Evaluation of Volatile Induction and Maintenance Anesthesia (VIMA) With Sevorane in Adult Patients Requiring General Anesthesia for Surgery in Terms of Quality of Anesthesia and Its Influence on the Cardiovascular System in Common Clinical Practice: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Evaluation of Volatile Induction and Maintenance Anesthesia (VIMA) With Sevorane in Adult Patients Requiring General Anesthesia for Surgery in Terms of Quality of Anesthesia and Its Influence on the Cardiovascular System in Common Clinical Practice (NCT01282086), a registered phase not stated study. The primary outcome is Time to Loss of Consciousness of Patients Administered Anesthesia.

2. Clinical Question

The registry describes an observational study of volatile induction and maintenance anesthesia with Sevorane (sevoflurane) in adults requiring general anesthesia for surgery. Its stated aim was to collect information about anesthesia use in common clinical practice in Ukraine and support the development of local recommendations. The primary question concerns the time from anesthetic administration to loss of consciousness, defined by loss of the eyelash reflex. The registry also lists cardiovascular and other secondary outcomes.

This is not a randomized comparison of sevoflurane with another anesthetic or with a control group. The record describes a group of adults requiring anesthesia for surgery, and it does not identify a like-for-like comparator. Consequently, the main question is descriptive: what was the measured time to loss of consciousness among participants with available data, and what observations were recorded for the listed outcomes? The primary result itself is not reported in the registry record, so its magnitude and precision cannot be assessed from the reported information.

3. Trial Design

SEVOPROTECTION is identified as a post-marketing observational study. Its stated objective was to collect information about general anesthesia in patients undergoing surgery and use evaluation of volatile induction and maintenance anesthesia with Sevorane to inform local recommendations. The setting described in the study summary is common clinical practice in Ukraine. The registry lists 1365 participants under enrollment and one group description: adults requiring anesthesia for surgery.

The record marks the study as completed. Its start is listed as 2011-04 and primary completion as 2011-12. Abbott (Ukraine) is named as sponsor. These registry entries describe the study’s administrative record; they do not establish how consistently participants were managed or what other clinical factors were recorded.

The record does not describe a randomized allocation or a control group suitable for a like-for-like comparison. It also does not report a protocol-level account of treatment selection, data collection procedures, or an analysis plan. Therefore, the results should be read as observational descriptions rather than as estimates of a comparative treatment effect. Differences in patient characteristics or clinical practice could affect observed outcomes, but the registry record does not provide details sufficient to characterize or adjust for such factors.

The primary outcome is time to loss of consciousness, measured from anesthetic administration until loss of the eyelash reflex, with a timeframe listed as up to 16 minutes. Secondary outcomes include systolic blood pressure, diastolic blood pressure, mean arterial pressure, heart rate, electrocardiogram deviations during anesthesia, cardiac troponin T and creatine kinase myocardial isoenzyme when available, and a correlation between anesthesiologists’ clinical experience and hemodynamic parameters. The record lists 14 outcome measures, but the number of analyses is 0. Outcome descriptions alone do not provide numerical results or establish which secondary findings were available for analysis.

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

Analysis population for the primary outcome, as defined in the registry: All participants with available data were included in the analysis.

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 Time to Loss of Consciousness of Patients Administered Anesthesia, measured over Up to 16 minutes.

The primary endpoint is the time from administration of the anesthetic until loss of consciousness, operationalized as the loss of the eyelash reflex. The registry specifies minutes as the unit and gives a timeframe of up to 16 minutes. It states that the endpoint is summarized as a mean with standard deviation and that all participants with available data were included in the analysis.

This measure is used to describe the timing of an observable point during anesthetic induction. A defined clinical sign makes the endpoint more concrete than an undefined judgment of when a person became unconscious. The interval begins at anesthetic administration and ends when the specified reflex is lost. The measure therefore describes timing under the study’s clinical-practice conditions; by itself, it does not compare sevoflurane with another approach or explain why any individual’s time differed.

