Nasogastric tube aspirate pH values associated with typical enteral feeding patterns in infants admitted to an NICU

Comparison of 3 Methods for Measuring Gastric Tube Length in Newborns: A Randomized Clinical Trial

BACKGROUND

Incorrectly positioned gastric tubes occur in approximately 60% of infants hospitalized in the neonatal intensive care unit (NICU), increasing the risk of potentially serious complications.

PURPOSE

To compare 3 methods of determining gastric tube insertion length in infants in the NICU.

METHODS

In this randomized triple-blind clinical trial, 179 infants admitted to the NICU were randomized to have their gastric tube insertion length determined by 1 of 3 methods: (1) the nose, earlobe, mid-umbilicus (NEMU) method, (2) a weight-based method, or (3) an age-related height-based (ARHB) method. Positioning of the gastric tube was verified by radiograph. R software was used for analyses. To compare categorical variables, Fisher's exact test, χ2 tests, and simulated χ2 tests were used.

RESULTS

Overall, infants had a mean gestational age of 35 weeks, 115 (58.8%) were male, and the mean birth weight was 2481.5 g. Upon radiological assessment, 145 gastric tubes (81.3%) were correctly positioned in the gastric body or greater curvature of the stomach with the weight-based method having the highest percentage of correctly positioned gastric tubes (n = 53; 36.6%), followed by the ARHB method (n = 47; 32.4%) and the NEMU method (n = 45; 31.0%). No significant differences were identified between groups (P = .128).

IMPLICATION FOR PRACTICE AND RESEARCH

Despite the NEMU method being the most commonly used method in clinical practice, the weight-based and ARHB methods to determine gastric tube insertion length may be more accurate.

Ongoing pH testing to confirm nasogastric tube position before feeding to reduce the risk of adverse outcomes in adult and paediatric patients: A systematic literature review

BACKGROUND & AIMS

There is no agreed gold standard method to confirm nasogastric tube position before every use. However, many global guidelines recommend testing the pH of gastric aspirates obtained from an NGT before each use. This study aims to determine whether ongoing pH testing has been shown to reduce adverse events. Secondary aims are to determine how frequently aspirates can be obtained, and how often pH correctly confirms ongoing NGT tip position.

METHODS

Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were followed and protocol was published on PROSPERO. Keywords were used to search PubMed, Embase, CENTRAL, CINAHL and MEDLINE. Article assessment for inclusion was completed by two independent authors and risk of bias was assessed using ROBINS-I.

RESULTS

The systematic search and review methodology was followed due to wide variety and high risk of bias in the included studies. One full study and five abstracts met inclusion criteria for the primary aim. The full article contained one instance where pH testing and external NGT length together identified a misplaced NGT. The abstracts identified missed or delayed feeds and medications, and frequent unnecessary X-rays, as negative outcomes of ongoing pH testing. Ten full studies and one conference abstract addressed the secondary aims, but the studies varied widely which prevented meta-analysis and made it difficult to draw conclusions.

CONCLUSIONS

This review confirmed that ongoing pH testing is based on expert opinion due to limited evidence. More primary research is required to determine the clinical impact of ongoing pH testing to confirm NGT position.

Use of pH reagent strips to verify gastric tube placement in newborns

Objective:

to confirm the accuracy of the pH test in identifying the placement of the gastric tube in newborns.

Method:

double-blind, diagnostic test study conducted with 162 newborns admitted to a neonatal intensive care unit and an intermediate care unit. The subjects were submitted to enteral intubation, followed by pH test with reagent strip, which was analyzed by a nurse, and radiological examination, analyzed by radiologist. Blinding was kept among professionals regarding test results. Diagnostic accuracy analysis of the pH test in relation to the radiological exam was performed.

Results:

the sample consisted of 56.17% boys, with average birth weight of 1,886.79g (SD 743,41), 32.92 (SD 2.99) weeks of gestational age and the mean pH was 3.36 (SD 1.27). Considering the cutoff point of pH≤5.5, the sensitivity was 96.25%, specificity 50%, positive predictive value 99.35% and negative predictive value 14.29%.

Conclusion:

The pH test performed with reagent strips is sensitive to identify the correct placement of the gastric tube, so it can be used as an adjuvant technique in the evaluation of the gastric tube placement. In interpreting the results, pH ≤5.5 points to correct placement and values > 5.5 require radiological confirmation.

Comparison of Neonatal Nursing Practices for Determining Feeding Tube Insertion Length and Verifying Gastric Placement With Current Best Evidence

BACKGROUND

Oral-nasogastric feeding tubes (FTs) are often malpositioned, placing infants at risk for complications. Confusion exists regarding the accuracy of methods to determine FT insertion length and verify gastric FT placement, and it is unknown whether evidence-based methods are used by neonatal nurses.

PURPOSE

To compare individual and unit-based neonatal nursing practices regarding methods used to determine FT insertion length and verify gastric FT placement.

METHODS

Neonatal nurses were surveyed about individual and unit-based practices regarding methods used to determine FT insertion length and verify gastric FT placement in infants in the neonatal intensive care unit.

RESULTS

Sixty neonatal nurses completed the survey, with 63% utilizing the nose-ear-midway to the umbilicus method, which was included in 50% of protocols and is associated with up to a 90% accuracy rate. Although it has an unacceptably high inaccuracy rate, the nose-to-ear-to-xiphoid method was used by 32% of nurses and recommended in 30% of protocols. To verify gastric FT placement, 98% of nurses used auscultation of a whoosh sound and 83% used aspiration of gastric contents. Neither verification method is supported by evidence or recommended for use.

IMPLICATIONS FOR PRACTICE

A lack of consistency exists between nursing practice and evidence-based methods.

IMPLICATIONS FOR RESEARCH

Research is needed to determine more accurate and reliable ways to determine FT insertion depth and verify gastric FT placement in neonates.