Effect of Lidocaine and Esmolol to Improve the Quality of Recovery: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Effect of Lidocaine and Esmolol to Improve the Quality of Recovery (NCT01114997), a randomized phase 4 study. The primary outcome is Post Operative Pain.

2. Clinical Question

The trial description also names recovery outcomes beyond pain, including opioid consumption, nausea, return to normal activities, patient satisfaction, and time in the post-anesthesia care unit. These outcomes address different aspects of recovery and do not all measure the same treatment effect. The posted results include pain and some secondary outcomes, but not every outcome named in the registry record.

The central question is comparative: whether outcomes differed among the three active treatment groups. Because all posted arms received one or both study drugs, the results do not directly compare either drug regimen with no study drug. The record describes a factorial model, but it does not report a factorial interaction analysis or a prespecified contrast that isolates the contribution of each drug across the combinations.

3. Trial Design

This was a randomized phase 4 study with a factorial model and an enrollment of 32. The registry record lists three drug arms: lidocaine, esmolol, and lidocaine plus esmolol. It identifies lidocaine as the reference group for the posted comparisons. The record does not describe a placebo arm among the reported groups.

The masking information is not fully consistent in its wording: the registry design field identifies quadruple masking, while the brief study description calls the study double-blinded. The registry record does not explain this difference or specify which roles were masked. Allocation concealment procedures are not reported in the registry record.

The study was sponsored by Cedars-Sinai Medical Center. Its recorded start was 2010-04, primary completion was 2015-06, and its status is terminated. The reason for termination, whether recruitment stopped early, and any effect of termination on the analysis are not reported in the registry record. The record identifies the trial as phase 4 but does not give the original recruitment target or the planned duration of enrollment.

Interventions involved intravenous drug administration. The descriptions specify loading doses before induction and infusions after induction; the combination arm received both drugs. The record describes the intended assessment as postoperative outcomes while maintaining hemodynamic stability during general anesthesia. It does not report detailed anesthesia co-interventions or how hemodynamic stability was defined.

The arm sizes for the primary outcome were 11 for lidocaine, 10 for esmolol, and 11 for the combination. The registry record does not report whether all randomized participants were included in every outcome analysis, how missing outcome data were handled, or whether analyses followed intention-to-treat principles.

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 Post Operative Pain, measured over 1 day.

The primary endpoint is postoperative pain measured with a verbal rating scale during the first day in the post-anesthesia care unit. The scale runs from 0, meaning no pain, to 10, meaning intolerable pain. The posted summary reports a mean and standard deviation for each arm.

A pain score provides a continuous measure of symptom intensity rather than simply classifying participants as having pain or not having pain. Comparing group means can therefore describe differences in average reported pain while retaining more of the scale’s gradation. The standard deviation describes how dispersed individual scores were around each group mean; it is not the uncertainty in the mean itself.

Pain is relevant to the study’s recovery question because the registry description identifies postoperative pain as one intended outcome of the drug regimens. However, the endpoint represents only one component of recovery. It does not by itself summarize bowel function, nausea, opioid use, return to activities, satisfaction, or length of stay. Nor does a group mean show whether each participant experienced the same degree of pain or whether a particular change would be important to an individual patient.

The posted outcome concerns one day in the post-anesthesia care unit. The registry record does not report a longer-term pain endpoint or a threshold for interpreting a difference as clinically important. The reported scale and timeframe define what the primary result can describe; they do not establish a broader effect on recovery.

7. Results Posted in the Registry

• Esmolol: mean 2.00 versus 4.00 on control; difference -2.00 (95% CI -4.67 to 0.67), standardized effect d = -0.62; z-test p = 0.142.
• Lidocaine + Esmolol (Combo): mean 4.00 versus 4.00 on control; difference 0.00 (95% CI -2.95 to 2.95), standardized effect d = 0.00; z-test p = 1.000.

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.

Opioid Consumption Obtained From the Recorded Data

• 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:
  • Esmolol: mean 1.00 versus 1.50 on control; difference -0.50 (95% CI -1.27 to 0.27), standardized effect d = -0.55; z-test p = 0.204.
  • Lidocaine + Esmolol (Combo): mean 1.50 versus 1.50 on control; difference 0.00 (95% CI -0.84 to 0.84), standardized effect d = 0.00; z-test p = 1.000.
• Interpretation:
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between Esmolol and the control. The interval gives the range of effects that remain compatible with the data.
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between Lidocaine + Esmolol (Combo) and the control. The interval gives the range of effects that remain compatible with the data.

