Tegarderm® Placement for Bag Mask Ventilation in the Bearded Patient: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Tegarderm® Placement for Bag Mask Ventilation in the Bearded Patient (NCT04274686), a randomized na study. The primary outcome is Percent Air Leakage During Bag-mask Ventilation.

2. Clinical Question

The primary measure was percentage air leakage, defined as the difference between inspired and expired tidal volumes expressed as a percentage of inspired tidal volume. The registry lists a timeframe of <5 minutes. Resistance and peak inspiratory pressure were also assessed as secondary outcomes. The clinical question is therefore about short-duration ventilation measurements under the two conditions, not about longer-term outcomes or clinical consequences.

3. Trial Design

The registry describes NCT04274686 as a randomized, unmasked crossover trial sponsored by the University of New Mexico. Its title is “Tegarderm® Placement for Bag Mask Ventilation in the Bearded Patient.” The listed condition is pulmonary ventilation. The recorded enrollment is 25, and the trial status is terminated. The record lists a start date of 2020-02-12 and a primary completion date of 2021-05-03.

In a crossover design, participants are assessed under more than one condition, allowing comparisons to use measurements from the same person. This can be useful when individual baseline characteristics affect the outcome, because each participant can serve as their own comparator. The registry identifies the study as crossover and lists both bag-mask ventilation with Tegaderm® and bag-mask ventilation without Tegaderm®. The sequence allocation, any washout procedure, and the details of how the order of conditions was implemented are not reported in the registry record.

The study was unmasked: the masking field is listed as none. The record does not describe any blinding of participants, clinicians, or outcome assessors. Arm summaries report 24 observations for each condition. The registry’s posted analysis uses a paired t-test, consistent with a comparison that accounts for within-participant pairing. The reason the study was terminated, the number of participants who completed each condition, and the handling of any incomplete measurements are not reported in the registry record.

The primary outcome was percentage air leakage during bag-mask ventilation, with resistance and peak inspiratory pressure listed as secondary outcomes. All three outcomes have a registry timeframe of <5 minutes. Further protocol details, including the planned statistical methods and original design assumptions, are not reported in the registry record.

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

Reasons for not completing this period:

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 Percent Air Leakage During Bag-mask Ventilation, measured over <5 minutes.

The primary endpoint, percent air leakage during bag-mask ventilation, measures the gap between the inspired and expired tidal volumes. The registry defines leakage as the difference between those volumes, expressed as a percentage of inspired tidal volume. A larger percentage represents a larger measured discrepancy between the volume delivered and the volume expired during the measurement period.

This endpoint is relevant to the study question because the intervention was intended to alter the seal between the mask and the lower face in bearded patients. Measuring air leakage provides a direct ventilation-related quantity for comparing the two conditions. The registry lists the timeframe as <5 minutes, so the outcome reflects a brief measurement window rather than performance across an extended period.

The reported outcome is a continuous measure summarized as a mean and standard deviation for each condition. A mean describes the group’s average measured leakage, while the standard deviation describes how spread out individual measurements are around that mean. Both matter: similar means can coexist with substantial variation between participants. The posted summaries do not give individual participant measurements, so they cannot show how consistently the two conditions differed within each person.

The registry does not report a threshold defining an acceptable or clinically important amount of leakage. It also does not report how a change in this measurement would relate to other clinical outcomes. The endpoint therefore supports interpretation of the measured ventilation comparison, but it should not be treated as a direct measure of patient benefit or as evidence about outcomes beyond the short measurement window.

7. Results Posted in the Registry

• Bag-mask Ventilation Without Tegaderm Placement: mean 45.70 versus 47.60 on control; difference -1.90 (95% CI -15.18 to 11.38), standardized effect d = -0.08; z-test p = 0.779.

8. Secondary Efficacy Endpoints

The registry also posts results for secondary outcomes. For each outcome below, the endpoint type, the test applied to the posted summary statistics, the result and its interpretation are given in turn. Secondary endpoints are usually not adjusted for multiple testing, so they support rather than confirm the primary finding.

Resistance

• Endpoint type: Continuous: a mean value per participant, compared as a difference in means.
• Test: Unadjusted two-sample z-test for the difference in means, using the posted standard deviations.
• Result:
  • Bag-mask Ventilation Without Tegaderm Placement: mean 7.73 versus 8.83 on control; difference -1.10 (95% CI -3.77 to 1.57), standardized effect d = -0.23; z-test p = 0.420.
• Interpretation:
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between Bag-mask Ventilation Without Tegaderm Placement and the control. The interval gives the range of effects that remain compatible with the data.

