Predicting the insertion distance for placing gastric tubes

The clinical effectiveness of the corrected nose-earlobe-xiphoid distance formula in determining the internal length of a nasogastric tube in adults: A retrospective study

INTRODUCTION

Accurate determination of the internal length of nasogastric tubes is essential for the safe and effective completion of blind insertions, a routine nursing procedure. The widely used nose-earlobe-xiphoid distance lacks evidence and effectiveness. A recent randomized controlled trial proposed an alternative, the corrected nose-earlobe-xiphoid distance formula. However, its effectiveness in real-world clinical practice has not yet been studied.

OBJECTIVE

This study assessed the real-world clinical effectiveness of the corrected nose-earlobe-xiphoid distance formula for determining the internal nasogastric tube length in adult patients admitted to hospitalization or intensive care units.

DESIGN

A single-center retrospective clinical effectiveness study was conducted, utilizing routinely collected observational data.

SETTING AND MAIN OUTCOME MEASURES

Between October 2020 and November 2022, 358 adult patients in a general hospital requiring a nasogastric feeding tube were included. The primary outcome involved assessing nasogastric tube tip positioning (>3 cm below the lower esophageal sphincter) by an advanced practice nurse through X-ray verification. Secondary outcomes, obtained from patient records for a random subgroup of 100 participants, were reporting clarity and evaluation of the tip position by reviewing radiologists.

RESULTS

Following evaluation by an advanced practice nurse, all nasogastric feeding tubes were determined to be correctly positioned. Among the subgroup of 100 tubes, X-ray protocols, as documented by the reviewing radiologists, showed varying levels of reporting clarity for the tube tip: 4.0 % lacked reporting, 33.0 % had ambiguous reporting and 63.0 % had unambiguous reporting.

CONCLUSION

The corrected nose-earlobe-xiphoid distance formula demonstrates potential to emerge as a safer alternative to existing methods for determining the internal length of nasogastric tubes.

IMPLICATIONS FOR CLINICAL PRACTICE

In addition to healthcare provider education and training, a checklist-based framework is recommended for radiologists to unambiguously report nasogastric tube tip positions.

Indications, Measurements, and Complications of Ten Essential Neonatal Procedures

About 10% of newborns require some degree of assistance to begin their breathing, and 1% necessitates extensive resuscitation. Sick neonates are exposed to a number of invasive life-saving procedures as part of their management, either for investigation or for treatment. In order to support the neonates with the maximum possible benefits and reduce iatrogenic morbidity, health-care providers performing these procedures must be familiar with their indications, measurements, and potential complications. Hence, the aim of this review is to summarise ten of the main neonatal intensive care procedures with highlighting of their indications, measurements, and complications. They include the umbilical venous and arterial catheterizations and the intraosseous line which represent the principal postnatal emergency vascular accesses; the peripherally inserted central catheter for long-term venous access; the endotracheal tube and laryngeal mask airway for airway control and ventilation; chest tube for drainage of air and fluid from the thorax; and the nasogastric/orogastric tube for enteral feeding. Furthermore, lumber puncture and heel stick were included in this review as very important and frequently performed diagnostic procedures in the neonatal intensive care unit.

Nasogastric tube insertion length measurement and tip verification in adults: a narrative review

Nasogastric feeding tube insertion is a common but invasive procedure most often blindly placed by nurses in acute and chronic care settings. Although usually not harmful, serious and fatal complications with misplacement still occur and variation in practice still exists. These tubes can be used for drainage or administration of fluids, drugs and/or enteral feeding. During blind insertion, it is important to achieve correct tip position of the tube ideally reaching the body of the stomach. If the insertion length is too short, the tip and/or distal side-openings at the end of the tube can be located in the esophagus increasing the risk of aspiration (pneumonia). Conversely, when the insertion length is too long, the tube might kink in the stomach, curl upwards into the esophagus or enter the duodenum. Studies have demonstrated that the most frequently used technique to determine insertion length (the nose-earlobe-xiphoid method) is too short a distance; new safer methods should be used and further more robust evidence is needed. After blind placement, verifying correct gastric tip positioning is of major importance to avoid serious and sometimes lethal complications.

The accuracy of methods for determining the internal length of a nasogastric tube in adult patients: a systematic review

BACKGROUND

Blind insertion of nasogastric (NG) tubes is performed for several reasons: nutrition and medication administration, gastric aspiration/decompression, and other, diagnostic reasons. Accidental intraesophageal and intestinal placement is common, and increases the risk of serious complications. Therefore, accurate determination of the internal length of the NG tube before placement is considered a prerequisite for achieving correct gastric positioning.