Number of Participants With Postoperative Nausea One Day After Surgery

• 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:
  • Esmolol: 20.0% (2/10) versus 27.3% (3/11) on control; risk difference -7.3 percentage points (95% CI -43.4 to 28.9), risk ratio 0.73 (0.15–3.53); unadjusted two-proportion z-test p = 0.696.
  • Lidocaine + Esmolol (Combo): 27.3% (3/11) versus 27.3% (3/11) on control; risk difference 0.0 percentage points (95% CI -37.2 to 37.2), risk ratio 1.00 (0.26–3.91); unadjusted two-proportion z-test p = 1.000.
• Interpretation:
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between Esmolol and the control. The interval gives the range of effects that remain compatible with the data.
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between Lidocaine + Esmolol (Combo) and the control. The interval gives the range of effects that remain compatible with the data.

Return to Normal Activities of Daily Living Using Follow up Questionnaires

• 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:
  • Esmolol: 80.0% (8/10) versus 90.9% (10/11) on control; risk difference -10.9 percentage points (95% CI -41.0 to 19.1), risk ratio 0.88 (0.61–1.26); unadjusted two-proportion z-test p = 0.476.
  • Lidocaine + Esmolol (Combo): 72.7% (8/11) versus 90.9% (10/11) on control; risk difference -18.2 percentage points (95% CI -49.5 to 13.1), risk ratio 0.80 (0.53–1.20); unadjusted two-proportion z-test p = 0.269.
• Interpretation:
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between Esmolol and the control. The interval gives the range of effects that remain compatible with the data.
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between Lidocaine + Esmolol (Combo) and the control. The interval gives the range of effects that remain compatible with the data.

The posted secondary outcomes cover several parts of recovery: opioid consumption, postoperative nausea, return to normal activities, patient satisfaction, and post-anesthesia care unit stay. Results are included for opioid consumption, nausea, and return to activities. Results for patient satisfaction and post-anesthesia care unit stay are not reported in the registry record.

Across the secondary outcomes with posted results, the estimates do not present a uniform pattern of clear separation between the treatment groups. Some point estimates favor one group and others are similar, while the associated uncertainty is substantial. This broad pattern is consistent with the primary pain results: the posted comparisons are not precise enough to establish a clear difference, but they also do not establish equivalence.

These outcomes are related to postoperative recovery but are not interchangeable with pain. Opioid consumption is a recorded amount, nausea is a participant count, and return to normal activities is a later recovery measure. They differ in scale, timing, and clinical interpretation. A result on one measure cannot be assumed to apply to the others.

The secondary comparisons are unadjusted, and the registry record does not report a multiplicity plan. When many outcomes and pairwise comparisons are examined, the chance of observing an apparently unusual result by chance can increase. Without a prespecified hierarchy or adjustment, individual secondary p-values deserve less weight than a result from a clearly documented primary analysis. The record also does not report whether secondary outcomes were prespecified in the statistical plan or how missing questionnaires were handled.

The secondary evidence should therefore be read as descriptive and exploratory. It can indicate what was observed in the recorded groups, but it does not independently confirm a broad improvement in recovery or resolve the uncertainty in the primary pain comparison.

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

• Opioid Consumption Obtained From the Recorded Data
• Number of Participants With Postoperative Nausea One Day After Surgery
• Return to Normal Activities of Daily Living Using Follow up Questionnaires
• Patient Satisfaction
• Post-anesthesia Care Unit (PACU) Stay

9. Statistical Interpretation

10. Statistical Methods Explained

What does a mean difference describe?

The pain outcome is continuous, so the comparison is expressed as the difference between two group means. A negative mean difference in these comparisons means the mean in the named intervention arm is lower than the mean in the lidocaine reference arm. For the esmolol comparison, the posted estimate is -2.0; for the combination comparison, it is 0.0. These are unadjusted differences based on the posted group summaries, not estimates from an adjusted regression model described in the registry record.

General statistical explanation: a mean difference is a compact description of how far apart two group averages are on the outcome’s original scale. It does not show the full distribution of individual responses. Two groups can have different means while their participant-level scores overlap considerably, especially when variation within groups is large.

What does the standard deviation describe?

The standard deviation describes variation among observed scores within a group. For pain, the posted standard deviations are 4.0 for lidocaine, 2.0 for esmolol, and 3.0 for the combination. They indicate that individual scores were not all concentrated at the group means. A standard deviation is not a confidence interval and does not directly quantify how uncertain the mean difference is.

