Different Positions on the Diffusion and Blockade Effect of Ultrasound-guided Erector Spinae Plane Block

Study Overview
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Brief Summary
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After the completion of exploring the vertical erector spinae plane block, the patient maintains different positions to assess the diffusion of local anesthetic and the effect of the block.

Detailed Description
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Thirty patients were selected to undergo CT guided puncture localization of pulmonary nodules under local anesthesia, and the patients were divided into groups using a computer-generated random number in a ratio of 1:1:1. To ensure objectivity, a nurse who was not involved in the study prepared a sealed opaque envelope containing grouping information. Randomly divide patients into three groups: supine position group (S group, 10 cases), prone position group (P group, 10 cases), and lateral position group (L group, 10 cases). The patient underwent ultrasound guided ESPB on the puncture side before CT puncture localization. Ultrasound guided ESPB method: Using an ultrasound high-frequency linear array probe (5-13MHz, Sonosite, USA), the probe is placed parallel to the spine on the surface of the transverse process tip of the fifth thoracic vertebrae. Under ultrasound, the transverse process and surface vertical spinal muscles are clearly exposed. Then, a short inclined plane puncture needle is used, and the needle is inserted from the head side using in-plane technology. After the needle tip reaches below the transverse process plane vertical spinal muscles, 2ml of physiological saline is injected using water separation technology to confirm the position of the needle tip, Then inject 30ml of local anesthetic solution (0.375% ropivacaine 25ml+iohexol 5ml). After the block was completed, patients in Group S remained in a supine position; Patients in group L maintained the blocking side above; Patients in Group P maintained a prone position. After 1 hour of block completion, CT scan and puncture localization were performed, followed by 3D reconstruction. Observation and recording of local anesthetic solution: 1. Diffusion range towards the head and tail; 2-way diffusion range of rib gap on one side 3; Diffusion to the paravertebral space; 4. Diffusion into the epidural space.

Official Title
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The Effects of Different Positions on the Diffusion and Blockade Effect of Ultrasound-guided Erector Spinae Plane Block

Conditions
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Erector Spinea Plane Block

Intervention / Treatment
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* Other: Alteration of patients' position after erector spinae plane block


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Patients received CT guided puncture localization of pulmonary nodules under local anesthesia Exclusion Criteria: Allergic to local anesthetic History of opioid abuse Severe skin infection Peripheral neuropathy Dysfunction of blood coagulation

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 80 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Prevention
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| No Intervention: Supine group<br>Patients remained supine | |
| Experimental: Prone group<br>Patient remained prone | Other: Alteration of patients' position after erector spinae plane block<br>* After the erector spinae plane block was completed, the patients kept lateral or prone position according to the group allocated for one hour to ensure the spread of local anesthetic<br>|
| Experimental: Lateral position group<br>Patient remained in a lateral position | Other: Alteration of patients' position after erector spinae plane block<br>* After the erector spinae plane block was completed, the patients kept lateral or prone position according to the group allocated for one hour to ensure the spread of local anesthetic<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Incidence and number of local anesthetic diffusion segment into the paravertebral space | Observation of local anesthetic spread spread into the paravertebral space with CT by a researcher who was blinded to group allocation | 1 hour after completion of the ESPB block | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Diffusion of local anesthetic into intercostal space | The diffusion of local anesthetics to intercostal space was observed with CT by a researcher who was blinded to group allocation | 1 hour after completion of the block | 
| Diffusion of local anesthetic into the epidural space | Incidence and segment of local anesthetic spread into the epidural was assessed by a researcher who was blinded to group allocation | 1 hour after completion of the block | 
| Sensory loss of cold | The extent of sensory loss was assessed with cold stimulation, including the anterior chest wall (midclavicular line), lateral chest wall (posterior axillary line), and posterior chest wall (paraspinal zone) by a researcher who was blinded to group allocation | 30 min and 60 min immediately after completion of the nerve block |