Ultrasound Needle Transducer for Regional Anesthesia Validation Study

Study Overview
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Brief Summary
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To validate the efficacy of miniaturized ultrasound needle transducer as the primary guide for thoracic regional anesthesia.

Detailed Description
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Paravertebral (PVB) and intercostal nerve block (ICNB) are both techniques of injecting local anesthetics for pain management at thoracic and upper abdominal region. Today, PVB and ICNB are performed under the guidance of surface two dimensional B-mode ultrasound. However, the procedure still carries potential risks for inexperienced operators since the target zone is very close (2-3 mm) to the pleura. In certain patients, such as those with obesity, the steep needle trajectory and poor quality of the anatomic image make the nerve block even more difficult. Inaccurate identification of the anatomical structures or suboptimal positioning of the needle tip could result in complications and blockade failure. We designed an intra-needle ultrasound (INUS) system to improve the identification of anatomical structures and needle tip position. The system passed all safety standards including electrical safety test, biocompatibility test, software certification. This study is to investigate the feasibility and image quality of INUS during ICNB and PVB. The study protocol is approved and under monitoring for safety and compliance from both Institutional Review Board of Taipei Veterans General Hospital and Ministry of Health and Welfare, Taiwan, Republic of China.

Official Title
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High Frequency Ultrasound Spring-load Front-and-side Firing Needle Transducer Developments and Pre-clinical Regional Anesthesia Validation Study

Conditions
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Thorax; Pain, Spine, With Radicular and Visceral Pain, Acute Post-thoracotomy Pain, Pain, Postoperative, Ultrasound Therapy; Complications

Intervention / Treatment
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* Procedure: Intercostal nerve blocks
* Procedure: Paravertebral block


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Patients scheduled for elective thoracic surgery Patients scheduled for elective upper abdominal surgery Patients scheduled for elective breast surgeries. Exclusion Criteria: Known coagulopathies, Skin lesion or infection at site of nerve block Pregnant women Allergic to local anesthetics Cognitive diseases Unstable hemodynamics Chronic substance abuse (ex. alcohol, hypnotics, opioids)

Ages Eligible for Study
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Minimum Age: 20 Years
Maximum Age: 80 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Intercostal nerve block with surface ultrasound<br>Number of participants: 10 Intercostal blocks will be performed under guidance of surface ultrasound. After we reach the injection site, the puncture stylet will be replace by Intra-needle ultrasound transducer (INUS). Collect signal from Intra-needle ultrasound transducer and then inject local anesthetics. Code name: ICNB-INUS-check | Procedure: Intercostal nerve blocks<br>* Intercostal nerve block is a regional anesthetic procedure for peri-operative pain management. It inhibits the action of the ipsilateral sensory and motor branches, and produces analgesic effects at the targeted thoracic level.<br>* Other names: ICNB;|
| Paravertebral block with surface ultrasound<br>Number of participants: 10 Paravertebral blocks will be performed under guidance of surface ultrasound. After we reach the injection site, the puncture stylet will be replace by Intra-needle ultrasound transducer (INUS). Collect signal from Intra-needle ultrasound transducer and then inject local anesthetics. | Procedure: Paravertebral block<br>* Paravertebral block is the technique of injecting local anesthetic alongside the thoracic vertebra close to where the spinal nerves emerge from the intervertebral foramen. This produces unilateral, segmental, somatic, and sympathetic nerve blockade, which is effective for anesthesia and in treating acute and chronic pain of unilateral origin from the chest and abdomen<br>* Other names: PVB;|
| Intercostal nerve block with intra-needle and surface ultrasound<br>Number of participants: 10 Intercostal blocks will be performed under guidance of intra-needle and surface ultrasound. The intra-needle transducer will be placed inside the puncture needle and it will be the primary guidance to reach target injection site. Surface ultrasound will be the secondary image guide for simultaneous comparison. Collect signal from both Intra-needle ultrasound transducer and surface ultrasound, and then inject local anesthetics. Code name: ICNB-INUS-guide | Procedure: Intercostal nerve blocks<br>* Intercostal nerve block is a regional anesthetic procedure for peri-operative pain management. It inhibits the action of the ipsilateral sensory and motor branches, and produces analgesic effects at the targeted thoracic level.<br>* Other names: ICNB;|
| Paravertebral nerve block with intra-needle and surface ultrasound<br>Number of participants: 10 Paravertebral blocks will be performed under guidance of intra-needle and surface ultrasound. The intra-needle transducer will be placed inside the puncture needle and it will be the primary guidance to reach target injection site. Surface ultrasound will be the secondary image guide for simultaneous comparison. Collect signal from both Intra-needle ultrasound transducer and surface ultrasound, and then inject local anesthetics. Code name: PVB-INUS-guide | Procedure: Paravertebral block<br>* Paravertebral block is the technique of injecting local anesthetic alongside the thoracic vertebra close to where the spinal nerves emerge from the intervertebral foramen. This produces unilateral, segmental, somatic, and sympathetic nerve blockade, which is effective for anesthesia and in treating acute and chronic pain of unilateral origin from the chest and abdomen<br>* Other names: PVB;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Needling time | Needle insertion to needle withdrawal (minutes) | Needle insertion to needle withdrawal, up to 20 minutes | 
| Nerve block procedure time | How long the procedure takes in minutes, starting from ultrasound contact with skin to needle withdrawal | Time from ultrasound contact with skin to needle withdrawal, up to 20 minutes | 
| Success rate of blockade | Successful blockade will be determined by 1.ultrasound evidence of ideal spreading or 2.evidence of fluid accumulation around intercostal nerves or at paravertebral space under thoracoscope, or 3. loss of cold sensation on the chest or abdomen at block level. | 20 minutes post administration of local anesthetics (by ultrasound or cold sensation) or intraoperative (at the time of video-thoracoscope exploration) | 
| Visibility of needle tip and anatomic structure | Record the visibility of needle tip, intercostal muscle, superior costotransverse ligament, pleura. Assessed by the inserting anesthetist on a 5 point Likert scale | During block procedure, up to 60 minutes. | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Inadvertent pleural puncture or pneumothorax | Calculate the rate of Inadvertent pleural puncture or pneumothorax, defined by image evidence of pleura injuries or pneumothorax by thoracoscope, X-ray, or CT. | 20 minutes post-procedure or intraoperative (if needle injuries on pleura noted by thoracoscope) | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Intercostal nerve block, Paravertebral block, Ultrasound-guided pain intervention, Thoracic surgery, Breast surgery, Abdominal surgery, Ultrasound-guided peripheral nerve block, Postoperative pain