Gastric Ultrasound in Tube Fed Intubated Patients: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Gastric Ultrasound in Tube Fed Intubated Patients (NCT04612348), a registered phase not stated study. The primary outcome is Average Gastric Volume.

2. Clinical Question

3. Trial Design

NCT04612348 is titled Gastric Ultrasound in Tube Fed Intubated Patients. The official title describes the intended use of point-of-care gastric ultrasound to confirm whether the stomach is empty in intubated patients receiving feeds through a nasogastric or nasojejunal tube. The condition listed is critical illness, and the brief summary identifies critically ill children as the population of interest. Enrollment is 45. The registry status is COMPLETED; the recorded study start is 2021-02-26 and the primary completion date is 2026-03-17.

The intervention is listed as ultrasound, classified as a diagnostic test. The registry describes a nasojejunal tube-fed group and a nasogastric tube-fed group. The nasojejunal group is described as critically ill children receiving nutrition via a nasojejunal feeding tube; the nasogastric group is described as critically ill children receiving nutrition via a nasogastric feeding tube. The registry identifies these arms as not a like-for-like control comparison and does not state allocation. It therefore does not support treating the contrast as a randomized treatment comparison.

The primary outcome is median gastric volume measured by ultrasound, with an inter-quartile range as the specified dispersion measure and a timeframe of Baseline - 5 days. Risk of Aspiration is listed as a secondary outcome. The record lists two outcome measures and zero analyses. Numerical outcome results, analysis populations, participant flow, and reasons for any exclusions are not reported in the registry record.

The stated study rationale is to examine whether nasojejunal feeding is associated with minimal to no gastric content, with the intended possibility of reducing the time feeds are held before procedures or whether they need to be held. The summary also mentions potential avoidance of x-ray exposure to confirm tube placement. These are motivations described in the registry, not findings established by posted results. The registry record does not report a detailed protocol, a sample-size justification, or a statistical analysis plan.

4. Participant Flow and Accounting

The registry reports how participants moved through each stage of the study. All counts below are exactly as posted; missing counts are not inferred from other stages.

Overall Study

5. Baseline Characteristics

The table reproduces the baseline characteristics posted in the registry, which describe the participants analysed at baseline and help show whether the randomized groups were comparable.

6. Primary Endpoint

The registry lists the primary outcome as Average Gastric Volume, measured over Baseline - 5 days.

The primary endpoint measures the volume of gastric contents detected by ultrasound, expressed in mL/kg. The registry specifies that the outcome is summarized by the median and inter-quartile range. A median describes the central value after observations are ordered, while the inter-quartile range describes the spread of the middle portion of those observations. These summaries can be useful when measurements are skewed or include unusually large values, because the median is less influenced by extreme observations than the arithmetic mean. This is a general statistical explanation, not a statement about the distribution in this study.

Gastric volume is relevant to the study question because the registry proposes using ultrasound to assess whether the stomach contains little or no gastric content during tube feeding. The stated timeframe is Baseline - 5 days. The record does not clarify the measurement schedule within that timeframe, whether measurements were repeated, how measurements were combined for each participant, or how ultrasound readings were standardized. Those details are not reported in the registry record.

The endpoint is a measurement of gastric contents, not a direct count of aspiration events. Risk of Aspiration is separately listed as a secondary outcome. Thus, even a difference in measured gastric volume would not by itself establish a difference in aspiration outcomes. The primary endpoint’s numerical values, inter-quartile ranges, and comparison between the feeding groups are not reported in the registry record. No direction or magnitude of an endpoint effect can therefore be described from the posted results.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The record’s primary outcome is a continuous measurement: gastric volume measured by ultrasound and expressed in mL/kg. The specified summary is the median with an inter-quartile range. As a general statistical concept, the median identifies the center of ordered observations, and the inter-quartile range describes the spread around that center. These summaries are often informative when a measurement is asymmetric or has influential extreme observations. The registry does not report the observed distribution, so it is not possible to assess whether this summary choice matched the data characteristics in this study.

