Diagnostic accuracy of point-of-care ultrasound for confirming endotracheal tube placement in pediatric acute care settings: a systematic review and meta-analysis

Abstract

Objective

To evaluate the diagnostic accuracy of point-of-care ultrasound (POCUS) for confirming endotracheal tube (ETT) placement in pediatric patients within emergency and critical care settings, compared with standard methods such as chest radiography and capnography.

Methods

A systematic search of PubMed, Embase, Scopus, Web of Science, and the Cochrane Library was conducted from inception to May 2025. Prospective studies assessing POCUS for confirmation of endotracheal placement in pediatric patients (birth to 18 years) within acute care settings (including emergency departments, intensive care units, and operating rooms) were included. Data on diagnostic accuracy (Sensitivity, Specificity, Summary receiver operating characteristic (SROC) curve, and Diagnostic odds ratio (DOR)), POCUS success rate, Confirmation of ETT placement, Time to adequate view, Reintubation rate, as well as baseline and summary characteristics of the studies were extracted. A bivariate random-effects model was used to pool diagnostic accuracy estimates, and heterogeneity and publication bias were evaluated. Sensitivity analyses were performed using the leave-one-out method to assess the robustness of the findings. The Quality Assessment of Diagnostic Accuracy Studies-2 tool assessed bias risk.

Results

Ten studies involving 697 pediatric patients met the inclusion criteria. The pooled sensitivity of POCUS for confirming endotracheal placement was 0.95 (95% CI: 0.88–0.98; I² = 84.6%), and specificity was 0.70 (95% CI: 0.34–0.92; I² = 84.5%). The pooled DOR was 37.14 (95% CI: 6.17–223.47), and the AUC was 0.95 (95% CI: 0.91–0.99). Time to adequate ETT visualization was 45.8 s, the pooled procedural success rate was 97% (95% CI: 80–100%), and the reintubation rate was 2% (95% CI: 1–4%).

Conclusion

POCUS is a highly sensitive, rapid, radiation-free, and feasible adjunct method for confirming endotracheal placement in critically ill pediatric patients. This integration could reduce the risk of complications associated with ETT misplacement, thereby improving patient outcomes. This meta-analysis finds that POCUS is a highly sensitive adjunct for confirming pediatric ETT placement. However, the pooled specificity was only moderate, and significant heterogeneity across studies in populations, settings, and techniques was a major finding. This variability currently limits its utility as a standalone test. Our results underscore the need for standardized protocols and operator training to improve specificity and consistency before POCUS can be more broadly relied upon for this critical task.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12873-025-01455-x.

Introduction

Proper placement of the endotracheal tube (ETT) is critical for effective airway management in pediatric patients. Misplacement rates during emergencies in neonates and children are significant and range from 15% to 30% [1]. Incorrect placement can lead to serious complications, such as esophageal intubation, which may cause gastric insufflation and aspiration, or mainstem intubation, which can result in unilateral ventilation, atelectasis, and persistent air leak syndrome [2]. It is important to acknowledge that findings from adult populations are frequently not transferable to pediatric patients due to inherent anatomical, physiological, and procedural distinctions. The unique anatomy of the pediatric airway further emphasizes the need for precise tube depth placement. Key differences include a more cephalad larynx, a shorter trachea, and a narrower cricoid ring [3].

End-tidal CO₂ detection is the most accurate method for confirming ET tube placement; however, it depends mainly on adequate cardiopulmonary perfusion, which means its sensitivity decreases in low perfusion states such as cardiac arrest [4–6]. It has been demonstrated that chest radiographs post-intubation remain informative in pediatric/neonatal critical care despite increasing on-scene time [8]. Thus, a fast, non-invasive, and perfusion-independent tool is needed, especially in critical pediatric emergencies. A comprehensive systematic review encompassing 33 studies and 1,934 airway ultrasound assessments indicated that ultrasound can reliably verify endotracheal tube placement in 90.6–100% of pediatric cases [7].

Point-of-care ultrasound (POCUS) has emerged as a promising modality for confirming endotracheal placement. It provides real-time visualization, requires minimal setup, and avoids radiation exposure [7, 9–11].

Our study aims to build on existing evidence to evaluate the utility of ET tube placement POCUS by comparing its diagnostic accuracy to that of traditional methods (capnography, chest radiograph, auscultation, direct visualization, esophageal detection device, combination of methods). Therefore, the objective of this systematic review and meta-analysis was to determine the diagnostic accuracy of POCUS for confirming ETT placement in pediatric patients. Our PICO question was: In pediatric patients (birth to 18 years) undergoing endotracheal intubation in acute care settings (P), what is the diagnostic accuracy of point-of-care ultrasound (I) compared to standard confirmation methods like capnography and chest radiography (C) for detecting ETT misplacement (O).

