Evidence map›Paper›PMID 42005658›Full record

ArticleHealth science reports2026

Practical pH Testing for Nasogastric Tube Verification: A Prospective Method-Comparison Study of Low-Cost Handheld Meters and Colourimetric Strips.

Luca D Zambetti

Abstract read
In one paragraph

Article in Health science reports, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.

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1 · What the graph read from it

What it found

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The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

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Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

0 citing papers in PubMed.

No citing paper in PubMed yet.

4 · The record

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5 · Who and what money

Authors and funding

1 author.

Luca D ZambettiDepartment of Internal Medicine Frere Hospital East London South Africa.ORCID https://orcid.org/0009-0007-8086-8246

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

Background and Aims: Nasogastric (NG) tubes are widely used for enteral nutrition, medication administration, and gastric decompression, but misplacement can cause serious, preventable harm. International guidelines recommend gastric aspirate pH testing with pH strips to reduce reliance on X-rays, but subjective color interpretation and stock shortages limit their reliability in resource-constrained settings. Commercial handheld pH meters offer objective digital readings and reusability, but their performance in routine clinical practice is uncertain. Methods: A prospective method-comparison study was conducted among adult inpatients requiring NG tube insertion in a South African public hospital. Gastric aspirate pH was measured using pH strips, followed immediately by a commercially available handheld pH meter on the same sample. Agreement was assessed using Bland-Altman analysis and Cohen's kappa, and diagnostic accuracy at a threshold of pH ≤ 5.5 was secondarily explored using routinely obtained chest radiography, where available, as the reference standard. Results: Forty-five patients were enrolled; gastric aspirate was obtained from 40 (89%), and 26 (58%) had both an aspirate and an interpretable chest X-ray. The handheld pH meter showed a mean bias of +0.17 pH units, with 95% limits of agreement from -0.46 to +0.80. At pH ≤ 5.5, categorical agreement with pH strips was substantial (κ = 0.754; Conclusions: In this cohort, a low-cost handheld pH meter showed a small mean bias and substantial categorical agreement with pH strips at pH ≤ 5.5. Its objective digital readout and reusability address key limitations of color-based strips and support its use in resource-constrained settings as a practical bedside tool for confirming gastric NG tube placement. However, pH values > 5.5 do not reliably exclude gastric placement, and chest radiography remains necessary when results are inconclusive or discordant with clinical expectations.

Indexed as

gastric aspiratenasogastric tubepatient safetypH measurementpH meterpH test striptube verification

Identifiers

PMID42005658
PMCPMC13087631

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