Indian Journal of Anaesthesia

: 2012  |  Volume : 56  |  Issue : 1  |  Page : 104--105

Ultrasound-guided transversus abdominis plane block in obese patients

Gokul Toshniwal1, Vitaly Soskin2,  
1 Department of Anaesthesiology and Pain Medicine, University of Pittsburgh Medical Center, Pittsburgh, PA, USA
2 Department of Anaesthesiology, Wayne State University, Detroit, MI, USA

Correspondence Address:
Gokul Toshniwal
7467, Lighthouse Point, Pittsburgh, PA 15221

How to cite this article:
Toshniwal G, Soskin V. Ultrasound-guided transversus abdominis plane block in obese patients.Indian J Anaesth 2012;56:104-105

How to cite this URL:
Toshniwal G, Soskin V. Ultrasound-guided transversus abdominis plane block in obese patients. Indian J Anaesth [serial online] 2012 [cited 2020 Sep 30 ];56:104-105
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Full Text


Ultrasound-guided (USG) transversus abdominis plane (TAP) block is routinely performed in adults for abdominal surgeries like caesarean section and open appendectomy. [1],[2] This block is usually performed in the supine position under ultrasound guidance (in-plane approach). The ideal position of the needle during TAP block is along the anterior axillary line, as the lateral cutaneous branch of the intercostal nerves, which supply the antero-lateral aspect of the abdominal wall, leave the neurovascular plane (TAP) along the mid-or anterior axillary line. [3]

In obese patients, the performance of this block can be challenging due to excessive subcutaneous fat and increased depth of TAP. It is recommended that USG-TAP block is performed under real-time ultrasound guidance in obese patients. In the supine position, the subcutaneous fat hangs over the flank and leads to difficulty in probe handling and poor visualization of the needle during the procedure [Figure 1]. Hence, we perform USG-TAP block with the patient in a semilateral position by placing a wedge under their flank on the ipsilateral side of the block, which pushes the subcutaneous fat medially and flattens the procedure field. This makes handling of the ultrasound probe easier and visualization of the needle is also improved because the depth of the TAP is decreased and we are able to introduce the needle at a more obtuse angle in relation to the ultrasound probe [Figure 2].{Figure 1}{Figure 2}

Needle-beam angle is one of the most important factors influencing the visualization of the needle during the in-plane approach of an USG procedure. [4] It is difficult to attain a desired (>55 degrees) needle-beam angle with the increasing depth of the target during USG procedures. Hence, we suggest performing USG-TAP block in a semilateral position rather than in a supine position in obese patients, as the handling of the ultrasound probe is easier and needle visualization improves due to better needle-to-probe alignment.


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