Materials and methods

Protocol registration

This systematic review and meta-analysis of ten prospective studies directly assesses POCUS’s diagnostic accuracy for confirmation of endotracheal placement in pediatric emergency or intensive care units acute care settings. The study followed the Cochrane Handbook for Systematic Reviews of Diagnostic Test Accuracy [12] and reported the results as specified by the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2020 statement and the PRISMA for Diagnostic Test Accuracy (PRISMA-DTA) extension [13]. The study has been registered with PROSPERO under the identification number (CRD420251082432).

Data sources and search strategy

A comprehensive search of PubMed, Embase, Scopus, Web of Science, and the Cochrane Library was conducted from inception to May 2025, October 2025 to identify relevant studies. An initial search was completed in May 2025, with an updated search performed prior to submission to ensure currency. The search strategy integrated Medical Subject Headings (MeSH) and free-text keywords related to “endotracheal intubation”, “ultrasonography”, acute care settings (like “emergency” and “ICU”), and diagnostic accuracy, combined with Boolean operators. Detailed search strategies for each database are presented in Supplementary Table 1. Finally, additional references were identified through manual citation searching.

Inclusion criteria

Studies were included based on the following predefined PICOS inclusion criteria: population (P): pediatric patients (birth to 18 years of age) who underwent endotracheal intubation in an acute care setting, including the emergency department (ED), pediatric intensive care unit (PICU), neonatal intensive care unit (NICU), or operating room (OR); intervention (I): Use of ultrasonography for confirmation of ETT placement. Comparator (C): Any accepted reference standard for tube verification, such as capnography, or direct visualization; Outcome (O): The primary outcome was the diagnostic accuracy of POCUS in detecting ETT misplacement. The target condition was defined as any incorrect ETT placement, including esophageal intubation or incorrect endotracheal depth (e.g., mainstem bronchus intubation), as confirmed by a reference standard. We extracted data for constructing 2 × 2 contingency tables (true positive, false positive, false negative, true negative) for this primary outcome. Endotracheal intubation, esophageal intubation, sensitivity, specificity, Area Under Curve (AUC), true positive, true negative, false positive, false negative, diagnostic odds ratio, predictive value (positive, negative), likelihood ratio (positive, negative), Secondary outcomes included time to ETT confirmation by POCUS, time to ETT confirmation by reference standard, missed esophageal intubation rate, reintubation due to misplacement, POCUS-related complications, undetected esophageal intubation by POCUS, and time to adequate view.

Exclusion criteria

We excluded case reports, cadaveric or animal studies, conference abstracts lacking full text, non-English publications, and studies involving neonatal studies (patients under 28 days) and intraoperative studies due to significant differences in airway anatomy, intubation challenges, and the controlled environment in anesthesiology, limiting their relevance and applicability to acute care settings. While we initially planned to exclude neonatal and intraoperative studies, we revised our protocol to include them to provide a more comprehensive overview of POCUS application across all pediatric acute care contexts, acknowledging that this would introduce significant heterogeneity that requires careful consideration in the analysis and discussion.

Screening and data management

After deduplication in a citation manager, two reviewers independently screened titles and abstracts in Rayyan [14]. Records deemed “include” or “unclear” by either reviewer proceeded to full-text assessment. Two reviewers independently assessed full texts against eligibility criteria; reasons for exclusion at full text were recorded and presented in a PRISMA-DAT 2020 flow diagram. Disagreements were resolved by consensus or arbitration by a third senior investigator.

Data extraction

Data extraction was performed independently by two reviewers using a standardized data collection form, with cross-verification by a second reviewer to ensure accuracy. Extracted data included four parts as follows:

1. Study characteristics (country, study design, setting (ER/ICU), sample size, period of recruitment, ultrasound technique, operator type, probe type, timing of US, type of reference standard, main inclusion criteria, primary endpoints, and the conclusion of the study).

2. Baseline characteristics, including age, sex, BMI, indication for intubation, medical history, admission timing (daytime/night), intubation difficulty (Cormack and Lehane grade 3 or 4), and intubation time.

3. Outcomes: as defined above.

4. Diagnostic accuracy data, including the raw numbers for 2 × 2 contingency tables (true positives, false positives, false negatives, and true negatives), which were extracted or calculated to allow for pooling of sensitivity and specificity. The reference standard used to define the final diagnosis in each study was also recorded. This data is presented in Supplementary Table 3.

