Dear Colleague,

a combination of the US-guided subcostal and lateral TAP blocks, termed the US-guided bilateral dual -TAP block and involving a total of 4 injections, has been proposed as a method of providing analgesia to the entire anterior abdominal wall.

In their evaluations of the US-guided bilateral dual-TAP block, Børglum et al. have shown that the lateral TAP block produces spread confined to the lower abdomen and a sensory block of T10-T12, whereas the subcostal TAP block produced spread in the upper abdominal TAP.

A major limitation of TAP blocks is the fixed duration of analgesia provided by a single-shot technique. Although pain scores and overall opioid consumption may be reduced in some settings for up to 24 to 48 hours.

Preoperative placement may require technical modification to avoid interference with the surgical field. Postoperatively, surgical wound dressings and disruption of tissue planes can make percutaneous US-guided insertion difficult and contribute to a primary technical failure rate of 20% to 45%.

Bilateral catheters are needed for incisions crossing the midline. Coverage of both supraumbilical and infraumbilical regions requires insertion and management of 4 separate catheters, which, although feasible, may be too complex for routine use. There are no data to indicate whether a catheter dosing regimen of intermittent boluses or continuous infusion , is preferable, what the optimal infusion rate is, and to what extent these choices are influenced by the TAP block technique and the type of surgery.

Finally, there is still relatively little evidence for the clinical benefit of continuous TAP blocks. It is unnecessary for surgery where postoperative pain is mild to moderate and may confer little additional benefit compared with single-shot TAP blocks, given that the latter often have an analgesic effect that outlasts clinically apparent block duration. Although TAP catheters are a logical alternative to epidural analgesia where this is contraindicated and may provide comparable analgesia, the technical and logistical issues involved would seem to preclude their widespread use.

Dear Colleague,

In my opinion and clinical experience none of them works efficiently for postoperative analgesia after laparatomy. Both aformentioned techniques may work well during rest but patient will still ask for extra analgesics for visceral pain. Rather than performing TAP block with multiple injections or a catheter, I prefer using erector spinae plane block with single injection on both sides. ESPB has a longer duration of action than TAP block. Moreover, you achieve analgesia for both visceral and somatic pain after laparatomy.

Stijn,

In my practice, when choosing to administer TAP blocks, I find that my decision is based upon whether a single shot block fits the plan. If my anesthetic plan consists of catheters, I prefer T-8 erector spinae plane (ESP) catheters versus TAP.

Rationale: To cover the entire abdomen, one would need a four quadrant TAP to provide coverage (if one quadrant fails, the patient experiences pain). The ESPB provides a wider coverage and is more consistently successful in obese patients. The ESPB catheters are remote to the incision and dressing which decreases the chance of dislodging of catheters during dressing changes.

Full Disclosure: I am biased towards ESPB and currently submitting an IRB application to begin a study using ESPB.

Cheers,

Christopher