The registry record does not report the observed mean, standard deviation, number of participants with endpoint data, or an uncertainty interval. Without those results, the endpoint’s observed distribution and precision cannot be evaluated. The stated measurement definition and analysis population clarify what the outcome was intended to represent, but they are not a substitute for the numerical result.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The primary outcome is a continuous measure: elapsed time in minutes from anesthetic administration to loss of consciousness, defined by loss of the eyelash reflex. The record specifies a mean and standard deviation as its summary. These statistics answer different questions. The mean describes the central value of the measured times, while the standard deviation describes how dispersed individual times are around that mean. The registry record does not report either statistic for this endpoint, so neither the central value nor the observed variability can be assessed.

What does a mean describe?

In general, a mean is calculated from measured values and provides a compact description of their average. It does not show the full distribution. Two groups of observations can share a mean while differing in spread, skew, or unusual values. For a time measure, the mean also does not describe the proportion of participants reaching the endpoint at particular times. Those details would require additional summaries or a different analysis, and they are not reported in the registry record.

What does a standard deviation add?

In general, the standard deviation describes variability among observations on the same measurement scale. It is not the same as the uncertainty in the estimated mean. Uncertainty in a mean is commonly described with a confidence interval, which gives a range of values compatible with the data under the analysis assumptions. The registry record does not report a standard deviation, confidence interval, or other uncertainty measure for the primary endpoint. Without the observed estimate and its precision, readers cannot judge whether the endpoint was measured consistently across participants or how precisely its average was estimated.

How should the endpoint definition be read?

The endpoint is defined by a start point and an observed clinical sign: timing begins when the anesthetic is administered and ends at loss of the eyelash reflex. A clear operational definition helps specify what is being measured. The timeframe is listed as up to 16 minutes. That timeframe states the endpoint’s measurement window; it does not give the observed time or indicate how many participants reached the endpoint within that window. The record does not explain what happened to observations that might not have met the endpoint within the stated timeframe.

What can an observational design establish?

In general, observational studies describe outcomes as they occur in practice, without requiring randomized assignment. They can provide information about real-world use and observed events. But when treatment selection is not randomized, patient characteristics, clinical decisions, or other circumstances can be related to both the treatment received and the outcome. This can make a causal comparison difficult. In this record, no like-for-like comparator is described, so there is no registry-reported comparative effect to interpret. The allocation method is not stated.

The study’s post-marketing observational purpose is consistent with collecting practice-based information, but the record does not specify the detailed procedures used to enroll participants, collect measurements, or handle differences in clinical practice. It also does not report a statistical analysis plan. These omissions limit assessment of how measurements were standardized and whether potential sources of bias were considered.

What do the listed planning assumptions mean?

The record describes planning illustrations based on an observed effect, using a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. It also states that the effect to detect is a stated fraction of the observed effect, and that time-to-event illustrations use a total event count while other illustrations use participants per arm. These are planning assumptions, not evidence that the study was designed with those parameters. The record specifically distinguishes the illustrations from the trial’s own design. It does not report the resulting sample-size values in the registry record for this analysis, so no such values can be assessed.

In general, planning calculations estimate the amount of information a future study might need under specified assumptions. Their values depend on assumptions about the effect, variability, significance level, allocation, and analysis method. Such calculations are not observed power and do not show that a completed study had a particular probability of detecting an effect. No sample-size justification for the actual study is reported in the registry record.

Why does over-dispersion matter in general?

For count outcomes, over-dispersion means that variability is greater than a model’s assumptions would predict. If it is ignored, standard errors can be understated and uncertainty can appear too small. This is a general consideration for count data; the registry record does not identify a count model or report an over-dispersion assessment for this study. The primary endpoint is described as a continuous measure, and no specific modeling details are reported.

Finally, the record lists 14 outcome measures but reports 0 analyses. In general, assessing many outcomes can raise multiplicity concerns because repeated testing can increase the chance of apparently notable findings. Whether and how to address that issue depends on a prespecified analysis plan and the role of each outcome. The registry record does not report a multiplicity adjustment or a detailed testing strategy. Since numerical analyses are not reported, there are no p-values or estimates in the registry record for which adjustment can be evaluated.

10. Confidence Intervals for Each Arm

No two-arm comparison is shown for this trial, but each arm's mean can be given with a t-based 95% confidence interval computed from the posted mean, spread and number of participants.