Risk of bias assessment

The methodological quality of included studies was evaluated using the Quality Assessment of Diagnostic Accuracy Studies-2 (QUADAS-2) tool. This tool assesses the risk of bias in four domains: patient selection, index test, reference standard, and flow and timing, as well as the applicability concerns of these domains to the review question [15]. Two reviewers independently performed the assessments, and discrepancies were resolved through consensus discussion.

Statistical analysis

The statistical analysis for this meta-analysis was conducted using R software (version 4.3.0) with the “meta” and “metafor” packages. Diagnostic accuracy measures, including sensitivity and specificity, were pooled using a bivariate random-effects model to account for between-study heterogeneity and the intrinsic correlation between sensitivity and specificity. SROC curves were generated to evaluate the overall diagnostic performance of POCUS for ETT confirmation, with the area under the curve (AUC) serving as a measure of discriminative ability.

The proportions and totals were pooled as odds ratios (OR) for dichotomous variables, such as the incidence of esophageal intubation. For continuous outcomes, such as time to ETT confirmation, mean differences (MD) with 95% confidence intervals (CI) were calculated using inverse-variance random-effects models. Heterogeneity was assessed using the I² statistic and Cochran’s Q test, with I² > 50% or a p-value < 0.10 indicating substantial heterogeneity.

Publication bias was evaluated using funnel plots and Egger’s regression test for asymmetry, with p < 0.05 suggesting potential bias. Sensitivity analyses were conducted by sequentially excluding individual studies to assess the robustness of pooled estimates. All statistical tests were two-tailed, with p < 0.05 considered statistically significant.

Results

Search results and study selection

The initial database search yielded 3,824 records. After removing duplicates, 3,277 unique studies were screened based on titles and abstracts. Forty-seven full-text articles were assessed for eligibility, of which ten studies met the inclusion criteria and were incorporated into the qualitative and quantitative synthesis (Fig. 1).

Fig. 1.

PRISMA flowchart of screening and study selection

Study characteristics

Table 1 includes ten prospective studies (10,16–24) encompassing 697 pediatric patients. Of these, 358 participants underwent point-of-care ultrasound (POCUS) evaluation, and 339 underwent conventional methods of endotracheal tube (ETT) confirmation. In these diagnostic accuracy studies, all 697 patients underwent ETT placement and were assessed with both POCUS (the index test) and a reference standard (e.g., capnography, chest radiography) to determine tube position. The studies were conducted between 2005 and 2024 across various countries, including the United States, India, and France. Most studies were set in pediatric intensive care units (PICUs), neonatal intensive care units (NICUs), or emergency departments (EDs). The settings were diverse, including pediatric intensive care units (PICUs), neonatal intensive care units (NICUs), emergency departments (EDs), and operating rooms (ORs).

Table 1.