OBJECTIVES

We aimed to identify, assess, and summarize the evidence on the accuracy of methods for determining the internal length of an NG tube in adults.

METHODS

Cochrane Library, Excerpta Medica database (EMBASE), PubMed, Cumulative Index to Nursing and Allied Health Literature (CINAHL), and Web of Science were searched up to 31 January, 2022. Studies were eligible when reporting data on the accuracy of methods for determining internal NG tube length in adults. Study selection, risk-of-bias assessment, and data extraction were performed independently by 2 investigators. Risk-of-bias was assessed using the Cochrane Risk-of-Bias Tool and the Joanna Briggs Institute Critical Appraisal Checklist for Cross Sectional Studies. A narrative synthesis of the results was then conducted.

RESULTS

Twelve articles were included in this review. All studies were observational, cross-sectional in nature, except for 1 randomized controlled trial. Ten methods for determining the internal length of an NG tube were described. Correctly positioned NG tubes ranged from 13% to 99%. Results showed that the tip of the nose-earlobe-xiphoid distance (NEX) + 10 cm (mean: 59.9-60.7 cm) and (NEX × 0.38696) + 30.37 + 6 cm (mean: 56.6-56.7 cm) could potentially result in accuracy as high as 97.4% and 99.0%, respectively.

CONCLUSIONS

Current data do not provide conclusive evidence of 100% accuracy in finding a correctly placed NG tube when using a method for determining the internal length. Blind placement, using any of the documented methods, cannot be considered safe without additional verification of tube tip positioning. Furthermore, using any of these 10 methods does not reduce the risk of pulmonary intubation.This systematic review was registered at https://www.crd.york.ac.uk/PROSPERO/ as CRD42021243180.

Placement of Nasogastric Feeding Tube and Postinsertion Care Review

Insertion and postinsertion care of enteral nasogastric feeding tubes are common procedures in the United States, with more than 1.2 million temporary nasogastric feeding tubes inserted annually. Although there are some evidence-based practice guidelines and recommendations for care of these tubes, variation in practice still exists. Additional research is needed to determine the best methodology for insertion and confirmation of nasogastric feeding tubes. Routine competency and training on feeding tube insertion, enteral nutrition, and postinsertion care is crucial to prevent patient safety events. Variable results have been reported with different technologies; however, radiographic confirmation remains the criterion standard. It is important that health care institutions develop standardized procedures for insertion and confirmation on the basis of evidence-based practices to minimize risks and complications from temporary nasogastric feeding tubes.

Clinical nurses' nasogastric feeding practices in adults: a multicenter cross-sectional survey in China

OBJECTIVE

We aimed to investigate practices of nasogastric tube (NGT) intubation and feeding for adults by clinical nurses in China.

METHODS

A self-designed and validated questionnaire comprising 30 questions was distributed to 560 clinical nurses in three comprehensive hospitals of Xiamen, China. The questionnaire covered participants' demographic characteristics, NGT placement, administration of enteral nutrition (EN), and monitoring or management of feeding intolerance.

RESULTS

A total 464 (82.9%) questionnaires were completed; 36.2% of nurses used nose-ear-xiphoid and 79.5% forehead-xiphoid measurement to define the internal length of the NGT. Many participants still used traditional methods to confirm NGT placement (auscultation of injected air 50.2%, bubble test 34.7% and observing feeding tube aspirate 34.3%). Bolus feeding was the most commonly used technique to administer EN. A total 97.0% of all nurses used syringes to measure gastric residual volume (GRV), and 62.7% measured GRV every 4-8 hours. The most frequently used GRV threshold values were 200 mL (44.6%) and 150 mL (25.2%). Most nurses stopped feeding immediately when encountering high GRV (84.3%) or diarrhea (45.0%). The nasogastric feeding practices of many clinical nurses were not consistent with international guidelines.

CONCLUSIONS

Our study can provide an impetus for nursing administrators to revise their nasogastric feeding procedures, to promote compliance with evidence-based guidelines.

