Infrared Thermography to Evaluate the Effect of Paravertebral Block

Study Overview
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Brief Summary
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The aim of this prospective observational study was to evaluate the changes of skin temperature after the paravertebral block measured by infrared thermography.

Detailed Description
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Methods: Patients scheduled for elective surgery with paravertebral block will receive infrared thermography measures 5 min before the block and continous to 20 min after the block. The sensitivity, specificity of infrared thermography as diagnostic methods will be determined by receiver operator characteristic analysis.

Official Title
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Changes of Skin Temperature for Evaluation of Paravertebral Block: A Prospective Observational Study Using Infrared Thermography

Conditions
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Paravertebral Block

Intervention / Treatment
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* Procedure: Paravertebral block at T4 and T5 level


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: With informed consent American Society of Anesthesiologists physical status Ⅰ-Ⅱ Undergo elective surgery with planned paravertebral block Exclusion Criteria: Refusal to participate in the study pre-existing infection at the block site younger than 18-yr-old BMI>35 significant thoracic kyphoscoliosis Those who had taken vasodilatory drugs before surgery history of previous thoracic or breast surgery Preoperative analgesic medications Any contraindications to peripheral nerve block such as coagulation abnormalities, allergy to local anaesthetics, peripheral neuropathy.

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 70 Years

Sexes Eligible for Study
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All

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Successful Paravertebral block<br>Pinprick test was evaluated at 20 min after Paravertebral block. Pinprick sensation was assessed using a 22-gauge short bevel needle from T2 to T10 at midclavicular line bilaterally . Pinprick response was recorded quantitatively as 1 (sensation) or 0 (no sensation/numb). Successful block was defined as the pinprick score was 0 at 20 min after block. Otherwise, it was defined as a failed block. | Procedure: Paravertebral block at T4 and T5 level<br>* Paravertebral block is performed at T4 and T5 level under realtime ultrasound guidenance with 10ml of 0.5% ropivacaine for each block, respectively.<br>|
| Failed Paravertebral block<br>Pinprick test was evaluated at 20 min after Paravertebral block. Pinprick sensation was assessed using a 22-gauge short bevel needle from T2 to T10 at midclavicular line bilaterally . Pinprick response was recorded quantitatively as 1 (sensation) or 0 (no sensation/numb). Successful block was defined as the pinprick score was 0 at 20 min after block. Otherwise, it was defined as a failed block. | Procedure: Paravertebral block at T4 and T5 level<br>* Paravertebral block is performed at T4 and T5 level under realtime ultrasound guidenance with 10ml of 0.5% ropivacaine for each block, respectively.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Changes of skin temperature | Changes of skin temperature determined by infrared thermography | From baseline up to 20 minutes after block | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Noinvasive blood pressure | Vital signs | From baseline up to 20 minutes after block | 
| Heart rate | Vital signs | From baseline up to 20 minutes after block | 
| SPO2 | vital signs | From baseline up to 20 minutes after block | 
| Sensory block level | Sensory block level determined by pinprick. | From baseline up to 20 minutes after block | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Paravertebral block, Infrared thermography