Safety and Efficacy of Laryngeal Mask Airways in Sinonasal Surgery: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Safety and Efficacy of Laryngeal Mask Airways in Sinonasal Surgery (NCT02311153), a randomized na study. The primary outcome is Number of Participants With Presence or Absence of Blood/Secretions in Trachea and Larynx Based on Soiling Score.

2. Clinical Question

The study was designed as a prospective, randomized, single-blind comparison in sinonasal surgery. Its stated aim was to compare the safety and efficacy of LMA airway management with endotracheal intubation. “Safety and efficacy” is the study’s broad aim, not a single result: the registry lists a primary endpoint focused on airway soiling and secondary outcomes related to anesthesia time, recovery time, laryngeal spasm, post-operative pain medication requirements, and airway complications.

The clinical question is therefore specific to the airway-management approaches and the recorded surgical setting. It is not a comparison of surgery versus no surgery, nor does the registry describe comparisons across different kinds of sinonasal procedures. The registry record does not report enough detail to determine which types of participants or procedures were represented, or whether the findings differed across subgroups.

3. Trial Design

The registry describes a randomized, parallel-group study with single masking. It lists an enrollment of 104 and a completed status. The study start is recorded as 2014-11-25, and primary completion as 2016-07-26. The sponsor is Vanderbilt University Medical Center. The phase is recorded as NA.

Participants were assigned to one of two airway-management groups: endotracheal intubation or a laryngeal mask airway. Both approaches were used for airway management and ventilation during sinonasal surgery. The brief description characterizes the study as prospective and single-blind, but the identity of the masked parties and the practical method of masking are not reported in the registry record. Randomization procedures, including sequence generation and allocation concealment, are also not reported.

The registry lists six outcome measures, including the primary soiling outcome and secondary outcomes. The secondary outcomes include anesthesia time in minutes, recovery time in minutes, presence of laryngeal spasm, post-operative pain medication requirements, and presence or absence of airway complications. The record does not provide results for these secondary measures in the information available for this analysis.

The primary endpoint timeframe is intraoperative, within about 1 hour. The registry says participants who started the study were analyzed and notes that data were missing for 1 participant in each arm. Further details about the analysis population, treatment received, protocol deviations, or the handling of missing observations are not reported in the registry record.

The trial’s randomized design can support a comparison between assigned approaches when outcomes are reported and the analysis is appropriate. However, the design alone does not establish that groups were comparable in every respect or resolve uncertainty about missing data, outcome assessment, or masking. The registry record does not report the detailed statistical plan or the outcome estimates needed to evaluate the primary comparison.

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.

Before assignment: 2 patients were consented and enrolled in the clinic setting, but they did not end up being randomized: 1 did not proceed with surgery 1 was diagnosed with sleep apnea, which is exclusionary

Overall Study

Reasons for not completing this period:

Analysis population for the primary outcome, as defined in the registry: Participants that started the study were analyzed. Data was missing for 1 participant in each arm.

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 Number of Participants With Presence or Absence of Blood/Secretions in Trachea and Larynx Based on Soiling Score, measured over intraoperative, within about 1 hour.

The primary endpoint concerns the number of participants with the presence or absence of blood or secretions in the trachea and larynx, assessed during surgery. The registry describes a surgeon-completed soiling score ranging from 0, meaning no contamination or soilage, to 3, meaning contamination of the tube or bloody secretions. The stated timeframe is intraoperative, within about 1 hour.

This endpoint is relevant to the study’s airway-management question because it records whether blood or secretions were observed in the airway during sinonasal surgery. A surgeon’s rating provides an assessment tied to the operative setting and the specific anatomical locations named in the endpoint. The score’s ordered range also distinguishes levels of observed soiling rather than merely naming the two airway approaches.

The registry record does not report definitions for intermediate score values, the exact method for turning the score into the stated presence-or-absence outcome, or the results by treatment group. It also notes that the primary outcome has several categories or time points and was not reduced to one comparison. Consequently, a single binary effect estimate, such as a difference between groups, is not available in the registry record. The record notes missing data for 1 participant in each arm, but does not explain how these observations were handled in the endpoint analysis.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The study is registered as randomized and parallel-group. In a randomized trial, assignment is intended to make treatment groups comparable on average, including with respect to factors that are measured and those that are not. Randomization does not guarantee that the groups will be identical, particularly in a study of limited size. The registry record does not report how the random sequence was generated, how assignment was concealed, or whether any stratification was used. Those details matter when assessing how well the assignment process protected against predictable group allocation.

What does single-blind mean?

Single-blind indicates that masking was used for one party or role, but the registry record does not identify who was masked or how masking was implemented. In a procedural comparison, masking may be difficult for people delivering the airway intervention. The record does not establish whether outcome assessors, participants, surgeons, or other staff were unaware of assignment. Because the primary endpoint is based on a surgeon-completed score, knowing who completed the rating and whether they knew treatment assignment would help readers assess possible measurement bias; these details are not reported in the registry record.