Orogastric intubation with dental fixation for enteral nutrition: a proof-of-concept study

In this crossover trial, we evaluated a new technique for enteral nutrition using orogastric intubation. Twelve volunteers were randomly assigned to both orogastric (OGI) and conventional nasogastric intubation (NGI) with a 15-day interval. The tip of the orogastric tube was fixed intraorally into an upper molar. Participants were asked to remain intubated for 24 hours and rated efficacy and safety using a Likert scale (1: worst / 10: best). Tolerance in hours was longer during OGI (median 21 versus 12.5; p=0.022). OGI was superior in comfort (median 7 versus 3; p=0.002), aesthetic (median 10 versus 1; p=0.002), speech (median 5.5 versus 3; p=0.014) and swallowing (median 8 versus 2; p=0.004). Both procedures were tolerated with mild local complaints. Diet volume through the tube was greater during NGI (p = 0.014). In healthy participants, orogastric intubation with dental fixation showed greater efficacy and similar safety to nasogastric intubation. CLINICAL TRIALS NUMBER: NCT03670238.

Methods of Estimating Nasogastric Tube Length: All, Including "NEX," Are Unsafe

BACKGROUND

Predominance of blind feeding tube placement makes esophageal tube misplacement and aspiration risk commonplace. Accurate estimation of nose-to-stomach length could reduce this risk. Standards for estimating this length were audited against the length measured from guided tube placement.

METHODS

This prospective, single-center observational study used electromagnet-guided tube placement to measure the length from nose to gastric body flexure as part of routine care. This measurement was used to audit standard equations used to estimate this length from external measures: xiphisternum-ear-nose + 10 cm (XEN+10), nose-ear-xiphisternum (NEX), and Hanson_A and Hanson_B.

RESULTS

From April 23, 2015, to March 2, 2020, measurements were obtained from 200 primary tube placements. Median length to the gastric body flexure (61 cm) was significantly different from that to the pre-gastroesophageal junction flexure (48 cm) or lengths predicted by NEX (51 cm) or Hanson_A (50.5 cm) and Hanson_B (56.1 cm) (all P < .00001) but similar to XEN+10 (61 cm). Esophageal placement was a potential risk for all methods (NEX: 96.3%, Hanson_A: 99.5%, Hanson_B: 86.9%, XEN+10: 43.2%) and a definite risk for most (NEX and Hanson_A: 14.9%, Hanson_B: 1%, XEN+10: 0%).

CONCLUSIONS

NEX and Hanson methods of predicting the length from nose to gastric body flexure are too short and risk esophageal misplacement. XEN+10 reduces but does not eliminate this risk. External measurement predictions are clinically unsafe as a guide blind tube placement. Guided placement is recommended.

Accuracy of the corrected nose-earlobe-xiphoid distance formula for determining nasogastric feeding tube insertion length in intensive care unit patients: A prospective observational study

BACKGROUND

As nasogastric feeding tube insertion is a frequently applied, non-risk-free nursing technique, a high level of evidence-based nursing care is required. Little evidence is available regarding the accurate determination of the insertion length of nasogastric feeding tubes. The method of using the nose-earlobe-xiphoid distance as measurement is inadequate and not supported by evidence. Findings from a recent randomized trial led to an alternative calculation: the corrected nose-earlobe-xiphoid distance formula: (nose-earlobe-xiphoid distance × 0.38696) + 30.37 + 6 cm.

OBJECTIVES

To test the accuracy of the corrected nose-earlobe-xiphoid distance formula for determining the required nasogastric feeding tube insertion length in adults admitted on an intensive care unit and to investigate the probability to successfully obtain gastric aspirate for pH measurement.

DESIGN

Prospective, single-center observational study.

PARTICIPANTS AND METHODS

Adult intensive care unit patients in a general hospital (N = 218) needing a small-bore nasogastric feeding tube were included between March and September 2018. Correct tip positioning was defined as a tube tip located > 3 cm under the lower esophageal sphincter. Tip positioning was verified using X-ray.

RESULTS

All nasogastric feeding tube tips were correctly positioned > 3 cm under the lower esophageal sphincter. The chance of successfully obtaining gastric aspirate within 2 h after placement of the tube was 77.9%.

CONCLUSIONS

With all tips positioned > 3 cm in the stomach and zero tubes migrating back into the esophagus, the corrected nose-earlobe-xiphoid distance formula can be considered a more accurate method to determine nasogastric feeding tube insertion length.

Adequacy of different measurement methods in determining nasogastric tube insertion lengths: An observational study

BACKGROUND

Distance from the tip of the nose to earlobe to xiphisternum is commonly used to determine the length of nasogastric tube to be inserted. However, it is not evidence-based and frequently leads to improper positioning.

