This module describes the ultrasound guided caudal block in adults

Andrew Donowan from Musgrove Park Hospital, Taunton, UK, has provided the material

Indications:

– postoperative analgesia for rectal, perineal and vulval surgery

– surgical anaesthesia for perineal or rectal surgery

The transducer is moved dorsally keeping the transverse orientation until the QL muscle is identified with its attachment to the lateral edge of the transverse process of the L4 vertebral body

With the psoas major muscle (PM) anteriorly, the erector spinae muscle (ESM) posteriorly and the QL muscle adherent to the apex of the transverse process, a well recognizable pattern of a shamrock with three leaves can be seen:

The transverse process of vertebral body L4 is visualized as the stem of the shamrock. The three leaves are the muscles: quadratus lumborum, psoas major, and the erector spinae muscle.

The needle is inserted in-plane to the transducer (lateral edge) and the tip of the needle is advanced through the QL muscle, penetrating the ventral proper fascia of the QL muscle and LA is finally injected between the QL and PM

Analgesia of abdominal visceral and somatic pain

Hanson NA & Auyong DB: Systematic ultrasound identification of the dorsal scapular and long thoracic nerves during interscalene block. Reg Anesth Pain Med 38: 54-57 (2013)

The subcostal, ilioinguinal and iliohypogastric nerves are sandwiched between the QL muscle and the psoas major muscle (PMM)

The subcostal nerve (T12), ilioinguinal nerve (L1) and iliohypogastric nerve (L1) run across the anterior side of the quadratus lumborum (QL) muscle between the QL muscle and the transversalis fascia (TF)

The upper two of the three spinal nerve root branches of the long thoracic nerve typically pierce the middle scalene muscle together with the dorsal scapular nerve

It is important to visualize and/or stimulate the long thoracic and dorsal scapular nerves with electrical nerve stimulation during the performance of an interscalene brachial plexus block

Place the patient supine

Place the high-frequency linear probe in the axial plane and visualize the C5 and C6 spinal nerve roots in the interscalene groove between the anterior and middle scalene muscles. Visualize the long thoracic and dorsal scapular nerves inside the middle scalene muscle posterior to the interscalene groove (see second next page)

Advance the needle with in-plane technique from the posterior end of the probe. Confirm the identity of the long thoracic and dorsal scapular target nerves with electrical nerve stimulation

Inject 5 mL of local anaesthetic until complete perineural spread around the target long thoracic nerve

Place the patient supine

Place the high-frequency linear probe in the axial plane in the corner between the clavicle and coracoid process

Visualize the long thoracic nerve where it runs across the anterior serratus muscle (see second next page)

Insert the needle with in-plane technique from the medial end of the probe and advance the needle until the needle tip is in contact with the target nerve

Inject 5 mL of local anaesthetic until complete perineural spread is obtained

At the level just below the clavicle, the long thoracic nerve runs across the serratus anterior muscle between the major psoas muscle and the pleura