General statistical explanation: uncertainty in a difference depends on both the variability of the outcome and the number of observations. More variability or fewer participants generally leads to less precise estimates. This is one reason that the pain confidence intervals are broad in this trial.

How should the confidence interval be read?

A confidence interval gives a range of values compatible with the observed data under the calculation’s assumptions. The esmolol-versus-lidocaine interval spans -4.669 to 0.669. It includes zero, so the data do not rule out no difference under this interval calculation. It also includes values on either side of zero, so the result does not pin down the direction or magnitude precisely. The combination-versus-lidocaine interval spans -2.955 to 2.955 and likewise includes zero and differences in either direction.

General statistical explanation: a confidence interval is not a guarantee that the true effect lies within the particular interval, nor is it a range containing a stated proportion of individual participants’ outcomes. Its width is useful for judging precision, while its location describes the range of group effects compatible with the calculation.

What do the p-values contribute?

The reported unadjusted p-values are 0.142 for esmolol versus lidocaine and 1.0 for the combination versus lidocaine. A p-value measures how unusual the observed data, or more extreme data, would be under a specified null model of no difference, given the assumptions of the test. It is not the probability that the null hypothesis is true, and it does not measure the clinical importance of a difference.

General statistical explanation: interpreting a p-value requires attention to the estimate and its confidence interval, the study design, and the analysis plan. A p-value that does not cross a conventional threshold does not prove there is no effect. In a small study, meaningful differences can remain compatible with the data because estimates are imprecise.

What does the factorial label establish?

The registry record labels the model factorial, but the posted groups and comparisons do not include a reported factorial analysis. A factorial analysis might evaluate effects associated with each treatment component and whether the combination behaves differently from what would be expected from the components separately. The record does not report such estimates, an interaction test, or the exact planned factorial contrasts. The pairwise comparisons against lidocaine should not be treated as substitutes for those missing analyses.

General statistical explanation: an interaction concerns whether the effect associated with one treatment component varies according to the presence of another component. It is a different question from comparing each listed arm with a reference arm. Without a reported interaction analysis, the posted pairwise estimates cannot establish whether the two drugs act independently or jointly.

What does over-dispersion mean for these outcomes?

General statistical explanation: over-dispersion arises when the observed variability in data is greater than a statistical model assumes. It can make standard errors too small and confidence intervals too narrow if the model does not account for the extra variability. The registry record does not report a model-based analysis of the pain scores or a specific assessment of over-dispersion. The primary outcome is summarized with means and standard deviations, so no claim about an over-dispersion adjustment can be made.

The secondary binary outcomes are counts of participants with an outcome, while opioid consumption is a continuous measure. Different outcome types call for different analytic approaches. The registry record does not report the statistical methods used for those secondary outcomes. The posted pairwise secondary calculations are unadjusted and should be distinguished from a prespecified model-based analysis.

Overall, the methods that can be described from the record are limited to the random allocation, masking and factorial labels, the posted summaries, and the unadjusted recalculations. The planned statistical analysis, any covariate adjustment, any handling of repeated measurements, and any model diagnostics are not reported in the registry record.

11. Confidence Intervals and Precision

Precision concerns how narrowly the data estimate a group difference. The pain comparison of esmolol with lidocaine has a point estimate of -2.0, but its confidence interval stretches from -4.669 to 0.669. It covers a range that includes no difference and possible differences in either direction. The combination comparison has an estimate of 0.0 and an interval from -2.955 to 2.955. That interval also allows a wide range of possible effects.

These intervals are wide in relation to the point estimates, so the posted results do not identify the pain contrasts precisely. The small arm sizes—11, 10, and 11 participants—are relevant context. A few individual scores can have substantial influence on group means in a small sample, particularly when the standard deviations are large.

General statistical explanation: a confidence interval’s width reflects sampling uncertainty under the calculation’s assumptions. It should not be read as a measure of how variable outcomes are for individual participants; the standard deviation addresses that different question. A narrow interval would indicate greater precision, but it would not by itself establish clinical importance or freedom from bias.

The record does not report a clinically important difference threshold for the pain scale. As a result, the confidence intervals cannot be classified using a registry-defined threshold for meaningful benefit or harm. The absence of a statistically clear difference is not evidence that the treatments are equivalent. Equivalence requires a defined margin and an analysis designed to assess whether the interval lies within that margin; these are not reported in the registry record.

Precision is also limited by the absence of reported adjusted analyses and details about missing outcomes. The posted intervals describe the unadjusted comparisons based on the available summaries. They do not account for any unreported covariates, missing-data procedures, or multiplicity adjustment.

