Effects of Intravenous Lidocaine Associated With Magnesium Sulfate on the Cisatracurium-Induced Neuromuscular Block: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Effects of Intravenous Lidocaine Associated With Magnesium Sulfate on the Cisatracurium-Induced Neuromuscular Block (NCT02483611), a randomized phase 4 study. The primary outcome is Latency.

2. Clinical Question

The trial’s stated context is the use of magnesium sulfate and lidocaine during anesthesia, including alongside neuromuscular blocking agents. The record notes concern that residual block can occur after anesthetic procedures and identifies the possibility of serious consequences. That background explains the pharmacodynamic focus, but it does not establish that a difference in latency would itself predict patient-important outcomes. The posted primary endpoint is a measured response to cisatracurium during the procedure.

3. Trial Design

The registry describes a randomized, triple-masked, parallel-group phase 4 trial sponsored by the University of Sao Paulo. It lists the trial as completed, with a start in 2015-07 and primary completion in 2015-08. The enrollment field reports 48. The three named groups were Group M, receiving magnesium sulfate; Group ML, receiving magnesium sulfate plus lidocaine; and Group C, receiving isotonic solution.

For Group M, the record describes magnesium sulfate 40 mg/Kg as a bolus and 20 mg/kg/h by continuous intravenous infusion during surgery. For Group ML, it describes 40 mg/kg magnesium sulfate and 3 mg kg-1 lidocaine as boluses, followed by continuous infusions at 20 mg/kg/h and 3 mg/kg/h, respectively. The text describing the cisatracurium dose in this group is truncated in the registry record. Group C received isotonic solution in a volume equivalent to that infused in the experimental groups, followed by 0.15 mg/kg cisatracurium infused over 5 seconds. Group M also received 0.15 mg/kg cisatracurium over 5 seconds.

The primary endpoint is latency, measured in seconds. The outcome description defines it as time from cisatracurium infusion until T1 response falls to 5% of initial contraction force. The registry says the sample size was calculated with 80% power to detect differences of 20% in clinical onset timing and duration of neuromuscular block. It identifies one-way analysis of variance and a Tukey post-hoc test, with p value < 0.05, for comparison between groups. Details of the randomization process, masking roles, eligibility criteria, and the full original statistical plan 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:

Analysis population for the primary outcome, as defined in the registry: The sample size was calculated with a power of 80% to detect differences of 20% in the timing of clinical onset and the duration of NMB. This pharmacodynamic variable was compared between the groups by analysis of variance (Anova one way) and Tukey post-hoc test (p value \< 0.05)

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.

Population: Forty-eight 18-60 yr. old ASA I/II patients, with a body mass index of 18 - 29 kg/m2 undergoing surgery at least 90 min. were randomly allocated to 3 treatment groups.Patients who were taking medications that could affect NMB and patients with neuromuscular, renal, hepatic, cardiac dysfunction, hypermetabolic or hypometabolic states were excluded.

6. Primary Endpoint

The registry lists the primary outcome as Latency, measured over Participants were followed during the anesthetic - surgical procedure, an average of 90 minutes.

The primary endpoint, latency, is the elapsed time from cisatracurium infusion until the measured T1 response has declined to 5% of its initial contraction force. It is reported as a mean in seconds with standard deviations. This is a continuous pharmacodynamic measure: it describes how quickly the specified neuromuscular response occurs after the study drug infusion.

Latency is used to characterize clinical onset timing, which is distinct from the duration of neuromuscular block. The registry’s background also discusses duration, but the posted primary outcome is latency. The registry describes the measurement as occurring during the anesthetic-surgical procedure, which averaged 90 minutes. It does not provide further detail about the measurement instrument, assessment schedule, or how missing measurements were handled.

In general, a group mean describes the average observed latency, while the standard deviation describes the spread of participant measurements around that mean. A difference in means expresses the contrast in average latency between groups. It does not, by itself, show how every participant responded, establish a causal mechanism, or indicate a patient-important benefit. The clinical interpretation depends on the size and precision of the estimated contrast as well as the endpoint’s relevance to outcomes beyond the measured neuromuscular response.

7. Results Posted in the Registry

• Group ML: mean 151.30 versus 139.70 on control; difference 11.60 (95% CI -21.62 to 44.82), standardized effect d = 0.24; z-test p = 0.494.
• Group C: mean 147.80 versus 139.70 on control; difference 8.10 (95% CI -19.79 to 35.99), standardized effect d = 0.20; z-test p = 0.569.

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.

