Use of High Flow Nasal Cannula During Sedation of Morbidly Obese Patients in the Endoscopy Suite: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Use of High Flow Nasal Cannula During Sedation of Morbidly Obese Patients in the Endoscopy Suite (NCT02859597), a randomized na study. The primary outcome is Ability to Maintain Oxygenation.

2. Clinical Question

The registry record describes a randomized comparison in a specific procedural setting: morbidly obese patients receiving sedation for gastrointestinal procedures. It does not report a broader comparison across other populations, procedures, or care settings. The primary outcome is an operational measure of the effort involved in maintaining oxygenation, rather than a direct measurement of oxygen saturation itself. Two additional outcomes were registered: participants requiring airway adjuncts and participants needing an increase in the fraction of inspired oxygen. Results for the latter outcome are posted; results for airway adjuncts are not reported in the registry record.

3. Trial Design

This was a randomized, controlled, parallel-group trial with no masking reported. The registry lists the study as completed and records enrollment of 41 participants. The posted primary-outcome groups include 22 participants assigned to high-flow nasal cannula and 19 assigned to nasal cannula. The record does not describe the randomization procedure, allocation concealment, or whether participants or outcome assessors knew the assigned device; masking is listed as none.

The study evaluated oxygen delivery during moderate to deep sedation for gastrointestinal procedures in morbidly obese patients. The brief summary describes moderate to deep sedation, while the arm descriptions refer to deep sedation. The primary outcome was assessed during the period of sedation, described as on average up to 1 hour. The registry identifies the study as not applicable for phase, consistent with its device comparison rather than a drug-phase designation.

The record lists three outcome measures: the primary measure of ability to maintain oxygenation, plus two secondary outcomes concerning airway adjuncts and an increase in inspired oxygen. It reports numeric results for the primary outcome and for the increase-in-oxygen outcome. Airway-adjunct results are not reported in the registry record. The registry lists no reported analyses. Details such as the original sample-size rationale, intended statistical model, analysis population, missing-data approach, and handling of multiple outcomes are not reported in the registry record.

The study dates recorded are 2016-12-28 for the start and 2018-09-28 for primary completion. These dates describe the registered study timeline; they do not establish how long each participant was followed beyond the stated outcome timeframe. The trial’s design supports a comparison between the assigned groups, but the posted aggregate results do not provide participant-level data or adjustment for characteristics that may differ between groups.

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 Ability to Maintain Oxygenation, measured over During the period of sedation, on average up to 1 hour.

The primary endpoint is titled ability to maintain oxygenation and is expressed as the mean number of manipulations during sedation. In the registry’s description, manipulations reflect how much adjustment or intervention the anesthesiologist needed to maintain adequate oxygenation. The description defines the direction of the measure: more manipulations indicate that the device was less effective at maintaining saturation for this population. The measure therefore captures procedural effort in maintaining oxygenation, rather than oxygenation as a continuous physiologic reading.

This kind of endpoint can be useful when the practical question concerns how often clinicians need to intervene while a procedure is underway. It converts a clinical process into a count that can be compared between groups. Its interpretation depends on what qualified as a manipulation and how consistently that judgment was applied. Those operational details, including whether manipulations were prespecified or adjudicated, are not reported in the registry record.

The endpoint was assessed during the sedation period, described as on average up to 1 hour. The high-flow group had a posted mean of 0.55 manipulations, with a standard deviation of 0.55. The nasal-cannula group had a mean of 0.61, with a standard deviation of 1.03. These group summaries describe the observed distribution of the recorded count but do not, by themselves, show how individual participants’ oxygenation changed over time or what types of manipulations occurred.

Because the outcome is a count summarized by means and standard deviations, its statistical behavior may not be fully captured by a simple normal model, especially if counts are concentrated near zero or vary substantially between participants. The registry record does not report the count distributions or the analysis model used by the sponsor.

7. Results Posted in the Registry

• Nasal Canula: mean 0.61 versus 0.55 on control; difference 0.06 (95% CI -0.46 to 0.58), standardized effect d = 0.07; z-test p = 0.820.

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.

