Good Afternoon

DO TAP BLOCKS AFFECT OPIOID ADMINISTRATION

IN THE POSTOPERATIVE PERIOD?

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

Introduction How our subject came to fruition Purpose

A brief historyAnatomyHow does it work?BackgroundResults from researchPossible clinical implications

We hope you enjoy the presentation

TAP Blocks: A Brief History• 1855-Friedrich Gaedcke: First to chemically isolate

cocaine, naming it erythroxyline • 1884-Karl Koller: Tested anesthetic effectiveness of

2% cocaine solution• 1885-William Halsted: First brachial plexus blocked

performed• 1885 - James Leonard Corning: Injected cocaine

between the lumbar spinous processes, first to publish descriptions of spinal anesthesia

• 1898 - August Bier: Considered the "Father of Spinal Anesthesia", performed the first surgery under spinal anesthesia

TAP Blocks: A Brief History 2001-A.N. Rafi: Published "Abdominal field block: a

new approach via the lumbar triangle"• The article described a single shot abdominal block, using

the lumbar triangle of Petit as an anatomical landmark• At the time of publication, Rafi had been using this blind

technique for 2 years, on over 200 patients• Referred to as the RAFI technique, Regional Abdominal

Field Infiltration 2004-2007-J.G. McDonnell et al., used computerized

tomography and MRI to study the spread and effectiveness of the single shot abdominal block• Coined the term transversus abdominal plane (TAP) block

Background The transversus abdominis plane block is a

regional anesthetic technique first described in 2001

It is useful in procedures requiring nerve block in the anterior abdominal wall region, from T6 to L1

It was first used as a blind landmark technique but more recently it has been used under ultrasound guidance

TAP blocks are important because they can be used as an alternative analgesic solution in surgery

Background The ultimate goal of TAP blocks is to increase

analgesia with the use of local anesthetic Absolute contraindications include infection at

the site, allergy to local anesthetic and patient refusal

Although complications are rare, TAP blocks are underutilized

Beneficial for hysterectomies, prostatectomies, Caesarean sections, laparoscopic cholecystectomies and other abdominal surgeries

Background The purpose of this research analysis

was to investigate the potential benefits of the TAP block.

Seven journal articles were reviewed. Some research studies focused on how

effective TAP blocks were in reducing postoperative opioid use in various populations.

Anatomy

http://www.hindawi.com/journals/arp/2012/731645/fig2/

Transverse section of the abdominal wall demonstrating the relevant muscular structures and course of nerves (T7 – T12) within the TAP.

Anatomy

http://image.slidesharecdn.com/920307ultrasound-guidedtransversusabdominisplanetapblockrasoul-141227030506-conversion-gate02/95/ultrasound-guided-transversus-abdominis-plane-tap-block-12-638.jpg?cb=1419650072

TAP Block Technique Ultrasound Anatomy

https://www.youtube.com/watch?v=9TIHDn7uBZI&feature=youtu.be&t=92 (at 1:31)

TAP Block Technique https://www.youtube.com/watch?v=ab8Dvja

uk_U&feature=youtu.be&t=14

STUDY SAMPLE SIZE

STUDY DESIGN

VARIABLES OF INTEREST

FINDINGS RECOMMENDATION

Baeriswyl, M., et al.

1611 Meta analysis of 31 randomized controlled studies

Cumulative IV morphine consumption postoperatively.Pain scores at rest and on movement at 6 and 24 hours postoperatively.

Cumulative IV morphine consumption was reduced by an average of 6 mg in favor of the ultrasound-guided TAP block group at 6 hours postoperatively.

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

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.

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.

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.

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.

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.

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.

Results

• Average opioid amount given was lower in TAP block groups

• Average lower postoperative pain scores in TAP block groups

• Increase time to first request for further analgesia in TAP block groups

Recommendations By utilizing the TAP block patients may

be able to consume less opioids and experience less pain postoperatively than if the case was strictly a general anesthesia case with opioids as the sole pain relief adjunct

Article Author

Strengths Weaknesses Grade

Baeriswyl, M., et al.

This meta-analysis examined 31 controlled trials including 1611 adult participants. This study included all types of abdominal surgeries in adult patients. The large and varied sample size allows results to be generalized to a large population.

Evidence of publication bias in favor of TAP blocks. Large amount of heterogeneity between stuides.

1A

Belavy, D., et al.

There was no evidence of researcher bias throughout the study. The study only had one independent variable so the internal validity was high.

Study had small sample size, & only compared pt’s undergoing cesareans.

1B

Fields, A.C., et al.

Internal validity high, independent variable consistent throughout the study. External validity-because of this study generalizations can be made about pt’s undergoing LVHR will benefit from receiving TAP block , by reducing post-op pain & opioid use.

Surgeons had knowledge of group assignments, some pt’s excluded from study, & data not collected on clinical differences.

1A

Mrunalini, P., et al.

Internal validity high. Confounding information not included like morbidly obese, drug dependence on opioids, and psychiatric disorders. Researcher bias not present.

Findings limited to 24hr post op. Ultrasound guided not used. External validity. Not easily generalized to all patients undergoing laparoscopic procedures.

1A

Peterson, P.L., et al.

Internal validity high, external validity also high for any patients having laparoscopic abdominal surgery. Sampling technique: randomized, double-blind. Data collected at regular intervals and consistent. No evidence of researcher bias throughout the study.

No assessment data b/ 8-24hrs, no sensory assessment done after blocks were performed to compare their effectiveness.

1A

Siddiqui, M.R., et al.

Inclusion was completed by three separate researchers, eliminating personal bias. Despite small sample size, meta-analysis provides opportunity to for comparison of results among separate studies.

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

1A

Wu, Y., et al. Internal validity high, external validity also high. Independent variables were consistent throughout the study. Sampling technique was randomized and single-blind. No evidence of research bias was notable.

Pt’s w/ ASA>III & BMI>30 were excluded, which limits the external generalizability. Only single-injection subcostal TAP block was studied vs. continuous-infusion TAP block, even though a continuous epidural was used for comparison.

1A

Clinical Implications

Opioid Amount?

VAS Pain Scores?

Time to Request (More Analgesia)

Conclusion• In our studies the use of TAP

blocks provided higher pain relief and reduced opioid consumption when compared to placebo groups

• TAP blocks were found especially beneficial during times of activity or coughing postoperative lay

ConclusionWhile all the 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

 Baeriswyl, M., Kirkham, K. R., Kern, C., & Albrecht, E. (2015). The Analgesic Efficacy of Ultrasound-Guided Transversus Abdominis Plane Block in Adult Patients. Anesthesia & Analgesia, 121(6), 1640-1654. Retrieved December 21, 2015.

 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