Summary of included studies

Study ID	Country	Study design	Sample size	Main inclusion criteria	Exclusion criteria	Setting (ER/PICU/NICU)	Period of recruitment	Operator type	Operator Training/Experience for US	Ultrasound technique	Probe/Transducer Type	Probe/Transducer Frequency (MHz)	Specific POCUS Signs	Timing of US	Type of Reference Standard (Gold Standard)	Capnography used (yes/no)	Chest ultrasound used (yes/no)
Chandnani 2020	USA	Prospective validation study	92	Age 0.75-212mo, cuffed ETT in PICU/PCICU	Cervical collar, neck deformities, uncuffed ETT	PICU & PCICU	Mar 2016-Oct 2017	Pediatric intensivists	Varied experience (no formal US certification)	Combined: (1) Sternal notch cuff visualization (2) Bilateral lung sliding	Linear	13 MHZ	Saline-filled cuff position, pleural sliding	Within 30 min post-CXR	CXR	Yes	Yes
Datta 2024	India	Prospective cross-sectional	62	Age 2mo-17y, cuffed ETT in PICU	Difficult airway, moribund, airway anomalies, parental refusal	PICU	Dec 2021-Oct 2022	PICU residents	3-month training + 25 supervised scans	3 methods: (1) Suprasternal (2) Cricoid-cuff distance (3) Tracheal rings	Linear	13 − 6 MHz	Saline-filled cuff position, tracheal rings	Within 1 h post-intubation	CXR (T1-T3 vertebrae)	Yes	No
Galicinao 2007	USA	Prospective feasibility study	99 total (50 in Phase II)	Age 1d-17y requiring ETI in PICU/ED	Unstable patients, US gel allergy, age ≥ 18y	PICU & ED	Jan 2005-Jun 2006	Pediatric emergency physicians	1-year experience + ACEP course credentialing	Cricothyroid membrane view (transverse/longitudinal)	Linear & curvilinear	5–8 (LFCT), 10 (HFLT)	Comet tail sign, parallel lines	During/immediately post-intubation	CXR + CECD + clinical exam	Yes	No
Gautam 2024	India	Prospective observational	155	Children 3mo-12y requiring ETI in PER/PICU	Pre-intubated, tracheostomy, difficult airway, obesity, pneumothorax	PER + PICU	Jan-Dec 2021	Pediatric residents + intensivists	2-hour theory + 25 supervised scans	3-point US (suprasternal notch + bilateral anterior chest)	Linear	12 MHz	Bilaminar sign (neck), pleural sliding (lungs)	Immediately post-intubation	Chest radiograph (CXR)	No	Yes
Guerder 2021	France	Prospective diagnostic study	71	Critically ill children (0–18 yrs) requiring urgent intubation	Preterm infants, instability, thoracic trauma, pleural effusion	PICU	Dec 2016-Nov 2018	PICU physicians (seniors/residents)	1-hour workshop + prior basic POCUS experience	Pleural window only	Linear	9	Lung sliding sign	Immediately post-intubation	Chest radiography (CXR)	Yes	Yes
Sanjay K.G. et al. (2024)	India	Prospective Observational	40	Pediatric patients (5–14 yrs), ASA I–II	Age < 5 or > 14 yrs, difficult airway, CPR	PICU + Operation Theaters	Not specified	Anesthesiologists	Not specified	Transverse suprasternal notch placement	Linear	5–13 MHz	Tracheal: Single A-M interface + shadowing Esophageal: Double-tract sign	Post-intubation	Waveform capnography (gold standard)	Yes	No
Subramani et al. (2022)	India	Prospective observational	135	Age 1-60mo, intubated	Hemodynamic instability, airway anomalies	PICU	Oct 2016-Jun 2018	PICU MD	2-month radiology training	Suprasternal/supraclavicular	Microconvex	8	Bullet sign, ETT-aortic arch distance	Post-intubation (< 6 h pre-CXR)	CXR (PACS)	NR	Yes
Tessaro et al. (2015)	United States	Prospective feasibility study	42	Age 3 months – 18 years ASA class 1  and 2 Scheduled for surgery with ETT intubation	Developmental delay Difficult airway Congenital anomalies Nasogastric tube Non-English guardians	Operating room (ambulatory surgery)	Not specified (2013 IRB)	Pediatric emergency US fellow	Fellowship-trained + 10 prior airway US exams	T.R.U.S.T.: Suprasternal notch view Saline-inflated cuff visualization	Linear	5–10 MHz	Cuff visible (tracheal) Cuff absent (endobronchial)	During endobronchial intubation and tracheal repositioning	Fiberoptic bronchoscopy (tip-to-carina)	Likely (not stated)	No
Uya et al. 2020	USA	Prospective observational	f75	• Age 0–18 years • Elective cardiac catheterization • Cuffed ETT intubation	• Difficult airways • Uncuffed ETT • Non-English/Spanish speakers	Cardiac catheterization lab	Not specified	Pediatric anesthesiologist	Single investigator with > 1 year POCUS experience	Transverse scan at suprasternal notch with saline-inflated cuff	Linear transducer	13 − 6 MHz	Saline-filled cuff at suprasternal notch	Immediately post-intubation	Cine-fluoroscopy (CXR equivalent)	Yes	No
Wani et al. (2021)	Qatar	Prospective non-randomized trial	80 pediatric patients (age 1–78 months)	Children < 8 years requiring ETT intubation for surgery	Airway anomalies, tracheoesophageal fistula, preterm infants, lung disease	Operating Room (Sidra Medicine)	June 2020 – September 2020	3 anesthesiologists	Clinically trained in POCUS	Longitudinal sagittal neck scan with saline-filled cuff	Linear transducer (Sonosite Titan)	12 MHz	1. Double tract sign (ETT walls) 2. Cricoid/tracheal rings 3. Saline cuff	Immediately post-intubation	Anatomical landmarks (cricoid & tracheal rings)	Yes	No

Patient populations included critically ill children and those with complex airway anatomy, with age ranges generally spanning from 1 day to 18 years. The POCUS techniques varied, incorporating suprasternal, cricoid, pleural, or tracheal views, typically using linear or curvilinear transducers. Operator experience ranged from formally trained emergency physicians to clinicians with prior ultrasound familiarity. Reference standards included capnography, chest radiography, and direct visualization.