OBJECTIVES

This study evaluated four formulae and the distance from the tip of the nose to earlobe to xiphisternum in estimating the internal length of nasogastric tube required for optimal positioning.

DESIGN

Observational Study.

SETTINGS

Tertiary hospital in Singapore involving patients from the medical and surgical intensive care units and a neurosurgical ward.

PARTICIPANTS

Inclusion criteria were patients who required a nasogastric tube insertion and age > = 21 years old and =<85 years old. Patients who required an orogastric tube insertion or did not require a chest x-ray post nasogastric tube insertion were excluded.

METHODS

Upon nasogastric tube insertion, the external length of the tube was measured and the corresponding internal length calculated. Several anatomical measurements were taken as required in the formulae below: 1. ((Distance from tip of nose to earlobe to xiphisternum-50 cm)/2) + 50 cm. 2. 29.38 + 4.53*gender+0.34*distance from nose to umbilicus with head flat on bed-0.06*weight (gender = 1 for male, and 0 for female). 3. Distance from xiphisternum to earlobe to nose + 10 cm. 4. Distance from earlobe to xiphisternum to umbilicus-distance from tip of the nose to earlobe. Post insertion chest x-rays were examined to evaluate the position of the nasogastric tube. For those with optimal positioning, the distance from tip of the nose to earlobe to xiphisternum and the four formulae were compared to determine which provided the least difference with the internal length of the nasogastric tube.

RESULTS

Ninety-two participants were recruited. The average age of the cohort was 62.9 years old with 54% being male. Twenty-five had nasogastric tubes in optimal position; 13 had it too short and 54 had it too long. For nasogastric tubes in optimal position, distance from xiphisternum to earlobe to nose + 10 cm provided the best estimate of the internal length. Average difference between the distance from xiphisternum to earlobe to nose + 10 cm and internal length of the nasogastric tubes in optimal position was only 1.8 cm which was by far the least difference compared to other formulae.

CONCLUSION

This study found distance from xiphisternum to earlobe to nose + 10 cm to provide the best estimate for the internal length of nasogastric tube required. However, even this formula could result in placement that is not optimal due to anatomical differences.

Enteral Access Devices: Types, Function, Care, and Challenges

Enteral access feeding devices are placed in patients who have a functional and accessible gastrointestinal (GI) tract but are not able to consume or absorb enough nutrients to sustain adequate nutrition and hydration. For many individuals, enteral nutrition support is a lifesaving modality to prevent or treat a depleted nutrient state that can lead to tissue breakdown, compromised immune function, and poor wound healing. Psychological well-being is also affected with malnutrition and dehydration, triggering feelings of apathy, depression, fatigue, and loss of morale, negatively impacting a patient's ability for self-care. A variety of existing devices can be placed through the nares, mouth, stomach or small intestine to provide liquid nutrition, fluids, and medications directly to the GI tract. If indicated, some of the larger-bore devices may be used for gastric decompression and drainage. These enteral access devices need to be cared for properly to avert patient discomfort, mechanical device-related complications, and interruptions in the delivery of needed nutrients, hydration, and medications. Clinicians who seek knowledge about enteral access devices and actively participate in the selection and care of these devices will be an invaluable resource to any healthcare team. This article will review the types, care, proper positioning, and replacement schedules of the various enteral access devices, along with the prevention and troubleshooting of potential problems.

Comparison of Two Methods for Estimating the Tip Position of a Nasogastric Feeding Tube: A Randomized Controlled Trial

BACKGROUND

Several studies have shown that the nose-earlobe-xiphoid distance (NEX) is inadequate to estimate the insertion length of nasogastric tubes. An alternative approach tested in these studies, which leads to > 90% well-placed nasogastric tubes, used a corrected calculation of the NEX: (NEX × 0.38696) + 30.37. The primary aim of this study was to determine whether using the corrected NEX was more successful than the NEX in determining the insertion length. The secondary aim was to investigate the likelihood to successfully obtain gastric aspirate.

METHODS

Adult patients in a general hospital (N = 215) needing a nasogastric tube were randomized to the control (NEX) or intervention group (corrected NEX). Tip positioning was verified using X-ray. Correct tip positioning was defined as between 3 and 10 cm under the lower esophageal sphincter (LES).

RESULTS

In >20% of all patients, both methods underestimated the required tube length for correct positioning. The NEX showed an overestimation (17.2%) of the insertion length (>10 cm under the LES) compared with the corrected NEX (4.8%). There was no difference (P = 0.938) between the 2 groups in obtaining gastric aspirate (55.6% vs 56%). However, correct tip positioning resulted in a fourfold increase of obtaining gastric aspirate.

