Ultrasonography to confirm gastric tube placement in critical care and emergency: From diagnostic accuracy to an actionable safety pathway

Abstract

Accurate confirmation of gastric tube placement is a time-critical safety step in adult intensive care units/emergency department care. Feeding and medication are often urgent, but airway misplacement can be catastrophic. Chest radiography and aspirate pH testing are commonly used; however, they may be slow or unreliable when aspirate is limited, acid suppression is used, enteral feeding is ongoing, or infection-control measures limit imaging. This narrative review summarizes adult evidence on ultrasonography for tube confirmation, with a focus on technique, performance, and safe implementation. When visualization is adequate, ultrasound can support rule-in confirmation, particularly with a standardized two-window approach (cervical esophagus view plus upper abdominal/gastric view) and a small saline/air flush to produce an intragastric acoustic change. However, malposition is uncommon in most studies, and indeterminate scans are frequent in patients with obesity, bowel gas, or postoperative anatomy. Therefore, ultrasound should not be used as a stand-alone test without clear escalation criteria. We propose an ultrasound-first, safety-anchored pathway. The tube should be used only when findings are clearly positive, with escalation to radiography or institutional reference standards when results are inconclusive, discordant, or high-risk. Future pragmatic studies should evaluate time to first feeding/medication and adverse events and standardize protocols and competency targets.

Keywords

Nasogastric tube gastric tube point-of-care ultrasound ultrasonography tube confirmation enteral nutrition intensive care emergency medicine

Background

Gastric tubes (nasogastric or orogastric) are placed daily in adult emergency departments (EDs) and intensive care units (ICUs) to initiate early enteral nutrition, administer medications, and decompress the stomach.¹ Although the procedure is common, its harm profile is asymmetric. Airway placement and clinically significant malposition are uncommon; however, they can lead to aspiration, pneumothorax, and death. Patient-safety alerts have therefore cautioned against subjective bedside surrogates, such as auscultation or the “whoosh” test, and have identified misinterpretation of confirmation radiographs as a recurring cause of preventable harm.^2,3

Chest radiography (CXR) remains the most widely used reference method for initial confirmation; however, in ICU/ED workflows, it can delay the initiation of feeding or medication because image acquisition and interpretation are not always immediate. Prospective adult studies have reported bedside ultrasound confirmation times of approximately 3–10 min compared with approximately 42 min for radiography in one ED cohort.^4,5 pH-based checks also fail in routine practice when aspirate cannot be obtained and may be less reliable in patients receiving acid suppression therapy or ongoing enteral feeding.^1,6

This narrative review summarizes adult-focused evidence on ultrasonography for gastric tube confirmation and translates that evidence into a pragmatic ICU/ED workflow that is ultrasound-first but safety-anchored. Evidence was identified through targeted searches of MEDLINE/PubMed and the Cochrane Library, supplemented by backward and forward citation tracking of key primary studies, evidence syntheses, and guideline and safety documents. We prioritized adult cohorts and studies using radiography as a reference comparator, and we also incorporated safety standards that shape verification processes in routine clinical practice. This review was guided by the Scale for the Assessment of Narrative Review Articles (SANRA).⁷

Main text

Current verification standards and their ICU/ED limitations

CXR is widely used as the reference method for the initial confirmation of blindly inserted feeding tubes. In ICU/ED workflows, however, imaging can become a bottleneck that delays the initiation of feeding or medication, and its safety value remains dependent on correct acquisition and interpretation, a concern repeatedly highlighted in patient-safety reports as a preventable source of harm. Guideline frameworks also support aspirate pH testing, with escalation to imaging when aspirate cannot be obtained or when pH results are inconclusive.⁸ However, these “routine” steps often fail under ICU/ED conditions. Aspirate may not be obtainable, and pH thresholds can be misleading in patients receiving acid suppression therapy or continuous enteral feeding. Against this background, perioperative series reporting clinically significant malposition after blind insertion reinforce a pragmatic stance: when risk is high, the threshold for escalation should be low.^9,10

When the clinical priority is to rapidly exclude airway placement, capnography or capnometry can be useful. These methods have been evaluated as adjuncts for airway exclusion and may perform better than epigastric auscultation when inadvertent tracheobronchial placement is the concern. However, they cannot confirm intragastric position and therefore should not be used as stand-alone confirmation methods.¹¹ The practical implication is straightforward and a safe verification process requires two answers: “the tube is not in the airway” and “the tube is in the stomach.” It also requires a preplanned escalation pathway when either answer remains uncertain.

