This page provides an independent statistical analysis and educational interpretation of publicly reported results. ClinicalTrials.gov provides the official trial registry record. Numerical trial results on this page are restricted to the results posted in the ClinicalTrials.gov record; calculations added by Clinical Biostats are labelled as such.
1. Trial at a Glance
This page covers the registry results for The Study of Regional Hemodynamic Changes After Specific Brachial Plexus Block by Ultrasound Guidance (NCT02139982), a randomized phase 1 study. The primary outcome is Changes in Hemodynamic Parameters of Radial/Ulnar Artery From Baseline to 30min After Specific Nerve Block Followed by 30min After Brachial Plexus Block(Phase 1).
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT02139982 |
| Phase | Phase 1 |
| Condition | Upper Limb Nerve Block |
| Allocation | Randomized |
| Design model | Parallel |
| Masking | Double |
| Enrollment | 110 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Wenzhou Medical University |
| Results posted | Yes |
2. Clinical Question
Population
The record concerns upper limb nerve block. It does not report detailed eligibility criteria, participant characteristics, or whether participants were patients undergoing microvascular surgery. The summary describes the study as intended to inform further research in that setting, rather than establishing that this was the population enrolled.
Intervention
In the phase 1 component, the interventions were specific musculocutaneous, ulnar, radial, or median nerve blocks. The summary also describes a phase 2 dose-response component using ropivacaine after supraclavicular block, with listed concentrations from 0.125% to 0.75% in a 30ml volume.
Comparator
The phase 1 groups correspond to different specific nerve blocks, and the phase 2 groups correspond to different ropivacaine concentrations. The record does not specify a single control group or a primary pairwise comparison. Allocation is listed as randomized, but the allocation sequence and group sizes are not reported in the registry record.
Primary question
The primary endpoint asks how radial and ulnar artery hemodynamic parameters change from baseline to 30 minutes after a specific nerve block and then to 30 minutes after brachial plexus block. The measures are peak systolic velocity, end-diastolic velocity, and time average maximum velocity, measured by pulsed-wave Doppler ultrasound. No numerical endpoint results or between-group estimates are reported in the registry record.
3. Trial Design
The registry record lists a randomized, double-masked, parallel design and a Phase 1 classification. It lists enrollment of 110 and a completed status. The record dates the study start to 2011-01 and primary completion to 2012-12. It identifies Wenzhou Medical University as sponsor. These design details do not establish how participants were allocated, how masking was maintained, or how many participants entered each group; those details are not reported in the registry record.
The listed phase 1 groups received specific musculocutaneous, ulnar, radial, or median nerve blocks. The primary endpoint follows radial and ulnar artery parameters at baseline, 30 minutes after the specific nerve block, and 30 minutes after a brachial plexus block. Skin temperature change is also listed as a secondary outcome over this sequence.
The study summary additionally describes a phase 2 randomized, double-blind, prospective dose-response component. Its listed groups received 30ml ropivacaine at concentrations of 0.125%, 0.2%, 0.25%, 0.375%, 0.5%, or 0.75%. The stated aims include estimating ED50 and ED95 for sympathetic block after supraclavicular block. The summary also notes block success and skin temperature change as phase 2 secondary outcomes. Although those details appear in the summary, the registry record’s phase classification is Phase 1. The relationship between the phase 1 and phase 2 components, including their enrollment and analysis populations, is 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.
Only the first 6 of 10 groups are shown.
Overall Study
| Stage | Group MC(Phase 1) | Group UL( Phase 1) | Group RA (Phase 1) | Group ME (Phase 1) | Group A(Phase 2) | Group B(Phase 2) |
|---|---|---|---|---|---|---|
| STARTED | 8 | 8 | 8 | 8 | 13 | 13 |
| COMPLETED | 8 | 7 | 8 | 7 | 13 | 13 |
| NOT COMPLETED | 0 | 1 | 0 | 1 | 0 | 0 |
Reasons for not completing this period:
| Reason | Group MC(Phase 1) | Group UL( Phase 1) | Group RA (Phase 1) | Group ME (Phase 1) | Group A(Phase 2) | Group B(Phase 2) |
|---|---|---|---|---|---|---|
| Lack of Efficacy | 0 | 1 | 0 | 1 | 0 | 0 |
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.
