Rectus Sheath Block 2018-07-24T02:29:56+00:00

Anatomy

  • Innervation of the anterolateral abdominal wall arises from the anterior rami of spinal nerves T7 to L1.
  • Intercostal nerves T7 to T11 exit the intercostal spaces and run in the neurovascular plane between the internal oblique and the transversus abdominis muscles. The subcostal nerve (T12) and the ilioinguinal/ iliohypogastric nerves (L1) also travel in the plane between the transversus abdominis and internal oblique, innervating both these muscles.
  • The T7-T12 nerves continue anteriorly from the transversus plane to pierce the rectus sheath and end as anterior cutaneous nerves and are therefore targeted in rectus sheath blocks.
  • Bilateral rectus sheath blocks provide analgesia from the xiphi sternum to the symphysis pubis. The T7-T11 nerves provide sensory innervation to the rectus muscle and overlying skin.

Transverse section of the abdominal wall showing the path of nerves T7-T12 as they travel from the spine to the anterior abdomen

Distribution of somatic analgesia after bilateral rectus sheath block

Ultrasound Anatomy

Ultrasound image of Anterior Abdominal wall muscles

Anterior abdominal wall muscles

Formation of Rectus sheath

Rectus Muscle

Tramlines of Posterior Rectus sheath

INDICATIONS

  • Operations with midline or para median incisions extending above the umbilicus

CONTRAINDICATIONS

  • Patient refusal
  • Previous adverse effects with local anaesthetics
  • Superficial infection at site of potential insertion
  • Inadequate knowledge to perform block
  • Inadequately experienced ward staff to care for patient post operatively
  • Bleeding disorders

COMPLICATIONS

  • Failure
  • Rectus sheath haematoma (damage to superior and inferior epigastric vessels)
  • IV administration of local anaesthetic causing toxicity
  • Puncture of peritoneum and/or bowel
  • Infection

EQUIPMENT

  • Asepsis: hat; mask; gown; gloves; Chlorhexidine 0.5% spray to skin and allowed to dry
  • Ultrasound machine with ultrasound probe cover and lubricant.
  • 22G Stimuplex needle with saline 0.9% to hydro dissect posterior rectus sheath space
  • Choice of catheter lie with operator, here are examples:

Epidural sets (Portex 16G Tuohy Epidural)/ Pajunk Rectus sheath catheters

Method of skin fixation; epifix, skin glue, Tegaderm dressing

Inplane Lateral to Medial Rectus Sheath Block

Ultrasound image after injection of local anaesthetic

LOCAL ANAESTHETIC DOSING GUILDELINES FOR CONTINUOUS REGIONAL ANALGESIA

Total dose of Bupivacaine recommended per BNF= 400mg in 24 hours

  • i.e. 400mg/24 hours= 160 mls of 0.25% Bupivacaine/24 hours or 320mls of 0.125% Bupivacaine/24 hours
  • Max allowed rate of 0.125% Bupivacaine= 14mls/hour
  • Dosage range to prescribe for Rectus sheath infusions = 10-14mls/hr of 0.125% Bupivacaine.

If you select Protocol B, prescribe the rescue boluses on the PRN side

Video of Rectus Sheath Catheter insertion