Effect of Posture on the Pattern of Stomach Emptying in the Newborn

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Effect

of Posture

on the Pattern

of Stomach

Emptying

in the Newborn

Ivan Blumenthal, M.B.B.S., Anna Ebel, B.Sc., and Rosita S. Pildes, M.D.

Front time Division of Neonatology, Cook County Hospital, and the Department of Pediatrics of time University of Illinois College of Medicine, Chicago

ABSTRACT. To determine the effect of posture on the

patterim of neonatal stomach emptying, 56 test meals of a 10% dextrose were given to 14 healthy infants over a period of two or three consecutive days. The infants, whose postnatal age ranged between 5 and 27 days, were studied in each of four positions. The emptying pattern was determined by the double-sampling dye-dilution technique. The results indicate that there are no significant postural differences in the pattern of stoimiach emptying. They also indicate that neona-tal and adult patterns are similar. Pediatrics 63:532-536, 1979, stomach emptying, posture, neonates.

The best position for the neonate has been the

subject of controversy for decades, yet presently

there is no uniformity in the posture adopted by

nurseries throughout the world, the position

being based more on custom than reason. Most of

the debate has concentrated on the prone and

supine positions, probably because of the

difficul-ty of maintaining neonates in the lateral positions.

The supine position is said to favor sensory

perception, particularly the eyes, whereas

roent-genographic evidence has suggested that stomach

emptying is facilitated by placing the infant in the

prone and right lateral positions.’5 In 1975, Yu6

used the modified serial test meal technique to

study the effect of posture on stomach emptying

at 30 minutes. He confirmed earlier

roentgeno-graphic studies by showing that stomach

empty-ing was most rapid in the prone and right lateral

positions. Based on the hypothesis that posture would not only influence the rate but also the pattern of stomach emptying, we studied the

effect of posture on the stomach-emptying

pattern of neonates.

to 26 days were well when studied, and informed

consent was obtained from the mother before

entry into the study. The reason for admission,

birth weight, sex, maturity, type of delivery,

Apgar score, and volume of test meals given are

shown in Table I.

A polyvinyl feeding tube (No. 8 French) was

passed through the nose into the stomach body.

Before each test meal, the infant lay in the

designated position for intervals ranging from 1#{189} to 3#{189}hours, after which the stomach was washed

out completely. Each infant was studied in four

positions: right lateral, left lateral, prone, and

supine. The positional sequence in which the

infants were studied was varied.

Residual stomach volume was measured at 20-minute intervals for two hours by using a modification of the double-sampling dye-dilution

method of George,7 as subsequently explained.

The method is based on the principle that the

volume in a container (stomach) can be measured

by determining the increase in concentration of

dye produced by the addition of a small

concen-trated measure of the same dye.7 The test meals

consisted of a dilute solution of phenol red (.03

mg/dl) in 10% dextrose and was given over two to

three minutes. The amount varied depending on

size and age of child and ranged from 20 to 31

ml/kg of body weight (mean ± SD, 24.6 ± 3.8

ml/kg of body weight). At exactly 20-minute

intervals, a sample of stomach contents (C’) was

removed and, immediately afterward, a known

volume (V2) of concentrated solution (C2) of

phenol red (0.8 mg/dl) in 10% dextrose was

added. The stomach contents were then mixed by

PATIENTS AND METHODS

Fifty-six test meals were given to 14 neonates

admitted to the Special Care Nursery. Test meals

were given over two or three consecutive days.

These infants, whose postnatal age ranged from 5

Received March 15; revision accepted for publication July 15, 1978.