R code and output

arm <- c("Adults Requiring Anesthesia for Surgery")
n   <- c(1343)
m   <- c(3)
sp  <- c(1.8)
sd  <- sp      # posted standard deviations
for (i in seq_along(n)) {
  se <- sd[i] / sqrt(n[i]); h <- qt(0.975, n[i] - 1) * se
  cat(sprintf("CARM|%s|%d|%.3f|%.3f|%.3f|%.3f\n", arm[i], n[i], m[i], sd[i], m[i] - h, m[i] + h))
}

CARM  Adults Requiring Anesthesia for Surgery  1343  3.000  1.800  2.904  3.096

11. Multiplicity, Missing Data and Analysis Populations

The registry lists 14 outcome measures and reports 0 analyses. The primary outcome is time to loss of consciousness; listed secondary outcomes include blood pressure measures, heart rate, electrocardiogram deviations, cardiac biomarkers when available, and a relationship between anesthesiologists’ clinical experience and hemodynamic parameters. The list identifies planned or recorded measures but does not establish which were analyzed or yield results for them.

In general, testing multiple outcomes can increase the chance of a seemingly notable result arising by chance. A study’s analysis plan may address this through a prespecified hierarchy, adjustment, or other approach. No multiplicity strategy is reported in the registry record. With no analyses or outcome estimates listed, it is not possible to determine whether multiplicity was handled or to assess its implications for reported findings.

For the primary endpoint, the stated population is all participants with available data. This indicates that participants without available endpoint data were not included in that analysis, but the registry does not report how many had available data, how much information was missing, why values were missing, or how missingness was handled beyond this population description. The record also does not report an imputation method or sensitivity analysis.

Two biomarker outcomes are explicitly conditional on availability: cardiac troponin T and creatine kinase myocardial isoenzyme, each listed as measured if available. The registry does not give their availability or results. It does not report a detailed analysis population for the secondary outcomes. Therefore, the enrollment figure should not be taken as the number contributing data to every endpoint.

12. 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.

Most frequent serious adverse event terms

Most frequent non-serious adverse event terms

Serious events with the highest arm-level rate: laryngospasm (0.1%), operative hemorrhage (0.1%).

The registry’s safety listing gives 1365 at risk for the serious-event category and 2 affected, and 1365 at risk for the other adverse-event category and 7 affected. These are the figures recorded for the listed group. They should be read as descriptive registry entries, not as evidence of a difference from another treatment, since no like-for-like control comparison is described.

The top serious-event terms are laryngospasm at 0.1% and operative hemorrhage at 0.1%. These percentages are presented as recorded; the registry information does not provide further detail about timing, duration, severity beyond the serious-event classification, or attribution to anesthesia. The terms identify events in the safety listing but do not establish that the anesthetic caused them.

The deaths entry is null. This means deaths are not reported in the registry record; it should not be interpreted as a reported count of zero. The listed at-risk figures also do not establish that every participant had complete safety follow-up. The record does not describe the follow-up procedures or explain how safety events were collected. These limits matter when interpreting sparse event listings.

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

The record establishes that SEVOPROTECTION was a completed post-marketing observational study in adults requiring general anesthesia for surgery, with a stated aim of collecting information about sevoflurane-based anesthesia in common clinical practice in Ukraine. It defines the primary endpoint as time from anesthetic administration to loss of the eyelash reflex and states that the mean and standard deviation were the intended summary measures. It also identifies a range of cardiovascular and other secondary outcomes.

Those descriptions do not reveal the primary endpoint result. The registry record does not report the observed mean or standard deviation, and it does not report an uncertainty interval or a p-value. It therefore cannot show how long the measured time was, how variable it was, or how precisely it was estimated. The listed endpoint definition makes the intended measurement understandable, but it is not a numerical finding.

The observational design also sets limits on interpretation. No like-for-like control comparison is described, and allocation is not stated. The study cannot, on the information in the record, establish that an observed outcome was caused by sevoflurane or that it differs from the outcome under another anesthetic approach. Its stated aim of supporting local recommendations is a study objective, not evidence that the results justify a particular recommendation.

