The intertransverse process block single- or multiple-injection? A study protocol

Area of Science:

• Anesthesiology
• Pain Management
• Regional Anesthesia

Background:

• Intertransverse process (ITP) blocks are posterior thoracic paravertebral space blocks.
• ITP blocks are considered a proxy for thoracic paravertebral blocks, potentially offering similar analgesia.
• Evidence on dermatome anesthesia and sensory loss from ITP blocks is limited.

Purpose of the Study:

• To compare the efficacy of single-injection versus multiple-injection ITP blocks.
• To determine the number of anaesthetised thoracic dermatomes for each block type.
• To explore the clinical utility of thermography in assessing nerve block effectiveness.

Main Methods:

• A randomized, double-blinded, crossover trial involving 12 healthy male volunteers.
• Participants received either a single-injection or multiple-injection ITP block with ropivacaine, followed by sham blocks or the alternative injection on separate days.
• Sensory testing (pinprick, temperature) and anterior truncal thermography were performed post-block; blood pressure was also monitored.

Main Results:

• The study aims to quantify the extent of cutaneous sensory loss following ITP blocks.
• It will compare the number of anaesthetised thoracic dermatomes between single and multiple injection techniques.
• Changes in skin temperature via thermography will be analyzed to assess block efficacy.

Conclusions:

• This research will significantly enhance understanding of the sensory deficits associated with ITP blocks.
• Findings may validate thermography as a reliable tool for measuring the effectiveness of nerve blocks.
• The study contributes to the evidence base for thoracic paravertebral analgesia techniques.