Only the first 6 of 11 groups are shown.
| Characteristic | Unit | Group MC(Phase 1) | Group UL( Phase 1) | Group RA (Phase 1) | Group ME (Phase 1) | Group A(Phase 2) | Group B(Phase 2) |
|---|---|---|---|---|---|---|---|
| Participants analysed | 8 | 8 | 8 | 8 | 13 | 13 | |
| Age, Continuous | years | 41 (SD 13) | 31 (SD 7) | 42 (SD 19) | 38 (SD 17) | 31 (SD 10) | 36 (SD 14) |
| Sex: Female, Male: Female | Participants | 3 | 3 | 4 | 3 | 8 | 5 |
| Sex: Female, Male: Male | Participants | 5 | 5 | 4 | 5 | 5 | 8 |
| Region of Enrollment: China | participants | 8 | 8 | 8 | 8 | 13 | 13 |
6. Primary Endpoint
The registry lists the primary outcome as Changes in Hemodynamic Parameters of Radial/Ulnar Artery From Baseline to 30min After Specific Nerve Block Followed by 30min After Brachial Plexus Block(Phase 1), measured over baseline(t0), 30 min after specific nerve block(t1), 30 min after brachial plexus block(t2).
| Element | Registry entry |
|---|---|
| Result type | Mean |
| Measure of spread | Standard Deviation |
| Unit | cm/s |
| Endpoint classification | Continuous Endpoint |
The primary endpoint is a set of continuous hemodynamic measurements from the radial and ulnar arteries. It includes peak systolic velocity (PSV), end-diastolic velocity (EDV), and time average maximum velocity (TAMAX), measured using pulsed-wave Doppler ultrasound. The unit is cm/s, and the endpoint describes means with standard deviations. Measurements are scheduled at baseline (t0), 30 minutes after specific nerve block (t1), and 30 minutes after brachial plexus block (t2).
These measures characterize blood-flow velocity at different points in the study sequence. Comparing measurements across those time points can describe whether the recorded arterial velocities change after each block. The timing is relevant to the stated research question about regional hemodynamic changes following specific nerve block and subsequent brachial plexus block. General statistical context: repeated measurements on the same participant are related, so an analysis should account for that dependence when estimating changes or comparing groups. The registry record does not report the statistical method used for the endpoint.
The endpoint contains several measures and time points rather than one registry-reported contrast. Numerical means, standard deviations, and estimates of change are not reported in the registry record. As a result, the endpoint definition can be described, but the magnitude, direction, and precision of any observed change cannot be assessed from the registry record.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry record defines the primary outcome but does not provide its numerical results. It gives no group-specific means or standard deviations for PSV, EDV, or TAMAX at baseline, t1, or t2, and no estimated changes between those times. No confidence intervals, p-values, or other inferential results are reported. Accordingly, the record does not support a conclusion about the size, direction, or statistical precision of the hemodynamic changes.
The endpoint covers multiple arterial parameters and measurement times. Without reported estimates, it is not possible to distinguish whether the measurements changed after the specific nerve block, after the subsequent brachial plexus block, or differently across the nerve-block groups. The listed secondary outcomes include skin temperature changes in the phase 1 sequence, block success in phase 2, and skin temperature changes in phase 2. Numerical results for these outcomes are also not reported in the registry record.
The summary states an aim to determine ED50 and ED95 in the dose-response component. The registry record does not report estimates for either quantity or the data and analysis used to obtain them. The presence of listed ropivacaine concentrations alone does not show how response varied with concentration.
General statistical context: an estimate describes the observed magnitude of a difference or change, while a confidence interval conveys the range of values compatible with the data under the analysis assumptions. A p-value, if reported, would address compatibility with a specified null model; it would not by itself establish clinical importance. None of these numerical results is available in the registry record. The completion status and planned enrollment do not substitute for outcome data, and they cannot be used to infer a treatment effect.
9. Statistical Methods Explained
What does a mean and standard deviation describe?
The primary endpoint specifies means and standard deviations for continuous arterial velocity measures. General statistical context: a mean represents the arithmetic average of observations, while the standard deviation describes their spread around that average. Together they can describe a group’s measurements, but they do not by themselves show the uncertainty in a comparison or account for how measurements from the same participant are related. Numerical means and standard deviations are not reported in the registry record.