Baseline characteristics

The mean age across POCUS groups ranged from approximately 3.8 months to 80 months, while that of control groups ranged from 0.2 months to 72 months. The proportion of male participants ranged between 47% and 64.5% in the POCUS groups and 60% to 62% in the control groups. Reported indications for intubation included respiratory failure, airway obstruction, trauma, central nervous system depression, and cardiac arrest, though reporting was inconsistent. Limited data were available regarding comorbidities, anthropometric measures, and procedural details such as time of intubation or Cormack–Lehane grading. (Supplementary Table 2).

Risk of bias assessment

The assessment of bias was conducted using the QUADAS-2 tool. A total of two studies (20%) were found to have a low risk of bias across all assessed domains (Sanjay et al., 2024 [20]; Tessaro et al., 2015 [22]). Five studies (50%) received an unclear rating due to inadequate reporting in key areas such as patient selection, blinding of the index test, and timing of the assessment (Datta et al. 2024 [16]; Galicinao et al. 2007 [17]; Gautam et al. 2024 [18]; Subramani et al. 2022 [21]; Uya et al. 2020 [23]). Three studies (30%) were identified as high risk, primarily due to concerns within the index test or reference standard domains (Chandnani et al., 2020 [10]; Guerder et al., 2021 [19]; Wani et al., 2021 [24]) (Supplementary Figs. 1).

Regarding applicability concerns, most studies were considered low concern across all domains, indicating strong clinical relevance to the review question. Minor issues were noted for the index test in a few studies (Galicinao et al.2007 [17]; Gautam et al.2024 [18]; Uya et al. (2020) [23]). Only Guerder et al. 2021 [19] exhibited a high applicability concern in the index test domain. In summary, while the overall methodological quality was deemed acceptable, notable limitations included variances in study design, dependence on the operator, and issues with blinding procedures (Supplementary Figs. 2).

Outcomes

Diagnostic accuracy

All ten studies (10,16–24 patients) contributed to the analysis of diagnostic accuracy for POCUS in confirming ETT placement. The pooled sensitivity was 0.95 (95% CI: 0.88–0.98), while the pooled specificity was 0.70 (95% CI: 0.34–0.92) (Supplementary Fig. 2A–B). Considerable heterogeneity was observed for sensitivity (I² = 84.6%) and specificity (I² = 84.5%). SROC curve demonstrated an area under the curve (AUC) of 0.95 (95% CI: 0.91–0.99) (Fig. 2).

Fig. 2.

Diagnostic accuracy SROC curve

The pooled favorable likelihood ratio (+ LR) was 2.91 (95% CI: 1.53–5.55), and the negative likelihood ratio (− LR) was 0.14 (95% CI: 0.05–0.37) (Supplementary Figs. 3–4, respectively). The diagnostic odds ratio (DOR) was 37.14 (95% CI: 6.17–223.47), with substantial heterogeneity observed (I² = 80.9%) (Fig. 3).

Fig. 3.

Forest plot of Diagnostic Odds Ratio (DOR)

Feasibility and safety outcomes

Several studies reported on outcomes related to the feasibility of the POCUS procedure and the subsequent clinical course of the patient.

POCUS success rate

Seven studies (10,17–20,22,24), including 530 patients, reported the procedural success rate of POCUS-based confirmation. The pooled success rate was 97% (95% CI: 80%–100%) (Fig. 4). Heterogeneity was substantial (I² = 91.2%, τ² = 5.33, p < 0.0001). Sensitivity analyses demonstrated stable pooled estimates (94%–98%) without significant influence from individual studies (I² > 85% throughout) (Supplementary Fig. 5).

Fig. 4.

Forest plot of POCUS Success Rate

Proportion of successful ETT confirmation

Across ten studies (10,16–24), the pooled proportion of successful ETT confirmation was 0.98 (95% CI: 0.92–0.99) (Fig. 1B). Heterogeneity was considerable (I² = 85.7%, τ² = 3.24, p < 0.0001). Exclusion of Guerder et al. [19] notably reduced heterogeneity (I² = 53.7%) (Supplementary Fig. 6). Egger’s regression test indicated potential publication bias (p = 0.001) (Supplementary Fig. 7).

Time to adequate view

Three studies (10,17,19) provided data on the time required to achieve adequate sonographic visualization of ETT placement. The pooled mean was 45.8 s (95% CI: 1.02–90.58), with extreme heterogeneity (I² = 98.7%, τ² = 1545.36, p < 0.0001) (Supplementary Fig. 8A). Study-level means ranged from 17.1 s (95% CI: 15.91–18.29; Galicinao et al. [17]) to 92 s (95% CI: 76.82–107.18; Chandnani et al. [10]), with Guerder et al. [19] reporting an intermediate duration of 30 s (95% CI: 27.21–32.79). Sensitivity analysis excluding Chandnani et al. [10] reduced the pooled mean to 23.5 s (95% CI: 10.84–36.13) but did not eliminate heterogeneity (I² = 98.6%) (Supplementary Fig. 9).