Number of Participants Who Need an Increase in Fraction of Inspired Oxygen

• Endpoint type: Binary: the number of participants with the event, compared as proportions.
• Test: Unadjusted two-proportion z-test, with a Wald 95% confidence interval for the risk difference.
• Result:
  • Nasal Canula: 15.8% (3/19) versus 27.3% (6/22) on control; risk difference -11.5 percentage points (95% CI -36.3 to 13.3), risk ratio 0.58 (0.17–2.01); unadjusted two-proportion z-test p = 0.376.
• Interpretation:
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between Nasal Canula and the control. The interval gives the range of effects that remain compatible with the data.

The registry lists two secondary outcomes: the number of participants requiring airway adjuncts during the procedure and the number needing an increase in the fraction of inspired oxygen. Numeric results are posted for the increase-in-oxygen outcome, while results for airway adjuncts are not reported in the registry record. Thus, the secondary evidence is incomplete across the outcomes listed.

The available secondary result adds information about oxygen-management decisions, but it does not replace the primary endpoint or settle its uncertainty. The primary measure counts manipulations as a way of describing the effort needed to maintain oxygenation; the secondary measure records whether an increase in inspired oxygen was needed. They concern related aspects of procedural oxygen management, but they are not interchangeable outcomes. A pattern in one measure should not be assumed to imply the same pattern in the other.

The secondary comparison is unadjusted. In general, when multiple outcomes are examined, the chance of at least one apparently unusual result can rise even if there is no underlying effect. A multiplicity adjustment or a prespecified hierarchy can address some of that concern, but the registry record does not report such a strategy. The unadjusted secondary result therefore carries less confirmatory weight than a prespecified primary outcome, particularly when the number and ordering of planned tests are unclear.

The registry also lists no reported analyses. The missing airway-adjunct results and the absence of a documented analysis strategy limit how fully the secondary outcome pattern can be assessed. The available secondary information can be considered alongside the primary result as descriptive evidence, but it should not be used alone to claim that one device is better or worse.

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

• Number of Participants Requiring Airway Adjuncts During Procedure
• Number of Participants Who Need an Increase in Fraction of Inspired Oxygen

9. Statistical Interpretation

10. Statistical Methods Explained

For a continuous outcome such as the mean number of manipulations, a group mean describes the average recorded value among participants with an outcome summary. A standard deviation describes how dispersed individual values are around that group mean. It is not the uncertainty in the mean itself. The high-flow group’s mean was 0.55 and its standard deviation was 0.55; the nasal-cannula group’s mean was 0.61 and its standard deviation was 1.03. The larger standard deviation in the nasal-cannula group indicates more spread in the posted values, though the aggregate summaries do not reveal the shape of either group’s distribution.

What does the mean difference represent?

The reported contrast is the nasal-cannula mean minus the high-flow nasal-cannula mean. Its estimate is 0.06 manipulations. A positive value means the recorded mean was higher in the nasal-cannula group; because more manipulations are described as less effective maintenance of saturation, that direction corresponds to a higher average manipulation count in that group. This interpretation concerns the endpoint as defined, not a direct statement about oxygen saturation or patient benefit.

A difference is a measure of absolute separation between group averages. It should be read together with its uncertainty interval and the outcome’s units. It is not a percentage change, and no percentage interpretation is needed to understand this contrast. The comparison is unadjusted in the recalculation represented by the posted contrast; the registry does not report a covariate-adjusted primary analysis.

What does a confidence interval express?

A confidence interval gives a range of values that are reasonably compatible with the observed data under the method used to calculate it. The primary 95% interval extends from -0.457 to 0.577 manipulations. The range includes no mean difference and also includes positive and negative differences. It therefore communicates more than whether a single test crossed a conventional threshold: it shows that the point estimate is not precise enough to rule out a range of possible contrasts. The interval is not a probability statement that the true effect lies within this one calculated interval.

How should the p-value be read?

The unadjusted p-value for the primary comparison is 0.82. In general, a p-value measures how unusual data at least as incompatible with a specified null hypothesis would be if that null hypothesis and the test assumptions were correct. It is not the probability that the null hypothesis is true, nor is it a measure of clinical importance. A large p-value does not demonstrate equivalence or prove that a difference is absent. The registry record does not report whether the sponsor used this same test, its assumptions, or any adjusted analysis; it lists no reported analyses.

Why might count outcomes need special attention?

The primary outcome is a count of manipulations. In general, count outcomes can be skewed, contain many zeros, or have variability that differs from what a simple model assumes. Over-dispersion means that outcome variability exceeds what a model expects; if present and ignored, it can make standard errors and confidence intervals unreliable. That is a general statistical consideration, not a claim that over-dispersion occurred in this trial. The registry record does not report a distributional assessment or identify whether a count-specific model was used.

