The Efficacy of Intermediate Cervical Plexus Block Versus Cutaneous and Thyroid Capsular Blocks

Study Overview
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Brief Summary
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Thyroid gland surgery is one of the most commonly performed operations for either benign or malignant pathologies Pain related to thyroid surgery is of moderate intensity .which may be treated with NSAIDs or opioids. However, Opioids have many well-known undesirable effects, including postoperative nausea and vomiting, which are frequent after this type of procedure.

Detailed Description
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Regional techniques of anesthesia may help to decrease post-operative pain and reduce systemic analgesic requirement. Classically, the cervical plexus is considered to have two distributions, the superficial cutaneous and the deep motor nerves. Anatomically, the thyroid gland has an inner true capsule which is thin and adheres closely to the thyroidal tissue [Fancy et al., 2010]. External to this is a false capsule formed by the middle layer of the deep cervical fascia, which splits anterolaterally to ensheathe the thyroid gland, thus forming the thyroid sheath [Bliss et al., 2000]. In this fashion, the potential space called the capsule-sheath space is formed. It contains also loose connective tissue, blood vessels, nerves and parathyroid gland. Anesthetic deposited in this space would block the surface of thyroid gland and permeate directly into the parenchyma producing effective local anesthesia for thyroid surgical procedures. It is supposed also to involve autonomic nerve block of the thyroid gland [Fliers et al., 2010]. Additionally, a subcutaneous injection along the sternocleidomastoid muscle (SCM) would also enhance effective local anesthesia for the initial skin incision and further contribute to a more ideal working environment for the surgeon. Therefore, anesthetic technique termed ultrasound-guided capsule-sheath space block (CSSB) combined with anterior cervical cutaneous nerves block (CCNB) for thyroidectomy is done [Wang et al., 2015] . Our hypothesis is that a combination of simple dual techniques including superficial cutaneous block to provide sensory blockade, and surgeon mediated capsular block may afford autonomic thyroid blockade. In comparison, ultrasound guided intermediate cervical plexus block may provide these blocks but using a machine and deep penetration possibly involving unwanted blocks for phrenic and recurrent laryngeal nerves. So, if the simple safe technique can provide the same intra and postoperative anesthetic conditions it will be preferred.

Official Title
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The Efficacy of Intermediate Cervical Plexus Block Versus Cutaneous and Thyroid Capsular Blocks in Thyroid Surgeries

Conditions
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Thyroid Surgery

Intervention / Treatment
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* Procedure: Capsule and cutaneous blocks
* Procedure: US-intermediate cervical plexus block


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: American Society of Anesthesiologists physical status grade I and grade II. Euthyroidism after thyroid function tests Exclusion Criteria: Patient refusal. Thyroid gland more than 5 cm size. Retrosternal extension. Planned block neck dissection. Neuromuscular diseases Hematological diseases. Bleeding diseases. Coagulation abnormality. Psychiatric diseases. Drug abuse. Local skin infection sepsis at site of the block. Known intolerance to the study drugs. Body Mass Index > 40 Kg/m2. Known diaphragmatic motion abnormalities major respiratory disease. Previous history of cervical surgery.

Ages Eligible for Study
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Minimum Age: 20 Years
Maximum Age: 60 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: Other
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Capsule and cutaneous blocks<br>7.5 mL of 0.5% bupivacaine + Epinephrine 5 ug/ ml for both blocks per side. once before surgery | Procedure: Capsule and cutaneous blocks<br>* 7.5 mL of 0.5% bupivacaine + Epinephrine 5 ug/ ml for both blocks once before surgery per side<br>|
| Active Comparator: US-intermediate cervical plexus block<br>15 mL of 0.5% isobaric bupivacaine + Epinephrine 5 microgram/ ml. per side. once before surgery | Procedure: US-intermediate cervical plexus block<br>* 15 mL of 0.5% bupivacaine + Epinephrine 5 ug/ ml once before surgery per side.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Total dose of opioid analgesics used | The total dose of opioid analgesics required in the post-operative periods | For 24 hours after surgery | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Postoperative pain | Postoperative visual analogue score (VAS) (0 no pain -10 worst imaginable pain), | For 24 hours after surgery | 
| Time to first analgesic request | Time to first request for a rescue analgesic | For 24 hours after surgery | 
| Fentanyl use | Intraoperative use of fentanyl | For 5 hours after start of anaesthesia | 
| Rocuronium use | Intraoperative use of rocuronium | For 5 hours after start of anaesthesia | 
| Sensory blockade | Assessment of sensory blockade | for 1 hour after surgery | 
| Diaphragmatic dysfunction | Diaphragmatic dysfunction using ultrasound assessment and possible x ray | for 5 hours after performing blockade | 
| Sedation score | Sedation score using Modified Ramsay scale | for 5 hours after performing blockade | 
| Patient satisfaction | Patient satisfaction regards analgesia using a score of (0-10) with 10 represents the highest satisfaction | for 24 hrs after surgery | 
| Postoperative nausea and vomiting | frequency | For 24 hours after surgery | 
| Postoperative headache | frequency | For 24 hours after surgery | 
| Hoarseness of voice | frequency | For 24 hours after surgery | 
| Dysphagia | frequency | For 24 hours after surgery | 
| Respiratory difficulty | Peripheral oxygen saturation less than 92% | For 24 hours after surgery |