Peak Inspiratory Pressure

• Endpoint type: Continuous: a mean value per participant, compared as a difference in means.
• Test: Unadjusted two-sample z-test for the difference in means, using the posted standard deviations.
• Result:
  • Bag-mask Ventilation Without Tegaderm Placement: mean 19.40 versus 19.30 on control; difference 0.10 (95% CI -0.72 to 0.92), standardized effect d = 0.07; z-test p = 0.812.
• Interpretation:
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between Bag-mask Ventilation Without Tegaderm Placement and the control. The interval gives the range of effects that remain compatible with the data.

Across the two secondary outcomes, the posted summaries do not show a consistent pattern of clear separation between the ventilation conditions. Their registry-reported paired analyses also have confidence intervals that include zero and p-values that do not indicate strong evidence against a no-difference value. The same broad caution applies as for the primary outcome: these results do not establish that the conditions are identical, and the intervals leave room for differences in either direction.

The secondary findings are relevant as additional measurements of ventilation conditions, but they do not replace the primary endpoint. Their pattern is broadly compatible with the primary result in that none provides strong evidence of a difference in the posted analyses. That consistency should not be mistaken for independent confirmation, since the outcomes arise from the same trial and may be related to one another.

Multiplicity matters because testing several outcomes creates more opportunities for apparently notable results to occur by chance. The registry lists three outcome measures and reports analyses for the primary endpoint and the two secondary endpoints. Whether a formal adjustment or hierarchical testing plan was used is not reported in the registry record. Without that information, secondary p-values should be treated as unadjusted evidence and interpreted cautiously rather than as definitive standalone findings.

The record does not report prespecified criteria for judging which secondary outcomes were most important, how they were intended to support the primary question, or how results across outcomes were to be combined. In this context, the secondary outcomes can add descriptive context about measured ventilation, but they do not establish a broader clinical conclusion or resolve the uncertainty around the primary comparison.

Secondary outcomes registered for this trial, for reference (only those above were recalculated):

• Resistance
• Peak Inspiratory Pressure

9. Statistical Interpretation

10. Statistical Methods Explained

Three statistical ideas help place the results in context: how the study design affects comparisons, what the reported summaries and tests mean, and what the planning calculations can and cannot say. The registry identifies a randomized, unmasked crossover study and reports a paired t-test for the primary outcome. This design information matters because analyses that account for paired observations can use the fact that measurements from the same participant tend to be related.

What does a paired comparison use?

In a crossover study, each participant receives or is assessed under more than one condition. A paired analysis first considers the within-person difference between those conditions, then summarizes those differences across participants. This can account for stable person-to-person variation that affects both measurements. It also depends on having paired measurements and on the assumptions of the chosen method. The registry reports a paired t-test, but does not describe diagnostic checks, transformations, or alternative analyses.

For context, a separate unadjusted recalculation can be made from the posted arm means and standard deviations. That calculation treats the two sets of summaries as separate groups and does not incorporate the within-person covariance. In a crossover trial, that missing pairing information can affect the standard error and the confidence interval. The recalculated estimate is therefore a simple comparison of posted summaries, not a replacement for the registry’s paired analysis. The registry’s primary analysis is the paired t-test.

What do means and standard deviations describe?

The primary endpoint and both secondary outcomes are continuous measurements. A mean is the arithmetic average of the observations for a condition. A standard deviation describes dispersion: larger values indicate that measurements are more spread out around the mean. The standard deviation is not the uncertainty in the mean itself, and it is not a range containing every participant’s measurement. Individual-level distributions are not reported in the registry record.

The primary endpoint is a percentage of inspired tidal volume. The secondary outcomes are resistance, measured in cm H2O/L/s, and peak inspiratory pressure, measured in cm H2O. Their units differ, so their numerical scales should not be compared directly. The registry reports means and standard deviations for each condition and paired t-test results for the comparisons.

How should a confidence interval be read?

