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
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!kg1 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
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
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
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.