MAP - M1 (Mean Arterial Pressure in the Moment 1)

• 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:
  • Group ML: mean 88.75 versus 94.63 on control; difference -5.88 (95% CI -12.89 to 1.13), standardized effect d = -0.58; z-test p = 0.100.
  • Group C: mean 100.10 versus 94.63 on control; difference 5.47 (95% CI -4.31 to 15.25), standardized effect d = 0.40; z-test p = 0.273.
• Interpretation:
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between Group ML 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 Group C and the control. The interval gives the range of effects that remain compatible with the data.

MAP - M2 (Mean Arterial Pressure in the Moment 2)

• 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:
  • Group ML: mean 84.69 versus 87.63 on control; difference -2.94 (95% CI -11.08 to 5.20), standardized effect d = -0.25; z-test p = 0.479.
  • Group C: mean 92.47 versus 87.63 on control; difference 4.84 (95% CI -3.76 to 13.44), standardized effect d = 0.40; z-test p = 0.270.
• Interpretation:
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between Group ML 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 Group C and the control. The interval gives the range of effects that remain compatible with the data.

MAP - M3 (Mean Arterial Pressure in the Moment 3)

• 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:
  • Group ML: mean 73.88 versus 75.88 on control; difference -2.00 (95% CI -9.57 to 5.57), standardized effect d = -0.18; z-test p = 0.605.
  • Group C: mean 76.73 versus 75.88 on control; difference 0.85 (95% CI -6.12 to 7.82), standardized effect d = 0.08; z-test p = 0.811.
• Interpretation:
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between Group ML 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 Group C and the control. The interval gives the range of effects that remain compatible with the data.

The registry lists secondary measures of mean arterial pressure at multiple moments and heart rate at multiple moments, and reports 24 secondary outcomes. The posted results include a subset of the blood-pressure measurements. Across those available measurements, the recalculated contrasts do not show a consistent direction or a clear separation between the groups: some point estimates favor lower values in an experimental group, while others favor higher values. Their uncertainty intervals include zero.

This general pattern does not change the interpretation of the primary latency result. Blood pressure measures are different outcomes, taken at specified moments in the anesthetic procedure, and they do not directly answer whether time to the defined T1 response differed. Nor do results from a subset of secondary measures resolve the uncertainty in the primary endpoint. The complete set of secondary outcome results is not reported in the record material, so a comprehensive account of their pattern is not possible.

Secondary outcomes are often examined to understand additional effects or describe the clinical setting, but multiple testing makes isolated nominal results less persuasive. When many outcomes or time points are assessed, the chance of at least one apparently unusual result can increase even if there is no underlying effect. The registry describes Tukey post-hoc testing for the primary comparison, but it does not report a multiplicity strategy for the secondary outcomes. Therefore unadjusted secondary results should be treated as exploratory and interpreted alongside their uncertainty, the number of analyses, and the primary endpoint, rather than as independent confirmation.

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

• MAP - M1 (Mean Arterial Pressure in the Moment 1)
• MAP - M2 (Mean Arterial Pressure in the Moment 2)
• MAP - M3 (Mean Arterial Pressure in the Moment 3)
• MAP - M4 (Mean Arterial Pressure in the Moment 4)
• MAP - M5 (Mean Arterial Pressure in the Moment 5)
• MAP - M6 (Mean Arterial Pressure in the Moment 6)
• HR - M1 (Heart Rate in the Moment 1)
• HR - M2 (Heart Rate in the Moment 2)

9. Statistical Interpretation

10. Statistical Methods Explained

The primary outcome is continuous, and the registry reports a mean and standard deviation for each group. A mean difference compares the average measured latency in one group with the average in another. The recalculated comparisons use Group M as the reference: the reported estimate is the comparison-group mean minus the Group M mean. A positive estimate therefore corresponds to a higher observed mean latency in the comparison group; a negative estimate would correspond to a lower mean.

A confidence interval describes a range of values compatible with the estimate under the method’s assumptions. It communicates uncertainty about the underlying difference, rather than a range containing a specified proportion of individual participant measurements. When an interval includes zero, the data are compatible with no difference as well as with differences in either direction. This does not demonstrate equivalence. Equivalence requires a prespecified margin and an analysis designed to assess whether the plausible differences lie within that margin; such a margin is not reported in the registry record.

The recalculated p-values are unadjusted pairwise results based on posted summary statistics. A p-value measures how incompatible the observed data are with a specified null hypothesis, under the assumptions of the analysis. It is not a measure of effect size, clinical importance, or the probability that a treatment has no effect. These recalculations do not account for the registry’s stated Tukey post-hoc procedure. The sponsor’s own analysis is reported separately as ANOVA with Tukey post-hoc testing.

