Chapter 153. Regional Analgesia for Abdominal Surgery

A comprehensive approach of analgesia after abdominal surgery is based on the understanding of parietal and visceral innervation (see Chapter 151).

Intercostal, ilioinguinal, and iliohypogastric nerves can be blocked at different levels, from proximal to distal.

Epidural analgesia (EDA):

• Remains the gold standard for pain relief after open abdominal surgery
• Low thoracic catheter for at least 48 hours after surgery
• Mixture of local anesthetics and opioids
• Patient-controlled administration
• Risk–benefit ratio questionable after laparoscopic surgery

Intrathecal morphine (ITM):

• Small dose of PF morphine (100–500 μg) in the lumbar area
• Limited duration of action
• No demonstrated benefit on postoperative rehabilitation
• Need for prolonged monitoring (risk of delayed respiratory depression)
• Interest of ITM is questionable as better regional techniques available

Transversus abdominis plane block (TAP block):

• TAP block consists of blocking intercostal nerves at the level of lateral abdominal wall between internal oblique and transverse abdominis muscles
• Variable success rate, probably improved by ultrasound guidance
• Subcostal TAP block must be considered for incisions on dermatome higher than T10
• Must be performed bilaterally in order to cover a midline incision
• Duration of action (using long-lasting local anesthetics) after a single injection: up to 24 hours
• No clear benefit demonstrated on postoperative rehabilitation

Ilioinguinal/iliohypogastric block (IIB):

• Actually a variant of the TAP block, with the injection being more specifically oriented toward these nerves (i.e., more anterior in the abdominal wall)
• At this level, nerves to be blocked are between the internal and external oblique muscles
• Usually indicated for anesthesia and analgesia after inguinal hernia repair. But also highly effective for pain relief after abdominal gynecological procedure as well as for C-section (bilateral blocks)
• Keep in mind that a genitofemoral block must be associated with an IIB in order to provide optimal analgesia during inguinal hernia repair. Moreover, nerves coming from the contralateral intercostal nerves have to be blocked by a local infiltration at the medial side of the incision

Rectus sheath block:

• Consists of injecting the local anesthetic directly into the rectus abdominis muscle at the level where intercostal nerves enter the muscle
• Only intended for midline incision (usually for umbilical hernia repair)
• Very easy to perform. Ultrasound-guided techniques could improve success and safety (look out for the epigastric artery, which is very close to the injection point)
• Usually 10 mL of long-acting local anesthetic on each side
• Multiple injections should be performed to block more than one dermatome level

Wound infiltration:

• Consists of injecting local anesthetic directly into the wound
• Should be used as a component of a multimodal analgesic regimen
• Duration of action after a single bolus injection is usually too limited to provide clinically significant benefit
• A multiperforated catheter can be inserted into the wound by the surgeon at the end of the ...