Multimodal Nerve Block and Pulse Radiofrequency for Acute Herpes Zoster Pain

Summary

The primary objective of this clinical trial is to evaluate the efficacy of liposomal bupivacaine and ropivacaine in the treatment of pain associated with herpes zoster (shingles). This trial will also assess the safety profiles of both liposomal bupivacaine and ropivacaine.

The study aims to address the following key questions:

Does nerve blockade with liposomal bupivacaine or ropivacaine reduce the required dosage of gabapentin in participants? What medical issues, if any, arise in participants undergoing paravertebral block, intercostal nerve block, RISS (Radiofrequency Intervention for Spinal Segment); or pulsed radiofrequency (PRF)? Can nerve blocks, specifically paravertebral block, intercostal nerve block, RISS; and PRF, effectively treat severe postherpetic neuralgia (PHN)? The study will compare these interventions.

Study Procedures:

Participants will:Receive ultrasound-guided nerve blocks or pulsed radiofrequency every 48 hours, for a total of 3 treatments.

Undergo assessments, either in-person or via telephone, at the following time points: before therapy (baseline), on the day of treatment (Day 1), Day 7, Day 30, and Day 90 post-treatment.

Have their symptoms recorded, along with their scores on the Numerical Rating Scale (NRS) and the Zoster Brief Pain Inventory (ZBPI).

Conditions

• Herpes Zoster (HZ)

Interventions

DEVICE

Ultrasound-Guided Pulsed Radiofrequency (PRF)

A high-frequency linear ultrasound transducer will be used for this procedure. The transducer will be placed transversely over the target rib area to obtain a clear visualization of the rib, intercostal muscles, and pleura. The entry point for needle insertion will be selected 1-2 cm inferior to the inferior border of the target rib. Using a 22G radiofrequency (RF) needle, an in-plane approach will be used for needle advancement. The needle will be advanced slowly until it reaches the inferior border of the rib. The needle will then be withdrawn 1-2 mm to ensure the needle tip is positioned adjacent to the intercostal nerve. The RF needle will then be connected to the RF generator for sensory testing. Stimulation parameters will be set at 50 Hz and 0.5-1V. The target location will be considered accurate if stimulation induces pain in the participant. Pulsed radiofrequency treatment will then be administered using the following parameters: voltage of 45V, frequency of 2 Hz, pulse width

DEVICE

Intercostal nerve block (2% ropivacaine or 133 mg of liposomal bupivacaine)

The patient is positioned in either the lateral decubitus or sitting position, with the affected side facing upwards, ensuring adequate exposure of the targeted intercostal region. A high-frequency linear ultrasound transducer is placed transversely over the posterior lateral aspect of the targeted rib, using the vertebral column as a reference point. The transducer is then scanned laterally to identify the target rib, clearly visualizing the rib, intercostal muscles, and pleura. The intercostal nerve appears as a small hyperechoic structure located between the internal and innermost intercostal muscles. The needle is advanced until it contacts the inferior border of the rib. The needle is then slightly withdrawn and positioned between the internal and innermost intercostal muscles to avoid pleural puncture. After negative aspiration, 10 mL of 0.5% ropivacaine (or 133 mg of liposomal bupivacaine) combined with 10 mg of triamcinolone acetonide is injected slowly.

DEVICE

Paravertebral (PVB) Block (2% ropivacaine or 133 mg of liposomal bupivacaine)

For the Paravertebral (PVB) block, a high-frequency linear ultrasound transducer was placed transversely, parallel to the spinous processes, approximately 2-3 cm lateral to the spinous process of the target thoracic vertebral segment. The position and angle of the transducer were adjusted to clearly visualize the transverse process (TP) and the axial view of the lamina of the target vertebra. In the ultrasound image, the transverse process appeared as a hyperechoic structure, typically with a characteristic acoustic shadow posterior to it. Subsequently, the transducer was slightly slid caudally, causing the transverse process and its acoustic shadow to gradually disappear from view. At this point, the ultrasound image revealed components of the paravertebral space (PVS), including the parietal pleura, the superior costotransverse ligament, and the intercostal fascia, which exhibited a heterogeneous mixed echogenicity. Using an in-plane technique, a puncture needle was advanced from lat

DEVICE

Rhomboid Intercostal and Subserratus Plane (RISS) Block (2% ropivacaine or 133 mg of liposomal bupivacaine)

The RISS block is a composite nerve block technique that involves two injection sites: the inter-rhomboid plane and the sub-serratus plane. The selection of block plane was determined by the patient's specific location of pain. Rhomboid Intercostal Plane Block (RIPB): For the Rhomboid Intercostal Plane Block (RIPB), a high-frequency linear ultrasound transducer was initially positioned in a sagittal orientation, medial to the scapular border. It was then slightly rotated to obtain an oblique sagittal view (oblique paramedian sagittal view), located 1-2 cm lateral to the scapular border. Upon obtaining the appropriate ultrasound image, the following anatomical structures were identified sequentially, from superficial to deep: the trapezius muscle, the rhomboid muscles (specifically, the major rhomboid), the intercostal muscles (located between the ribs), the pleura, and the lung. The target injection plane was the fascial plane situated between the rhomboid muscle and the intercostal

DRUG

Drug (famciclovir and gabapentin)

All patients will receive famciclovir and gabapentin. All participants will receive standard antiviral therapy with famciclovir 500 mg orally three times daily for 7 days. Gabapentin will be initiated at a typical starting dose of 300 mg per day, administered in three divided doses. The dosage may be gradually increased, as needed and tolerated, up to a maximum dose of 1800 mg per day.

Sponsors & Collaborators

• Xiaguang Duan

  lead OTHER

Study Design

Allocation

RANDOMIZED

Purpose

TREATMENT

Masking

QUADRUPLE

Model

PARALLEL

Eligibility

Min Age

20 Years

Sex

ALL

Healthy Volunteers

No

Timeline & Regulatory

Start

2025-02-01

Primary Completion

2025-06-01

Completion

2025-06-10

FDA Device

Yes

Countries

• China

Study Locations