What would a group comparison estimate?

A comparison of the feeding groups could describe how gastric-volume measurements differed between children receiving nasojejunal feeds and children receiving nasogastric feeds. An estimate of the difference, together with an uncertainty interval, would communicate both the observed contrast and its precision. The registry record does not post group-specific endpoint summaries, an estimated contrast, or an uncertainty interval. No direction or size of a group difference can be stated.

Because the outcome is summarized using medians, the analysis might use methods designed for distributions or ranks rather than assume that the measurements follow a normal distribution. That is a general methodological possibility, not a description of the analysis used. The registry does not report the test or model, assumptions, covariates, handling of repeated measurements, or method for calculating uncertainty. The record lists zero analyses, so it does not identify an analysis method for the outcome.

Why does the group structure matter?

The record describes feeding-route groups and says the arms are not a like-for-like control comparison. Allocation is not stated. In general, random assignment can help balance both measured and unmeasured baseline characteristics, while a nonrandomized group comparison can be affected by why a child received one feeding route rather than another. The registry does not report enough information to assess group comparability or to determine whether an adjusted analysis was planned or performed. Any contrast should therefore be interpreted as descriptive unless a suitable analysis and its assumptions are reported.

Gastric volume is the primary measurement, whereas Risk of Aspiration is named as a secondary outcome. In general, a surrogate or intermediate measurement does not automatically establish a corresponding change in a clinical event. The record does not report how aspiration risk was defined, whether aspiration events were observed or adjudicated, or how this secondary outcome was analyzed. Nor does it report a relationship between ultrasound measurements and aspiration outcomes.

How should uncertainty and significance be read?

A confidence interval is a general way to show the uncertainty around an estimated effect. Its width depends on features such as the amount and variability of data and the analysis method. A narrow interval generally indicates more precise estimation than a wide interval, though interpretation also depends on the clinical question and the values the interval includes. No confidence interval is reported for the primary or secondary outcomes, so precision cannot be evaluated.

A significance test assesses compatibility between observed data and a null hypothesis under a specified model. A p-value alone would not describe the magnitude or clinical importance of an effect. The registry does not post a p-value or a defined hypothesis test for either outcome. It also does not report whether interim analyses were planned or performed; that information is not reported in the registry record.

What does the planning note mean?

The registry’s planning note characterizes a sample-size illustration as being based on the observed effect, with a two-sided significance level of 0.05, equal allocation between the two arms, and a normal approximation. It describes the effect to detect as a stated fraction of the observed effect. Such an illustration is a planning exercise, not observed power and not evidence that the study was designed around a particular target effect. The numerical planning outputs and the observed effect needed to evaluate them are not reported in the registry record. The record also does not report the trial’s own sample-size justification.

In general, a sample-size calculation depends on assumptions about the target effect, variability, significance level, allocation, and analysis. If those assumptions do not reflect the study design or data, the resulting planning estimate may not be informative. No conclusion about adequacy of enrollment can be drawn from enrollment alone. The posted record does not give the statistical plan needed to connect the enrollment of 45 with a target precision or power.

10. Multiplicity, Missing Data and Analysis Populations

The registry lists two outcome measures: median gastric volume as the primary outcome and Risk of Aspiration as a secondary outcome. It lists zero analyses. The record does not report which hypotheses were formally tested, whether the secondary outcome was exploratory, or whether any adjustment for multiple comparisons was planned. When several outcomes or analyses are examined, the chance of at least one apparently notable finding can increase; multiplicity methods are used in some settings to manage that issue. This is a general statistical concern, not evidence that a particular adjustment was required or used in this study.

Missing-data handling is not reported in the registry record. The record does not state whether every enrolled participant contributed primary endpoint measurements, how unavailable or technically inadequate ultrasound readings were handled, or whether any imputation or sensitivity analysis was used. The safety group counts do not establish completeness of the primary outcome data. Without participant flow and endpoint availability, the amount and possible effect of missing measurements cannot be assessed.

