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

Reducing Postpyloric Feeding Start Times in Patients With Large Hemispheric Infarction Receiving Therapeutic Hypothermia

BACKGROUND

Early postpyloric feeding provides effective and safe enteral nutrition for patients with large hemispheric infarction receiving therapeutic hypothermia.

LOCAL PROBLEM

Patients with large hemispheric infarction undergoing therapeutic hypothermia often have gastrointestinal dysfunction and undergo repeated bedside attempts at blind postpyloric feeding tube placement. Confirming tube position via radiography can delay nutrient intake, increase costs, and expose patients to unnecessary radiation.

METHODS

In this quality improvement study, specialist nurses were trained to use ultrasonography instead of radiography to confirm postpyloric feeding tube position, reducing reliance on ancillary services. Preimplementation and postimplementation data included time from tube placement to first feeding and the frequency of radiography use. Surveys were conducted to assess the health care team's satisfaction with the new process.

RESULTS

Sixty-seven placements (30 before implementation, 37 after implementation) were evaluated. Feeding start times significantly decreased by 34.85% (mean [SD], 741.20 [192.73] minutes before implementation vs 482.86 [166.15] minutes after implementation; P < .001). The addition of ultrasound guidance for postpyloric feeding tube placement significantly decreased the number of abdominal radiographs per patient by 56.0% (mean [SD], 2.5 [0.9] before implementation vs 1.1 [0.4] after implementation; P < .001). Most health care team members indicated that this practice change reduced the time to initiation of enteral nutrition for patients with large hemispheric infarction receiving therapeutic hypothermia.

CONCLUSIONS

By improving processes, we reduced feeding start times, minimized radiography use, and enhanced the health care team's satisfaction with postpyloric feeding tube placement for patients receiving therapeutic hypothermia.

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.

Aspiration pneumonia in nursing literature-a mapping review

Introduction

Aspiration pneumonia (AP) is an infection of the lungs caused by inhalation of material. The reported incidences vary across literature and clinical populations and is associated with high morbidity and mortality. Management of AP is best carried out by a multidisciplinary team.

Methods

This aim of this review was to collate and describe the available evidence on AP to develop a greater understanding of the concept of AP as it is represented in the nursing literature. As a collaborative team, we undertook the six stages of a systematic mapping review. We searched for the term aspiration pneumonia in 200 peer reviewed nursing journals across 10 databases, over a ten-year period (2013-2023).

Results

In this review, 293 papers were coded. Dysphagia, oral health and tube feeding emerged as the most frequent risk factors for AP, and the most reported factors for preventing this condition. Mortality was the most commonly described consequence of AP, followed by hospitalisations and morbidity. Multiple management approaches were reported including dysphagia assessment, risk evaluation, oral care and texture modification of food and fluids. The role of nurses and interprofessional collaborations were described.

Discussion

Despite limited evidence related to the topic of AP in the nursing literature, the complexity of the causes, prevention, management and consequences of AP emerged. Certain factors, such as dysphagia, oral health, and tube feeding, were described under prevention, cause and management of AP. The importance of multidisciplinary approach in the management and prevention of AP was presented.

Enhancing nasogastric tube insertion skill performance by using updated checklist among nursing students

Background

Nasogastric tube (NGT) insertion is one of the most commonly performed procedures for critically ill patients through the nostril or mouth into the stomach, which is indicated for multiple reasons.

Objective

This study is, therefore, aimed to enhance the NGT insertion skill performance of third-year nursing students using the updated checklist, 2021.

Method

A facility-based pre-post intervention study was conducted among third-year nursing students of the School of Nursing, Jimma University. An updated checklist and intervention package were used among 26 randomly selected nursing students. The collected data was entered into EpiData version 3.1, EpiData Association, Denmark and exported to SPSS version 23, IBM Corp, Armonk, NewYork for analysis. Descriptive statistics were made for each item and Paired T-test analysis was conducted to summarize the findings.

Result

The highest NGT skill insertion performance score from 40% before the intervention was 35; however, after the intervention, the score increased to 40.3. Their mean score in NGT skill performance was increased by 11 after the intervention of implementing the intervention package using the updated checklist from 26.5 ±5 0.3 the pre-intervention to 37.8 ±5 1.7 post-intervention. The finding indicated that the improvement was statistically significant at p < 0.001.