Reintubation rate

Eight studies (n = 605) (10,17–20,22–24) reported reintubation rates following initial confirmation of ETT placement. The pooled reintubation rate was 0.02 (95% CI: 0.01–0.04), indicating a low incidence of tube malposition or secondary procedural failure (Supplementary Fig. 8B).

Discussion

This systematic review and meta-analysis synthesize evidence on the diagnostic accuracy of POCUS for ETT placement across a broad pediatric population, from neonates to adolescents, in various acute care settings. A primary finding of our review is the substantial heterogeneity (I² > 80%) across studies, which is largely attributable to our inclusive approach. By incorporating studies involving neonates and those conducted in operating rooms, we captured a wide spectrum of clinical practice. However, this also introduced variability stemming from significant anatomical and physiological differences between neonates and older children, as well as procedural differences between emergency and controlled settings. For instance, the neonatal airway is characterized by a more cephalad larynx and shorter trachea, which can alter sonographic landmarks and interpretation [28, 34]. This inherent heterogeneity is a crucial finding in itself, underscoring that a single set of diagnostic accuracy metrics may not apply uniformly across all pediatric subgroups. Therefore, the results must be interpreted with careful consideration of the specific patient population and clinical context.

Our review underscores the importance of point-of-care ultrasound (POCUS) as a vital instrument in pediatric emergency and critical care settings. The findings indicate a high sensitivity and moderate specificity for confirming endotracheal tube (ETT) placement. POCUS is an effective adjunct to conventional confirmation methods due to its rapid and non-invasive nature, demonstrating a pooled sensitivity of 95% and specificity of 70% (AUC = 0.95). It is important to interpret these results specifically within the context of pediatric airway management, rather than generalizing them to all ultrasound applications, especially in resource-limited or high-acuity environments where capnography or radiography may be delayed or unavailable.

Our results are consistent with prior meta-analyses in neonatal and adult populations, highlighting POCUS’s utility for airway confirmation [25]. Yang et al. reported a pooled sensitivity and specificity of 93% and 75% for lung ultrasound in confirming intubation [26]. Similarly, studies in neonates have demonstrated high success when using tracheal or lung sliding assessment [27]. It is essential to recognize that utilising neonatal data for older pediatric populations presents challenges and potential inaccuracies, owing to notable anatomical and physiological differences. For instance, neonates have shorter necks, tracheas, and more cylindrical larynxes, significantly affecting ultrasound interpretation [28, 34]. These variations underscore the importance of validating findings specifically for pediatric patients, rather than depending on neonatal or adult data. By prioritizing this tailored approach, we can enhance our young patients’ quality of care and outcomes.

The observed moderate specificity (70%) highlights a key limitation in using POCUS for ETT confirmation. While it reliably detects correct tube placement, its ability to exclude incorrect placement as esophageal or mainstem intubation remains limited. False-positive interpretations may arise from technical factors, including restricted acoustic windows, reverberation artefacts mimicking tracheal rings or lung sliding, or inadequate esophagus visualisation. Variability in probe type (linear vs. curvilinear), selected view (suprasternal, tracheal, or pleural), contributes to these challenges [29, 30]. Accordingly, POCUS should serve as a complementary tool rather than a replacement for capnography or direct visualization when confirmation must be definitive [35]. Furthermore, it is essential to recognize that POCUS and chest radiography (CXR) provide different, complementary information. POCUS offers a rapid, real-time assessment of tube location (tracheal vs. esophageal) and dynamic confirmation of bilateral ventilation (via lung sliding), while CXR provides a static, anatomical measurement of tube depth relative to the carina, which POCUS cannot determine.

Several evidence-based strategies emerge to promote the specificity of POCUS. First, A protocolized and methodical technique that utilizes tracheal and thoracic ultrasound can verify endotracheal intubation placement [36]. Second, implement organized training. Chenkin et al. indicated that following a short online tutorial and two practice attempts, emergency physicians reached a sensitivity of 98.3% and a specificity of 100% in accurately identifying correct tube placement [37]. Third, implementing simulation-based training models provides an ethical and economical solution for training healthcare professionals in ultrasound confirmation of ETT placement [38]. Finally, integrating POCUS findings with other conventional methods minimizes false positives and ensures higher specificity [39, 40].