CONCLUSIONS

Both methods resulted in a high risk of incorrectly placed tubes due to malposition of the tip near the LES or distal esophagus. This may increase the risk of reflux and pulmonary aspiration. Based on these results, the development of more reliable methods requires consideration.

ASPEN Safe Practices for Enteral Nutrition Therapy [Formula: see text]

Enteral nutrition (EN) is a valuable clinical intervention for patients of all ages in a variety of care settings. Along with its many outcome benefits come the potential for adverse effects. These safety issues are the result of clinical complications and of process-related errors. The latter can occur at any step from patient assessment, prescribing, and order review, to product selection, labeling, and administration. To maximize the benefits of EN while minimizing adverse events requires that a systematic approach of care be in place. This includes open communication, standardization, and incorporation of best practices into the EN process. This document provides recommendations based on the available evidence and expert consensus for safe practices, across each step of the process, for all those involved in caring for patients receiving EN.

Methods to determine the internal length of nasogastric feeding tubes: An integrative review

OBJECTIVES

Improper placement of nasogastric tube used for feeding may lead to serious complications, including death of the patient. There are several different methods used to determine the appropriate length of nasogastric tube for optimal placement in adults. This integrative review of the literature was designed to identify the most accurate method to determine the internal length of nasogastric feeding tube in adults.

DESIGN

An integrative review of the research literature (1979-2015) using the population-intervention-comparison-outcomes strategy.

DATA SOURCES

The literature search included the Cumulative Index to Nursing and Allied Health Literature (CINAHL), Cochrane Library, Joanna Briggs, PubMed (MEDLINE), SCOPUS, and Web of Science electronic databases.

REVIEW METHODS

Two researchers evaluated the literature to determine if an article met inclusion and exclusion criteria. The quality of the evidence was assessed using the Johns Hopkins Strength of the Evidence critical appraisal tool.

RESULTS

Twenty studies, published between 1979 and 2014, met inclusion criteria. Of these, nine articles were expert opinion, seven were original research, three were review articles, and one was a guideline. Despite seven original research papers being found, only five reports were about the methods to determine the internal length of nasogastric feeding tube in adults. The literature suggests that four different methods for measuring the tube length are likely to result in proper placement of the tip of the tube in the stomach and all side ports inside it: [nose-to-ear-to-xiphisternum - 50]cm/2+50cm]; [gender-weight and nose-umbilicus-flat]; [xiphisternum-to-ear-to-nose+10cm]; [earlobe to xiphisternum to umbilicus - tip of the nose to earlobe]. Four studies found nose-to-ear-to-xiphisternum was most likely to result in a tube that is positioned incorrectly, either ending in the esophagus, in the stomach but too close to the esophagus, or too far into the stomach or duodenum.

CONCLUSIONS

The nose-to-ear-to-xiphisternum and Hanson method should no longer be taught in nursing programs or used in practice by the nurse. The [gender-weight and nose-umbilicus-flat] method has been shown to be safer.

Nomograms in oncology: more than meets the eye

Nomograms are widely used as prognostic devices in oncology and medicine. With the ability to generate an individual probability of a clinical event by integrating diverse prognostic and determinant variables, nomograms meet our desire for biologically and clinically integrated models and fulfill our drive towards personalised medicine. Rapid computation through user-friendly digital interfaces, together with increased accuracy, and more easily understood prognoses compared with conventional staging, allow for seamless incorporation of nomogram-derived prognosis to aid clinical decision making. This has led to the appearance of many nomograms on the internet and in medical journals, and an increase in nomogram use by patients and physicians alike. However, the statistical foundations of nomogram construction, their precise interpretation, and evidence supporting their use are generally misunderstood. This issue is leading to an under-appreciation of the inherent uncertainties regarding nomogram use. We provide a systematic, practical approach to evaluating and comprehending nomogram-derived prognoses, with particular emphasis on clarifying common misconceptions and highlighting limitations.