A confidence interval describes uncertainty around an estimated difference. In general, a 95% confidence interval is produced by a procedure that, under its assumptions, would cover the true parameter in 95% of repeated samples. It is not a statement that there is a 95% probability that this particular interval contains the true value. When an interval includes zero for a difference, the data remain compatible with zero difference as well as with nonzero differences covered by the interval.

The width of an interval conveys precision: narrower intervals indicate more precise estimates, while wider intervals indicate less precision. Precision depends on factors such as the amount of information in the data, variability, and the analysis design. In crossover data, within-person correlation can affect precision. The registry’s paired interval reflects the reported paired method; the recalculated interval does not use pairing.

What does the p-value address?

A p-value measures how unusual the observed data, or data more extreme, would be under a specified null hypothesis and the model assumptions. It is not the probability that the null hypothesis is true, and it does not measure the size or clinical importance of an effect. A larger p-value does not establish equality. Interpretation should consider the estimate and confidence interval together with the design and the endpoint’s relevance.

The primary registry analysis reports p = 0.667. The summary-statistic recalculation reports an unadjusted p-value of 0.779. These differ because the calculations are not based on the same treatment of the crossover data. The posted paired test is the trial’s own reported inferential result. The recalculated test is a basic, unadjusted illustration from group summaries and should not be treated as an independent confirmation of the paired result.

Why can over-dispersion matter?

Over-dispersion is a general concern when the variation in observed outcomes exceeds what a statistical model assumes. For continuous outcomes summarized with standard deviations, large variability relative to the mean contrast can make estimates less precise. A model that understates variability may produce intervals that are too narrow. Here, the registry reports standard deviations, but does not report a formal assessment of model fit or over-dispersion. The general concept explains why variability is relevant; it does not establish that a model problem occurred in this trial.

What can planning calculations tell us?

Sample-size calculations describe how many participants might be needed under specified assumptions to target a particular statistical power for a chosen effect. The displayed planning illustrations use the observed effect as a reference and consider smaller fractions of it. They are not the original trial’s design calculation. The original design assumptions, including any planned target effect or enrollment rationale, are not reported in the registry record.

The planning calculations use a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. The intended detectable effect is the stated fraction of the observed effect. Smaller target effects require more participants under these assumptions because smaller contrasts are harder to distinguish from random variation. These calculations are prospective planning illustrations, not evidence that the trial had a particular chance of detecting its result.

11. Confidence Intervals and Precision

Precision is reflected most directly by the width of a confidence interval. For the primary outcome, the registry’s paired analysis reports a mean difference of 1.9, with a 95% confidence interval from -7.0 to 10.7. The recalculated unadjusted summary-statistic comparison gives a mean difference of -1.9, with a 95% confidence interval from -15.18 to 11.38. Both intervals include zero, and they differ because one is the registry’s paired analysis while the other is a recalculation that does not account for paired observations.

The paired interval allows a range of values on either side of zero. It therefore does not identify a single precise direction or size of difference. The broad interval relative to the point estimate indicates that the primary result is uncertain: the data are compatible with no mean difference and with nonzero differences within the stated bounds. The interval should not be read as a range containing most individual participants’ outcomes; it concerns uncertainty in the estimated mean difference.

The interval also does not establish that the conditions are practically equivalent. Equivalence requires a defined margin representing the largest difference considered unimportant, together with an analysis designed to assess that margin. Such a margin and an equivalence analysis are not reported in the registry record. A conventional superiority test that does not reject a no-difference hypothesis cannot substitute for that evidence.

Because the study is a crossover trial, the paired analysis is particularly relevant to precision. Measurements from the same participant can be correlated, and that correlation contributes to the variability of within-person differences. The registry reports the paired result, but does not report the participant-level data or the correlation between measurements. The posted group means and standard deviations alone cannot recover that information.

Thus, the point estimate gives the direction and scale of the reported contrast, while the interval conveys substantial uncertainty around it. The registry does not report a clinical threshold for interpreting the interval’s bounds, so statistical precision cannot be translated into a judgment about clinical importance from the record alone.

12. Planning a Similar Trial: Sample Size

This is a planning illustration, not a re-evaluation of the original trial. It asks: if a new study wanted to detect a difference like the one observed, or a smaller one, how large would it need to be? It is deliberately not “observed power” of the finished trial, which is not a meaningful quantity.