The pooled diagnostic odds ratio of 37.14, combined with a high sensitivity, suggests that the test’s overall performance is robust. However, the significant heterogeneity observed across studies (I² > 80%), attributable to variations in operator training (including experience and skill level), reference standards (such as different criteria for diagnosing airway obstruction), and scanning protocols (like the use of different ultrasound machines or settings), necessitates a careful interpretation of the findings [30].

Point-of-Care Ultrasound (POCUS) showed impressive procedural success (97%) and confirmation success (98%). More importantly, it demonstrated a low reintubation rate of just 2%, indicating its reliability in managing pediatric airways. This evidence supports its practicality and safety. Beyond diagnostic accuracy, our analysis of secondary outcomes suggests that incorporating POCUS into the airway confirmation workflow is highly feasible. The pooled procedural success rate for obtaining adequate sonographic views was 97%, and the time to visualization was rapid, often under a minute. It is important to note that these metrics reflect the feasibility of performing the test, not its diagnostic quality. Similarly, the low pooled reintubation rate (2%) is a multifactorial outcome reflecting the entire airway management episode, not solely the performance of POCUS. However, it suggests that the use of POCUS does not appear to be associated with an increase in subsequent airway-related adverse events. Additionally, POCUS provides rapid confirmation, typically within one minute, and even quicker at 25 s when outlier confirmation times (Chandnani et al.) [10] are excluded. This efficiency highlights its utility in time-sensitive scenarios such as cardiac arrest or respiratory failure [31–33].

A key source of heterogeneity in our analysis stems from the varied definitions of “correct placement” and the different capabilities of the POCUS techniques used to assess it. The primary diagnostic challenge in ETT placement involves two distinct questions: (1) Is the tube in the trachea (vs. the esophagus)? and (2) If in the trachea, is it at the correct depth (i.e., not in a mainstem bronchus)? Tracheal ultrasound, which visualizes the tube or its artifacts in the neck, is primarily used to answer the first question. In contrast, pleural ultrasound, which assesses for bilateral lung sliding, is used to address the second. Our meta-analysis pooled studies using tracheal, pleural, or combined approaches, thereby conflating these two diagnostic goals. This methodological amalgamation contributes to the wide confidence intervals and high heterogeneity, particularly for specificity. Future research should stratify analyses based on the specific type of misplacement being investigated and the corresponding ultrasound technique employed.

Strengths and weaknesses of different POCUS techniques

The high heterogeneity in our findings is a direct reflection of the variety of POCUS techniques employed. Presenting POCUS as a single entity is a simplification; in practice, different sonographic approaches target different aspects of ETT placement as follow:

1. is recognized for its speed and accuracy, delivering confirmation in only a few seconds and making it especially useful in emergency or urgent settings. However, it can be less effective in patients with neck edema, high body mass index, or unusual anatomy, and artifacts from adjacent air structures sometimes reduce clarity. Operator skill is also a critical factor influencing results [35, 41].​.

2. focuses on the presence or absence of bilateral lung sliding to ensure ETT placement and rapidly identify issues like one-lung or esophageal intubation. This approach enhances patient safety by enabling early detection of complications such as pneumothorax. Nevertheless, interpretation can be complicated in lung disease states (e.g., ARDS or pleural adhesions) and may take slightly longer to yield results compared to transtracheal scanning. Novice users, particularly under time pressure, may find it challenging to apply this method reliably [41, 42].​

3. leverages both airway and lung imaging strategies, providing higher diagnostic sensitivity and specificity reducing the likelihood of missed or incorrect tube placements. However, these added views come at the cost of longer confirmation times and increased need for operator coordination and experience. In emergency or high-acuity settings, this may be a limiting factor despite the increased diagnostic confidence [41, 43].

Limitations

The analysis reveals several methodological and practical drawbacks that could affect the reliability and generalizability of the aggregated findings. These results highlight the necessity for additional research. Notably, considerable heterogeneity was identified, attributed to differences in probe types, ultrasound views, operator skills, and reference standards. Small sample sizes and ambiguous blinding protocols also introduced potential verification biases in certain studies. In contrast, publication bias (Egger’s test p = 0.001) indicates a likelihood of overestimating the effectiveness of Point-of-Care Ultrasound (POCUS). The inconsistent documentation of patient characteristics and definitions of outcomes further limits the comparability of studies. Furthermore, the predominance of research conducted in academic settings may restrict the applicability of these findings in resource-constrained environments, and the insufficient capture of real-time clinical decision-making obstructs the evaluation of POCUS’s actual impact on patient outcomes.