Ultrasonography techniques for confirmation

Ultrasonography is used to answer two bedside questions. 1. Does the tube pass through the esophagus rather than the airway? 2. Is the distal tip in the stomach so that the tube can be used for feeding or medication? In adult ICU/ED practice, this approach aligns with a simple two-window protocol that combines a neck view with an upper abdominal view, with an optional flush maneuver when direct visualization is limited. Ultrasound can also facilitate difficult postpyloric placement in critically ill adults when blind techniques fail, reflecting its broader value as a procedural tool in addition to a confirmation test.¹²

Figure 1(a) summarizes a standardized two-window scanning technique, and Table 1 lists practical rule-in criteria and mandatory escalation triggers for situations in which visualization is incomplete. The neck window examines the cervical esophagus in the lower neck or suprasternal region, usually posterolateral to the trachea, and can demonstrate tube passage through the upper esophageal segment when feasible.^13,14 However, it does not provide continuous tracking through the thoracic or distal esophagus. The upper abdominal window then targets discrete confirmation points, including the stomach, antrum, fundus, left upper quadrant, or the region of the gastroesophageal junction, to identify the tube tip or distal portion within the stomach. When direct visualization is limited, a small standardized saline flush with or without air may create a transient intragastric acoustic change that supports rule-in confirmation; however, this indirect sign should be interpreted only within a safety-anchored pathway and not as a stand-alone clearance test.^13,15 Published adult ICU data suggest that two-window confirmation is often feasible, although not universal. Real-time cervical esophageal visualization was reported in 52/56 patients (92.8%) in one ICU series, whereas a larger ICU cohort reported overall ultrasound feasibility in 246/276 patients (89.1%) and direct gastric visualization in 189/246 patients (76.8%).^14,16 These findings help define the boundaries of the pathway. Ultrasound samples specific anatomical checkpoints rather than continuously imaging the entire tube course, and abdominal visualization remains the limiting step in a meaningful minority of patients.

Figure 1.

Ultrasound-first confirmation of gastric tube placement in adult ICU/ED using a standardized two-window POCUS strategy. (a) Standardized two-window technique. The cervical window images the upper cervical esophagus adjacent to the trachea and, when feasible, demonstrates tube passage within this segment; it supports airway exclusion and gastrointestinal trajectory but does not track the tube through the thoracic or distal esophagus. The upper abdominal/LUQ window then samples gastric confirmation points, including the stomach, antrum, fundus, and region of the gastroesophageal junction, to identify the tube tip/distal portion or demonstrate a transient intragastric acoustic change after a standardized saline/air flush. Dynamic flush signs should be interpreted only in an adequate gastric window and after reasonable airway exclusion; otherwise, the examination is considered inconclusive and requires escalation. Examinations are reported as positive, inconclusive, or discordant to trigger predefined escalation rules. (b) Ultrasound-first, safety-anchored pathway. When ultrasound is clearly positive (adequate window with rule-in findings), the tube may be used immediately for feeding/medication with documentation. Inconclusive, discordant, or high-risk findings require escalation to chest radiography or an institutional reference standard before first use. Suspected malposition warrants tube removal/reinsertion and repeat verification.

Table 1.

Practical ultrasound criteria and escalation triggers.

Domain	Suggested “positive” criteria (rule-in)	Mandatory “inconclusive/escalate” triggers
Neck/esophagus window	Tube passage visualized in esophagus (supports GI course)	Nondiagnostic neck scan with concern; difficult insertion
Gastric window (direct)	Tube tip or distal portion clearly visualized in stomach/antrum/fundus	Poor window or uncertain structure
Gastric window (dynamic flush)	Convincing intragastric echogenic change (“swirl/fogging”) on an adequate gastric window after reasonable airway exclusion	Absent/equivocal change; nondiagnostic neck view with unresolved airway concern; no direct gastric visualization; operator uncertainty; discordant signs
Overall decision	Clearly positive overall → GREEN (use)	Any inconclusive/discordant/high-risk → AMBER (CXR/reference standard)

GREEN refers to tube use permitted after clearly positive findings; AMBER indicates not use the tube until confirmation by CXR or another institutional reference standard.

GI: gastrointestinal; CXR: chest radiography.