Nasogastric tube depth: the 'NEX' guideline is incorrect

Misplacing 17-23% of nasogastric (NG) tubes above the stomach ( Rollins et al, 2012 ; Rayner, 2013 ) represents a serious risk in terms of aspiration, further invasive (tube) procedures, irradiation from failed X-ray confirmation, delay to feed and medication. One causal factor is that in the National Patient Safety Agency (NPSA) guidance to place a tube, length is measured from nose to ear to xiphisternum (NEX) ( NSPA, 2011 ); NEX is incorrect because it only approximates the nose to gastro-oesophageal junction (GOJ) distance and is therefore too short. To overcome this and because the xiphisternum is more difficult to locate, local policy is to measure in the opposite direction; xiphisternum to ear to nose (XEN), then add 10 cm. The authors determined whether external body measurements can be used to estimate the NG tube length to safely reach the gastric body. This involved testing the statistical association of body length, age, sex and XEN in consecutive critically ill patients against internal anatomical landmarks determined from an electromagnetic (EM) trace of the tube path. XEN averaged 50 cm in 71 critically ill patients aged 53±20 years. Tube marking and the EM trace were used to determine mean insertion distances at pre-gastro-oesophageal junction (GOJ) (48 cm), where the tube first turns left towards the stomach and becomes shallow on the trace; gastric body (62 cm), where the tube reaches the left-most part of the stomach; and gastric antrum (73 cm) at the midline on the EM trace. Using body length, age, sex and XEN in a linear regression model, only 25% of variability was predicted, showing that external measurements cannot reliably predict the length of tube required to reach the stomach. A tube length of XEN (or NEX) is too short to guarantee gastric placement and is unsafe. XEN+10 cm or more complex measurements will reach the gastric body (mid-stomach) in most patients, but because of wide variation, external measurements often fail to predict a safe distance. Only the EM trace or possibly direct vision can show in real time whether the tip has safely reached the gastric body.

Enteral feeding tubes: are insertion techniques and positioning based on anatomical evidence?

Patients in whom oral energy intake is insufficient for daily needs may develop malnutrition and its complications, such as increased infection rates, increased length of hospitalization, and death. Enteral feeding is beneficial for these patients. However, this therapy is not without complications related to the insertion and placement of enteral feeding tubes. This review aims to identify from the literature different techniques for insertion and the methods used to evaluate the placement of enteral feeding tubes.

Methods of enteral feeding in preterm infants

Whenever possible, oral feeding is the preferred method in neonatal feeding. However, many premature infants are unable to suck and swallow effectively; in these cases alternative methods of nutrient delivery must be used. We briefly review the different feeding methods used in neonatal units, with particular attention to their theoretical advantages, disadvantages and to the current best evidence available.

[Neurally adjusted ventilatory assist (NAVA). A new mode of assisted mechanical ventilation]

The aim of mechanical ventilation is to assure gas exchange while efficiently unloading the respiratory muscles and mechanical ventilation is an integral part of the care of patients with acute respiratory failure. Modern lung protective strategies of mechanical ventilation include low-tidal-volume ventilation and the continuation of spontaneous breathing which has been shown to be beneficial in reducing atelectasis and improving oxygenation. Poor patient-ventilator interaction is a major issue during conventional assisted ventilation. Neurally adjusted ventilator assist (NAVA) is a new mode of mechanical ventilation that uses the electrical activity of the diaphragm (EAdi) to control the ventilator. First experimental studies showed an improved patient-ventilator synchrony and an efficient unloading of the respiratory muscles. Future clinical studies will have to show that NAVA is of clinical advantage when compared to conventional modes of assisted mechanical ventilation. This review characterizes NAVA according to current publications on this topic.

Accurate positioning of the 24-hour pH monitoring catheter: Agreement between manometry and pH step-up method in two patient positions

AIM: To investigate the agreement between esophageal manometry and pH step-up method in two different patient positions.

METHODS: Eighteen subjects were included in the study. First, the distance from the nose to the proximal border of the lower esophageal sphincter (LES) was measured manometrically. Then a different investigator, who was blinded to the results of the first study, measured the same distance using the pH step-up method, with the patient in both upright and supine positions. An assessment of agreement between the two techniques was performed.

RESULTS: In the supine position, the measurement of only one subject was outside the range accepted for correct positioning (≤ 3 cm distal or proximal to the LES). In the upright position, errors in measurement were recognized in five subjects. Bland-Altman plots revealed good agreement between measurements obtained manometrically and by the pH-step up method with the patient in the supine position.

CONCLUSION: In the case of nonavailability of manometric detection device, the pH step-up method can facilitate the positioning of the 24 h pH monitoring catheter with the patient in the supine position. This should increase the use of pH-metry in clinical practice for subjects with suspected gastroesophageal reflux disease if our results are supported by further studies.