An Early Phase 1 interventional study of Sevoflurane and Peripheral Nerve Stimulation in Anesthesia, Pain and Amnesia, sponsored by Keith M Vogt. Completed at 1 site in United States. Open to participants aged 18 Years to 59 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-04-15.
Sponsored by Keith M Vogt · Early Phase 1, Interventional, and Basic science
The purpose of this study is to determine the effects of acute pain on long-term memory and conditioned physiologic responses in the presence and absence of low dose sevoflurane. Functional magnetic resonance imaging will be used to identify the neural correlates of these phenomena. The study will occur over 2 visits and involves no long-term follow up.
This is a non-randomized, clinical trial study of healthy volunteer subjects, which will employ neuroimaging and behavioral measures to characterize the effects of inhalational sevoflurane on pain processing and cognitive function. Sedative doses of sevoflurane will be targeted, and steady-state end-tidal (expired) concentrations achieved, while subjects perform a pain and memory cognitive task. At both no-drug baseline and the targeted doses, task and resting-state functional magnetic resonance imaging (MRI) scans will be acquired, and this data will be analyzed subsequently for task-related brain activity(from pain processing and memory formation) and functional connectivity. This work will use a systems neuroscience approach to fill an important knowledge gap about the central effects of inhalational sevoflurane in the context of painful stimulation.
The investigators propose to complete the following 3 Aims, at a sedative dose of Sevoflurane, compared to no-drug baseline, using functional MRI:
Aim 1: Determine how the brain response to acute pain stimulation is modulated by sevoflurane. It is anticipated that sevoflurane will correlate to decreased activation in both somatosensory (thalamus, insula, primary somatosensory/motor) and affective (anterior cingulate) components of the pain processing brain areas.
Aim 2: Determine how memory encoding is modulated by sevoflurane, in the context of periodic painful stimulation. It is anticipated that sevoflurane will correlate to decreased activation in both the explicit memory (hippocampus, parahippocampus) and associative learning (amygdala, anterior cingulate) brain systems.
Aim 3: Determine the neural effects of inhalational sevoflurane on brain connectivity both at rest and during the combined pain and memory task performance. It is anticipated that hypothesize that sevoflurane will cause widespread dose-dependent decreases in long-range functional connectivity between brain areas known to be involved in pain processing and to the default mode network, and that this connectivity will differ between the resting (task-free) and periodic pain states.
10,054 studies on the registry are indexed under Pain; 1,649 are open to participants now.
This study's enrollment of 42 is below the median of 66 across 8,493 interventional studies indexed under Pain.
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Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.
What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.
On an ECG, the QT interval is the time the heart’s lower chambers take to activate electrically and recover in each beat. QTc is that time adjusted for heart rate (QTcF by Fridericia’s formula, QTcB by Bazett’s). Some medicines lengthen it, and a long QTc can raise the risk of a dangerous heart rhythm.
The study may name a correction formula and a limit in milliseconds, often around 450–480.
An allergy, or another reaction of the immune system, to a substance. “Hypersensitivity to the study drug” means a known allergic reaction to it — not every side effect a medicine can have.
BMI (body mass index)
Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.
What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
QT and QTc
On an ECG, the QT interval is the time the heart’s lower chambers take to activate electrically and recover in each beat. QTc is that time adjusted for heart rate (QTcF by Fridericia’s formula, QTcB by Bazett’s). Some medicines lengthen it, and a long QTc can raise the risk of a dangerous heart rhythm.
The study may name a correction formula and a limit in milliseconds, often around 450–480.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Hypersensitivity
An allergy, or another reaction of the immune system, to a substance. “Hypersensitivity to the study drug” means a known allergic reaction to it — not every side effect a medicine can have.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Single-arm study. All subjects receive sevoflurane and painful electric nerve stimulation, as described in the interventions.
Drug: Sevoflurane · Device: Peripheral Nerve Stimulation
After a no-drug control period, subjects will inhale sevoflurane, administered via a breathing circuit and face mask, until a steady-state target end-tidal expired concentration of 0.4% (corresponding to 0.2 Minimum Alveolar Concentration) is reached.
Also known as: Ultane
Experimental acute pain stimulus will be delivered using a nerve stimulator. These painful shocks will be paired with a fixed number of the experimental cues, in a pattern that appears random to participants.
Also known as: Electric Nerve Stimulation
functional magnetic resonance imaging activation in response to experimental tasks
Event-related blood-oxygen level dependent (BOLD) Magnetic Resonance Imaging (MRI) responses will be determined for each experimental item presented, revealing localized changes in blood flow, which correlate to increased neuronal activity. These will be averaged across the multiple repetitions of each type of experimental item (memory only, pain only, and memory+pain), creating an anatomical map of Z-scores. Cross-condition comparisons will be the main effect of interest, comparing no sevoflurane to low concentration sevoflurane.
Time frame: Visit 1: Immediate; average activity, calculated from each task scan
Functional connectivity
Whole-brain functional connectivity will be determined in each condition (no-sevoflurane, low-dose, and high-dose). This generates a matrix of cross-correlation values. Cross-condition comparisons will be the main effect of interest, comparing no sevoflurane to low concentration sevoflurane sevoflurane.
Time frame: Visit 1: Immediate; brain activity captured in data acquired across entire 6-8 minute scan.
Explicit memory performance
Recognition memory testing, using the Remember-Know procedure, in which subjects indicate whether they recognize previously experienced experimental items among novel items (not previously in the experiment). This allows calculation of interdependent measures of recollection \& familiarity using the signal detection statistic, d'. d' is calculated as the cumulative Gaussian distribution of false positive responses subtracted from the cumulative Gaussian distribution of correctly identified previously-experienced items. d' is on a (theoretically infinite) scale of standard deviation units, with negative values representing performance worse than chance guessing and positive values representing stand deviations of performance above chance.
Time frame: Visit 2: 24-hrs post-learning experiment
PDFs hosted by the registry, ClinicalTrials.gov.
Plan to share: Yes — De-identified data to share: age, height, weight, sex survey instruments to quantify pain predispositions (catastrophizing, vigilance \& anxiety), depression, anxiety, stress, and sleep pain intensity \& unpleasantness, and observer assessment of sedation at the targeted drug dose Behavioral performance data for long-term memory structural and functional MRI images
Supporting information: Study protocol
Time frame: After analysis is complete and results have been published, all the above data will be shared in de-identified format, linked together by an assigned subject number.
Access criteria: Data will be shared via a publicly-accessible online platform that allows user download at no cost.
This study is completed, as verified in Apr 2026. You cannot join it, but the record below documents what was studied.
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Studies of the drug tested here: Sevoflurane
Keith M Vogt