The safety entries describe a small set of registry-listed events and terms, including the stated figures for serious and other adverse events and the top serious-event terms. They do not provide a comparative safety assessment. The deaths entry is not reported in the registry record, and should not be read as evidence of no deaths.

In short, the registry record is informative about the study’s purpose, endpoint definition, outcome categories, and selected safety entries. It does not report the analyzed primary outcome result or the details needed to evaluate its precision, missingness, or comparative meaning. Conclusions should remain within those descriptive limits.

14. Why This Trial Matters Statistically

Post-marketing observational studies address questions arising in routine clinical use. Their value depends not only on the stated objective and the number enrolled, but also on transparent reporting of measured outcomes, data availability, and analytical choices. SEVOPROTECTION is relevant in this respect because its stated purpose was to collect practice-based information about general anesthesia and evaluate volatile induction and maintenance anesthesia with Sevorane in Ukraine.

The primary endpoint is clearly framed around a specific interval and clinical sign: time from anesthetic administration to loss of the eyelash reflex. The record also identifies cardiovascular measures and other outcomes that reflect its broader interest in anesthesia quality and cardiovascular influence. Naming these measures clarifies what the study intended to observe, even though the registry record does not give their numerical results.

The study also illustrates why design and results must be considered together. An observational record can describe what was observed in practice, but the absence of a like-for-like comparator prevents a direct treatment contrast. Without reported estimates and uncertainty, the enrollment figure alone cannot indicate how precisely an outcome was measured. Nor can a planning illustration be treated as a finding about the completed study’s statistical power or effectiveness.

For readers evaluating clinical evidence, the record’s omissions are consequential: the primary numerical result, analysis details, and extent of missing data are not reported. That means the study’s objective and endpoint can be understood, while its outcome magnitude and precision cannot be assessed from the registry record. Recognizing that distinction is an important part of interpreting observational evidence responsibly.

15. 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 central limitation for interpreting this record is that the numerical result for the primary endpoint is not reported in the registry record. The mean and standard deviation are identified as the intended summaries, but their values are absent. The record also does not report an uncertainty interval or a p-value. The primary outcome’s magnitude and precision therefore cannot be evaluated.

The record describes an observational study and does not identify a like-for-like control comparison. The allocation method is not stated. As a result, there is no reported comparative estimate, and the record does not support attributing outcomes to the anesthetic in a causal sense. Details about treatment selection, clinical practice variation, and potential confounding are not reported.

Although the primary analysis population is described as participants with available data, the number with available endpoint data and the extent or reasons for missing data are not reported. The record does not describe an imputation method or sensitivity analysis. The biomarker outcomes are conditional on availability, but their availability and results are not stated. The listed 14 outcome measures and 0 analyses do not permit evaluation of secondary findings or the approach to multiplicity.

The safety listing gives event figures and top serious-event terms but does not describe collection procedures, follow-up, or attribution. The deaths entry is null and deaths are not reported in the registry record. A detailed statistical analysis plan, sample-size justification for the study itself, and interim-analysis information are also not reported in the registry record.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: Evaluation of Volatile Induction and Maintenance Anesthesia (VIMA) With Sevorane in Adult Patients Requiring General Anesthesia for Surgery in Terms of Quality of Anesthesia and Its Influence on the Cardiovascular System in Common Clinical Practice — NCT01282086.
• Registry record last updated 2013-02-04; status last verified 2013-01.
• Results first posted 2013-02-04.
• 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.

19. Record Summary

SEVOPROTECTION (NCT01282086) is a completed post-marketing observational study sponsored by Abbott (Ukraine). The registry lists enrollment of 1365, a start of 2011-04, and primary completion of 2011-12. Its objective was to collect information on general anesthesia in common clinical practice in Ukraine, evaluating volatile induction and maintenance anesthesia with Sevorane in adults undergoing surgery.

The primary outcome is time to loss of consciousness, defined by loss of the eyelash reflex and measured from anesthetic administration. The registry specifies a mean and standard deviation, but does not report their values. It lists cardiovascular and other secondary outcomes, 14 outcome measures, and 0 analyses. No like-for-like control comparison is described. Safety entries list 2 affected in the serious-event category and 7 in the other adverse-event category; deaths are not reported in the registry record.