Comparison of US-Guided Paravertebral and Proximal Intercostal Nerve Blocks

Not Applicable

• Conditions: Pain
• Interventions: Procedure: Proximal Intercostal Block; Procedure: Paravertebral Block

• Registration Number: NCT02911168
• Lead Sponsor: Brigham and Women's Hospital

Brief Summary

The purpose of this study is to compare the proximal intercostal block to the more medial (classic) ultrasound-guided paravertebral block. The investigators hypothesize that the proximal intercostal block will allow for improved needle visualization, shorter block time, and improved safety profile compared to the classic paravertebral bock.

Detailed Description

Although previous studies have made advances towards applying ultrasound guidance to the performance of paravertebral blocks (PVB), a technique combining both safety and technical ease remains elusive. The ideal technique (1) permits continuous visualization of the entire needle shaft and tip, (2) avoids aiming the needle tip and injectate directly toward the neuraxis or lung, and (3) is easy to perform. Visualization of all structures by ultrasound is essential to minimize the risk of vascular puncture, nerve root or spinal cord injury, and pneumothorax. Failure to consistently and quickly identify the transverse process and pleura, as occurs when using older techniques, results in several needle redirections, causing pain and discomfort to patients, and increases the potential risk of pneumothorax. The technical difficulty of applying previously-described US-guided techniques takes an inordinate amount of time and is clinically less practical within a busy surgical practice.

In the current study, the investigators describe a novel, modified approach to real-time ultrasound-guided single shot paravertebral blockade, the proximal intercostal block (PICB), which utilizes a sagittal paramedian US probe placement to identify the intercostal space and PVS. In this method, instead of placing the probe at a fixed traditional distance of 2.5 cm from the spinous processes, the probe is moved laterally to obtain a comprehensive image, with a clear view of the ribs, internal intercostal membrane, and the parietal pleura.

The investigators propose that moving the probe laterally towards the proximal intercostal space allows clearer simultaneous visualization of both pleura and needle as it advances towards the PVS, while achieving comparable injectate spread and, ultimately, similar or better clinical results. Such improved visualization will reduce the number of needle passes, increase confidence in the user, decrease block placement time, and improve overall block success. This technique combines the advantages of more lateral approaches (better visualization of structures, in particular the pleura) with the advantage of the more medial approaches (in-plane, closer, and not directed at the neuraxis).

Study Timeline

• Study First Submitted: 2016-08-12
• Status Verified: 2016-09
• Study Start: 2016-09
• Study First Submitted QC: 2016-09-20
• Last Update Submitted: 2016-09-20
• Study First Posted: 2016-09-22
• Last Update Posted: 2016-09-22
• Primary Completion: 2017-09
• Study Completion: 2018-07

Recruitment & Eligibility

• Status: UNKNOWN
• Sex: Female
• Target Recruitment: 48

Inclusion Criteria

1. Females age 18-85 years old
2. ASA 1-3
3. Patient scheduled for unilateral or bilateral mastectomy with or without reconstruction

Exclusion Criteria

1. Coagulopathy
2. Patient refusal
3. Allergy to local anesthetics

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
Proximal Intercostal Block	Proximal Intercostal Block	See Intervention Section
Paravertebral Block	Paravertebral Block	See Intervention Section

Primary Outcome Measures

Name	Time	Method
Ultrasound Image Quality Score	Evaluated at time of block	The following will be assessed for each image and video, and saved during each block performed: 1. Best possible image of block anatomy (including the pleura, transverse process/rib, costotransverse ligament/internal intercostal membrane, as appropriate) as well as needle location.; 2. Video of the space during injection, reflecting the injectate spread. The images will be rated by a separate regional anesthesiologist not involved in study, but proficient with both types of blocks and ultrasound imaging.; 3. The following score 3 point scale will be used to rate visibility: 0=not visible, 1=hardly visible, 2=well visible, 3=very well visible. Maximum score possible=18 including both pieces of media.

Secondary Outcome Measures

Name	Time	Method
Opioid requirement	Evaluated at 1 hour after extubation, and then at 24 hours following the block	Opioid requirement, including intraoperative, PACU, and during the entire hospital admission, normalized to morphine equivalents.
Number of Needle Passes	Established during block performance	Initial needle insertion will be counted as "first pass". Any subsequent needle advancement, preceded by a retraction of more than 2 cm, will be counted as an additional pass.
Effectiveness of the Block	One hour following extubation, and at 24 hours following block placement	Patients will be asked to provide a verbal rating score of pain (0-10) at two time points: one hour following extubation, and 24h following block placement. At the 1 hour following extubation time point, we will be checking the coverage of the block in terms of dermatomal spread (see below).
Prolonged postoperative pain	6 and 12 months after surgery	Postoperative contact via secure e-mail at will assess for the incidence of chronic pain.
Needling Time	Established during block performance	Defined as the time interval between the start of the skin wheal and the end of local anesthetic injection through the block needle.
Block Performance Time	Evaluated at time of block	Defined as the sum of imaging and needling times
Imaging Time	Established during block performance	Defined as the time interval between contact of the ultrasound probe with the patient, and the acquisition of a satisfactory image (which will be saved and analyzed later by a regional anesthesiologist blinded to the particular aims of the study).
Distance of Injection Sites from Midline	Established during block performance	Measured and recorded (one of our clinical aims)
Presence of Perioperative Block-Related Complications	Within 24 hours of block placement	The presence of the following complications will be recorded: 1. Horner's syndrome; 2. Pneumothorax; 3. Local anesthetic systemic toxicity (LAST); 4. Pain on injection; 5. Evidence of contralateral block (for unilateral procedures)
Dermatomal spread	One hour following extubation	Number of dermatomal block levels, determined by loss of sensation to cold (ice) or to loss of pinprick sensation in the PACU one hour after extubation.

Trial Locations

Locations (1)

Brigham and Women's Hospital; 🇺🇸 Boston, Massachusetts, United States