Standardization becomes increasingly important as protocols scale across teams. Structured multipoint approaches, such as “4-point” protocols, provide a checklist that may improve reproducibility in ICU workflows and reduce overreliance on any single acoustic window.⁴

Evidence synthesis: What ultrasound can and cannot guarantee

Adult diagnostic studies generally support ultrasonography as a useful bedside “rule-in” test when visualization is successful. A systematic review and meta-analysis reported favorable diagnostic accuracy compared with radiography, supporting ultrasound as a confirmation strategy in routine workflows when the tube can be clearly visualized.¹⁵ A large prospective multicenter cohort reached a similar conclusion and, importantly, demonstrated why a simple “ultrasound-only clearance” mindset is unsafe. False positives occur, and a meaningful proportion of examinations are nondiagnostic; therefore, an escalation plan is part of the test itself rather than an optional add-on.¹⁷ Evidence from ED and prehospital settings points in the same direction. When acoustic windows are adequate, ultrasound can confirm correct placement rapidly, but nonvisualization and occasional misplacement remain predictable failure modes, again making escalation rules the practical safeguard.^6,14,18,19

This framework aligns with the most up-to-date Cochrane review, which concluded that current evidence is insufficient to support ultrasound as a stand-alone confirmation test for feeding tube use across settings. Additionally, it highlighted that data remain limited on incorrect placement, indeterminate scans, and complications.²⁰ The key implication is not that ultrasound is “not useful.” Rather, the evidence base supports a narrower and more actionable conclusion. Ultrasound has rule-in value when the scan is clearly positive, but it should function within an integrated pathway with explicit escalation criteria rather than replacing radiography across all adult ICU/ED situations.

Why does this distinction matter in critical care? Nutrition guidelines encourage early enteral nutrition for appropriate adults, often within 24–48 h when feasible, creating steady pressure to shorten the interval from insertion to first use.²¹ Ultrasound is particularly useful in situations where delays occur, including crowded departments, limited transport capacity, and repeated checks after repositioning or transfers, because it is available at the bedside and can be repeated without radiation exposure. Reports from the coronavirus disease 2019 (COVID-19) era also demonstrated that neck-plus-epigastric workflows remain feasible when infection-control constraints make imaging more difficult to obtain.^16,22 Adjunctive techniques have been proposed to improve conspicuity in selected patients, including color Doppler approaches; however, these methods still require interpretation within the same safety-anchored framework rather than being treated as separate “clearance” tests.²³

Time-based data provide a pragmatic complement to accuracy metrics. Adult ICU/ED studies suggest that complete bedside ultrasound confirmation can often be performed within minutes. In a COVID-19 ICU cohort, the mean examination time was 3.8 ± 3.4 min per assessment.¹⁶ In an emergency cohort, the mean confirmation time was 3.0 min (2.0–3.0), and repeat confirmation was feasible in patients with frequent position changes.⁵ In a 4-point ICU protocol, procedure time was approximately 10 min and was reported to be shorter than the time required for radiographic acquisition and interpretation.⁴ A color Doppler technique has also been reported to reduce confirmation time compared with radiography (approximately 3 min vs. 42 min).⁵ These findings support an ultrasound-first approach when time to tube use is clinically important. However, they also reinforce the same boundary condition: speed is advantageous only when indeterminate or discordant scans trigger timely escalation rather than premature tube use.²³

Aspirate assessment may still be useful as an adjunct in selected cases. When gastric contents are readily obtainable after a clearly positive or near-positive ultrasound examination, aspiration with or without pH assessment can provide corroborative evidence. However, inability to obtain aspirate does not exclude correct placement, and aspirate-based confirmation may be less reliable in patients receiving acid suppression therapy or ongoing enteral feeding. We therefore view aspiration as supportive rather than definitive, and it should not replace escalation when ultrasound findings are inconclusive or discordant.

An actionable ICU/ED pathway: Ultrasound-first, safety-anchored

A practical bedside pathway should be simple enough for time-pressured use and sufficiently conservative to avoid false reassurance. We therefore use three interpretation categories. A scan is considered positive when the gastric window is adequate and demonstrates clear intragastric visualization of the tube tip or distal segment, or a convincing intragastric dynamic change after a standardized flush performed under protocol and after reasonable airway exclusion, ideally with a neck window supporting esophageal passage. A scan is considered inconclusive when the windows are nondiagnostic, direct gastric visualization is absent, or dynamic signs are equivocal. A scan is considered discordant or high-risk when the ultrasound findings do not fit the clinical picture, when insertion was difficult, or when patient factors make technical failure likely despite a partial sign.