Conclusion

Implementing an intervention package and employing an updated NGT insertion checklist improved the performance of third-year nursing students' NGT insertion skills by an average of 11 points compared to their pre-test scores. A large-scale control randomized trial study was recommended to control for the effects of confounding factors on the implementation of intervention packages.

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.

A Randomized Clinical Trial to Compare Three Different Methods for Estimating Orogastric Tube Insertion Length in Newborns: A Single-Center Experience in China

Background: Orogastric (OG) and nasogastric (NG) tubes are frequently used in the NICU. Obtaining a relatively accurate estimated length before insertion could significantly reduce complications. While previous studies have mainly focused on the NG tube, OG tubes are more commonly used in China. Purpose: The objective was to determine whether there were differences in the rate of accurate placement among the adapted nose-ear-xiphoid (NEX) method, nose-ear-midway to the umbilicus (NEMU) method, and weight-based (WB) equation in estimating the OG tube insertion distance. Methods: A randomized, controlled, open-label clinical trial to compare the three methods was conducted in a single center. After enrollment, newborns were randomly assigned into three groups. By radiological assessment, the anatomical region for OG tube placement was analyzed. The primary metric was the tip within the gastric body, and the second metric was strictly accurate placement defined as the tube was not looped back within the stomach and the end was located more than 2 cm but less than 5 cm into the stomach, referred to as T10. Results: This study recruited 156 newborns with the majority being preterm infants (n = 96; 61.5 percent), with an average birth weight of 2,200.8 ± 757.8 g. For the WB equation, 96.2 percent (50 cases) of the OG tubes were placed within the stomach, and the rates were 78.8 percent (41 cases) in the adapted NEX and NEMU methods. The strictly accurate placement rates were highest for the WB equation at 80.8 percent (42/52), followed by the adapted NEX method at 65.4 percent (34/52), and the NEMU method at 57.7 percent (30/52). Conclusion: The WB equation for estimating the insertion depth of the OG tube in newborn infants resulted in more precise placement compared to the adapted NEX and NEMU methods.

Optimal Insertion Depth of Gastric Decompression Tube with a Thermistor for Patients Undergoing Laparoscopic Surgery in Trendelenburg Position

Monitoring core temperature is crucial for maintaining normothermia during general anesthesia. Insertion of a gastric decompression tube (GDT) may be required during laparoscopic surgery. Recently, a newly designed GDT with a thermistor for monitoring esophageal temperature has been introduced. The purpose of the present study was to evaluate the optimal insertion depth of a GDT with a thermistor. Forty-eight patients undergoing elective laparoscopic surgery in the Trendelenburg position were included in the study. The GDT was inserted to a depth of nose-earlobe-xiphoid distance (NEX) + 12 cm and withdrawn sequentially, 2 cm at a time, at 5-min intervals. Temperatures of the GDT thermistor were compared with the core temperature of the tympanic membrane (TM) using Bland and Altman analysis. The correlation between optimal insertion depth of the GDT and anatomical distance (cricoid cartilage to the carina, CCD; carina to the left hemidiaphragm, CLHD) was evaluated, and a mathematical model to predict the optimal insertion depth of the GDT with a thermistor was calculated. Temperatures of TM and GDT thermistor at NEX + 4 cm showed good agreement and strong correlation, but better agreement and stronger correlation were seen at the actual location with the most minor temperature differences. The optimal insertion depth of the GDT was estimated as -15.524 + 0.414 × CCD - 0.145 × CLHD and showed a strong correlation with the actual GDT insertion depth (correlation coefficient 0.797, adjusted R² = 0.636). The mathematical formula using CCD and CLHD would be helpful in determining the optimal insertion depth of a GDT with a thermistor.

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.

Nasogastric tube placement under sonographic observation: A comparison study of ultrasound and chest radiography in mechanically ventilated patients

BACKGROUND

Nasogastric tube insertion in the intensive care setting is common. Placement verification is required to avoid complications of bronchotracheal misplacement that range from aspiration of infused contents to death from associated causes. The gold standard of practice is chest radiography. Ultrasound is a growing modality and is readily available in most intensive care units.

OBJECTIVE

The objective of this study was to examine the diagnostic accuracy of ultrasound imaging of nasogastric tube placements by nonradiologists compared with chest radiography in mechanically ventilated patients.