The registry identifies one-way analysis of variance for the primary comparison. In general, analysis of variance assesses whether the group means are compatible with a common mean, considering the variability within groups. A post-hoc procedure such as Tukey’s can be used to make pairwise comparisons while accounting for the fact that multiple group contrasts are being examined. The registry record does not provide the full model specification, diagnostics, or detailed results of the Tukey pairwise contrasts.

Standard deviation describes the dispersion of individual observations around a group mean. It is not the same as the standard error, which describes uncertainty in an estimated mean. In general, standard errors become smaller when estimates are based on more observations or when observations are less variable. Here the group standard deviations and sample sizes underpin the uncertainty of the mean estimates, but the small group sizes leave appreciable uncertainty around the pairwise contrasts.

In general, over-dispersion matters when observed variability exceeds what a statistical model expects. A model that understates variability can produce confidence intervals that are too narrow and p-values that are too small. The primary outcome is analyzed as a continuous measure, and no over-dispersion assessment is reported in the registry record. The issue is therefore a general consideration rather than a claim about this trial’s fitted model.

The posted sample-size illustrations use a two-sided significance level of 0.05, equal allocation between the two arms, and a normal approximation. They use fractions of the observed effect as planning targets. These are planning calculations based on the observed contrasts, not the trial’s original design calculation. The registry separately states that its sample size calculation targeted 80% power to detect differences of 20% in onset timing and duration of neuromuscular block, but additional original design assumptions are not reported in the registry record.

General interpretation also depends on how participants were analyzed. An intention-to-treat analysis usually retains participants in their randomized groups, while a per-protocol analysis applies specified adherence criteria. Which analysis population was used for the primary outcome is not reported in the registry record. The record also does not describe imputation or other missing-data handling. These omissions limit assessment of whether the analysis population and missing observations could affect the results.

11. Confidence Intervals and Precision

The primary pairwise confidence intervals are wide relative to their point estimates. For Group ML compared with Group M, the estimated mean difference is 11.6 seconds and the 95% confidence interval runs from -21.62 to 44.82 seconds. For Group C compared with Group M, the estimated difference is 8.1 seconds and the 95% confidence interval runs from -19.79 to 35.99 seconds. Each interval includes zero and allows for differences in either direction.

In general, a 95% confidence interval is produced by a procedure that, under its assumptions and repeated application, would cover the true value in 95% of such intervals. It does not mean there is a 95% probability that the true difference lies within this particular interval. The interval is a useful expression of estimation uncertainty, but its validity depends on the analysis assumptions and the quality of the underlying data.

The confidence intervals do not indicate that the groups are equivalent. They show that these data are compatible with a range of mean differences, including no difference and differences on either side of zero. The registry does not report a threshold defining a clinically important difference in latency, so it is not possible to determine whether the entire plausible range would be considered clinically negligible or important.

Precision is also distinct from statistical significance. A p-value can summarize evidence against a null hypothesis, while a confidence interval shows the range and direction of effect estimates compatible with the data. Here, the pairwise recalculated p-values are 0.494 and 0.569, while both intervals span zero. The overall message is uncertainty about the magnitude and direction of the contrasts, rather than evidence that the effects are exactly zero.

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 sample-size figures are planning illustrations based on the observed pairwise effects, not the original trial’s design calculation. For these continuous-outcome comparisons, the figures are participants per arm, not total events. The assumptions are a two-sided significance level of 0.05, equal allocation between the two arms, and a normal approximation. The calculation considers the stated fraction of the observed effect as the effect to detect.

The 80% power column gives the number of participants per arm that the illustration estimates would be needed to have an 80% chance of detecting the selected effect at the stated significance level, if the assumptions hold and that effect is the true one. The 90% power column uses a higher chance of detecting that effect and therefore requires more participants per arm. The rows for planning for 75% or 50% of the observed effect represent smaller target effects than planning for the full observed effect. Smaller effects need more participants to detect with the same power under otherwise similar assumptions.

These figures are not observed power. They are not a retrospective measure of whether the completed trial was adequately powered, and they do not show that the effects in a future study will match the observed estimates. Planning from an observed effect is particularly uncertain when the estimate comes from a small study and has a wide confidence interval. A future design would need a justified target effect, variability assumptions, and design choices appropriate to its intended analysis.

The registry’s stated original planning basis is distinct: it says the sample size was calculated with 80% power to detect differences of 20% in clinical onset timing and duration of neuromuscular block. Further details of those original assumptions are not reported in the registry record.