The posted means and standard deviations permit a simple summary-level comparison, but they cannot reproduce all analyses that might be performed on participant-level data. A count model, a rank-based approach, or a model accounting for procedural features could give a different analysis, depending on the prespecified plan and available data. The appropriate method cannot be inferred from the outcome label alone.

What does an unadjusted secondary comparison mean?

The secondary outcome concerning an increase in inspired oxygen is binary: each participant either was or was not recorded as needing an increase. Its posted comparison is a risk difference, an absolute contrast in the proportions with the event. The record also includes relative measures and an unadjusted p-value, but these are secondary to the primary question and are not adjusted for testing multiple outcomes. The registry record does not report a multiplicity strategy. In general, evaluating several outcomes creates more opportunities for a chance finding, which is one reason unadjusted secondary results are interpreted cautiously.

All numerical summaries should be read in light of the small enrolled group and the missing detail about analysis methods. Randomization supports a group comparison in principle, but the registry record does not provide enough detail to assess implementation, missing observations, adherence, or the sponsor’s complete statistical analysis plan.

11. Confidence Intervals and Precision

The primary estimated difference is 0.06 manipulations, comparing nasal cannula with high-flow nasal cannula. Its 95% confidence interval runs from -0.457 to 0.577. The interval is important because the point estimate alone can make the observed groups seem more definitively different than the data warrant. In this case, the interval includes zero and spans possible differences in both directions.

In general, a confidence interval represents uncertainty in an estimated contrast under the assumptions of the calculation. A narrower interval would indicate greater precision; a wider interval indicates that the data are compatible with a broader range of values. The primary interval is broad relative to the small estimated difference. It does not identify a single likely value with high precision, and it does not exclude potentially meaningful differences in either direction. The registry record does not define a threshold for clinical importance, so the interval cannot be divided into clinically important and unimportant values using a registered criterion.

The group sizes for the primary outcome were 22 and 19. With a limited number of participants, estimates may be imprecise, particularly when individual outcome values vary. The observed standard deviations were 0.55 and 1.03. Those summaries suggest that outcome variability was not identical across groups, but the record does not report a variance model or a diagnostic assessment.

The confidence interval should not be interpreted as evidence of equivalence. Equivalence requires a prespecified acceptable range and a design intended to test whether the true difference lies within that range. A non-significant test and an interval that includes zero do not by themselves establish that the treatments perform the same. The registry record does not report an equivalence or noninferiority objective.

Precision is also limited for uncommon safety outcomes in a trial of this size. No events were recorded in the posted categories, but zero observed events do not show that the underlying risk is zero. The record does not provide an uncertainty interval for those safety counts.

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 for 80% power and participants per arm for 90% power. They are not total participants across both groups and are not observed trial counts. The assumptions listed for these illustrations are a two-sided significance level of 0.05, equal allocation between the two arms, and a normal approximation. The effect to detect is set at the stated fraction of the observed effect. The original trial’s own sample-size assumptions and justification are not reported in the registry record.

For the primary continuous outcome, planning for 100% of the observed effect gives 2,846 participants per arm for 80% power and 3,810 participants per arm for 90% power. Planning for 75% of the observed effect gives 5,059 participants per arm for 80% power and 6,772 participants per arm for 90% power. Planning for 50% of the observed effect gives 11,382 participants per arm for 80% power and 15,237 participants per arm for 90% power.

In plain language, 80% power is the planned chance of detecting the chosen effect under the calculation’s assumptions if that effect is the true one; 90% power sets a higher target chance and therefore requires more participants for the same effect. Smaller effects are harder to distinguish from random variation, so planning to detect a smaller fraction of the observed effect requires more participants. The corresponding illustration for the binary secondary outcome is based on participants per arm as well. The record’s planning note says time-to-event calculations, if any, use total events, but the posted outcomes are not identified as time-to-event measures.

These figures are planning illustrations based on the observed effect, not observed power. They should not be interpreted as a retrospective measure of whether the completed trial was adequately powered, nor as evidence that a particular effect is true. Since the observed primary estimate is uncertain, planning directly from it is also uncertain; a future design would ordinarily need a justified target effect that is clinically meaningful and prespecified.