METHODS

This is a dual-centre prospective, single-blind study. Correct placement was captured with a hyperechoic ultrasound image of a nasogastric tube in the oesophagus and epigastrium, which was compared with chest radiography. Patient enrolment included general adult intensive care unit admissions who were mechanically ventilated and required a nasogastric tube for either the treatment or monitoring of their illness.

RESULTS

A total of 25 patients were enrolled (15 men, 10 women), and their mean age was 68.1 ± 13.8 years. Outcome measures were the percentage of correctly identified nasogastric tubes in the oesophagus and epigastrium. The sensitivity of oesophagus ultrasound was 88%, and the positive predictive value was 100%. The subxiphoid sensitivity was 64%, and the positive predictive value was 100%. Comparison sensitivity and specificity of oesophagus versus subxiphoid ultrasound was 64% and 33%, respectively. There was a positive predictive value of 88% and a negative predictive value of 11%. The results showed a variance in detection sensitivity in the ultrasound scans of the oesophagus (0.88) and subxiphoid (0.64) (N = 25, p = 0.012).

CONCLUSION

Nasogastric tube placement verification via ultrasound in critically ill mechanically ventilated patients conducted by nonradiologists with minimal training is associated with diagnostic accuracy. These results add to the limited evidence in the current literature; however, they should be considered with awareness that placement in the stomach in this study was detected in 64% of cases, alongside the missed captured evidence of the sonographer's ability to identify misplacement.

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.

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.

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.

Study to determine the likely accuracy of pH testing to confirm nasogastric tube placement

Objective

To establish the likely accuracy of pH testing to identify gastric aspirates at different pH cut-offs to confirm nasogastric tube placement.

Methods

This prospective observational study included a convenience sample of adult patients who had two (one fresh and one frozen) gastric and oesophageal samples taken during gastroscopy or two bronchial and saliva samples taken during bronchoscopy. The degree of observer agreement for the pH of fresh and frozen samples was indicted by kappa (k) statistics. The sensitivities and specificities at pH ≤5.5 and the area under the receiver operating characteristics (ROC) curve at different pH cut-offs were calculated to identify gastric and non-gastric aspirates.

Results

Ninety-seven patients had a gastroscopy, 106 a bronchoscopy. There was complete agreement between observers in 57/92 (62%) of the paired fresh and frozen gastric samples (k=0.496, 95% CI 0.364 to 0.627). The sensitivity of a pH ≤5.5 to correctly identify gastric samples was 68% (95% CI 57 to 77) and the specificity was 79% (95% CI 74 to 84). The overall accuracy to correctly classify samples was between 76% and 77%, regardless of whether patients were taking antacids or not. The area under the ROC curve at different pH cut-offs was 0.74.

Conclusion

The diagnostic accuracy of pH ≤5.5 to differentiate gastric from non-gastric samples was low, regardless of whether patients were taking antacids or not. Due to the limited accuracy of the pH sticks and the operators’ ability to differentiate colorimetric results, there is an urgent need to identify more accurate and safer methods to confirm correct placement of nasogastric tubes.

Nasogastric tube placement confirmation: where we are and where we should be heading

Background:

Insertion of a tube via the nasal passage is a common procedure which has been practiced for many years. There are various ways to assess the position of the nasogastric tube (NGT).

Objectives:

The objective of this study was to discuss the advantages and limitations of each method of NGT placement confirmation, to identify gaps in literature, and provide suggestions for future research.

Methods:

A search was performed with Pubmed, CINAHL, and Embase. The following keywords were used: “nasogastric,” “tube,” “placement,” “insertion,” and “measurement.” The results were narrowed down to those with full text available, published in the English language, those published within the last 10 years, and those studies done in the adult population. The reference lists of those articles were also referred to and relevant articles were retrieved. A final 26 relevant articles were included in this review, including six that were published more than 10 years ago but still relevant in this review.

Results:

A method to confirm NGT placement that is accurate, affordable, does not require gastric aspirates, and is able to be used not only upon insertion but also at regular intervals is lacking.

Conclusions:

This article provides a summary of the different methods of NGT placement confirmation and discusses their advantages and limitations. Gaps in literature and suggestions for future research were also deliberated.