Why does the timing of measurements matter?
The stated schedule has baseline, a measurement 30 minutes after specific nerve block, and a measurement 30 minutes after brachial plexus block. General statistical context: a change from baseline can be analyzed by comparing each participant’s later measurement with their own baseline, or by modeling measurements over time. These approaches address the repeated nature of the observations in different ways. The registry record does not report which approach was used, whether the primary comparison concerned t1, t2, or both, or how the sequence was represented in the analysis.
How should multiple measures and times be considered?
The endpoint includes PSV, EDV, and TAMAX at several time points, and the study also lists secondary outcomes. General statistical context: examining multiple outcomes or contrasts creates multiplicity. When many statistical tests are considered, the chance of at least one apparently unusual result can increase unless the analysis plan accounts for the testing structure. An analysis may specify one primary contrast, adjust for multiple comparisons, or present estimates descriptively with appropriate caution. The registry record does not report a multiplicity strategy or identify a single primary contrast among the listed measures and time points.
What can be inferred from the design description?
Randomization can, in general, help balance measured and unmeasured characteristics between groups, while masking can reduce some influences of expectations on conduct or assessment. Those benefits depend on implementation. The record lists randomized allocation and double masking, but details of sequence generation, concealment, who was masked, and whether masking was maintained are not reported in the registry record. The listed parallel model indicates distinct assigned groups, but it does not supply group sizes or establish the analysis population.
What do the planning assumptions mean?
General statistical context: a sample-size planning illustration asks what amount of information might be needed to detect a specified effect under stated assumptions. The planning assumptions described for this study use a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation; the effect to detect is expressed as a stated fraction of the observed effect. Such illustrations are conditional calculations, not evidence about the trial’s actual design or findings. They are not observed power. The registry record does not report the trial’s own sample-size justification, and no numerical planning outputs are reported in the registry record.
The record also cautions that the primary outcome has several categories or time points and is not reduced to one comparison. General statistical context: a planning calculation tied to a single contrast may not represent the information needed for a study with several correlated outcomes or repeated measurements. The assumptions and estimand would need to match the intended analysis for a planning result to be informative.
What statistical analysis is reported?
No analysis entries are reported for the outcomes. The registry record does not specify a model, adjustment variables, handling of repeated measures, missing-data method, or inferential procedure. General statistical context: reporting an estimate together with its uncertainty and a clear description of the analysis helps readers judge both the magnitude and precision of a finding. Without those details and results, the endpoint’s operational definition is not enough to reconstruct or evaluate the analysis.
10. Multiplicity, Missing Data and Analysis Populations
The primary outcome includes three named velocity measures at baseline and two post-block time points. The record does not identify one measure or one time contrast as the sole inferential target, and it does not report a multiplicity adjustment or hierarchy among outcomes. The secondary outcomes add skin temperature at specified times and phase 2 block success. The registry record does not report whether these outcomes were analyzed as confirmatory or descriptive, or how any multiple testing was handled.
Missing-data details are not reported in the registry record. There is no description of the number of participants with measurements at each time, reasons for missing observations, exclusions after enrollment, or methods for handling incomplete repeated measurements. Group-specific analysis populations and participant flow are also not reported. Without this information, the completeness of the endpoint data and the potential influence of missingness cannot be assessed.
General statistical context: missing observations can affect estimates if the chance of missingness is related to participant characteristics or outcomes. An analysis should describe how missing data were handled and what assumptions support that method. Similarly, an analysis population should be defined so readers know which participants contributed to each estimate. No such methods or population definitions are reported in the registry record.
The adverse-event listing contains zero values for at-risk and affected counts in each listed group, while death entries are null. These fields do not establish the extent of safety monitoring, the denominators assessed, or whether adverse-event information is complete. Those details are not reported in the registry record.
11. What the Result Does, and Does Not, Mean
The registry record establishes that the study was completed and describes a randomized, double-masked, parallel design, a primary endpoint, and a set of intervention groups. It also reports enrollment of 110. These registry entries describe the registered study, not its outcome findings. Because numerical primary and secondary results are not reported, the record does not show the direction or size of arterial velocity or skin temperature changes, the success of brachial plexus block, or the relationship between ropivacaine concentration and response.
