Regional Anesthesia to Relief Zoster Pain

Study Overview
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Brief Summary
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Pain in Herpes is a serious issue for patients. at the acute phase it is a moderate to severe pain . 30% patients will develop a post herpetic neuralgia this percentage up to 70 % after 60 years old. this post herpetic neuralgia will affect their life. Publication showed the efficiency of regional anesthesia on pain at the acute phase and a recent meta-analysis showed the role of efficient pain relief on the prevention of post herpetic neuralgia. there are still 2 questions to answer: 1/ do we need to perform the regional anesthesia to relief the pain at an early stage of after no response to the medical treatment? 2/ Are repeated blocks more efficient than a single block?

Detailed Description
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Study Model: Randomized prospective registered After approval by the ethical committee of VinMec international Hospitals Institution , after approved registration prior to start the study to www.clinicaltrial.gov, 80 patients will be enrolled to participate to the study. Inclusion criteria; Acute zona diagnosed by the dermatologist Acute skin rash with blisters in a limited area on one side of the body Eruption Unilateral On dermatome between C5 and S2 Age 18 to 85 years Old [YO], males and females American Society of Anesthesiologists score [ASA] grades I & II Patient who accepted to participate as volunteers and signed an informed consent Exclusion criteria; Psychiatric disease Central nervous system disease or pre-existing neuropathy Coagulation abnormalities or anti-coagulant treatment (heparins Anti vit K anti thrombin) Contra indication to perform a peripheral nerve block or interfascial block Infection of the skin overlying the puncture site of the block Allergy to local anaesthetic or prednisolone Contra indication to prednisolone ASA III and IV Morbidity Obese BMI > 30 Pregnant woman Baseline evaluation; Date of first rash appeared Pain VAS score from 0 no Pain to 10 the worst imaginable pain Localization of the pain (Skin mapping of the painful area and allodynia area) Quality of life before the rash evaluated by the quality of Life questionnaire SF36 published with a certified translation in Vietnamese As soon as the diagnosis will be done by dermatologist the following treatment will be prescribed according to international published standards of Herpes; Oral administration of Acyclovir 800 mg 5 times a day for 7 days Oral administration of prednisolone except if contra indication 30mg twice daily on d1 > 7 15mg twice daily on d8 > 14 7.5mg twice daily on d15 > 21 Patient flow chart: Randomization Done by an administrative assistant using a computer program with block randomization. Group Control = medical treatment with the following pain killers Pain medications Oral administration of Gabapentin 300 mg/d on day 1 and 2 600 mg on day 3 and 4 if pain persists 900 mg on day 5 and 6 if pain persists Oral administration of Paracetamol up to 3 g per day Use of oral narcotic contra-indicated A pain assessment will be done at day 7 if Pain scores < 4 medical treatment will be continued. If Pain score > 4 Patient will be shifted to the group Intervention and will follow the same protocols of this group with randomization done by an administrative assistant using a third computer program table of randomization. Group Intervention = Early block a second randomization will be done immediately after the first one by an administrative assistant using a second computer program table of randomization. Single Shot [SS] block : the patient will receive a regional anaesthesia by Inter fascial block, peripheral nerve block. The type of block would be the most appropriate to cover the dermatomes involved in the Herpes according to the mapping done with the higher ration benefit risks. Choice of Block by an anesthesiologist expert in regional anaesthesia techniques. After the block performance if the pain comes back patient will receive the standard medical treatment as in the group medical treatment Repeated [R] Blocks : the patient will receive a regional anaesthesia by Inter fascial block, peripheral nerve block. The type of block would be the most appropriate to cover the dermatomes involved in the Herpes according to the mapping done with the higher ratio benefit risks. The choice of the block will be done by an anesthesiologist expert in regional anaesthesia techniques. The block will be repeated every 48h until the pain will reach VAS < 3 6 h after block recovery. all the blocks will be performed under US guidance combined if peripheral nerve block or peri plexic block with Neurostimulation guidance to increase the safety of the block performance at the higher level. The choice of Local anesthetics used will be Ropivacaine 0.5% with the same posology used to performed a regional anaesthesia for surgery. The patient will be discharged 2 hours after the block performance Follow up The follow up will be done by : an pain nurse to analyse VAS at Week 1, 2 and 3 after the inclusion of the patient Satisfaction of patient 0-10 a pain physician to analyse at Month 1, 2 3 and 6 after 1st eruptive sign of Herpes Zona [HZ] eruption development of post herpetic neuralgia defined as Persisting pain beyond the crusting of lesion Pain lasting more than 1, 2 ,3 or 6 months after the acute infection Neuropathic pain with a Douleur Neuropathic 4 [DN4] scale score > 4 DetectPain scale score > 19 Pain level VAS Mapping area of pain to calculate surface Quality of life score at Month 2 3 6 after start of eruptive phase Primary Outcome Quality of pain relief in acute phase VAS score at 1 day / 3 day/ 7 day / 14 Day / 21 day Mapping area surface at day 1, 7 , 14 and 21 Secondary Outcome Development of Neuropathic pain Scale DN4 score > 4 Scale Pain detect Score > 17 Pain intensity Quality of life (QoL) Using the 36 item Short form Health survey [SF36] variation compared to initial assessment Sample size calculation An estimated 14 patients per group were required to detect a 25% reduction in the mean VAS score in block groups compared to standard treatment group, with a power of 80%, a 2-tailed α of 5%, and a mean VAS-score of 7.25 (SD 1.51) [14] of standard treatment group in the pre-test. The sample size of 80 patients allowed for a 10% loss to follow-up. Statistical analysis plan Statistical analysis will be performed using STATA 14.0 software. Statistical significant will be set at 5% level (2-tailed). A QoL score will be derived from related variables as stated above, using factor analysis. Data will be summarized using n (%) for categorical data and median (inter-quartile ranges) for continuous data. Analyses will include Chi-square or Fisher's exact test where appropriate for binomial data. Continuous data will be compared by non-parametric tests.