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 = 11.600; pooled standard deviation σ = 47.945.
2. n = 2 × (1.96 + 0.842)² × 47.945² / 11.600² = 268.2, rounded up to 269 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 <- 11.6                      # observed difference in means
sigma <- 47.9450065178846                     # 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(2483611)
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 = 269 (80% power), 360 (90% power)
 75% of observed effect: n per arm = 477 (80% power), 639 (90% power)
 50% of observed effect: n per arm = 1,073 (80% power), 1,437 (90% power)
power.t.test: 269.1 
Simulated power at n = 269 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 sponsor’s reported primary method is one-way ANOVA with a Tukey post-hoc test. The registry lists ANOVA entries for the individual groups, with values of 149, 145.30, and 147.80, 95% confidence intervals, and a reported p-value of 0.965. Those entries are not presented as the same pairwise mean-difference estimates calculated from the posted group means and standard deviations. The registry record does not clarify the apparent difference in how the reported entries are labeled and presented.

The recalculated pairwise results are straightforward unadjusted comparisons derived from the posted summary statistics. They give mean differences of 11.6 seconds for Group ML versus Group M and 8.1 seconds for Group C versus Group M, each with a confidence interval that includes zero. These calculations are useful for reading the size and uncertainty of the pairwise contrasts, but they are not a replacement for the sponsor’s stated ANOVA and Tukey analysis.

The record does not flag a discrepancy between the registry’s analysis and the recalculation. Even so, the sponsor’s own analysis remains the trial’s reported analysis; the recalculations should be treated as supplementary unadjusted estimates, not as a correction to the sponsor’s method. The full Tukey contrasts and enough methodological detail to reconcile the different formats are not reported in the registry record.

15. Multiplicity, Missing Data and Analysis Populations

The registry describes one-way ANOVA and a Tukey post-hoc test for the primary outcome. Tukey’s procedure is generally intended to account for multiple pairwise comparisons among group means. However, detailed results of those post-hoc comparisons are not reported in the registry record. The pairwise recalculations presented alongside the posted summary statistics are unadjusted, so their p-values should not be interpreted as multiplicity-adjusted results.

The record lists many outcome measures and analyses, including secondary outcomes measured at multiple moments. It does not report a comprehensive multiplicity plan covering the full set of primary and secondary outcomes, specify a hierarchy of hypotheses, or identify which outcomes were confirmatory versus exploratory. In general, testing many outcomes increases the chance that at least one result will appear noteworthy by chance. This makes unadjusted secondary findings less conclusive unless they are supported by a prespecified analysis plan or independent evidence.

The record does not describe missing-data handling for the primary or secondary outcomes. It does not state whether observations were excluded, how missing measurements were treated, or whether sensitivity analyses were conducted. The analysis population is also not reported in the registry record: it is unclear whether the results use all randomized participants, a per-protocol subset, or another defined population. These details matter because exclusions and missingness can affect both the estimated means and the reliability of standard errors and confidence intervals.

Further information about allocation concealment, the exact masking procedures, statistical diagnostics, and protocol deviations is not reported in the registry record. These are not grounds for assuming that the analysis is biased, but their absence limits an independent assessment of the analysis process and of how robust the reported estimates are to alternative assumptions.

16. 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 adverse-event record lists zero serious adverse events and zero other adverse events for each named group. The reported at-risk counts are 16 for Group M, 16 for Group ML, and 15 for Group C. These entries describe what was recorded in the registry; they should not be interpreted as proof that no adverse events occurred outside the registry’s definitions, observation period, or reporting process.

Deaths are not reported in the registry record. The record does not provide event definitions, severity criteria beyond the serious-event category, collection procedures, or a detailed observation window for adverse events. It also does not provide information about event-specific exposure time. With limited group sizes and no events listed, the safety record has limited ability to characterize uncommon harms or compare risks precisely. These figures are a report of the posted safety data, not a comprehensive estimate of safety.

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

The posted results show observed mean latency values of 139.7 seconds in Group M, 151.3 seconds in Group ML, and 147.8 seconds in Group C. The recalculated pairwise mean differences are modest relative to the uncertainty reflected in their confidence intervals. Both intervals include zero and allow for effects in either direction. The data therefore do not establish a clear difference in the average measured latency between the compared groups, but they also do not establish that the groups are equivalent.

The registry’s reported analysis uses ANOVA and Tukey post-hoc testing, while the recalculated contrasts are unadjusted. Those analyses serve related but not identical purposes and should be distinguished. The registry’s own reported analysis takes precedence as the trial’s analysis; the recalculations help describe pairwise estimates from the posted summary statistics but do not replace the sponsor’s method.

