Transversus Abdominis Plane block

Ultrasound guided Transversus Abdominis Plane block
The transversus abdominis plane (TAP) block is an effective method of providing postoperative analgesia in patients undergoing midline abdominal wall incisions and laparoscopic surgeries.

Anatomy
The abdominal wall is innervated by anterior division of spinal nerves. These nerves run laterally between the transverses abdominis and internal oblique muscle layers of the abdominal wall. There is a lateral branch at the midaxillary line and an anterior branch through the rectus muscle, which supplies the skin from the midline to approximately the anterior axillary line.

Patient position
Position the patient supine

Equipment
1. A high frequency (10 MHz) probe
2. Depth 2.5-4cm
3. 50 -100mm short beveled needle
4. Sterile preparation kit, syringes and local anaesthetic

Ultrasound scanning technique
The probe is placed perpendicular to abdominal wall behind the midaxillary line between the iliac crest and the most inferior extent of the ribs. Moving the probe slightly medially we can see the edge of rectus. Scanning laterally we can see the three distinct layers of external and internal oblique and transversus abdominis in the lateral abdominal wall. Between the fascial plane just above the transversus abdominis muscle sometimes nerves could be seen.