Ultrasound-guided Approach Combined With Pressure Measurement Technique to Thoracic Paravertebral Block

Study Overview
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Brief Summary
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Posterolateral thoracotomies are among the most painful procedures of surgery and may cause severe postoperative chest pain and impaired respiratory performance. Paravertebral block (PVB) is an established method of administering postoperative analgesia for thoracic procedures. PVB blocks the somatic and sympathetic nervous systems and is placed by injecting a local anesthetic (LA) into the paravertebral space where the nerve and its branches are located after exiting the intervertebral foramen. But previous study showed 5-10% of failure rate in PVB using ultrasound machine. Pressure measurement during needle advancement could improve reliability of correct needle placement. When the needle tip reaches paravertebral space, there is a sudden lowering of pressures due to respiratory cycle. Therefore, sensitivity and specificity could be improved and correct needle placement become objective and reproducible when PVB using ultrasound is combined with pressure measurement during needle advancement.

Official Title
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Comparison of Ultrasound-guided Approach and Ultrasound-guided Approach Combined With Pressure Measurement Technique to Thoracic Paravertebral Block for Open Thoracotomy

Conditions
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Thoracotomy

Intervention / Treatment
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* Procedure: thoracic paravertebral block using pressure measurement technique


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Scheduled for elective thoracotomy ASA status 1,2 Exclusion Criteria: Inability to provide adequate informed consent Any contraindication to the placement of thoracic paravertebral catheters Unstable vertebral and transverse process fractures Any chronic painful conditions or preoperative opioid use Any chronic painful conditions or preoperative opioid use Coagulation abnormalities or expectation to be on therapeutic anticoagulants postoperatively Allergy to any of the drugs/agents used in study protocol Altered mental status or emergency surgery Comorbid conditions such as sepsis, unstable angina, congestive heart failure

Ages Eligible for Study
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Minimum Age: 19 Years
Maximum Age: 85 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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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Interventional Model Description: Each participant is randomized to one of two groups.
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| No Intervention: ultrasound group<br>The participants have continuous thoracic paravertebral block performed using only the ultrasound approach. | |
| Experimental: pressure measurement group<br>The participants have continuous thoracic paravertebral block performed using the ultrasound-guided approach combined with pressure measurement techniqueduring needle advancement. | Procedure: thoracic paravertebral block using pressure measurement technique<br>* The continuous thoracic paravertebral block using ultrasound machine is combined with pressure measurement during needle advancement.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| visual analogue scale for pain (VAS) at 2 hour after the arrival of postanesthetic care unit (PACU) | VAS score is measured at 2 hour after a patient arrives in PACU. The pain VAS is a unidimensional measure of pain intensity. The pain VAS is a continuous scale comprised of a horizontal (HVAS) line, usually 10 centimeters (100 mm) in length, anchored by 2 verbal descriptors, one for each symptom extreme (no pain 0, maximal pain 100). | 2 hour after the arrival of PACU |