Clinical Trial Details
— Status: Enrolling by invitation
Administrative data
| NCT number |
NCT05822076 |
| Other study ID # |
NKBBN/948/2022 |
| Secondary ID |
|
| Status |
Enrolling by invitation |
| Phase |
|
| First received |
|
| Last updated |
|
| Start date |
February 2, 2023 |
| Est. completion date |
June 2024 |
Study information
| Verified date |
January 2024 |
| Source |
Medical University of Gdansk |
| Contact |
n/a |
| Is FDA regulated |
No |
| Health authority |
|
| Study type |
Observational
|
Clinical Trial Summary
Aim of the study is to determine the presence and direction of electrocardiographical changes
of cardiac repolarization after thoracic paravertebral block, depending on block laterality.
Injection of local anaesthetic into paravertebral space (paravertebral block, PVB)
temporarily impairs transmission in nerve fibers in proximity of the deposition site. In case
of PVB covering the rami of upper thoracic spinal nerves, among the others thoracic
sympathetic cardiac nerves are blocked, possibly affecting action potential time of heart,
especially the repolarization, and the related electrocardiographic phenomena.
The risk of life-threatening polymorphic ventricular tachycardia (torsade des pointes, TdP)
is associated with certain electrocardiographical symptoms, like QT interval prolongation and
increased transmural repolarization dispersion (TDR). Determining the presence and direction
of cardiac repolarization changes after a thoracic PVB will allow to conclude about its
impact on TdP risk: protective or, contrary, arrhythmogenic.
Description:
After obtaining written informed consent, 60 women above 18 years of age scheduled to
elective breast surgery in combined regional and general anaesthesia will be enrolled to
study, divided in two groups depending of the side of operation. Participants will undergo
the ultrasound-guided paravertebral block with single injection of 0.5% ropivacaine (0.3
ml·kg-1, not exceeding 30 ml, based on ideal body weight in obese patients) without
adjuvants. Before injection (T0) and after confirmation of sufficient sensory block area
covering 1st to 4th thoracic dermatomes (T1), 12-lead electrocardiogram (ECG) will be
recorded using a Holter device. First examination of sensory block distribution will be
performed 6 minutes after injection, with subsequent examinations if needed - every minute up
to 15 minutes. No sedative premedication, general anaesthesia induction or additional
medications (except of neutral saline maintaining intravenous access) will be administered
until completions of ECG recording. Both T0 and T1 electrocardiogram will be preceded by rest
in supine position for at least 5 minutes, without any medical procedures other than
monitoring. Cases with baseline QT or corrected QT longer than 440 milliseconds (ms) will be
excluded from study.
The QT interval and TDR (measured as time in milliseconds between ECG T wave peak [Tpeak] and
end [Tend]) values obtained from baseline and post-blockade electrocardiograms will be
statistically analyzed and compared between study groups.
The minimum sample size was calculated as 26 cases per study group, assuming a change in
corrected QT of 20 milliseconds from the baseline value, with a significance level of p=0.05
and a test power of 0.9. Sample size was expanded to 30 cases per group, due to anticipated
exclusions at the stage of intervention or data analysis.