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 = 0.060; pooled standard deviation σ = 0.808.
2. n = 2 × (1.96 + 0.842)² × 0.808² / 0.060² = 2,845.4, rounded up to 2,846 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 <- 0.0599999999999999                      # observed difference in means
sigma <- 0.807793766521362                     # 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(2859597)
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 = 2,846 (80% power), 3,810 (90% power)
 75% of observed effect: n per arm = 5,059 (80% power), 6,772 (90% power)
 50% of observed effect: n per arm = 11,382 (80% power), 15,237 (90% power)
power.t.test: 2846.3 
Simulated power at n = 2,846 per arm: 0.798 (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. Multiplicity, Missing Data and Analysis Populations

The registry record does not report how the analysis handled multiplicity across the primary outcome and secondary outcomes. Multiplicity arises when several outcomes or statistical tests are assessed: even if there is no true effect, the chance of at least one result appearing unusual can increase as more comparisons are made. Common approaches include adjusting significance thresholds, prespecifying a hierarchy of tests, or treating secondary analyses as exploratory. No such approach is reported in the registry record, so the posted unadjusted secondary p-value should be interpreted cautiously.

Missing-data methods and the analysis population are also not reported in the registry record. The group summaries list 22 and 19 participants for the primary outcome and the same group sizes for the posted secondary outcome, but those counts do not establish whether every randomized participant was analyzed as assigned, whether any outcome observations were missing, or whether exclusions occurred. The record does not describe an intention-to-treat or per-protocol analysis, imputation, or sensitivity analyses. No conclusions about missingness or analysis populations can therefore be drawn from the group summaries alone.

The registry lists no reported analyses. It does not describe the statistical model for the primary count outcome, whether the comparison was adjusted for baseline or procedural factors, or whether the sponsor used a different analysis from the simple unadjusted summary comparison. The original protocol’s statistical analysis plan is not reported in the registry record. The distinction matters because a registered outcome definition does not by itself specify the model, assumptions, test, or handling of departures from those assumptions.

Randomization is recorded, but details of sequence generation and allocation concealment are not reported. Masking is listed as none. The record does not describe outcome-assessor procedures or how subjective decisions about manipulations and oxygen increases were standardized. These omissions do not establish that bias occurred; they limit the ability to assess how risks of bias were controlled.

15. 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 posted serious adverse event figures record zero serious events in the high-flow nasal-cannula group among 22 participants at risk and zero in the nasal-cannula group among 19 participants at risk. The posted other-adverse-event figures also record zero in each group, and no deaths are recorded in either group. These are observed counts for the participants represented in the registry record.

Zero recorded events should not be read as proof that a device has no risk or that an event could not occur. A trial with 41 participants has limited ability to characterize uncommon harms, and no uncertainty intervals are reported for these counts. The registry record does not describe the adverse-event collection procedures, definitions, or observation period beyond the information shown for the trial. The figures therefore summarize recorded events in this study, rather than establish a general safety profile or compare rare risks with precision.

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

The results describe a randomized comparison of two oxygen-delivery devices during sedation of morbidly obese patients undergoing gastrointestinal procedures. The primary endpoint was a count of manipulations intended to capture the effort involved in maintaining oxygenation. The posted means were 0.55 for high-flow nasal cannula and 0.61 for nasal cannula. The estimated difference was small in magnitude, but its 95% confidence interval, from -0.457 to 0.577, leaves substantial uncertainty about the direction and size of the underlying difference.

The result does not establish that the devices are equivalent. Equivalence requires a prespecified margin and an analysis designed to test that question; neither is reported in the registry record. Nor does the result demonstrate that either device improves oxygenation, because the primary endpoint is a count of manipulations rather than a direct measure of oxygen saturation and the estimated comparison is uncertain. No claim about patient benefit or clinical outcomes follows from these summaries alone.

The secondary outcome and safety counts add context but do not remove the limitations. Numeric results for increased inspired oxygen are posted, while airway-adjunct results are not reported in the registry record. Secondary comparisons are unadjusted, and the record does not describe a multiplicity plan. No adverse events or deaths were recorded in the posted figures, but the study size cannot establish the absence of uncommon risks.

The findings apply most directly to the enrolled trial population and procedural context described in the registry. Eligibility details and participant characteristics are not reported, limiting assessment of how closely the participants represent other groups. The record also does not provide enough information to assess outcome distributions, missing data, protocol adherence, or the sponsor’s complete analysis methods. The appropriate reading is therefore a descriptive one: the observed primary means were close, and the estimated contrast remains imprecise.