How should the soiling score be understood?

General statistical explanation: an ordered score represents categories with a natural ranking. The registry describes a scale from 0 for no contamination or soilage to 3 for contamination of the tube or bloody secretions. An ordered outcome can be analyzed in more than one way, and different approaches answer different questions. Treating it as ordered retains distinctions among categories; collapsing categories into presence or absence makes a simpler comparison but loses detail. The record states that the primary outcome had several categories or time points and was not reduced to one comparison. The exact category definitions, selected analysis, and primary effect estimate are not reported in the registry record.

Why do outcome estimates need uncertainty measures?

General statistical explanation: an effect estimate describes the observed contrast between groups, while a confidence interval describes the range of values reasonably compatible with the data and the statistical model. A narrow interval indicates more precision than a wide interval. A p-value addresses how unusual data at least as discrepant as those observed would be under a specified null model; it does not measure the size or importance of an effect. The registry record does not report an estimate, confidence interval, or p-value for the primary comparison, so its magnitude and precision cannot be judged.

What does over-dispersion mean in general?

General statistical explanation: over-dispersion occurs when observed variability is greater than a model assumes. If a method assumes that outcomes vary less than they actually do, standard errors can be too small and confidence intervals too narrow. The primary endpoint is described as a score-based count of participants with presence or absence of airway soiling, but the record does not report a model or analysis results. There is no basis in the registry record to determine whether over-dispersion was assessed or relevant to the analysis used.

How should planning illustrations be read?

General statistical explanation: a sample-size calculation is a planning exercise based on assumptions about the effect to detect, variability, significance level, allocation, and analysis method. It is not an observed treatment effect and cannot show whether a completed study had a particular probability of finding a result. The registry’s planning illustration is described as using the observed effect, a two-sided significance level of 0.05, equal allocation, and a normal approximation. It states that the effect to detect is a stated fraction of the observed effect. These are planning assumptions, not evidence that the original trial was designed using them. The trial’s own sample-size justification is not reported in the registry record.

The registry states that there are no analyses listed and provides no primary endpoint comparison in the record. No statistical model, adjustment set, handling of multiple outcomes, or inferential approach can therefore be attributed to the trial from this information. Those choices should not be inferred from the randomized design or from any planning illustration.

10. Multiplicity, Missing Data and Analysis Populations

The registry lists a primary outcome with several categories or time points and indicates that it was not reduced to one comparison. It also lists secondary outcomes involving anesthesia time, recovery time, laryngeal spasm, post-operative pain medication requirements, and airway complications. When a study evaluates multiple outcomes or multiple versions of an outcome, the chance of at least one apparently unusual result can increase if each is tested separately without an appropriate plan. General statistical approaches to multiplicity include defining a primary comparison in advance, adjusting inference, or interpreting secondary analyses as exploratory. The registry record does not report which approach, if any, was planned or used.

For the primary endpoint, the record says participants who started the study were analyzed and that data were missing for 1 participant in each arm. It does not state the total number included in the primary endpoint analysis by group, explain why the observations were missing, or describe whether missingness was handled by exclusion, imputation, or another method. Missing outcome data can affect a comparison when the chance of missingness is related to the outcome or differs in relevant ways between groups. The record does not provide enough information to assess that possibility.

The analysis population is not described beyond the statement that participants who started the study were analyzed. The registry record does not say whether this corresponds to an intention-to-treat analysis, a per-protocol analysis, or another population definition. It also does not report protocol deviations or crossovers. These distinctions matter because analysis according to randomized assignment and analysis according to treatment received can answer different questions.

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 0% reporting threshold.

The serious adverse event figures record 0 affected participants among 53 at risk in the endotracheal intubation group, and 0 affected participants among 49 at risk in the LMA group. The record also reports 0 deaths in each group. These are the counts presented for serious adverse events; no serious adverse event terms are listed.

A count of zero means that no event of that category was recorded among the participants at risk in that group. It does not demonstrate that the true risk is zero. With no recorded events, the data provide limited information about the frequency of uncommon events or about small differences between approaches. A comparative estimate and uncertainty interval would be needed to quantify how compatible the data are with different relative risks; neither is reported in the registry record.

These serious-event counts should also be kept distinct from the broader outcome list. The registry identifies airway complications and laryngeal spasm as secondary outcomes, but the serious adverse event summary does not establish the results for those outcomes. The counts are not a complete account of every possible adverse event, and the record does not report detailed event definitions or follow-up procedures. They describe the recorded serious adverse events, not all aspects of safety.

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

The registry describes a randomized comparison of LMA and endotracheal intubation for airway management and ventilation during sinonasal surgery. Its primary question concerned blood or secretions in the trachea and larynx during the procedure. The registry also identifies additional outcomes relevant to procedure and recovery, including anesthesia time, recovery time, laryngeal spasm, pain medication requirements, and airway complications.

