The transverse abdominis plane (TAP) block is a peripheral nerve block designed to anesthetize the nerves supplying the anterior abdominal wall (T6 to L1).  The TAP block was first described in 2001 as a traditional blind landmark technique using the lumbar triangle of Petit, however, currently TAP blocks are often placed under ultrasound guidance.  Local anesthetic is injected between the internal oblique and transverse abdominis muscles in the plane through which the sensory nerves pass.  

The goals for using TAP blocks in surgery are to reduce the need for postoperative opioid use, increase the time to first request for further analgesia, and provide more effective pain relief.  If these goals are achieved, opioid side effects such as sedation and postoperative nausea and vomiting are reduced while still providing adequate or optimal pain relief for the patient.

BACKGROUND

LITERATURE REVIEW

Five randomized double-blind studies, one review of 8 studies, and one meta-analysis of 174 patients were reviewed to assess the efficacy of TAP blocks in pain management and reduced opioid consumption postoperatively. The following results were found:

1) Average opioid usage was lower in TAP block groups. 2) Average postoperative pain scores were lower in TAP block groups. 3) Time to first request for postoperative analgesia was increased in TAP block groups.

RESULTS Conclusions

TAP blocks reduce the need for postoperative opioid use, increase the time to first request of postoperative analgesia, and provide pain relief following abdominal surgery.

All of the studies suggest that the use of TAP blocks in the postoperative period provide increased pain relief and reduced opioid consumption when compared to placebo groups.  TAP blocks were also found to be beneficial in pain management during postoperative periods of activity or coughing.

While all studies suggest a decrease in pain scores and opioid administration, there is a wide variation on the degree of benefit across the literature review. Additionally, none of the studies in the review show a significant decrease in opioid related side effects such as nausea, vomiting, or decrease GI motility.

REFERENCESBelavy, D., Colishaw, P., Howes, M. & Phillips, F. (2009). Ultrasound-guided transversus abdominis plane block for analgesia after Caesarean Delivery. British Journal of Anesthesia, 103(5), 726-730. doi:10.1093 Charlton, S., Cyna, A. M., Middleton, P., Griffiths, J.D. (2010). Perioperative transversus abdominis plane (TAP) blocks for analgesia after abdominal surgery. Cochrane Database of Systematic Reviews, Issue 12. Art. No.: CD007705. DOI:10.1002/14651858.CD007705.pub2 Fields, A.C., Gonzalez, D.O., Chin, E.H., Nguyen, S.Q., Zhang, L.P., Divino, C.M. (2015). Laparoscopic-assisted transversus abdominis plane block for postoperative pain control in laparoscopic ventral hernia repair: a randomized controlled trial. American College of Surgeons, 221(2), 462-469. doi: 10.1016/j.jamcollsurg Mrunalini, P., Raju, N.V.R., Nath, V.N., Saheb, S.M. (2014). Efficacy of transversus abdominis plane block in patients undergoing emergency laparotomies. Anesthesia: Essays and Researches, 8(3), 377-382. doi: 10.4103/0259-1162.143153  Peterson, P. L., Stjernholm, P., Kristiansen, V. B., Torup, H., Hansen, E. G., Mitchell, A. U., . . . Mathiesen, O. (2012). The beneficial effect of transversus abdominis plane block after laparoscopic cholecystectomy in day-case surgery: a randomized clinical trial. Anesthesia & Analgesia, 115(3), 527-533. doi: 10.1213/ANE.0b013e318261f16e Siddiqui, M.R., Sajid, M.S., Uncles, D.R., Cheek, L., Baig, M.K. (2011). A meta-analysis on the clinical effectiveness of transversus abdominis plane block. Journal of Clinical Anesthesia, 23(1), 7–14. [PubMed: 21296242]  Wu, Y., Liu, F., Tang, H., Wang, Q., Chen, L., Wu, H., . . . Xu, X. (2013). The Analgesic Efficacy of Subcostal Transversus Abdominis Plane Block Compared with Thoracic Epidural Analgesia and Intravenous Opioid Analgesia After Radical Gastrectomy. Regional Anesthesia, 117(2), 507-513. doi:10.1213/ANE.0b013e318297fcee

Author Contact Information

K. Allen, SRNA L. Allison, SRNA L. Camp, SRNA

J. Carlisle, SRNAM. Cochiaosue, SRNA

A. Hughes, SRNAJ. Jimenez, SRNA

katie.allen@mtsa.edulisa.allison@mtsa.edu

lindsay.camp@mtsa.edujoshua.carlisle@mtsa.edu

marian.cochiaosue@mtsa.eduamelia.hughes@mtsa.edujessica.jimenez@mtsa.edu

K. Allen, SRNA, L. Allison, SRNA, L. Camp, SRNA, J. Carlisle, SRNA, M. Cochiaosue, SRNA, A. Hughes, SRNA, J. Jimenez, SRNA Middle Tennessee School of Anesthesia

DO TAP BLOCKS AFFECT OPIOID ADMINISTRATION IN THE POSTOPERATIVE PERIOD?