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 participants, for the continuous and binary outcomes reported in this trial. They use a two-sided significance level of 0.05, equal allocation between the two arms, and a normal approximation. The effect to detect is set to the stated fraction of the observed effect. The trial’s own original sample-size assumptions and justification are not reported in the registry record.

The 80% power column describes the number of participants per arm estimated to give an 80% chance of detecting the specified effect under those planning assumptions, if that effect is truly present. The 90% power column describes a higher target chance of detection under the same assumptions and therefore generally requires more participants per arm. These are design-planning quantities, not descriptions of the trial’s actual ability to detect an effect after it was completed.

For the primary pain comparison of esmolol with lidocaine, the planning illustration gives 41 participants per arm for 80% power and 55 for 90% power when planning for 100% of the observed effect. Planning for 75% of the observed effect gives 72 and 97 participants per arm; planning for 50% gives 162 and 217. The smaller assumed effects require larger samples because they are harder to distinguish from random variation.

These planning calculations use an effect estimated from this small trial, so they are illustrative rather than a substitute for a prospectively justified design. They are not observed power. The assumptions used for this illustration are known, but the registry record does not report whether the original trial used these assumptions or another method. Interpretation should also account for the fact that planning from an observed effect can be sensitive to how imprecisely that effect was estimated.

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 = -2.000; pooled standard deviation σ = 3.212.
2. n = 2 × (1.96 + 0.842)² × 3.212² / -2.000² = 40.5, rounded up to 41 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 <- -2                      # observed difference in means
sigma <- 3.21182027418786                     # 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(1114997)
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 = 41 (80% power), 55 (90% power)
 75% of observed effect: n per arm = 72 (80% power), 97 (90% power)
 50% of observed effect: n per arm = 162 (80% power), 217 (90% power)
power.t.test: 41.5 
Simulated power at n = 41 per arm: 0.796 (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 multiplicity was handled. There is one primary outcome and several secondary outcomes, and the posted results include pairwise comparisons of the two other arms with lidocaine. Without a reported hierarchy, family of tests, or adjustment method, it is not possible to determine whether any p-values were intended to control the chance of false-positive findings across outcomes or comparisons.

General statistical explanation: testing many hypotheses creates more opportunities for a small p-value to appear by chance, even when no underlying effects are present. Multiplicity procedures can address this issue, but they can also affect how estimates and intervals are interpreted. Since the analysis plan is not reported in the registry record, the unadjusted p-values should not be interpreted as multiplicity-controlled evidence.

The registry record does not report the analysis population, whether participants were analyzed in their randomized groups, or whether any participants were excluded from outcome analyses. It also does not describe missing-data amounts, reasons for missingness, imputation, or sensitivity analyses. For the secondary outcome on return to normal activities, the record names follow-up questionnaires, but it does not provide a questionnaire response rate or a missing-data approach.

The study is labeled factorial, but no factorial contrasts, interaction analysis, or analysis plan for the factorial structure are reported. It is therefore unclear whether the posted comparisons reflect the intended primary analysis or a subset of planned analyses. The record also does not report interim analyses, stopping rules, a protocol-level analysis plan, or a sample-size justification.

These omissions limit assessment of the analysis beyond the posted summaries and unadjusted recalculations. They do not establish that a particular procedure was or was not used; they mean the relevant methods are not reported in the registry record.

15. Safety Results

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

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 summaries report zero affected participants in the lidocaine group, with 11 at risk; zero in the esmolol group, with 10 at risk; and zero in the combination group, with 10 at risk. For other adverse events, the record likewise reports zero affected participants, with 11 at risk for lidocaine, 10 for esmolol, and 11 for the combination.

These figures describe the counts recorded for the groups and the corresponding at-risk denominators. A count of zero means no affected participants were reported in that category for those participants. It does not demonstrate that adverse events cannot occur, and the small group sizes limit what can be inferred about uncommon events.

Death counts are not reported in the registry record. The registry record also does not list serious adverse event terms or provide details on event definitions, observation periods, severity, or relatedness to treatment. The safety summaries should therefore be interpreted as limited recorded counts, not as a complete characterization of safety.

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

The posted primary outcome describes average pain scores during the first day in the post-anesthesia care unit for participants assigned to three active regimens. The esmolol group had a lower mean score than the lidocaine group, while the combination and lidocaine groups had equal reported means. The unadjusted comparisons have wide confidence intervals that include no difference. These findings leave uncertainty about the actual size and direction of the group differences.

