The Minimal Effective Volume (MEV90) of Ropivacaine 0.75% for Ultrasound-guided Transmuscular Quadratus Lumborum Block

The Minimal Effective Volume (MEV90) of Ropivacaine 0.75% for Ultrasound-guided Transmuscular Quadratus Lumborum Block for Unilateral Percutaneous Nephrolitotomy: a Study Protocol for a Dose Finding Trial

This double-blind dose-finding trial is based on a biased coin up-and-down sequential design, where the volume of local anesthetic administered to each patient depends on the response from the previous one. The TQL block is performed preoperatively, and the first patient recruited receives 20 mL of ropivacaine 0.75%. In case of block failure, the next patient will receive a higher volume (defined as the previous volume with an increment of 2 mL). Given a successful block for the first patient, the next patient will be randomized to either a lower volume (defined as the previous volume with a reduction of 2 mL) or the same volume as the previous patient. The respective probabilities being b=0.11 for a reduced volume and 1-b=0.89 for the same volume. Block success is defined as patient reported numeric rated scale (NRS) pain (NRS value ≤ 3 (0-10/10)), 30 minutes after arrival in the post anesthesia care unit (PACU). The NRS pain value is our primary and only outcome in the evaluation of the block. A minimum of 25 eligible patients are needed to achieve precise estimation of MEV90 with narrow 95% confidence intervals derived by bootstrapping. Following inclusion of 25 patients early termination is considered when interim analysis shows sufficiently stabilization of MEV90 estimate. The final sample size is not known a priori, but a maximum of 40 patients will be enrolled in the trial.

Study Overview

• Status: Unknown
• Conditions: Percutaneous Nephrolithotomy
• Intervention / Treatment: Drug: Ropivacaine injection

• Study Type: Interventional
• Enrollment (Anticipated): 40
• Phase: Phase 4

Contacts and Locations

• Study Contact: Name: Jens B Børglum, PhD; Phone Number: +4530700120; Email: jens.borglum@gmail.com

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

Inclusion Criteria:

• Patients eligible for the trail must comply with all of the following requirements to be included:

  • Scheduled for elective PNL surgery in general anesthesia with propofol and remifentanil
  • Age > 18 years at the date of inclusion
  • Have received thorough information, oral and written, and signed the "informed consent" form on participation in the trail
  • ASA score 1-3

Exclusion Criteria:

• Inability to speak and understand Danish
• Allergy to local anesthetics or opioids
• Daily intake of opioids (evaluated by the investigators)
• Drug and/or substance abuse
• Local infection at the site of injection or systemic infection
• Difficult visualization of muscular and fascial structures necessary for successful block administration
• Pregnancy or breastfeeding

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Diagnostic
• Interventional Model: Sequential Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm

Intervention / Treatment

Experimental: Ropivacaine; This double-blind dose-finding trial is based on a biased coin up-and-down sequential design, where the volume of local anesthetic administered to each patient depends on the response from the previous one. The TQL block is performed preoperatively, and the first patient recruited receives 20 mL of ropivacaine 0.75%. In case of block failure, the next patient will receive a higher volume (defined as the previous volume with an increment of 2 mL). Given a successful block for the first patient, the next patient will be randomized to either a lower volume (defined as the previous volume with a reduction of 2 mL) or the same volume as the previous patient. The respective probabilities being b=0.11 for a reduced volume and 1-b=0.89 for the same volume. Block success is defined as patient reported numeric rated scale (NRS) pain (NRS value ≤ 3 (0-10/10)), 30 minutes after arrival in the post anesthesia care unit (PACU).

Drug: Ropivacaine injection; In a dose finding study the total volume of ropivacaine changes according to the biased coin up-and-down sequential design; Other Names: Sequential design

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Numeric rated scale	Pain score from numeric rated scale 0-10/10 Pain score, numeric rated scale 0-10/10. 0=no pain, 10=maximum pain	30 minutes after arrival in the post anesthesia care unit

Collaborators and Investigators

• Sponsor: Zealand University Hospital

Study record dates

Study Major Dates

• Study Start (Anticipated): January 5, 2020
• Primary Completion (Anticipated): October 1, 2020
• Study Completion (Anticipated): November 1, 2020

Study Registration Dates

• First Submitted: December 10, 2019
• First Submitted That Met QC Criteria: December 10, 2019
• First Posted (Actual): December 12, 2019

Study Record Updates

• Last Update Posted (Actual): December 16, 2019
• Last Update Submitted That Met QC Criteria: December 11, 2019
• Last Verified: December 1, 2019

More Information

Terms related to this study

• Keywords: dose finding study
• 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: Clinical Trials Zealand

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

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