ADDRESS FOR REPRINTS: (R.S.P.) 700 South Wood

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TABLE I

CLINICAL FEATURES OF SUBJECTS

No. Birth Weight (gum) Maturity (weeks) Delivery Apgar Score I

mm

Reason for Admission Age of Testing (Days) Vo!-mimime (mmml) mnl!kg

1 2,040 35 V#{176} 8 Transient tachypnea 10 40 19.6

2 2,877 40 V 8 Anemia 6 60 20.8

3 1,960 32 V 8 Transient tachypnea 13 40 20.4

4 3,520 42 V 4 Meconiuni aspiration 6 80 22.7

5 1,800 36 V 6 SCAt 26 50 27.8

6 2,268 37 V 10 Transient tachypnea 5 50 22.0

7 1,840 37 V 1 SGA 9 50 27.2

8 3,030 40 CS 1 Meconium aspiration 5 80 26.4

9 1,930 35 CS 8 Low birth weight 10 60 31.9

10 1,956 37 V 4 SGA 10 50 25.6

1 1 1,740 32 CS 6 Low birth weight 6 50 28.7

12 3,040 40 CS 4 Prolonged rupture of

membranes and meconium staining

6 90 29.6

13 1,914 35 V 7 Low birth weight 7 40 20.9

14 1,810 36 CS 9 Prolonged rupture of

membranes and SGA

8 40 22.1

#{176}V= Vaginal.

tSGA = Small for gestational age.

:l:CS = Caeserian section.

withdrawing and reinserting small syringefuls

about 12 times; after this, a second (C3) sample was obtained. To keep stomach contents constant, the amount (V2) of concentrated dye used was equal to the sum of the volumes removed before

and after addition of the concentrated dye. The

volume remaining in the stomach (V’) was calcu-lated from the formula:

where

VI V2(C2-C3)

C3_CI

V2 = volume of concentrated dye

C2 concentration of added dye

C’ = concentration of dye in V’ (first sample

removed)

C’ = concentration of dye in second sample

removed

When less than 2 ml of the stomach contents

could be removed, the stomach was washed out

with 20 ml of sterile water. The residual (RV)

volume was then calculated from the equation:

RV = 20 x Concentration of dye in washout

Concentration of dye at previous final testing

Concentration of phenol red was measured after

filtration on a spectrophotometer (wavelength,

560 nm). The percentage of stomach contents

remaining in the stomach at each 20-minute

interval was plotted for each infant in each of the

four positions. The results were analyzed by

paired Student’s t-test and regression analysis.

RESULTS

The percentage of the original volume retained

at 20-minute intervals is shown in Table II. There

were no significant differences in each of the four

positions except between right and left at 100

minutes and right and prone at 120 minutes

(P < .05). These differences were inconsistent.

The time taken for a quarter, half, and three

quarters of the volume to leave the stomach was

extrapolated from the graph of each infant and is

shown in Table III. There were no significant

postural differences. A graphic representation of

the emptying pattern as obtained from the mean

values in Table II is depicted in the Figure. There

is a rapid phase of emptying followed by an

exponential phase during which a constant

frac-tion of the remaining meal empties per minute.

The pattern appears similar in each of the four

positions. The combined mean of the four

posi-tions indicates a rate of emptying of 2.3% per

minute in the first 20 minutes and, thereafter, a

rate of 0.2% to 0.6% per minute.

There were no significant differences in the

rate of emptying at 20 or at 40 minutes by the five

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a Rgh oe,oI pos,hon

. Left loterol poshon

0 P,one post’on #{163}Supne 70

60

50

0

60 80 00 120 TIME (MINUTES)

40 60 (80

TABLE II

PERCENTAGE OF ORIGINAL VOLUME RETAINED AT 20-MINUTE INTERVALS

Position Tim e (Minutes)

20 40 60 80 100 120 140 160 180

Right .

0 13 14 13 13 13t 7t 8 5

Mean 51.4 37.9 30.8 24.3 17.4 12.3 10.4 8.9

SEM 3.7 3.1 3.7 3.4 3.0 2.8 3.3 1.9

Left

No. 14 14 14 14 lit 12 8 9 4

Mean 53.8 42.0 33.9 28.1 27.5 16.4 15.6 13.8 10.9

SEM 2.9 4.2 3.2 3.1 3.5 3.0 2.9 2.6 3.0

Prone

No. 14 14 13 13 8 lOt 6 8 3

Mean 57.6 43.6 37.1 27.4 22.1 16.0 8.8 11.2 9.8

SEM 2.1 2.2 2.4 3.1 2.9 3.1 1.2 1.8 3.5

Supine

No. 14 14 12 12 13 9 10 6 4

Mean 54.5 42.3 32.7 27.6 23.5 19.5 12.5 12.5 13.8

SEM 3.4 3.7 4.0 4.1 2.2 4.0 1.8 5.2 8.4

#{176}No.refers to number of samples available at each time period.

tDifferences at 100 minutes between right and left and at 120 minutes between right and prone were significant (P < .05).

as compared with those 36 to 39 weeks’

gestation-al age5 or those 40 to 42 weeks.

