Influence of Thoracic Paravertebral Block on Cardiac Repolarization

Evaluation of Influence of Thoracic Paravertebral Block on Cardiac Repolarization

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.

Study Overview

• Status: Enrolling by invitation
• Conditions: QT Interval; Paravertebral Block
• Intervention / Treatment: Procedure: Paravertebral block (ropivacaine) left; Procedure: Paravertebral block (ropivacaine) right

Detailed 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.

• Study Type: Observational
• Enrollment (Estimated): 60

Contacts and Locations

Study Locations

• Poland
  • Gdańsk, Poland, 80-214
    • Medical University of Gdańsk - Departament of Anesthesiology and Intensive Care

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

• Sampling Method: Non-Probability Sample

Study Population

Women above 18 years of age, without severe systemic comorbidities, patients of University Clinical Centre of Medical University of Gdańsk qualified for elective breast surgery

Description

Inclusion Criteria:

• woman above 18 years of age, legally able of giving informed consent
• participants previously qualified for elective breast surgery due to neoplasm, with or without axillary node dissection
• physical status corresponding to class I or II in American Society of Anaesthesiologist classification

Exclusion Criteria:

• lack of consent to participation or to regional anaesthesia for planned surgery
• bilateral operation planned
• symptomatic circulatory disease at the time of qualification, artificial heart pacemaker presence, positive history of arrythmia
• allergy to amide local anaesthetics
• use of medications with "known" or "possible" potential of QT prolongation, according to Arizona Center for Education and Research on Therapeutics [AZCERT] Inc. list, in 5 days preceding the intervention
• severe deformation of thoracic spine

Study Plan

How is the study designed?

Number of groups / cohorts

2

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
L - paravertebral block left; 30 woman above 18 years of age qualified for elective breast surgery on the left side of the body	Procedure: Paravertebral block (ropivacaine) left; Paravertebral block at the level of 3rd thoracic intervertebral space on the left side. 0.5% Ropivacaine 0.3 ml·kg-1, not exceeding 30 ml, based on ideal body weight in obese patients
P - paravertebral block right; 30 woman above 18 years of age qualified for elective breast surgery on the right side of the body	Procedure: Paravertebral block (ropivacaine) right; Paravertebral block at the level of 3rd thoracic intervertebral space on the right side. 0.5% Ropivacaine 0.3 ml·kg-1, not exceeding 30 ml, based on ideal body weight in obese patients

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
QT interval	difference in milliseconds of QT interval between baseline ECG [T0] and ECG after confirmation of sufficient area of sensory block [T1]	during procedure (6 minutes (prolonged until sufficient block distribution is achieved up to 15 minutes))
Corrected QT interval	difference in milliseconds of QT interval corrected [according to Bazett, Framingham, Fredericia formulas] between baseline ECG [T0] and ECG after confirmation of sufficient area of sensory block [T1]	during procedure (6 minutes (prolonged until sufficient block distribution is achieved up to 15 minutes))
Tpeak-Tend	difference in milliseconds of Tpeak-Tend time between baseline ECG [T0] and ECG after confirmation of sufficient area of sensory block [T1]	during procedure (6 minutes (prolonged until sufficient block distribution is achieved up to 15 minutes))

Collaborators and Investigators

• Sponsor: Medical University of Gdansk
• Investigators: Principal Investigator: Radosław Owczuk, MD, PhD, Medical University of Gdansk

Study record dates

Study Major Dates

• Study Start (Actual): February 2, 2023
• Primary Completion (Estimated): June 1, 2024
• Study Completion (Estimated): June 1, 2024

Study Registration Dates

• First Submitted: April 7, 2023
• First Submitted That Met QC Criteria: April 7, 2023
• First Posted (Actual): April 20, 2023

Study Record Updates

• Last Update Posted (Actual): February 1, 2024
• Last Update Submitted That Met QC Criteria: January 30, 2024
• Last Verified: January 1, 2024

More Information

Terms related to this study

• Keywords: Paravertebral block; QT Interval; Transmural dispersion of repolarization
• Additional Relevant MeSH Terms: Physiological Effects of Drugs; Central Nervous System Depressants; Peripheral Nervous System Agents; Sensory System Agents; Anesthetics; Anesthetics, Local; Ropivacaine
• Other Study ID Numbers: NKBBN/948/2022

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No