The analysis population is also not reported in the registry record. It is not stated whether analyses included all enrolled children, only those with an evaluable ultrasound, or another defined group. Inclusion and exclusion criteria for the reported analyses, if any, are not provided. Baseline characteristics, covariate adjustment, subgroup analyses, and the handling of repeated measurements are not reported.

The record does not report a statistical analysis plan or explain whether analyses were prespecified. It also does not report interim analyses. These omissions limit assessment of how outcomes were selected, how missing observations may have influenced results, and whether the reported analysis would have followed a plan established before data were examined. Since no numerical outcome analyses are posted, there is no estimate to assess for robustness to these decisions.

11. Safety Results

The registry reports serious adverse events as affected participants divided by participants at risk.

Deaths

Other (non-serious) adverse events

Participants with at least one non-serious event at or above the registry's 5% reporting threshold.

The registry lists safety entries for a Post-pyloric group and a Gastric group. In the Post-pyloric group, 16 participants are listed as at risk for serious adverse events, with 0 affected and 0 deaths. In the Gastric group, 29 participants are listed as at risk, with 0 affected and 0 deaths. The record also lists the same group denominators for other adverse events, with 0 affected in each group. No serious adverse event terms are listed.

These entries mean that the registry reports no serious adverse events or deaths in the listed groups. They should be read as counts within the recorded safety categories, not as proof that no unrecorded events occurred or that the groups have equal safety. The record does not report the safety observation period, event definitions, completeness of follow-up, or details of safety monitoring. Zero reported events also do not establish that the ultrasound measurement or a feeding route changes aspiration risk.

The group counts are descriptive safety information. They do not provide an adjusted comparison, an uncertainty estimate, or a formal safety analysis. Because the registry describes the feeding arms as not a like-for-like control comparison and does not state allocation, a direct causal interpretation of between-group safety counts is not supported by the record.

12. What the Result Does, and Does Not, Mean

The registry describes a study of point-of-care gastric ultrasound among critically ill children receiving nasojejunal or nasogastric tube feeds. Its primary measurement is median gastric volume by ultrasound, and its secondary outcome is Risk of Aspiration. The study summary explains why the investigators were interested in gastric contents: they aimed to assess whether feeding through a nasojejunal tube leaves minimal to no gastric content and whether that information could help inform decisions about holding feeds around procedures. Those statements describe the study’s rationale and intended use.

The registry record does not report numerical results for gastric volume or aspiration. It therefore does not show whether gastric contents differed between the feeding groups, how precise any estimate might be, or whether aspiration outcomes differed. It also does not establish that ultrasound can safely replace another method of tube-placement confirmation or that feed interruptions can be reduced. The rationale mentions potential avoidance of x-ray exposure, but no result on x-ray use is reported.

The listed groups are not described as a randomized, like-for-like control comparison, and allocation is not stated. Even if outcome values were available, interpreting a group difference would require attention to possible differences between children receiving the two feeding routes. The record does not provide baseline characteristics or adjusted analyses to address that issue.

The completed status and enrollment of 45 indicate that the registry marks the study as completed and records that enrollment figure. They do not, on their own, demonstrate that the primary question was answered or indicate the strength of evidence. The posted safety entries report zero serious adverse events and zero deaths in both listed groups, but those counts do not answer the primary endpoint question. The most defensible reading is that the registry documents the study question, design elements, and limited safety counts, while its outcome findings and statistical analyses are not reported in the registry record.

13. Why This Trial Matters Statistically

This trial is statistically interesting because it links a diagnostic measurement to a clinical concern. Ultrasound-measured gastric volume is the primary endpoint, while aspiration risk is listed separately as a secondary outcome. That distinction matters: a measurement that characterizes gastric contents is not itself an aspiration event. Establishing how well one reflects the other would require outcome data and an analysis of their relationship, neither of which is reported in the registry record.

