Lower esophageal sphincter position in premature infants cannot be correctly estimated with current formulas

doi:10.1016/S0022-3476(99)70179-4

The Journal of Pediatrics

Volume 135, Issue 4, October 1999, Pages 522-525

https://doi.org/10.1016/S0022-3476(99)70179-4 Get rights and content

Abstract

Objectives: Strobel’s formula (Esophageal length = 5 + 0.252 × Height) is frequently used as a guide for determining the distance from the nares to the lower esophageal sphincter (LES) in term infants. The aim of this study was to examine this relationship in premature infants. Study design: The distance from nares to LES was manometrically determined in 156 premature infants (26-40 weeks’ postmenstrual age; body weights of 610-3050 g). The ability of body weight, height (body length), head circumference, and postmenstrual age to predict the manometrically determined LES position was evaluated with linear and non-linear regression analyses. Results: Body weight and body length were the most predictive of distance from nares to LES (r² = 0.848 and 0.802, respectively). These relationships were non-linear and, in the case of body length, deviated substantially from Strobel’s model. Conclusions: In premature neonates, a different formula is needed for prediction of the distance between nares and LES than that applied to term infants and children. (J Pediatr 1999;135:522-5)

Section snippets

METHODS

Between February 1994 and October 1998, 156 infants (74 boys and 82 girls) underwent esophageal motility studies as part of an ongoing medical research program for the evaluation of esophageal motility and mechanisms of gastroesophageal reflux in this age group. Esophageal motility was recorded by perfusion manometry in infants weighing between 610 and 3050 g (mean, 1998 ± 468 g) and ranging in postmenstrual age (gestation at birth + postnatal age) from 26 to 40 weeks (mean, 35 ± 2 weeks). The

RESULTS

The relationships between distance from nares to LES and PMA, body length, body weight, and head circumference are shown in the Table.

Table. Regression equations for predicting the distance from nares to LES from PMA, body length, head circumference, and weight

Variable	Regression model	Regression equations	r² Value
PMA (wk)	Linear	y = –1.632 + 0.491x	0.571
	Logarithmic	y = –44.224 + 16.827ln(x)	0.595
	Polynomial (3rd order)	y = –41.671 + 2.327x + 0.003x² – 4.725E^–4x³	0.656
Body length (cm)	Linear	y = –0.762 +

DISCUSSION

This study has examined the relationship between the distance from nares to LES and variables of age and size in a population of premature infants. These data indicate that Strobel’s formula and other similar predictive formulas, which have been derived in older infants and children, overestimate the distance from nares to LES in premature infants.

In this study Strobel’s formula accurately predicted the distance from nares to LES of premature infants with body lengths over 40 cm, but not

Acknowledgements

We would like to acknowledge the help and assistance of the many people who have worked in our unit during the period over which these data were compiled: Mrs Ros Lontis, Mrs Louise Goodchild, Mr Antonie Snel, Ms Wendy Goldsworthy, Dr Robert Fraser, Dr Kasu Miki, Dr Hisa Kawahara, Dr Chellam Kirubakaran, and Mr Malcolm Bakewell.

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To assess the reliability of the KidZ Health Castle formula (KHC-F) to determine the correct probe position of a multichannel intraluminal impedance pH.
A retrospective cohort study was performed on 222 children between 1 month and 18 years of age undergoing multichannel intraluminal impedance pH. The primary outcome was the comparison of the pH sensor location determined by the KHC-F with the radiological target position. The margin of error was defined as 1 cm from the target position. Performance of the KHC-F and existing formulas was determined via the percentage with a correct position, mean error, 95% limits of agreement (Bland-Altman plots), and Spearman correlation. A post hoc analysis was performed with an updated KHC-F v2, subtracting −0.5 cm from the KHC-F.
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The KHC-F leads to reliable results. KHC-F v2 outperforms all other existing formulas in children, thereby reducing the need for repositioning and the amount of x-ray exposure. The age distribution of the sample may be a limitation, as well as the retrospective nature of the study.
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To characterize the pharmacodynamics and systemic exposure of esomeprazole in 26 preterm infants and term neonates with symptoms of gastroesophageal reflux and pathologic acid exposure.
Enrolled patients received oral esomeprazole 0.5 mg/kg once daily for 7 days. Twenty-four–hour esophagogastric pH-impedance monitoring was performed at baseline and on day 7. Pharmacokinetic analysis was performed on day 7. Symptoms occurring during the baseline and day 7 studies were recorded on a symptom chart.
There were no significant differences from baseline to day 7 of therapy in the frequency of bolus reflux, consistency of bolus reflux (liquid, mixed, or gas), extent of bolus reflux, or bolus clearance time. Acid bolus reflux episodes were reduced on therapy (median 30 vs 8, P < .001), as was the reflux index (mean % time esophageal pH < 4, 15.7% vs 7.1%, P < .001). The estimated geometric mean of area under the plasma concentration time curve during the dosing interval and observed maximum plasma concentration was 2.5 μmol · h/L and 0.74 μmol/L, respectively. The number of gastroesophageal reflux symptoms recorded over 24 hours was lower on therapy (median 22 vs 12, P < .05).
In preterm infants and term neonates esomeprazole produces no change in bolus reflux characteristics despite significant acid suppression.
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^☆: Supported by National Health and Medical Research Council of Australia, Women’s and Children’s Hospital Research Foundation, Channel 7 Children’s Research Foundation of South Australia, and JH and JD Gunn Foundation. Dr Benninga’s involvement in this project was supported by the Ter Meulen Fund, Royal Netherlands Academy of Arts and Sciences, Amsterdam, The Netherlands, The Netherlands Organisation for Scientific Research and the Netherlands Digestive Diseases Foundation.

^☆☆: 0022-3476/99/$8.00 + 0 9/22/100094

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Lower esophageal sphincter position in premature infants cannot be correctly estimated with current formulas☆,☆☆

Abstract

Section snippets

METHODS

RESULTS

DISCUSSION

Acknowledgements

J Pediatr

Lancet

Gastroenterology

J Pediatr

J Pediatr Surg

Gastroenterology

J Pediatr

Gastroenterology

A standardized protocol for methodology of esophageal pH monitoring and interpretation of the data for the diagnosis of gastroesophageal reflux

J Pediatr Gastroenterol Nutr

Usefulness of oesophageal pH monitoring

Aust J Paediatr

Gastro-oesophageal reflux in preterm infants

Arch Dis Child

24-hour oesophageal two-level pH monitoring in healthy children and adolescents

Scand J Gastroenterol

Prolonged pH recording in the study of gastroesophageal reflux

Br J Surg

Observation on oesophageal length

Thorax

An assessment of gastroesophageal reflux in children by extended pH monitoring of the distal esophagus

Surgery