STUDY =

SAMPLE SIZE

STUDY DESIGN

VARIABLES OF INTEREST

FINDINGS RECOMMENDATION WEAKNESSES

Belavy, D., et al.

50 Randomized, double-blind, placebo-controlled

Patients receiving an active TAP block and morphine PCA compared to patients receiving a placebo block and morphine PCA.

In the 24 hours following caesarean delivery the median morphine dose was 43% lower in the active block group compared to the placebo group.

The use of TAP blocks provides higher pain relief and reduces morphine requirements.

The study had a small sample size and it only compared patients undergoing caesarean delivery.

Charlton, S., et al.

358 Review of 8 randomized controlled trials

Comparison of TAP block with other anesthetic techniques on postoperative opioid consumption.

TAP blocks resulted in lower pain scores up to 24 hours after procedure.

TAP blocks are associated with a reduction in morphine requirements at 24 and 48 hours.

The use of TAP blocks reduces opioid requirements and pain scores after abdominal surgery.

Variation in protocols, types of surgery, and assessment tools contributed to a wide range of results.

Fields, A.C., et al.

100 Randomized, double-blind, placebo-controlled

TAP block vs. placebo injection for laparoscopic ventral hernia repair (LVHR)

Patients who received TAP blocks had decreased cumulative opioid use and pain scores compared with patients who received a placebo.

The study supports using TAP blocks in LVHR. It significantly decreases both short-term postoperative opioid use and pain experienced by patients.

The surgeons had knowledge of group assignments. Some patients were excluded from the study and the study did not collect data on clinical differences.

Mrunalini, P., et al.

60 Double-blind, randomized, controlled trial

TAP block vs. placebo on post op pain score and tramadol PCA pump use.

Mean total pain scores were significantly lower in the TAP block group when compared to the control group.

TAP block is effective for reducing post-op pain and opioid usage after laparotomy.

Findings limited to 24 hour post op. Ultrasound guidance was not used.

Peterson, P. L., et al.

80 Randomized, double-blind, placebo-controlled

Patients were assessed at 0, 2, 4, 6, 8, and 24 hours for post-op pain levels (when coughing and at rest), opioid consumption, and side effects.

Pain levels were reduced in the TAP versus the placebo group while coughing but not at rest. Median morphine consumption was 7.5 mg in the placebo group versus 5 mg in the TAP group.

TAP block after laparoscopic cholecystectomy may have some beneficial effect in reducing pain while coughing and on opioid requirements.

No assessment data between 8 hours and 24 hours. No sensory assessment was done after the blocks were performed to compare the effectiveness of each block.

Siddiqui, M.R., et al.

174 Meta-analysis of 4 randomized control studies

Mean 24 hour opioid use, time elapsed before first request for post-op analgesia, pain scores at three post-op intervals.

Reduction in post-operative opioid use, increased time between first request for analgesia, and reduction of pain scores in PACU in TAP block group.

TAP block is comparable to morphine for post-operative analgesia. Growing evidence points towards a role in routine abdominal surgery.

Small sample size for meta-analysis. Heterogeneity of studies associated with differing surgeries and timing/length of block administration.

Wu, Y., et al.

90 Randomized, double blind, intention to treat basis

TAP block vs. placebo on morphine consumption at 24 hours and pain scores.

TAP block with general anesthesia effectively reduces morphine consumption and lowers pain scores in the first 24 hours compared with general anesthesia alone.

TAP block along with general anesthesia may reduce postoperative pain.

Patients that were ASA > III and BMI > 30 were excluded which limits external generalizability.

Key: Internal Oblique Muscle (IO)

Transversus Abdominis Muscle (TA)External Oblique Muscle (EO)

Image Source: Arzola, C., Balki, M., Carvalho, J., Goldszmidt, E., Margarido, C., Mikhael, R., . . . Wieczorek, P. (n.d.). IIIH and TAP Blocks. Retrieved 2016, from http://pie.med.utoronto.ca/OBAnesthesia/OBAnesthesia_content/OBA_blocks_module.html

Image Source: Arzola, C., Balki, M., Carvalho, J., Goldszmidt, E., Margarido, C., Mikhael, R., . . . Wieczorek, P. (n.d.). IIIH and TAP Blocks. Retrieved 2016, from http://pie.med.utoronto.ca/OBAnesthesia/OBAnesthesia_content/OBA_blocks_module.html