The key limitation for interpreting effectiveness is that the primary outcome comparison is not reported in the registry record. The record says the endpoint involved several categories or time points and was not reduced to one comparison. Without results for the groups, there is no reported effect estimate or uncertainty measure that would show the size, direction, or precision of the primary contrast. The record also does not report results for the listed secondary outcomes.

The serious adverse event summary records no serious adverse events and no deaths in either group, with the group-specific numbers at risk as stated in the safety reading. These observations are informative as counts, but they cannot establish an absence of risk or rule out uncommon events. They also cannot be used to infer the results for non-serious or specifically named airway complications.

The study’s randomized design and completed status describe how the trial was organized and its administrative status. They do not fill in the missing outcome estimates. The registry record does not report the detailed statistical plan, the original sample-size justification, or sufficient information about outcome missingness and analysis populations to resolve those uncertainties.

Accordingly, the posted record describes the clinical question and some features of the trial, but it does not establish that either airway approach produced less soiling, shorter anesthesia or recovery time, fewer complications, or a better safety profile. Such conclusions would require reported comparisons and their uncertainty, interpreted in light of the trial’s analysis methods and missing data.

13. Why This Trial Matters Statistically

This trial is statistically notable because it addresses a concrete comparison between two airway-management approaches within sinonasal surgery, using randomized assignment. Randomization is a useful design feature for comparative research because it aims to reduce systematic differences between groups. The registry also identifies a procedure-specific primary endpoint: blood or secretions in the trachea and larynx, rated by the surgeon during surgery.

The endpoint illustrates a common analysis challenge. It is described as a soiling score with multiple categories, while the outcome title also refers to presence or absence. The registry notes that the primary outcome has several categories or time points and was not reduced to one comparison. Clear reporting of the selected endpoint definition, analysis, and group-level results is necessary for readers to understand what contrast was estimated and how precisely it was estimated.

The record also illustrates why a completed study and a stated outcome are not enough to support statistical interpretation. Without the primary result, uncertainty measure, or analysis details, readers cannot evaluate the size or precision of the comparison. Missing data are explicitly noted for 1 participant in each arm, yet the handling of those observations is not described. Those reporting gaps limit reproducibility and make it difficult to assess robustness.

Finally, the serious adverse event counts show the distinction between reporting observed events and estimating risk. Zero recorded events in both groups is a factual summary, but it cannot by itself establish that serious events cannot occur or that the groups have equivalent safety. The registry record therefore offers a useful example of how design information, outcome definition, missingness, and complete results all contribute to an interpretable clinical comparison.

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.

Several limitations of interpretation follow from the registry record. Most importantly, it does not report the primary outcome comparison. The primary endpoint is described as having multiple categories or time points, with no single comparison presented. Without group-specific outcome values, an effect estimate, or an uncertainty measure, the primary result cannot be evaluated for magnitude, direction, or precision.

The record identifies a surgeon-completed soiling score ranging from 0 to 3, but does not describe the intermediate categories or clarify the exact analysis used to derive the stated presence-or-absence outcome. It does not identify who was masked in the single-blind design. Because the primary measure depends on an assessment during surgery, the absence of detail about assessor masking and scoring procedures limits assessment of potential measurement bias.

Data were missing for 1 participant in each arm. The reason for missingness and the handling of these observations are not reported. The analysis population is described only as participants who started the study; the record does not specify whether the analysis followed randomized assignment or another population definition. Participant characteristics, procedure details, randomization methods, and protocol deviations are also not reported in the record used for this analysis.

Although several secondary outcomes are listed, their results and any plan for handling multiple outcomes are not reported. The registry does not provide the trial’s own sample-size justification or a detailed statistical analysis plan. The serious adverse event summary reports zero events in both groups, but does not provide estimates of uncertainty or detailed definitions and follow-up information. These limitations do not establish that the trial’s conduct or analyses were inadequate; they identify information that is not reported in the registry record and therefore cannot be assessed.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Safety and Efficacy of Laryngeal Mask Airways in Sinonasal Surgery — NCT02311153.
• Registry record last updated 2018-06-01; status last verified 2018-05.
• Results first posted 2018-06-01.
• 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

NCT02311153 is a completed, randomized, parallel-group, single-blind study sponsored by Vanderbilt University Medical Center. It enrolled 104 participants and compared a Laryseal laryngeal mask airway with a Mallinckrodt endotracheal tube for airway management and ventilation during sinonasal surgery. The registry records a study start of 2014-11-25 and primary completion on 2016-07-26; the phase is listed as NA.

The primary endpoint concerned blood or secretions in the trachea and larynx, assessed intraoperatively using a surgeon-completed soiling score. The record notes missing data for 1 participant in each arm and says the primary outcome had several categories or time points that were not reduced to one comparison. The primary comparison and the listed secondary outcome results are not reported in the registry record.

For serious adverse events, the record reports 0 affected participants and 0 deaths in each group. These counts describe recorded events but do not establish that risk was absent. The registry does not report the detailed statistical plan, sample-size justification, or handling of missing outcome data.