The planning figures are participants per arm, not total events. They are calculated from the observed effect as a planning illustration, with a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. Each planning row considers detecting the stated fraction of the observed effect. The original sample-size assumptions used to design this trial are not reported in the registry record.

The 80% power column gives the number of participants per arm estimated to provide an 80% chance of detecting the specified effect under the planning assumptions, if that effect is the true one and the assumptions hold. The 90% power column gives the corresponding per-arm planning figure for a 90% chance. Power is a property of a planned study under an assumed effect and model; it is not a measure of whether a particular observed result is true.

For the primary outcome, the planning illustration lists 2,398 participants per arm for 80% power and 3,210 participants per arm for 90% power when planning for 100% of the observed effect. For 75% of the observed effect, the figures are 4,262 and 5,706 participants per arm, respectively. For 50% of the observed effect, they are 9,590 and 12,838 participants per arm. The sample-size curve conveys the same general relationship across assumed effects: targeting smaller effects requires more participants.

These are planning illustrations based on the observed effect, not the trial’s original design plan and not observed power. They should not be interpreted as a judgment about the trial’s validity or as proof that the observed effect is real. Their values depend on the assumptions and on using the observed estimate as the reference effect.

13. How the Sample Size Is Derived

Power is the probability that a study of a given size rejects the null hypothesis when a specific true effect exists. It depends on four things: the effect to detect, the variability of the outcome, the significance level (here a two-sided α of 0.05, so z_1−α/2 = 1.960) and the desired power (z_1−β = 0.842 for 80% and 1.282 for 90%).

Formula

n is the number of participants in each arm, Δ is the difference in means to detect and σ is the common standard deviation.

Worked calculation for this trial

1. Observed difference Δ = -1.900; pooled standard deviation σ = 23.480.
2. n = 2 × (1.96 + 0.842)² × 23.480² / -1.900² = 2,397.3, rounded up to 2,398 participants per arm for 80% power.

The smaller-effect rows in the table above repeat the same calculation with the effect multiplied by 0.75 and 0.5 (for ratios, applied to the logarithm of the ratio).

R code

alpha <- 0.05
z_a   <- qnorm(1 - alpha / 2)          # two-sided
delta <- -1.9                      # observed difference in means
sigma <- 23.4797785338789                     # pooled standard deviation
n_per_arm <- function(power, frac = 1) {
  ceiling(round(2 * (z_a + qnorm(power))^2 * sigma^2 / (delta * frac)^2, 6))
}
for (f in c(1, 0.75, 0.5))
  cat(sprintf("%3.0f%% of observed effect: n per arm = %s (80%% power), %s (90%% power)\n", 100 * f,
              format(n_per_arm(0.80, f), big.mark = ","), format(n_per_arm(0.90, f), big.mark = ",")))

# Check against R's built-in function (t-based, so very slightly larger)
cat("power.t.test:", round(power.t.test(delta = delta, sd = sigma, power = 0.80)$n, 1), "\n")

# Simulation: exact two-sample t-test using simulated means and variances
set.seed(4274686)
n    <- n_per_arm(0.80)
reps <- 20000
m_diff <- rnorm(reps, delta, sigma * sqrt(2 / n))             # difference in sample means
s2     <- sigma^2 * rchisq(reps, 2 * (n - 1)) / (2 * (n - 1))   # pooled sample variance
tstat  <- m_diff / sqrt(s2 * 2 / n)
cat(sprintf("Simulated power at n = %s per arm: %.3f (%d replicates)\n", format(n, big.mark = ","), mean(abs(tstat) > qt(0.975, 2 * (n - 1))), reps))

Output from running the code

100% of observed effect: n per arm = 2,398 (80% power), 3,210 (90% power)
 75% of observed effect: n per arm = 4,262 (80% power), 5,706 (90% power)
 50% of observed effect: n per arm = 9,590 (80% power), 12,838 (90% power)
power.t.test: 2398.2 
Simulated power at n = 2,398 per arm: 0.803 (20000 replicates)

The simulation draws many sets of group means and variances at the planned sample size and counts how often the two-sample t-test rejects the null. It should land close to the target power; at very small required sample sizes it can fall below it, because the normal approximation is rough there.

14. Analyses Reported by the Sponsor

The registry’s own primary analysis is a paired t-test. It reports a mean difference of 1.9, a 95% confidence interval from -7.0 to 10.7, and p = 0.667. This is the reported inferential result for the crossover comparison.