Figure 1(b) translates these categories into a simple ICU/ED decision pathway. A clearly positive scan permits tube use with documentation. Any inconclusive or discordant/high-risk result requires escalation to CXR or another institutional reference standard before first use, as the safety risk lies in premature reassurance rather than delayed confirmation.²⁰

Implementation: training, documentation, and quality assurance

Ultrasound confirmation of gastric tube placement depends on both scan performance and result interpretation; therefore, implementation in ICU/ED settings is most effective when the technique is embedded within a simple governance framework. This framework should include a standardized scanning checklist (required windows, an optional flush maneuver, and routine image archiving), competency-based training (supervised cases plus structured image review), and a feedback loop that audits inconclusive or discordant examinations against CXR or another reference standard during rollout. These steps are not “extra work”; rather, they are what make an ultrasound-first approach safe in a high-pressure workflow, where the tendency is to act on partial signs and proceed rapidly.^4,17 Task-shifted models also support feasibility. Studies suggest that trained ICU nurses can acquire and interpret verification windows with acceptable accuracy when training is linked to unit documentation, predefined escalation rules, and routine audit.^24–27

What level of training is sufficient to support independent practice? Direct evidence on learning curves remains limited; however, available reports provide practical benchmarks for estimating training requirements. In the most recent Cochrane review, several included studies described operators already had experience with the technique, often defined as at least 20 prior examinations before participating in diagnostic-accuracy evaluations.²⁰ Individual studies also suggest that short, focused training, ranging from brief demonstrations to a few hours of structured instruction, can support bedside confirmation with performance comparable to CXR when a standardized protocol is used. It may also shorten time to confirmation when integrated into routine workflow.^17,28,29 These findings do not imply that a short course alone is sufficient. Rather, they support a competency-based approach in which operators complete a supervised logbook and image review, with the realistic expectation that each operator will require several hours of supervised, quality-reviewed scanning before working independently.

Documentation should make the decision traceable, as traceability enables teams to learn from indeterminate scans and near misses. A minimum dataset includes the indication (feeding, medication administration, or decompression), tube type and size, external length at fixation, windows obtained, whether a dynamic flush was used (including type and volume according to protocol), the interpretation category (positive, inconclusive, or discordant), the action taken (used or escalated), and the reference result when obtained.

Pitfalls and troubleshooting

Key failure modes and troubleshooting steps are summarized in Table 2. The operating rule is straightforward: only a clearly positive scan supports tube use; all other results require escalation.

Table 2.

Pitfalls and troubleshooting.

Pitfall/scenario	Likely cause(s)	Ultrasound troubleshooting steps	Safety threshold and escalation
Poor acoustic windows	Obesity, bowel gas, postoperative anatomy, and subcutaneous emphysema	(a) Reposition. Elevate head of bed; slight left tilt; (b) switch to left upper quadrant (LUQ) view; (c) repeat scanning/attempts.	If still uncertain → escalate to a confirmatory method (reposition for imaging, radiography, or institutional reference pathway).
Nondiagnostic cervical (neck) view	Limited access, soft-tissue/air artifact, and anatomic variation	Proceed to the gastric/epigastric window (aim for stomach/antrum/fundus/GEJ). Repeat as needed.	If gastric confirmation is not clearly positive → escalate; do not use tube.
Avoid false reassurance	Malposition events are uncommon in many datasets, risking overconfidence	Apply a safety-first interpretation: only “pass” when evidence is unequivocal.	Treat “not clearly positive” as unsafe-to-use; escalate rather than proceed.
Do not use auscultation (“whoosh test”)	High false-positive rate; cannot reliably exclude malposition	Do not use auscultation as a confirmation method; rely on imaging evidence.	If imaging confirmation is not achieved → escalate.
False positives from indirect signs	A “whoosh/dynamic fogging” response may occur despite distal esophageal malposition	Always combine cervical (esophageal window) and epigastric/gastric windows. Prefer direct visualization of the tube/tip in the stomach/GEJ when possible.	If direct tip visualization is not achieved, or findings are equivocal/discordant → escalate; do not use the tube based on indirect signs alone.
Prone ventilation	Epigastric/gastric window may be limited in the prone position	Prioritize linear-probe cervical esophagus view to exclude airway placement and document esophageal passage.	If gastric confirmation is indeterminate → defer feeding/medication until supination allows epigastric imaging or radiography becomes feasible.
Optional aspiration after ultrasound	Aspirate may be unavailable or misleading during acid suppression, continuous feeding, or limited gastric contents	Use aspiration only as adjunctive corroboration after a clearly positive or near-positive ultrasound examination.	Unavailable or nondiagnostic aspirate must not override inconclusive/discordant ultrasound; escalate before first use.