The endpoint concerns the timing of a specified neuromuscular response after cisatracurium infusion. It does not directly measure how long the block lasts, whether residual block occurs after the procedure, or whether a patient experiences a complication. The registry background discusses broader concerns about residual blockade, but the primary results do not test all of those outcomes. The record does not report a clinically important difference threshold for latency, so the clinical meaning of the observed contrasts cannot be determined from the reported estimates alone.

The findings are limited to the trial population and procedure described in the registry. Details about eligibility, the analysis population, missing-data handling, and several aspects of the statistical plan are not reported in the registry record. The results are therefore best read as uncertain estimates of a pharmacodynamic endpoint, with incomplete information for judging how broadly they apply or how sensitive they are to analysis choices.

18. Why This Trial Matters Statistically

This trial illustrates a central statistical distinction: an estimated effect and the uncertainty around it must be considered together. The observed group means differ, but the pairwise confidence intervals are broad enough to include zero and differences in either direction. Looking only at the point estimates would overstate how decisively the data determine the direction or size of the contrast.

It also illustrates why a non-significant result is not the same as evidence of equivalence. A result with an interval that includes zero may reflect a truly small difference, or it may reflect insufficient precision to distinguish among a range of plausible effects. Demonstrating equivalence would require a clinical margin and an analysis designed around that margin; neither is reported in the registry record.

The registry reports both a planned ANOVA with Tukey post-hoc testing and group-level outcome summaries. Recalculating simple pairwise differences can help readers understand the direction and scale of the observed contrasts, but such recalculations do not reproduce all features of the sponsor’s analysis. Keeping the reported analysis distinct from unadjusted estimates is important when a trial has multiple groups and several outcomes.

Finally, the trial connects a narrowly defined physiological endpoint to a broader clinical concern. Statistical results for latency can describe onset timing, but they do not automatically establish consequences for residual block or patient outcomes. Clear interpretation depends on respecting what the endpoint measures, what the uncertainty permits, and what the registry does not report.

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.

The registry record leaves important details unavailable for independently assessing the trial. Eligibility criteria, participant characteristics, randomization procedures, allocation concealment, and the specific roles covered by triple masking are not reported. The text for the Group ML cisatracurium administration is truncated, which also limits reconstruction of that arm’s complete procedure from the record.

The primary outcome summary reports group means and standard deviations, while the sponsor’s reported ANOVA entries list values and confidence intervals in a format that is not directly equivalent to the recalculated pairwise contrasts. The full Tukey results, statistical model details, and diagnostic checks are not reported in the registry record. The record also does not specify the analysis population, missing-data methods, protocol deviations, or whether sensitivity analyses were performed.

The trial’s listed enrollment and group outcome counts are limited, and the recalculated confidence intervals are broad. This restricts precision, especially for judging whether meaningful differences in latency are compatible with the data. The registry does not define a clinically important difference threshold, so the practical importance of the estimated contrasts cannot be assessed against a prespecified benchmark.

Secondary outcomes are numerous, but the complete results and a comprehensive multiplicity plan are not reported. The adverse-event record lists no events in the reported categories, but does not provide detailed definitions or enough information to assess uncommon harms. Finally, the results concern latency during an anesthetic-surgical procedure; the record does not report outcomes that would directly establish effects on duration, residual block, or postoperative consequences.

20. Related Tutorials

21. Related Statistical Calculators

22. Sources

• ClinicalTrials.gov: Effects of Intravenous Lidocaine Associated With Magnesium Sulfate on the Cisatracurium-Induced Neuromuscular Block — NCT02483611.
• Registry record last updated 2016-01-15; status last verified 2015-12.
• Results first posted 2016-01-15.
• 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

NCT02483611 is a completed, randomized, triple-masked, parallel-group phase 4 trial sponsored by the University of Sao Paulo. It compared magnesium sulfate, magnesium sulfate plus lidocaine, and isotonic solution in the setting of cisatracurium-induced neuromuscular block. The primary endpoint was latency in seconds, defined by the time until the T1 response fell to 5% of initial contraction force.

The observed primary means were 139.7 seconds for Group M, 151.3 seconds for Group ML, and 147.8 seconds for Group C. Recalculated unadjusted pairwise differences have confidence intervals that include zero and leave substantial uncertainty about direction and magnitude. The registry reports ANOVA with Tukey post-hoc testing, but detailed pairwise results and several analysis-plan details are not reported in the registry record.