The recalculated comparison uses the posted means and standard deviations as unadjusted group summaries. It reports a mean difference of -1.9, a 95% confidence interval from -15.18 to 11.38, and an unadjusted p-value of 0.779. Its direction is expressed as without Tegaderm® placement compared with placement, whereas the registry’s paired result uses the opposite sign convention. The recalculation also does not include the within-participant pairing.

The difference between these analyses is therefore not a contradiction in the underlying measurements. They use different comparison methods and direction conventions. The crossover design makes the paired test the more directly aligned analysis. The recalculation is useful as a transparent, unadjusted check based on the posted summaries, but it cannot reproduce the paired analysis without participant-level paired information. The registry does not flag a discrepancy, and the paired result should be read as the trial’s reported analysis.

15. Multiplicity, Missing Data and Analysis Populations

The registry lists one primary outcome and two secondary outcomes, with analyses reported for all three. When several outcomes are examined, the chance of at least one apparently unusual result can increase. Statistical approaches such as adjusting significance thresholds or specifying a testing hierarchy can address that issue, but the registry record does not report whether any multiplicity adjustment or hierarchy was prespecified or used.

Without a reported plan, the primary outcome should remain the main focus, and secondary results should be interpreted as additional, unadjusted evidence. The record does not describe whether the analyses were prespecified in a protocol, whether any additional outcomes were measured but not posted, or whether the listed analyses represent all planned analyses. Those details are not reported in the registry record. This limits the ability to assess selective reporting or the extent to which the posted comparisons reflect an original analysis plan.

Missing-data handling is also not described. The trial enrollment is 25, while each condition’s posted arm summary has 24 observations. The record does not state why those counts differ, whether the same participants contributed measurements in both conditions, whether all randomized participants were included in the paired analysis, or how incomplete measurements were treated. The analysis population is not reported in the registry record.

These gaps matter in a crossover study because a paired comparison generally requires usable measurements under both conditions for a participant. If some paired measurements are absent, the analyzed set may differ from the enrolled set. The record does not provide enough information to determine whether this occurred or what effect it might have had. The reason the trial was terminated and any consequences of termination for analysis or outcome reporting are also not reported.

Accordingly, the posted results can be interpreted as analyses of the recorded outcome data, but the registry does not provide enough detail to reconstruct the full analysis process or assess every potential source of missingness and multiplicity-related uncertainty.

16. 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 0% reporting threshold.

The registry reports zero serious adverse events among 25 participants at risk in the Tegaderm® condition and zero among 25 participants at risk in the condition without Tegaderm®. It also reports zero other adverse events in each condition and zero deaths. These are the event counts posted for the two conditions.

Zero reported events means that no events in those categories were recorded in the registry results for the listed at-risk groups. It does not establish that an event is impossible or that the conditions have been shown to be equally safe. With a limited number of participants, uncommon events may not occur during the observed study period, and the record does not provide a detailed adverse-event collection procedure or longer-term follow-up information.

The crossover design means that the same participants may contribute to both condition-specific at-risk counts; the record does not describe the event-counting conventions in detail. The posted figures should therefore be read as registry-reported counts by condition, not as evidence from two independent groups. No serious-event terms are listed.

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

The results describe short-term bag-mask ventilation measurements in a randomized, unmasked crossover trial involving bearded patients. The primary endpoint was the percentage of inspired tidal volume lost as leakage during a measurement timeframe of <5 minutes. The posted means were 47.6 with Tegaderm® placement and 45.7 without placement. The registry’s paired analysis estimated a mean difference of 1.9, with a 95% confidence interval from -7.0 to 10.7 and p = 0.667.

These data do not provide strong statistical evidence of a difference in the primary endpoint under the reported analysis. They also do not show that the conditions are equivalent. The interval includes zero and allows differences in either direction; the registry does not report an equivalence margin or a clinically important difference threshold. Consequently, the statistical result cannot be translated into a conclusion that any possible difference is practically negligible.

The findings apply to the measurements and participants represented in this trial. They do not, on their own, establish effects in all bearded patients, in other ventilation circumstances, over longer periods, or on clinical outcomes beyond the measured ventilation quantities. The record gives limited information about eligibility, the study setting, missing measurements, and the reason for termination, which further constrains how broadly the findings can be interpreted.