DISCUSSION

The pattern of neonatal gastric emptying

determined by this study is characterized by an

initial rapid phase followed by an exponential

phase. This pattern is similar to that of adults.5”

The findings differ from those of Vendel’#{176} in

TABLE III

TIME FOR A QUARTER, HALF, AND THREE QUARTERS OF

ORIGINAL VOLUME TO LEAVE STOMACH

Position Time fo t

r Fractions of Contents

0 Leave Stcnnach (Minutes)

1/4 Contents 1/2 Contents #{190}Contents Right

Mean 12.0 27.2 80.6

SEM 1.3 3.7 8.7

Left

Mean 11.4 31.9 88.8

SEM 0.7 4.7 11.4

Prone

Mean 12.6 34.6 87.5

SEM 0.8 4.4 5.9

Supine

Mean 13.4 31.3 86.8

SEM 2.2 5.6 10.7

infants aged 1 week to 1 1 months; he reported a

rectilinear pattern, that is, a constant rate per

unit of time until two thirds had disappeared

followed by a slower rate. The difference is most

40

30

20

10

Emptying pattern of the stomach in each of four positions Volume refers to percentage remaining in the stomach and

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likely due to methods used. 12 using the

double-sampling principle in infants 2 to 6 weeks

of age given a test meal of human milk, reported

results similar to those of our study. Our study is

the first to show that the characteristics of this

pattern are not influenced by posture.

The prone or right lateral position has been

recommended by Yu,6 who found less retention of

a test meal of 10% dextrose at 30 minutes in either

of these positions as compared with that in the

supine position. We were unable to confirm these

findings. The different results are unlikely to be

explained by methodology, since there is a close

correlation between the methods used, but might

be attributable to the age difference of the

infants. In this study, the postnatal ages ranged

between 5 and 26 days, whereas the neonates

reported by Yu were less than 24 hours old.

Barium studies indicate that true stomach

pen-stalsis may not begin until two to four days after

birth.4 Until that time, the stomach empties by its

tone, partly by an occasional final contracture,

and possibly also by hydrostatic pressure.

The percentage of test meal emptied in this

study and in that of Yu6 was similar in preterm as

compared with term infants. Comparison cannot

be made between studies as to the exact

percent-age of test meal emptied because the time of

sampling and the volume used were different in

the two studies. In our study, the mean volume of

test meal was 24.6 ± 1 ml/kg of body weight,

which is similar to that used by Husband and

Husband” but higher than the volume of 7 ml/kg

of body weight used by Yu.6 An increase in

volume increases the rate of emptying during the

first few minutes812 after a test meal. We did not

find any correlation by linear regression analyses

between volume of test meal and percent

empty-ing at either 20 or 40 minutes. This lack of

correlation may be due to the narrow range of

volume (20 to 31 ml/kg of body weight) used in

this study. The composition of the test meal may

also influence the rate of emptying in neonates;

saline,’2 5% dextrose,’3 and starch’4 empty more

readily than 10% dextrose or milk.’2 This

differ-ence is thought to be due to stimulation of

postpylonic osmoneceptors with resulting

inhibi-tion of gastric penistalsis.

The method used in this study, although not

optimal, is the best available for measuring gastric

emptying in the neonate. Unlike the modified

serial test meal method,’3 double sampling has the

advantage of obtaining the complete pattern of

emptying in a single test lasting a few hours. The

results are less reliable if the tube end is at or near

the pylonis. Because of the difficulty of aspirating

stomach contents from an almost empty stomach,

it may become necessary to move the tube near

the end of the test, thereby reducing the accuracy

of the results. However, the endpoint or residual

volume is accurate. Thus, the differences

observed at 100 minutes between night and left

lateral or between right and prone at 120 minutes

may have been due to sampling difficulties

toward the end of the test or to chance findings in

multiple t-test measurements. These differences

were not consistent and did not influence the

pattern of emptying.

Although this study has shown no benefit of

prone placement on either the rate or pattern of

stomach emptying, other reasons for preferring

this position have been reported. These include

improved respiratory function,’5 reduced

mci-dence of milk aspiration,’6 less diaper rash,’

advanced motor development,18 and more sleep

with less cyning.’9

REFERENCES

1. Smith CH, LeWald LT: The influence of posture on

digestion in infancy. Am J Dis Child 9:261, 1915. 2. DeBuys LR, Henriques A: Effect of body posture on the

position and emptying time of the stomach. Am I

Dis Child 15:190, 1918.

