Subcostal Transversus Abdominis Plane Block Under Ultrasound Guidance

In Response:

We have demonstrated in volunteers that the transversus abdominis plane (TAP) block with lidocaine 0.5% produced a sensory block which can extend, over several hours, from the L2 dermatome up to the T7 dermatome.¹ In clinical studies, we have demonstrated the analgesic efficacy of the TAP block in patients with incisions that extend above the umbilicus.^2,3 These findings strongly support the contention that the TAP block produces analgesia above the umbilicus. We cannot account for the lack of spread described by Dr. Hebbard.⁴

In regards to the subcostal approach to the TAP plane, we agree that this is a valid alternative approach for upper abdominal surgery and one we have used for patients undergoing open cholecystectomy, where faster spread of local anesthetic to the upper abdominal dermatomes is a clear advantage. We congratulate Dr. Hebbard for his description of the approach.

We are unclear, however, in regard to the need to advance the needle once it is in the TAP plane, as the local anesthetic injectate will spread easily within the plane. Excessive needle movement, albeit under ultrasound guidance, may increase the risk of neural and/or vascular injury.

John G. Laffey

Department of Anaesthesia, NUI Galway

Galway University Hospitals

[email protected]

John G. McDonnell, MB, FCARCSI

Department of Anaesthesia

Galway University Hospitals and

National University of Ireland, Galway, Ireland