GEJ: gastroesophageal junction.

Nondiagnostic windows are common in adult ICU/ED practice, and they cluster in predictable situations. Bowel gas, obesity, postoperative abdominal anatomy, subcutaneous emphysema, and prone positioning can all degrade the gastric view; therefore, “poor visualization” should be classified as inconclusive rather than interpreted as a negative result. A practical rule protects both patients and clinical teams: when ultrasound does not provide a clear rule-in finding, the tube should not be used rather confirmation should escalate to CXR or an institutional reference standard.^15,20 This approach is supported by ICU diagnostic-test studies in mechanically ventilated adults, which show that negative or nondiagnostic scans are more frequent in patients with higher body mass index (BMI) and other difficult-window patients, reinforcing conservative escalation rather than optimistic interpretation of partial signs.³⁰ In patients with morbid obesity, the abdominal window is often the rate-limiting step. However, the cervical esophagus window remains obtainable in many patients and can provide valuable airway-exclusion information, which is one reason the two-window strategy is important when feeding or medication administration is time-critical.

False-positive pitfalls also need to be emphasized because they are more likely to appear under time pressure. Indirect “dynamic” signs, such as fogging or a whoosh-associated acoustic change, can support confirmation; however, they are not definitive when direct visualization of the tube tip or distal portion is absent. For example, in a COVID-19 ICU cohort, a “whoosh image” was observed, whereas CXR later demonstrated esophageal malposition.¹⁶ Several scenarios can produce misleading appearances, including distal esophageal placement near the gastroesophageal junction, esophageal tortuosity, and foregut anatomic variants such as a large hiatal hernia or postoperative esophagogastric anatomy. These are not rare edge cases in critical care. They explain why the safest practice favors two windows (cervical plus epigastric), prioritizes direct intragastric visualization whenever feasible, and escalates when findings remain indeterminate.^14,18,20

Prone ventilation warrants separate attention because it is common in patients with severe respiratory failure and complicates routine imaging. In the prone position, the epigastric window is often limited; however, a linear-probe cervical esophagus view can still be obtained in many patients to exclude airway placement and support esophageal passage. In patients who alternate between prone and supine positioning, such as those with acute respiratory distress syndrome (ARDS), bedside ultrasound can also support repeat checks when portable radiography is difficult to obtain in real-time.¹⁶ When gastric confirmation remains uncertain in a prone patient, tube use should be deferred until confirmation becomes feasible through repositioning for a gastric view or through radiography.

This review extends the practice-oriented implementation framework to the adult diagnostic-accuracy literature by demonstrating how discrete ultrasound findings, documentation, and escalation rules can be integrated into ICU/ED workflows.

Future directions

The subsequent question is not whether ultrasound can detect a tube, but whether an ultrasound-integrated workflow improves care without increasing harm. Pragmatic trials are therefore prioritized, with comparisons against usual care and outcomes that matter at the bedside, including time to first feeding or medication administration, radiography use, and misplacement-related adverse events. These studies should report protocols in sufficient detail to allow replication across units. At a minimum, reports should specify which windows were required, how flush maneuvers were performed (type and volume), what competency targets were used, and how indeterminate or discordant scans triggered escalation rather than repeated “trying” or premature tube use.

Trial design must also reflect real ICU/ED case mix. Many existing studies include few true misplacements and a high proportion of technically easy scans; therefore, enriched cohorts that include difficult-window patients, including those with high BMI, postoperative anatomy, subcutaneous emphysema, and those receiving prone ventilation, are essential for estimating safety boundaries and workflow performance. Scalability is a second priority. Task-shifting models, including nurse-performed protocols, appear feasible in early studies; however, they remain safe only when documentation, image archiving, and audit processes are incorporated into unit governance. Newer prospective ICU cohorts may serve as pragmatic platforms for testing pathway-level outcomes because they can capture real delays, repeat checks after repositioning, and adverse events that diagnostic-accuracy studies are often underpowered to detect.