3. Miller RF, Ostrum HW: Hypertrophic pyloric stenosis in infants, roentgenologic differential diagnosis. Am

I Roentgenol 54:17, 1945.

4. Tornwall L, Lind J,Peltonen T, et al: The gastrointesti-nal tract of the newborn. Anal Paediatr Fenn 4:209, 1958.

5. Hood JH: Effect of posture on the amount and distribu-tion of gas in the intestinal tract of infants and

young children. Lancet 2: 107, 1964.

6. Yu VYH: Effect of body position on gastric emptying in

the neonate. Arch Dis Child 50:500, 1975.

7. George JD: New clinical method of measuring the rate of gastric emptying: The double sampling test meal. Gut 9:237, 1968.

8. Hunt JN, Macdonald I: The influence of volume on

gastric emptying. I Physiol 126:459, 1954.

9. Hunt JN, Spurrel WR: The pattern of emptying of the human stomach. I Physiol 113:157, 1951.

10. Vendel 5: The principle of evacuation of the stomach in

infants and prematures. Acta Physiolog Scand

11:380, 1948.

11. Gavell B: Gastric emptying in infants. Lancet 2:905, 1969.

12. Cavell B: Gastric emptying in infants. Acta Paediatr Scand 60:370, 1971.

13. Husband J, Husband P: Gastric emptying of water and glucose solutions in the newborn. Lancet 2:409, 1962.

14. Husband J,Husband P. Mallinson CN: Gastric emptying of starch meals in the newborn. Lancet 2:290, 1970.

15. Schwartz FCM, Fenner A, Wolfsdorf T: The influence

of body position on pulmonary function in low

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16. Hewitt VM: Effect of posture on the presence of fat in

tracheal aspirate in neonates. Aust Paediatr I

12:267, 1976.

17. Keitel HG, Cohn R, Harnish D: Diaper rash

self-inflicted excoriations and crying in full-term newborn infants kept in the prone or supine

posi-tion. I Pediatr 57:571, 1960.

18. Holt KS: Early motor development. I Pediatr 57:571, 1960.

19. Brackbill Y, Douthitt TC, West H: Psychophysiologic effects in the neonate of prone versus supine place-ment. I Pediatr 82:82, 1973.

THE ISOLATED PROFESSIONS

Professions used to be called mysteries, and certain skills must necessarily

remain esoteric. But this practical training in a profession surprisingly seldom

entails ideas and methods that are inexplicable, ineffable, or beyond the grasp

of a genuinely educated layman. True experts seek ways to communicate.

Psuedoexperts rely on the secrecy of their data for their place in society,

claiming that disclosure of their secret lore would make them helpless, when

actually it might only show them to be useless. ...

Within these isolated professions the patronizing attitude toward outsiders

becomes increasingly hand to avoid. Specialization in recent decades has made

the old divisions of knowledge and the old careers even narrower and more

excluding, with a consequent reduction of the number of people with whom

the specialist feels any solidarity. This intellectual fragmentation has made it

virtually impossible for universities to function as social units.

The misplaced emphasis on career training and the isolation of the

professions have produced a pair of effects which every teacher has seen in

class. The first effect emerges in all on a given subject because they are not

experts on it. Such people are the destined victims of false experts. The second

effect emerges in those students who believe that anything they say sincerely is

true. Much modern school teaching encourages this belief out of a fear of

discouraging the free flow of creativity. These two forms of mindlessness

reflect one another. By neglecting their intellectual contact with the untrained

majority of humanity, our experts have driven that majority into a dim realm

where, as nonexperts, they cannot think, but only feel. ...

R. L. BELKNAP and R. KUHNS

Submitted by Student

Froln Belknap RL, Kuhns R: General education: Coping with problems in the seventies.

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1979;63;532

Pediatrics

Ivan Blumenthal, Anna Ebel and Rosita S. Pildes

Effect of Posture on the Pattern of Stomach Emptying in the Newborn

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1979;63;532

Pediatrics

Ivan Blumenthal, Anna Ebel and Rosita S. Pildes

Effect of Posture on the Pattern of Stomach Emptying in the Newborn

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