Official Title
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Does Repetitive Peripheral Nerve Blocks Vs Single Peripheral Nerve Block Vs Standard Medical Treatment Provide a Better Pain Relief on Zoster Pain at the Acute Phase and Reduce the Risk of Post Herpetic Neuralgia?

Conditions
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Zoster Without Complications

Intervention / Treatment
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* Procedure: peripheral nerve block, inter fascial nerve block


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Acute zona diagnosed by the dermatologist o Acute skin rash with blisters in a limited area on one side of the body Eruption Unilateral On dermatome between C5 and S2 Age 18 to 85 years old, males and females American Society of Anesthesiologists Score [ASA ]grades I & II Patient who accepted to participate as volunteers and signed an informed consent Exclusion Criteria: Psychiatric disease Central nervous system disease or pre-existing neuropathy Coagulation abnormalities or anti-coagulant treatment (heparins Anti vit K anti thrombin) Contra indication to perform a peripheral nerve block or interfascial block Infection of the skin overlying the puncture site of the block Allergy to local anaesthetic or prednisolone Contra indication to prednisolone ASA III and IV Morbidity Obese BMI > 30 Pregnant woman

Ages Eligible for Study
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Minimum Age: 18 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: Patient randomized in Medical treatment group or Early block group medical treatment group will have standard pain medications and evaluation of pain relief at day 7 If pain reduce less or egal to VAS 4 medical treatment will continue it will be the control group If no pain relief VAS more than 4 patient will be randomized to have single block = Group late block single or repeated blocks = Group late block repeated ealy block group will be randomized to have single block = Group early block single or repeated blocks = Group early block repeated
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| No Intervention: Medical treatment<br>Patients receive the standard medical medication for herpes pain Oral administration of Gabapentin 300 mg/d on day 1 and 2 600 mg/d on day 3 and 4 if pain persists 900 mg/d on day 5 and 6 if pain persists Oral administration of Paracetamol up to 3 g per day prescription for 7 day and continue for 3 weeks after evaluation | |
| Experimental: Early block Single<br>the patient will receive a regional anaesthesia by Inter fascial block, peripheral nerve block. Local anesthetic used will be ropivacaine 0.5% dose according to the type of block and never exceeding 3mg/kg The type of block would be the most appropriate to cover the dermatomes involved in the Herpes according to the mapping done with the higher ration benefit risks. Choice of Block by an anesthesiologist expert in regional anaesthesia techniques. After the block performance if the pain comes back patient will receive the standard medical treatment as in the group medical treatment | Procedure: peripheral nerve block, inter fascial nerve block<br>* regional anaesthesia by Inter fascial block, peripheral nerve block. The type of block would be the most appropriate to cover the dermatomes involved in the Herpes according to the mapping done with the higher ratio benefit risks. The choice of the block will be done by an anesthesiologist expert in regional anaesthesia techniques. local anesthetic will be ropivacaine 0.5% posology according to the type of block<br>|
| Experimental: Early Repeated block<br>the patient will receive a regional anaesthesia by Inter fascial block, peripheral nerve block. The type of block would be the most appropriate to cover the dermatomes involved in the Herpes according to the mapping done with the higher ratio benefit risks. Local anesthetic used will be ropivacaine 0.5% dose according to the type of block and never exceeding 3mg/kg The choice of the block will be done by an anesthesiologist expert in regional anaesthesia techniques. The block will be repeated every 48h until the pain will reach VAS < 3 6 h after block recovery. | Procedure: peripheral nerve block, inter fascial nerve block<br>* regional anaesthesia by Inter fascial block, peripheral nerve block. The type of block would be the most appropriate to cover the dermatomes involved in the Herpes according to the mapping done with the higher ratio benefit risks. The choice of the block will be done by an anesthesiologist expert in regional anaesthesia techniques. local anesthetic will be ropivacaine 0.5% posology according to the type of block<br>|