Limitations

Several limitations should be acknowledged. First, true malpositions are uncommon in many adult datasets, which limits precise estimation of false reassurance risk. Second, operator training, required windows, flush techniques, and interpretation standards vary across studies. Third, several cohorts likely overrepresent technically easier examinations and underrepresent difficult-window patients, including those with obesity, postoperative anatomy, subcutaneous emphysema, or prone ventilation. Accordingly, the proposed pathway should be interpreted as a pragmatic framework to support safer implementation rather than a validated universal replacement for radiographic confirmation in all settings.

Conclusions

In adult ICU and ED practice, ultrasonography provides an immediately available bedside option that can speed confirmation of gastric tube placement when the scan is clearly positive. However, the evidence base still has an important gap: true misplacements are uncommon in most studies, and indeterminate scans are frequent in difficult-window patients. Therefore, ultrasound cannot be considered a universal replacement for radiography. The most defensible approach is ultrasound-first and safety-anchored strategy. Tube use may be considered when two-window findings are clearly positive, whereas escalation to CXR or an institutional reference standard is warranted when results are inconclusive, discordant, or obtained under high-risk circumstances. This pathway maintains the pace that ICU/ED care demands and preserves the safety margin required for tube verification.

Footnotes

Acknowledgments

The authors used Grammarly Premium and ChatGPT (OpenAI) to assist with language refinement during manuscript preparation. Google Gemini was used to assist with the visual rendering of based on author-provided descriptions. All content selection, scientific interpretation, figure labels, and final approval were performed by the authors, who take full responsibility for the accuracy and integrity of the manuscript and figure.

Author contributions

Gang Yang: Conceptualization, Methodology, Investigation, Writing—original draft.

Chenying Qu: Methodology, Data curation, Investigation, Writing—original draft.

Mengqi Cai: Literature search, Data curation, Visualization, Writing—review & editing.

Jialu Liang: Literature search, Data curation, Writing—review & editing.

Yaling Jin: Validation, Visualization, Writing—review & editing.

Yangtian Ye: Supervision, Methodology, Writing—review & editing.

Weiting Chen: Conceptualization, Supervision, Project administration, Writing—review & editing.

Xia Zhang: Supervision, Project administration, Writing—review & editing.

All authors read and approved the final manuscript and agree to be accountable for all aspects of the work.

Data availability statement

Data are contained within the article.

Declaration of conflicting interests

The authors declare no conflicts of interest.

Funding

This research received no external funding.

Institutional review board statement

Not applicable.

Informed consent statement

Not applicable.

ORCID iDs

Weiting Chen

Xia Zhang

References

National Institute for Health and Care Excellence (NICE). Nutrition support for adults: oral nutrition support, enteral tube feeding and parenteral nutrition (Clinical guideline CG32). London: NICE, 2006 (updated 4 August 2017).

Branch. HSI: placement of nasogastric tubes: investigation report. London: HSIB, 2021.

Agency. NPS: reducing the harm caused by misplaced nasogastric feeding tubes in adults, children and infants. London: NPSA, 2011.

Zatelli

Vezzali

4-Point ultrasonography to confirm the correct position of the nasogastric tube in 114 critically ill patients. J Ultrasound 2017; 20: 53–58.

Ong

Ahmad Zahedi

Zambri

, et al. Accuracy of colour Doppler ultrasound for nasogastric tube placement in emergency department: a prospective observational study. Emerg Med Australas 2025; 37: e70020.

Brun

Chenaitia

Lablanche

, et al. 2-point ultrasonography to confirm correct position of the gastric tube in prehospital setting. Mil Med 2014; 179: 959–963.

Baethge

Goldbeck-Wood

Mertens

SANRA-a scale for the quality assessment of narrative review articles. Res Integr Peer Rev 2019; 4: 5.

Muslu

Demircioglu

Gözdemir

, et al. Comparison of neck ultrasonography with a pH meter to confirm correct position of nasogastric tube. Clin Invest Med 2016; 39: 27520.

Kerforne

Chaillan

Geraud

, et al. Ultrasound diagnosis of nasogastric tube misplacement into the trachea during bypass surgery. Br J Anaesth 2013; 111: 1032–1033.

10.

Tollinche

Salamanca-Cardona

, et al. The incidence of intraoperative gastric tube malposition verified by Point-of-Care ultrasound. Minerva Anestesiol 2019; 85: 1168–1174.