The summary’s aims should not be mistaken for results. In particular, an aim to estimate ED50 and ED95 does not provide those estimates. Listing several concentrations does not show a dose-response pattern, and completion status does not establish that any prespecified endpoint was met.
General statistical context: a result’s practical meaning depends on the estimated magnitude, its uncertainty, the relevance of the measurement, and the analysis population. Statistical significance alone, if available, would not determine whether a difference is important. Here, the registry record supplies no estimates or uncertainty intervals for interpreting the endpoint. No treatment-effect conclusion can therefore be drawn from the record.
The planning assumptions are not evidence of observed effect or observed power. Any planning illustration based on an observed effect is a conditional sample-size calculation, not a substitute for reported trial results. The registry record does not report the trial’s own design justification or analysis plan, so readers cannot determine whether the planning illustrations match the original study decisions.
12. Why This Trial Matters Statistically
Statistically, the study raises a question about measurement over time and across more than one arterial parameter. Such a design calls for clear specification of the target contrast: for example, whether the principal interest is change after the specific nerve block, change after the subsequent brachial plexus block, or differences among the nerve-block groups. The registry record describes the measurement sequence but does not identify one such contrast as the unique analysis target.
The study also combines a phase 1 regional hemodynamic question with a described phase 2 ropivacaine dose-response question. Keeping these aims and their analysis populations distinct is important when interpreting outcomes. The record lists a Phase 1 classification while its summary describes both phases; the relationship between the components is not reported in the registry record.
General statistical context: repeated outcomes can contain useful information about timing, but they are correlated and can produce many possible comparisons. A prespecified analysis can clarify which contrast is primary and how uncertainty and multiplicity are handled. A dose-response analysis likewise needs to connect dose levels to a defined response and model. Although the record states the dose-response aim and concentrations, it does not report such an analysis or its estimates.
The statistical value of the record is therefore chiefly in its description of the planned questions and measurement schedule. The absence of endpoint estimates and analysis details means that it cannot answer whether or how strongly those questions were resolved.
13. 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 principal limitation for interpretation is that numerical outcome results are not reported in the registry record. There are no group-level arterial velocity summaries, changes over time, dose-response estimates, or uncertainty measures. The record therefore does not permit evaluation of effect magnitude or precision.
Several design details needed to understand the study are also not reported in the registry record: eligibility criteria, participant characteristics, group-specific enrollment, allocation procedures, details of masking, participant flow, and definitions of the analysis populations. The record does not explain how the phase 1 and phase 2 components relate to one another or report their separate enrollment and outcome reporting.
The primary endpoint covers multiple measures and time points, but the record does not identify a single principal contrast or describe statistical methods for repeated measurements. No multiplicity approach, missing-data method, or original sample-size justification is reported. Consequently, neither the intended inferential framework nor the robustness of an analysis can be assessed.
Safety interpretation is limited as well. The adverse-event entries show zero at-risk and affected counts, and death entries are null, but the record does not describe monitoring, denominators, completeness, or ascertainment. Those entries should not be treated as evidence that adverse events did not occur.
14. Related Tutorials
15. Related Statistical Calculators
16. Sources
- ClinicalTrials.gov: The Study of Regional Hemodynamic Changes After Specific Brachial Plexus Block by Ultrasound Guidance — NCT02139982.
- Registry record last updated 2014-08-01; status last verified 2014-07.
- Results first posted 2014-07-24.
- 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.
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17. Record Summary
NCT02139982 is listed as a completed, randomized, double-masked, parallel study sponsored by Wenzhou Medical University, with enrollment of 110. The registry classifies it as Phase 1. Its primary outcome is change in radial and ulnar artery hemodynamic parameters—PSV, EDV, and TAMAX—measured by pulsed-wave Doppler ultrasound at baseline, 30 minutes after specific nerve block, and 30 minutes after brachial plexus block.
The record lists musculocutaneous, ulnar, radial, and median nerve-block groups. Its summary also describes a phase 2 ropivacaine dose-response component, with six listed concentrations in a 30ml volume. Numerical results, inferential analyses, missing-data methods, and a statistical analysis plan are not reported in the registry record. Thus the registered questions and design can be described, but the posted record does not provide findings with which to assess the primary outcome or the stated dose-response aims.