They do not establish that esmolol reduces pain, that the combination has no effect, or that the regimens are equivalent. The point estimate is only one part of the evidence; precision, design, outcome reporting, and the analysis plan also matter. The registry record does not report a clinically important difference threshold or an equivalence margin.

The record includes some secondary recovery outcomes, but they measure different constructs and are not a substitute for the primary endpoint. Unadjusted secondary analyses and multiple comparisons warrant caution. Results for patient satisfaction and post-anesthesia care unit stay are not reported in the registry record.

These findings apply to the participants and outcomes recorded in this trial. The record does not provide enough information to establish how representative the participants were, how missing outcomes were handled, or what the original analysis plan specified. The trial’s terminated status is documented, but the reason and any implications are not reported.

In general, a small randomized trial can provide useful estimates while leaving wide uncertainty. A result that does not clearly distinguish groups should not be treated as proof of no difference. Likewise, a numerical difference alone does not prove a treatment effect. The posted statistics describe the observed comparisons; they do not support medical advice or a general conclusion about treatment for patients beyond the recorded study.

17. Why This Trial Matters Statistically

This trial is statistically informative because its results illustrate the distinction between an observed estimate and a precise conclusion. The pain means differ numerically between some arms, but the confidence intervals are broad and include no difference. A point estimate alone can give an overly definite impression when the sample is small; considering the interval shows how much uncertainty remains.

The factorial label also highlights the importance of matching the statistical question to the design. Pairwise comparisons against lidocaine answer whether each listed arm’s posted average differs from that reference. They do not, by themselves, estimate an overall effect of each drug component or test whether the drugs interact. Those analyses are not reported in the registry record.

The study also emphasizes the role of transparent analysis plans. The registry record identifies several outcomes and a factorial design, but does not report the planned sample-size justification, multiplicity approach, analysis population, or missing-data methods. Those details are important for determining how confirmatory the results are and how to interpret a set of unadjusted comparisons.

Finally, planning calculations based on observed effects can help illustrate how the required sample size changes when a smaller effect is targeted. They are not evidence about the power achieved by this trial and should not be mistaken for its original design rationale. Separating these planning illustrations from the observed outcome results keeps the interpretation grounded in what was actually recorded.

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.

The primary outcome is based on small groups: 11 participants in the lidocaine arm, 10 in the esmolol arm, and 11 in the combination arm. This limits precision and makes the estimates vulnerable to random variation in individual pain scores. The posted confidence intervals are wide, and the record does not report a clinically important difference threshold.

The comparisons are unadjusted recalculations from posted summaries rather than reported sponsor analyses. No reported primary analysis is listed in the registry record. It does not describe the planned factorial contrasts, an interaction test, covariate adjustment, or the statistical method used for the original analysis. The masking descriptions also differ: a design field says quadruple masking, whereas the brief description says double-blinded; the record does not resolve that discrepancy.

The study status is terminated, but the reason for termination and its effect on recruitment or analysis are not reported. The original sample-size target and justification are also not reported. Consequently, it is not possible to determine from the registry record whether enrollment met a prespecified target or why the study ended.

Outcome completeness is unclear. The registry record does not describe missing data, analysis populations, or sensitivity analyses. Results for patient satisfaction and post-anesthesia care unit stay are not reported, although those outcomes are named among the secondary measures. Safety reporting gives zero affected participants in the listed categories but does not include death counts or event details.

These limitations constrain conclusions about precision, generalizability, and the completeness of the analyses. They do not show that unreported procedures were absent; those methods and details are simply not reported in the registry record.

19. Related Tutorials

20. Related Statistical Calculators

21. Sources

• ClinicalTrials.gov: Effect of Lidocaine and Esmolol to Improve the Quality of Recovery — NCT01114997.
• Registry record last updated 2016-11-03; status last verified 2016-09.
• Results first posted 2016-06-23.
• 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

NCT01114997 is a randomized phase 4 study of intravenous lidocaine, esmolol, and their combination during abdominal surgery. The registry record labels the model factorial and reports an enrollment of 32. It lists the study status as terminated, with a start of 2010-04 and primary completion of 2015-06.

The primary outcome is postoperative pain measured with a 0-to-10 verbal rating scale during the first day in the post-anesthesia care unit. Posted group means are 4.0 for lidocaine, 2.0 for esmolol, and 4.0 for the combination. Unadjusted comparisons have wide confidence intervals that include no difference.

Some secondary outcomes are reported, while results for patient satisfaction and post-anesthesia care unit stay are not reported in the registry record. The record does not report the original sample-size justification, analysis plan, multiplicity approach, analysis populations, or missing-data methods.