| Experimental: Late block single<br>Patients receive the standard medical medication for herpes pain Oral administration of Gabapentin 300 mg/d on day 1 and 2 600 mg/d on day 3 and 4 if pain persists 900 mg/d on day 5 and 6 if pain persists Oral administration of Paracetamol up to 3 g per day at day 7 if pain more than VAS 4 the patient will receive a regional anaesthesia by Inter fascial block, peripheral nerve block . Local anesthetic used will be ropivacaine 0.5% dose according to the type of block and never exceeding 3mg/kg The type of block would be the most appropriate to cover the dermatomes involved in the Herpes according to the mapping done with the higher ration benefit risks. Choice of Block by an anesthesiologist expert in regional anaesthesia techniques. After the block performance if the pain comes back patient will receive the standard medical treatment as in the group medical treatment | Procedure: peripheral nerve block, inter fascial nerve block<br>* regional anaesthesia by Inter fascial block, peripheral nerve block. The type of block would be the most appropriate to cover the dermatomes involved in the Herpes according to the mapping done with the higher ratio benefit risks. The choice of the block will be done by an anesthesiologist expert in regional anaesthesia techniques. local anesthetic will be ropivacaine 0.5% posology according to the type of block<br>|
| Experimental: late block repeated<br>Patients receive the standard medical medication for herpes pain Oral administration of Gabapentin 300 mg/d on day 1 and 2 600 mg/d on day 3 and 4 if pain persists 900 mg/d on day 5 and 6 if pain persists Oral administration of Paracetamol up to 3 g per day prescription for 7 day and continue for 3 weeks after evaluation At day 7 if pain more than VAS 4 the patient will receive a regional anaesthesia by Inter fascial block, peripheral nerve block. The type of block would be the most appropriate to cover the dermatomes involved in the Herpes according to the mapping done with the higher ratio benefit risks. Local anesthetic used will be ropivacaine 0.5% dose according to the type of block and never exceeding 3mg/kg The choice of the block will be done by an anesthesiologist expert in regional anaesthesia techniques. The block will be repeated every 48h until the pain will reach VAS < 3 6 h after block recovery. | Procedure: peripheral nerve block, inter fascial nerve block<br>* regional anaesthesia by Inter fascial block, peripheral nerve block. The type of block would be the most appropriate to cover the dermatomes involved in the Herpes according to the mapping done with the higher ratio benefit risks. The choice of the block will be done by an anesthesiologist expert in regional anaesthesia techniques. local anesthetic will be ropivacaine 0.5% posology according to the type of block<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in pain intensity between baseline and the end of treatment | Measure by change in the numeric Visual Analogue Scale (VAS) score. The pain-VAS is a single-item scale which is score from 0 -10. A higher score indicates greater pain intensity (0 = no pain and 10 = worst pain imaginable) 0 is the best score 10 is the worse one | baseline - end of treatment at day 30 | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Incidence of postherpetic neuralgia (PHN) after treatment | PHN is defined as persisting pain beyond the crusting of cutaneous lesion. Pain lasts more than 1 month after the acute infection with the DN4 scale score > 4 and DetectPain scale score > 19 | day 30 - day 60 - day 90 - day 180 | 
| Chang in quality of life score | Using the 36-Item Short-Form Health Survey (SF-36) for quality-of-life measurement. Each item is scored on a 0 to 100 range so that the lowest and highest possible scores are 0 and 100, respectively. Higher score defines a more favorable health state. The overall quality-of-life score at each time-point will be created from all items using an ad-hoc analysis. | Day 1 day 30 - day 60 - day 90 - day 180 | 
| The total pain burden during 180 days of follow-up | The total pain burden is quantified using an area-under-the-curve (AUC) method, using the measures of pain intensity and pain duration. Each patient's AUC is calculated as the sum of all areas obtained by multiplying the average of 2 consecutive pain scores by the number of days between the scores. | baseline- every 2 days until day 30 - day 60 - day 90 - day 180 | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Zoster,, Pain relief, regional anesthesia, Prevention post herpetic neuralgia