle, the following average amounts of breast milk were taken at each feeding by a large series of normal breast-fed babies during the first ten days:

Day. Amount taken at each feeding.

2 13 «

3 27 «

4 46 "

5 57 «

6 64 "

7 68 «

8 71 «

9 76 "

10 81 "

The table below, showing the size of the stomach at different ages, is from Pfaundler and Schlossmann:

Size of the Stomach at Various Ages

1 month, 3 oz.

4 months, 4 oz.

7 months, 1\ oz.

5 " 6 «

3 « 31 «

* Gundobin, Die Besonderheiten des Kindesalters, Berlin, 1912. 2 Amer. Jour. Dis. Chil., vol. 20, No. 6, 1920.

Secretions of the Stomach, — The stomach secretes four substances of importance: pepsin, rennin, hydrochloric acid, and a fat-splitting enzyme. In breast-fed babies free HCl is found about 2 hours after the meal in a concentration of about 0.10 per cent. In bottle-fed babies it is found later, or not at all, on account of the greater powers of the cow's milk (casein) to combine with the acid. Inasmuch as free hydrochloric acid is a strong antiseptic agent, and undoubtedly destroys a good many of the bacteria which are introduced into the stomach, the stomach contents of a bottle-fed baby are less antiseptic than those of a breast-fed baby. This may be of considerable practical importance in causing digestive disturbances by allowing the bacteria which have not been killed off to attack the food in the digestive tract. Stomach digestion proceeds somewhat as follows (Tobler): Soon after the milk enters the stomach it is coagulated by the rennin. The curd and whey are separated, and in the first part of the digestive period the liquid portion of the chyme is passed into the duodenum. Most of the casein and fat remain behind in the stomach and is slowly digested and liquefied by pepsin and hydrochloric acid digestion. The products of this (protein) digestion are albumoses and peptones. The fat also undergoes a certain amount of digestion by the action of the gastric lipose. Sugar is not acted upon, and most of it leaves the stomach in the whey. It is probable that even in babies with severe digestive or nutritional disturbance there is little or no deficiency of the gastric digestive ferments. There is very little absorption of either water or food material from the stomach.

Motility and Emptying Time of the Stomach. — Peristalsis begins soon after taking food. The peristalsis of the stomach mixes the food thoroughly with the gastric juice, in the pyloric portion especially. At certain intervals the pyloric sphincter relaxes and the contraction wave squeezes some of the fluid into the duodenum (HowelP). According to Maynard Ladd,^ who

* Text-Book of Physiology, Philadelphia, 1915. 2 Amer. Jour. Dis. Chil., May, 1913, vol. 5.

has extensively studied gastric motility in infants by means of the Roentgen ray, "There is a curious lack of peristalsis to be seen in infants' stomachs as compared with adults.

"The stomach empties itself of the greater part of its contents in from one to two and one-half hours. This time varies considerably, however, in different babies. After the greater part of the stomach contents has passed into the small intestine, a considerable residue remains, which is emptied very slowly, after remaining for from four to seven hours, in both bottleand breast-fed babies."

In most cases Ladd found that the stomach was nearly empty after two hours. A new feeding tends to stimulate peristalsis and to push out ahead of it the residue of the previous feeding.

There is a very great difference in the emptying time in different babies, as Ladd found that with 3 infants of the same age on the same formula, 2 J, 3|, and 4| hours were required to empty their respective stomachs. The sort of food taken is, of course, important, and one infant in Ladd's series required on different occasions, with different formulas, 2^, 4i, 6, and 7| hours to completely empty his stomach. Sugar, either lactose or maltose, up to 7 per cent, has apparently no influence upon gastric motility. If the protein in the food is kept low even the fat fails to show any constant tendency to prolong the emptying time, and if the percentage of fat influences the motility at all the effect is not striking.^ Casein is the most important food element concerned in the emptying time; its effect in this respect depends considerably upon the form in which it is given. Protein in high percentage without the addition of alkali retards the emptying time; if it is converted into a non-coagulable form by the addition of alkali, the stomach empties much more quickly. Sodium citrate does not influence the empt3dng time as much as do soda bicarbonate or lime-water.

The duodenum secretes a not inconsiderable amount of alkaline juice, alkaline on account of its carbonate content. ^ According to Tobler, fat delays the emptying time.

This juice is not especially important in digestion (Burton- OpitzO. It contains invertin, which inverts cane-sugar, and also erepsin. Its chief importance is that it contains enterokinase, a substance which has the power of activating the pancreatic juice so that it is more efficient in the digestion of protein.

The Intestines. — ^Both the small and large intestines are relatively longer in the iafant than in the adult, which is probably necessary on account of the relatively large amount of food taken by the infant. The small intestine secretes large quantities of alkaline juice, the succus entericus. It is light yellow in color, and its chief function is to break down carbohydrates, specially sugar, by the two sugar-splitting ferments which it contains, maltase and invertase, whose functions are to change disaccharids to monosaccharids. It also contains erepsin, which converts proteoses to polypeptids and amino-acids.

The most import phases in the digestion of milk are carried on in the upper portion of the small intestine by the pancreatic juice and the succus entericus. The digestion of the various food elements are very delicately adjusted processes, which need a certain optimum reaction (not too acid or alkaline) in order to proceed satisfactorily. If there is an excessively acid or alkaline reaction in the small intestine where the digestion and absorption of food is taking place, these processes cannot proceed correctly. The ordinary cause of excessively alkaline or acid reactions in the small intestine is the action of bacteria on foods there, and it can therefore be easily seen how important it is for the small intestine to be relatively free from bacteria.

