Transversus Abdominis Plane (TAP) Block in Paediatrics A novel approach to block of the anterior abdominal wall Cathy Roulson UHL Thursday 15 th May 2008

Aim  Review the publications  Describe the technique  Demonstrate the ultrasound anatomy Videos Models

The Literature  Thus far solely in adults…  First publication Rafi, AN – Abdominal field block: a new approach via the lumbar triangle Anaesthesia 2001 Described a landmark approach palpating the lumbar triangle of Petit above the iliac crest

Copyright restrictions apply. McDonnell, J. G. et al. Anesth Analg 2007;104: Line drawing of the anatomy of the abdominal wall, including the lumbar triangle of Petit (TOP)

Rafi  Walk posterior from the ASIS until encounter a dip. Further posterior movement slip over muscle edge – lat. border of latissimus dorsi  Insert needle perpendicular, anterior to finger to touch bone of anterior lip. Advance further for ‘pop’ – plane between internal oblique and transversus abdominis  For child recommended 24G 1-inch needle (B. Braun)

The Analgesic Efficacy of Transversus Abdominis Plane Block After Abdominal Surgery: A Prospective Randomized Controlled Trial McDonnell JG et al, Anesth Analg 2007; 104(1):  32 adults, large bowel resection  Midline incision  Landmark 2 ‘pop’ technique – palpate triangle of Petit. Needle perpendicular above iliac crest. First ‘pop’ needle between external and internal oblique. Second entry into transversus abdominis fascial plane  20ml 0.375% L Bupiv bilaterally  No complications

The Analgesic Efficacy of Transversus Abdominis Plane Block After Abdominal Surgery: A Prospective Randomized Controlled Trial McDonnell JG et al, Anesth Analg 2007; 104(1):  VAS scores reduced throughout 24h period  Morphine requirement in 24h reduced (21.9 vs 80.4mg)  N.B. Use in retropubic prostatectomy (O’Donnell BD, McDonnell JG, 2006) showed clinically useful analgesia for at least 48h - debatable

Transversus Abdominis Plane Block: A Cadaveric and Radiological Evaluation McDonnell JG et al, Regional Anesthesia and Pain Medicine 2007; 32(5):  Study 1. 3 fresh, unfixed cadaveric specimens. 20ml methylene blue by landmark technique. Fixation then dissection  Study 2. Validation in volunteers using CT. 3 volunteers, 20ml radiopaque dye and lidocaine to 0.5% bilat. Imaging at 20 min.  Study 3. MRI. 3 volunteers. 20ml gadopentetate and 0.1% laevo bilat. MRI at 1,2,4 h

Results  Cadavers – dense dye deposition in the TAP plane from iliac crest to costal margin  Volunteers – CT dye in plane and more superficially. Sensory block T7 – L1  MRI – spread from iliac crest to subcostal margin. Reduced signal intensity at 4h. Block T7 – L1, receding at 4h and completely regressed at 24h

When?  Epidural gold standard Clotting Sepsis Refusal A hammer to crack a nut  Adults Bowel surgery Retropubic prostatectomy LSCS Laparoscopy  Children?

Ultrasound Guidance needle rectus ext. oblique int. oblique transversus

Equipment  22G spinal needle without stylette  Extension  Saline test dose  Laevobupivacaine / Ropivacaine Dose

Ultrasound anatomy

Relation to ‘Triangle of Petit’

Needle insertion

TAP injection

Thanks to John McDonnell

Too far – pulled back

Too superficial, too deep - just right

TAP injection – too superficial

Top tips  Flush equipment  Assess depth of plane before needle insertion  Ensure needle tip is posterior to the mid-axillary line  Flush with small test dose to confirm position then adjust position if necessary  Overshoot and pull back

Conclusions / Future  A technique with potential  ? Niche – needs further use to establish its role in children and adults  Paediatric publications due soon Case series RCT in progress  To be answered: Dose and plasma levels Is the plane crucial Duration  Catheters being used in adults, ? children

Further information  Lecture on TAP blocks and subcostal TAPs  Join free to communicate with others interested in RA Best on-line logbook CUSUM

Demo