The secondary outcomes and the adverse-event counts provide additional context, but neither resolves the uncertainty in the primary comparison. The secondary analyses are not reported as adjusted for multiple testing. The safety record reports no serious or other adverse events and no deaths in the listed groups, but those counts should not be read as proof that events cannot occur.

In short, the registry documents a comparison and its uncertainty; it does not support a claim that Tegaderm® placement improves or worsens ventilation, nor does it establish equivalence or a clinical benefit.

18. Why This Trial Matters Statistically

This trial illustrates why design and analysis need to be read together. A crossover study compares conditions within participants, and a paired analysis can account for that structure. The registry reports a paired t-test, while a simple recalculation from group summaries does not use the within-person relationship. The resulting estimates and intervals differ, demonstrating that aggregate means and standard deviations do not contain all the information needed to reproduce a paired analysis.

It also shows why a point estimate alone is not enough. The primary estimate is accompanied by an interval that spans zero and includes values in both directions. The p-value does not describe the magnitude of uncertainty, and a non-significant result does not establish that the conditions are equivalent. A clinical threshold and an appropriate equivalence design would be needed to make an equivalence claim; neither is reported in the registry record.

The planning illustrations offer another useful statistical lesson. Sample-size figures depend on assumptions about the effect to detect, allocation, significance level, and model. A planning calculation based on an observed effect can produce very large or small figures depending on the target fraction, but it is not the original design justification and does not measure the trial’s observed power.

Finally, registry interpretation depends on completeness of reporting. Enrollment and analysis counts differ, but the reason is not reported. The record does not describe missing-data methods, multiplicity procedures, or the reason for termination. These details are not peripheral: they help readers assess the analysis population and the strength of the conclusions. The case emphasizes careful separation of the reported result, an unadjusted recalculation, and what remains unknown.

19. 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.

Several limitations specific to this trial constrain interpretation. The registry reports an enrollment of 25 and posted summaries of 24 observations for each condition, but does not explain the difference. The number of participants with complete paired measurements and the analysis population are not reported. Without that information, it is not possible to assess how the analyzed observations relate to all enrolled participants.

The trial is listed as terminated, but the reason for termination is not reported in the registry record. The record also does not describe whether termination affected planned enrollment, measurement collection, or analysis. No protocol-level sample-size justification or original design assumptions are reported, so the planning illustration should not be used to infer what enrollment the investigators intended.

The study was unmasked, and the record does not report blinding of outcome assessors. It also does not provide details about sequence generation, condition order, any washout, or how possible order effects were addressed. These omissions matter for understanding how a crossover comparison was conducted, but they do not establish that a particular bias occurred.

The primary outcome is measured over a short timeframe of <5 minutes, and the registry does not report a clinical-importance threshold for leakage. Thus, the statistical estimates cannot be mapped to a judgment about meaningful benefit or harm. The record provides no individual-level data, no reported correlation between paired measurements, and no detailed missing-data or multiplicity plan. The secondary outcomes add context but are not reported as adjusted for multiple comparisons.

Finally, the brief summary identifies an anesthetized bearded population, but detailed eligibility and setting information are not reported. Generalization beyond the participants and measurement conditions represented in the record should therefore be cautious.

20. Related Tutorials

21. Related Statistical Calculators

22. Sources

• ClinicalTrials.gov: Tegarderm® Placement for Bag Mask Ventilation in the Bearded Patient — NCT04274686.
• Registry record last updated 2022-09-21; status last verified 2022-08.
• Results first posted 2022-09-21.
• 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.

23. Record Summary

NCT04274686 is a randomized, unmasked crossover trial sponsored by the University of New Mexico. It compared bag-mask ventilation with Tegaderm® placement against ventilation without placement in bearded patients, with a recorded enrollment of 25 and a status of terminated.

The primary endpoint was percentage air leakage during bag-mask ventilation, defined from inspired and expired tidal volumes and measured over <5 minutes. Resistance and peak inspiratory pressure were secondary outcomes. The registry reports a paired t-test for each outcome. For the primary outcome, the paired analysis reports a mean difference of 1.9, a 95% confidence interval from -7.0 to 10.7, and p = 0.667.

The posted results do not establish a difference or equivalence between conditions. The reason for termination, missing-data handling, analysis population, and original sample-size assumptions are not reported in the registry record.