17. Why This Trial Matters Statistically

This trial illustrates an important distinction between a point estimate and the information contained in its uncertainty interval. The two primary means are close, but the interval around their difference remains broad enough to include effects favoring either group. A non-significant p-value is not a finding of sameness; it can reflect uncertainty as well as a small underlying effect. Statistical interpretation requires considering the estimate, its precision, the endpoint’s meaning, and the study’s design together.

The endpoint also highlights how a clinical process can be translated into a quantitative measure. Counting manipulations may reflect the effort required to maintain oxygenation during a procedure, but it is not the same as measuring oxygen saturation or a patient-centered outcome. The meaning of a count depends on a clear, consistent definition and reliable recording. The registry’s description gives the intended direction of the measure, while further operational details are not reported.

Another statistical lesson is that the enrolled sample and the planning illustrations answer different questions. The completed trial enrolled 41 participants. The planning figures estimate how many participants per arm would be needed under stated assumptions to detect specified fractions of the observed effect. They are not retrospective evidence that the study had a particular probability of success. When the effect estimate itself is uncertain, sample-size illustrations derived from it should be treated as exploratory planning aids.

Finally, the record shows why transparent reporting matters. The primary and one secondary result are available, but airway-adjunct results, the original sample-size justification, the analysis populations, missing-data handling, and multiplicity plan are not reported. Those details affect how confidently readers can evaluate the estimates and how readily another researcher could reproduce the analysis.

18. 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 total enrollment was 41, divided into groups of 22 and 19 for the primary outcome. The resulting mean-difference interval is broad, and the group standard deviations differ. The aggregate results do not show individual manipulation counts or reveal whether a small number of participants contributed much of the observed variation.

The primary outcome is a count-based measure of clinician manipulations rather than a direct physiologic oxygenation measurement. The registry explains that more manipulations indicate less effective maintenance of saturation, but it does not report a detailed operational definition, measurement reliability, or how events were recorded. These omissions make it difficult to assess how reproducibly the endpoint was applied.

The registry describes the population as morbidly obese patients undergoing gastrointestinal procedures with moderate to deep sedation in the summary and deep sedation in the arm descriptions. Detailed eligibility criteria, baseline characteristics, procedural mix, and participant-level clinical information are not reported in the registry record. The applicability of the aggregate findings to other settings or patient groups cannot be assessed fully.

Masking is listed as none. The record does not explain whether outcome assessment was standardized or whether subjective decisions could have influenced manipulation counts. It also does not report the randomization method or allocation concealment. These are reporting gaps, not evidence that the procedures were inadequate.

Only one of the two registered secondary outcomes has numeric results. The airway-adjunct outcome is not reported in the registry record. The analysis plan, missing-data methods, analysis population, multiplicity strategy, and original sample-size justification are also not reported. The absence of those details limits assessment of selective reporting, assumptions, and reproducibility.

19. Related Tutorials

20. Related Statistical Calculators

21. Sources

• ClinicalTrials.gov: Use of High Flow Nasal Cannula During Sedation of Morbidly Obese Patients in the Endoscopy Suite — NCT02859597.
• Registry record last updated 2020-04-16; status last verified 2020-04.
• Results first posted 2020-04-16.
• 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.

22. Record Summary

The registry describes a completed randomized, unmasked, parallel-group comparison of high-flow nasal cannula and nasal cannula during sedation for gastrointestinal procedures in morbidly obese patients. Enrollment was 41. The primary outcome was the mean number of manipulations during sedation, described as lasting on average up to 1 hour.

The primary means were 0.55 for high-flow nasal cannula and 0.61 for nasal cannula. The estimated mean difference, comparing nasal cannula with high-flow nasal cannula, was 0.06, with a 95% confidence interval from -0.457 to 0.577 and an unadjusted p-value of 0.82. The posted results do not establish a clear difference or equivalence.

Results are posted for the secondary outcome concerning an increase in inspired oxygen; airway-adjunct results are not reported in the registry record. No serious adverse events, other adverse events, or deaths were recorded in the posted safety figures. The registry does not report the original sample-size rationale, detailed statistical analysis plan, missing-data approach, analysis populations, or multiplicity strategy.