In the large intestine there is practically no digestion carried on, and probably little absorption, except of water. Nearly all the food that is going to be absorbed is absorbed before the ileocecal valve is reached. The large intestine is swarming with bacteria of many kinds, which live on the undigested or unabsorbed food residue entering from the small intestine. If this residue is not too great in amount, excessive fermentation or ^ Text-Book of Physiology.

putrefaction will not take place; if it is large in amount, one or the other of these processes becomes excessive, and diarrhea results.

The liver in the infant is much larger in relation to the rest of the body than it is in the adult. In a newborn baby the liver is 4.33 per cent, of the body weight, in an adult, 2.85 per cent.

The functions of the liver are to change starches, sugars, protein, and possibly fat into glycogen, to produce bile, and to neutralize and destroy poisons arising from the intestines. The liver is frequently enlarged in nutritional disorders, especially those arising from overfeeding with carbohydrate.

The Bile. — Fresh bile is reddish-brown in color. Upon oxidation it changes to green, or upon reduction it may be colorless. Bile is what gives the color to the stools, and this color depends upon whether oxidation or reduction processes are taking place in the intestine. In the putrefaction that occurs when soap stools are produced the bile undergoes reduction and assumes a colorless form, so that the stools are nearly white. When sugar is fermenting, however, oxidation is taking place, and bilirubin is changed to biliverdin, which gives the characteristic green color to the stools.

The chief function of bile is to aid in the digestion and absorption of fat. In the presence of bile the steapsin of the pancreatic juice is much more active in splitting fats than without it. Fat digestion is best in a nearly alkaline solution, and very poor in a strongly alkaline or especially in a strongly acid solution. Bile in a strongly acid solution is easily decomposed and rendered inefficient. It is able under the right conditions to dissolve large amounts of fatty acids, and also probably aids in absorption by emulsifying soaps.

The Pancreas. — ^The juices of the pancreas are the most important and powerful of all the digestive juices. The pancreas has about the same significance in the infant as in the adult. It produces a strongly alkaline secretion in large amounts, which contains trypsin, amylopsin, and steapsin. These ferments digest protein, starch, and fat respectively, and are all present in the pancreas at birth. Pancreatic digestion cannot go on in a strongly acid medium.

Summary. — From a practical point of view we are chiefly interested to know what part if any a lack of digestive ferments plays in the various digestive and nutritional disturbances of babies. The evidence here is conflicting, some investigators have found that certain ferments, particularly the fat-splitting ferment of the pancreas, are present in very small quantity or are lacking entirely in severe nutritional disorders, such as marasmus. It is probable, however, that this deficiency is not the cause but the result of the condition, and most investigators have found that in most cases of digestive disturbances in babies a deficiency of the digestive ferments plays little if any part. Thus the artificial digestants are of small practical value in the treatment of digestive disorders in infants.

THE BACTERIOLOGY OF THE DIGESTIVE TRACT AND THE RELATION OF BACTERIA TO FOOD

Importance. — The bacteriology of the gastro-intestinal tract is intimately concerned with problems of practical infant feeding, as there is normally always a slight bacterial decomposition of food going on in the lower portions of the bowel. If this decomposition becomes excessive, owing to poor digestion of food or overfeeding, large amounts of irritating substances are formed, which immediately get the baby into trouble, evidenced especially by looseness of the bowel movements.

The intestinal bacteria act on the host not directly, but through the intermediate agency of food, and its decomposition products. They are not ordinarily true parasites, but saprophytes; they live not on the tissue of the gastro-intestinal tract, but on the food within it.

The intestinal contents at birth are sterile, and the first specimens of meconium passed usually fail to show bacteria. Infection takes place, in all probability, mostly through the mouth, but also probably partly through the anus, so that bacteria are ordinarily found in the meconium twenty-four hours after birth.^ "As a rule the proliferation of these first infecting organisms is limited, partly because the intestinal contents at this time are inadequate to support a large bacterial population, partly because a majority of the bacteria are unable to accommodate themselves to gastro-intestinal conditions.

"About the third day postpartum the alimentary canal of the infant becomes permeated with breast milk in place of the colostrum, and a marked change is discernible in the intestinal flora at this time. The heterogeneous, irregularly staining microbes disappear to a remarkable degree, and coincidently large numbers of long, slender. Gram-staining bacilli appear. A majority of these belong to the group of Bacillus bifidus, and they usually persist in dominant numbers during the nursing period."

The infecting bacteria come partly from the air, partly from the bath-water, or perhaps from the vagina of the mother. The initial bacterial flora is independent of the sort of food that there is in the intestine, but after the first two or three days is dependent upon the type of food that is present. According to Czerny and Keller it is not advisable to give sugar-water during the first day or two before the breast milk comes in, as is commonly done, because fermentation might be started which would be injurious to the child.

"If we feed the newborn in the first few days with foreign substances, we must remember that we may hinder or disturb the normal processes of invasion. It is best to give nothing but sterile water or water plus saccharin during the first twenty-four hours to a newborn baby."^

Bacteriology of the Stomach. — Many bacteria enter the stomach in the food of bottle-fed babies, but the gastric juice possesses strong antiseptic powers, and destroys a great many of them. The stomach, therefore, acts as a protection to the rest of the gastro-intestinal tract in this respect, and is on