The two feeding groups also illustrate why study design is central to interpretation. The registry does not describe a like-for-like control comparison and does not state allocation. In general, group differences in an observational or otherwise nonrandomized comparison may reflect the reasons participants received different care, as well as any effect associated with the care itself. Baseline information and a clearly reported analysis would be needed to understand the extent of that concern. Those details are not reported.

The endpoint uses a median and inter-quartile range, which can be suitable descriptive summaries for measurements that are skewed. But choosing a summary does not replace reporting the actual values, uncertainty, and analysis method. Here, the outcome values and analyses are not posted, so readers cannot evaluate either the observed pattern or its precision. The registry also lists zero analyses, leaving no inferential result to interpret.

Finally, the registry’s rationale connects ultrasound to decisions about feed interruption and possible x-ray exposure. These are clinically meaningful motivations, but they require evidence beyond a rationale: measured outcomes, clear methods, and adequate reporting. The record makes the question visible while leaving the statistical evidence needed to judge the proposed uses unavailable. This is a useful reminder that a completed study record and a plausible clinical rationale are not substitutes for reported results.

14. Limitations

• The posted summary statistics are the only data these results rest on; patient-level data, full protocols and statistical analysis plans are not available.
• Recalculated results are simple, unadjusted calculations from posted summaries. They do not replace the sponsor's prespecified analysis.

The principal limitation for interpretation is that numerical results for the primary endpoint are not reported in the registry record. Although median gastric volume and inter-quartile range are specified, no group values, effect estimate, confidence interval, or p-value is posted. The secondary Risk of Aspiration outcome also has no reported values or analysis. Consequently, the direction, magnitude, and precision of findings cannot be assessed.

The registry describes the feeding groups as not a like-for-like control comparison, and allocation is not stated. Baseline characteristics and any methods to address differences between groups are not reported. This limits causal interpretation of any hypothetical contrast and prevents assessment of how similar the groups were before measurement. The registry also does not report participant flow, endpoint availability, missing-data procedures, or analysis populations.

Details of the ultrasound measurement process are not reported in the registry record. The record does not explain the measurement schedule within Baseline - 5 days, reading procedures, handling of repeated measures, or whether assessors were blinded to feeding route. These are not claims that procedures were absent; they are details that cannot be assessed from the record.

The record lists no analyses and does not report a statistical analysis plan, a trial-specific sample-size justification, multiplicity handling, or interim-analysis procedures. The planning note describes an illustration based on an observed effect, but the numerical outputs and observed effect are not reported. The safety entries report zero events in the listed groups, yet the observation period and completeness of safety reporting are not specified. These limitations restrict conclusions to the design description and the safety counts actually posted.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Gastric Ultrasound in Tube Fed Intubated Patients — NCT04612348.
• Registry record last updated 2026-07-21; status last verified 2026-06.
• Results first posted 2026-07-21.
• Data retrieved from ClinicalTrials.gov on 2026-11-09.
• Group sizes, means, event counts and sponsor-reported p-values are reproduced as posted. Effect estimates, confidence intervals and p-values not attributed to the sponsor are independently calculated from the posted summary statistics.

18. Record Summary

NCT04612348, Gastric Ultrasound in Tube Fed Intubated Patients, is marked COMPLETED. The registry records a start date of 2021-02-26, a primary completion date of 2026-03-17, and enrollment of 45. The study concerns critically ill children receiving nasojejunal or nasogastric tube feeds, with point-of-care gastric ultrasound listed as the diagnostic test.

The primary outcome is median gastric volume measured by ultrasound in mL/kg over Baseline - 5 days, with inter-quartile range specified as the dispersion measure. Risk of Aspiration is listed as a secondary outcome. The registry lists two outcome measures and zero analyses. Numerical outcome findings, effect estimates, and statistical analyses are not reported in the registry record.

Safety entries list 0 serious adverse events and 0 deaths in the Post-pyloric group of 16 and the Gastric group of 29. The registry describes the groups as not a like-for-like control comparison and does not state allocation. These details support a description of the recorded study, but not a conclusion about comparative gastric-volume or aspiration outcomes.