11.

Heidarzadi

Jalali

Hemmatpoor

, et al. The comparison of capnography and epigastric auscultation to assess the accuracy of nasogastric tube placement in intensive care unit patients. BMC Gastroenterol 2020; 20: 196.

12.

Hernández-Socorro

Marin

Ruiz-Santana

, et al. Bedside sonographic-guided versus blind nasoenteric feeding tube placement in critically ill patients. Crit Care Med 1996; 24: 1690–1694.

13.

Kim

Jeong

, et al. The effectiveness of ultrasonography in verifying the placement of a nasogastric tube in patients with low consciousness at an emergency center. Scand J Trauma Resusc Emerg Med 2012; 20: 38.

14.

Gok

Kilicaslan

Yosunkaya

Ultrasound-guided nasogastric feeding tube placement in critical care patients. Nutr Clin Pract 2015; 30: 257–260.

15.

Lin

Gifford

Lan

, et al. Diagnostic accuracy of ultrasonography for detecting nasogastric tube (NGT) placement in adults: a systematic review and meta analysis. Int J Nurs Stud 2017; 71: 80–88.

16.

Tsolaki

Zakynthinos

Zygoulis

, et al. Ultrasonographic confirmation of nasogastric tube placement in the COVID-19 era. J Pers Med 2022; 12: 337.

17.

Mumoli

Vitale

Pagnamenta

, et al. Bedside abdominal ultrasound in evaluating nasogastric tube placement: a multicenter, prospective, cohort study. Chest 2021; 159: 2366–2372.

18.

Chenaitia

Brun

Querellou

; WINFOCUS (World Interactive Network Focused On Critical Ultrasound) Group Franceet al. Ultrasound to confirm gastric tube placement in prehospital management. Resuscitation 2012; 83: 447–451.

19.

Yaseen

Kumar

Bhoi

, et al. Point-of-care ultrasonography-assisted nasogastric tube placement in the emergency department: a randomized controlled trial. Eur J Emerg Med 2022; 29: 431–436.

20.

Tsujimoto

Kataoka

Banno

, et al. Ultrasonography for confirmation of gastric tube placement. Cochrane Database Syst Rev 2024; 7: CD012083.

21.

McClave

Taylor

Martindale

; American Society for Parenteral and Enteral Nutritionet al. Guidelines for the provision and assessment of nutrition support therapy in the adult critically Ill Patient: Society of Critical Care Medicine (SCCM) and American Society for Parenteral and Enteral Nutrition (A.S.P.E.N.). JPEN J Parenter Enteral Nutr 2016; 40: 159–211.

22.

Qian

, et al. Rapid positioning of nasogastric tube by ultrasound in COVID-19 patients. Crit Care 2020; 24: 568.

23.

Acosta Pedemonte

Bagilet

Rocchetti

, et al. Color doppler ultrasound is a precise method to evaluate the position of the nasogastric tube in critical ill patients. Med Intensiva (Engl Ed) 2021; 45: e11–e14.

24.

Birdal Güllüpınar

Karagöz

Tandon

Nasogastric tube placement verification with ultrasound by emergency nurses. Annals of Clinical and Analytical Medicine 2022; 13: 807–811.

25.

Robles-González

Arrogante

Sánchez Giralt

, et al. Verification of nasogastric tube positioning using ultrasound by an intensive care nurse: a pilot study. Healthcare (Basel) 2024; 12: 1618.

26.

Ferraboli

Beghetto

MG.

Bedside ultrasonography for the confirmation of nasogastric tube placement: agreement between nurse and physician. Rev Gaucha Enferm 2022; 43: e20220211.

27.

Mak

Tam

Ultrasonography for nasogastric tube placement verification: an additional reference. Br J Community Nurs 2020; 25: 328–334.

28.

Wong

Chan

Wong

, et al. Using color flow detection of air insufflation to improve accuracy in verifying nasogastric tube position. Am J Emerg Med 2017; 35: 333–336.

29.

Vigneau

Baudel

Guidet

, et al. Sonography as an alternative to radiography for nasogastric feeding tube location. Intensive Care Med 2005; 31: 1570–1572.

30.

Ragunathan

Teo

Mohamad Yusof

, et al. Performance of point-of-care ultrasonography in confirming feeding tube placement in mechanically ventilated patients. Diagnostics (Basel) 2023; 13: 2689.