A major limitation of our analysis is the pooling of studies that used different reference standards for ETT confirmation. The included studies employed a variety of standards, including capnography, chest radiography (CXR), fiberoptic bronchoscopy, or a combination of methods. Each standard has different strengths; for example, capnography is highly accurate for differentiating tracheal from esophageal placement but provides no information on tube depth, while CXR is the standard for assessing depth but is not real-time. By combining studies with these varied comparators, we introduced significant methodological heterogeneity and potentially biased the pooled accuracy estimates. The performance of POCUS for detecting esophageal intubation (compared to capnography) is a different diagnostic question than its performance for detecting mainstem intubation (compared to CXR). Unfortunately, the limited number of studies precluded a formal subgroup analysis based on the reference standard used. Future meta-analyses with more available data should stratify results accordingly.

Despite these limitations, this meta-analysis provides the most comprehensive synthesis on POCUS accuracy in pediatric airway confirmation in critical care settings.

Future scope

Standardizing Point-of-Care Ultrasound (POCUS) training and developing unified protocols could significantly improve diagnostic accuracy and consistency among operators in pediatric airway management. Incorporating airway ultrasound modules into the Pediatric Advanced Life Support (PALS) curriculum could encourage consistent and widespread adoption across various clinical settings. Future research should not only focus on diagnostic metrics but also evaluate patient-centered outcomes such as time to ventilation, rates of desaturation, the incidence of hypoxic injuries, and the need for unplanned re-intubation. Comparative studies examining tracheal versus pleural scanning methods across different pediatric age groups and investigations into inter-operator variability and learning curves are crucial for establishing evidence-based guidelines that can be applied universally.

Conclusion

Point-of-care ultrasound (POCUS) demonstrates high sensitivity and rapid performance for confirming endotracheal tube placement in pediatric emergency and critical care settings. However, its moderate specificity and methodological variability across scanning approaches (tracheal, pleural, and combined methods) limit its reliability as a standalone diagnostic test. When used as part of a structured multimodal confirmation pathway alongside capnography or radiography, POCUS can enhance the safety and timeliness of airway verification. Further prospective, age-stratified, multicenter studies with standardized imaging protocols, operator training, and uniform outcome definitions are warranted to refine its role in pediatric airway management.

Supplementary Information

Below is the link to the electronic supplementary material.

Abbreviations

AUC

Area Under the Curve

CI

Confidence Interval

DOR

Diagnostic Odds Ratio

ED

Emergency Department

ETT

Endotracheal Tube

EtCO₂

End–Tidal Carbon Dioxide

ICU

Intensive Care Unit

I²

I–squared (Measure of Heterogeneity)

LR

Likelihood Ratio

MD

Mean Difference

MeSH

Medical Subject Headings

OR

Odds Ratio

PICU

Pediatric Intensive Care Unit

POCUS

Point–of–Care Ultrasound

PRISMA

Preferred Reporting Items for Systematic Reviews and Meta–Analyses

PROSPERO

International Prospective Register of Systematic Reviews

QUADAS

2–Quality Assessment of Diagnostic Accuracy Studies–2

SROC

Summary Receiver Operating Characteristic

SD

Standard Deviation

+LR

Positive Likelihood Ratio

−LR

Negative Likelihood Ratio

τ²

Tau–squared (Between–study Variance)

Author contributions

M.A. (Mohammed Alsabri) conceived the idea, developed the study protocol, coordinated the project from start to submission, and served as the first and corresponding author. K.A. (Khaled Abouelmagd) and A.B.E. (Ahmed Bostamy Elsnhory) designed the research strategy and participated in database screening. M.T.H. (Mohammed Tarek Hasan) performed the statistical analysis. S.R. (Shree Rath) contributed to writing the discussion section. M.I.E. (Mohamed Ismaeil Elnady) wrote the results section. Y.C. (Yisha Cheng) wrote the introduction. E.A. (Eslam Abady) and A.M.T. (Abdelrahman M. Tawfik) participated in data extraction and manuscript writing. P.Y. (Patrick Yoo), A.H. (Aysha Hasan), M.N.S.(Mohamed Nasser ELshabrawi), and M.H. (Mohammed Hamzah) reviewed and edited the final manuscript. M.A. supervised the overall project. All authors reviewed, edited, and approved the final version of the manuscript.

Funding

We received no funding for this study.

Data availability

No datasets were generated or analysed during the current study.

Declarations

Ethics approval and consent to participate

Not applicable.

Consent for publication

Not applicable.

Competing interests

The authors declare no competing interests.