Reduction in consumption of opioid analgesia post operatively after transversus abdominis plane block in patients undergoing radical hysterectomy

 

 

Abstract              Background: Radical hysterectomy involves extensive dissection, which contributes to moderate to severe pain post operatively. Effective post operative pain management will result in better recovery.at the same time increased use of opoids foe analgesia can cause side effects of opoids like drowsiness nausea vomiting and respiratory depression.. Transversus abdominis plane(TAP) block complement the multi modal analgesic regimen, so that the requirement of opoids is reduced. This is a prospective randomized controlled trial. To evaluate the role of TAP block in reducing the opioid consumption. Methods: 100 patients of ASA grade 1 and 2 undergoing Radical hysterectomy were randomized as block group to undergo TAP block with bupivacaine 0.25% 20ml on each side (n=50) , versus non block group( n=50). All patients received general anesthethesia. Ultra sound guided Block was performed before surgical incision bilaterally in patients who were randomized to the block group. Intra operative analgesic regimen was with inj fentanyl 1.5 mic/k.g, repeated with 0.5mic /k.g depending on the requirement as assessed by the anaesthesiologist based on haemodynamic parameters and post operatively by pain scores on numeric visual analogue scale with inj paracetamol 1gm followed by tramadol 2mg/kg and fentany 0.5mic/kg . Each patient was assessed post operatively at 0, 2,4,6,8,12,16,20,24 hours for pain, nausea, vomiting and sedation . The data recorded .Descriptive and inferential stastical analysis has been carried out using student t test, chi square/ fisher exact test in the present study. Results: We studied 100 patients, The block group n(B 50) had significantly less pain scores compared to non block group (N,50) p value being < 0.001. Total requirement of opioids in 24 hours was reduced in the block group, p<0.001. Time to first request for analgesia was delayed in the block group where only 22% patients needed analgesic at 0 hours compared to 72% in non block group. Incidence of nausea and vomiting was reduced after 4 hours in block group. The non block group patients were less sedated at 0 and 2 hours probably due to pain. Conclusion: TAP block, provides improved quality of analgesia post operatively with reduced consumption of opioid there by avoiding their side effects for radical hysterectomy

Key Words: post operative pain, regional anaesthesia technique, opoids

 

INTRODUCTION

Radical hysterectomy is the surgical procedure. Indication being conditions like endometriosis or liomyosarcoma .and malignant conditions of the uterus ovary and endometrium. Surgical procedure involves removal uterus enblock with parametrium, upper one third to half of vagina. and bilateral pevic lymph node dissection Which is extensive and necessitates lot of tissue handling. This extensive dissection leads to substantial pain which is moderate to severe and causes discomfort to the patient .Effective post operative pain management is very crucial for early mobilization and better recovery .Multimodal analgesia is an approach where patient is administered combination of opoid, non opoid drugs ,nerve blocks, and non pharmacological approach that act at different sites within the central and peripheral nervous system .the advantage of multimodal analgesia being reduced consumption of opoids thereby minimizing the adverse effects of opoids like nausea vomiting sedation delirium and respiratory depression. Transversus abdominis plane (TAP) block are widely used regional anaesthesia technique that introduces local anaesthetic in to neuro vascular plane via triangle of petit, an area on the abdominal wall, illiac crest being the inferior border. laterally bordered by medial edge of external abdominal muscle, medially bordered by latismus dorsi. This block provides analgesia to parietal peritoneum as well as skin and muscles of anterior abdominal wall by blocking the sensory nerves of the anterior abdominal wall.^1,2 Cadaveric studies involving the ultrasound guided injection of 20 ml aniline dye in to the unembalmed specimen have suggested that the T10-L1 nerve roots can be reliably blocked by using this technique.⁸ Various prospective randomized trials have shown that TAP block is effective in reducing opioid consumption and improving the post operative pain relief with minimal side effects and improved out come in gyenecological surgeries.³ Hence This study was undertaken to assess the efficacy of TAP block in reducing the consumption of opoids in patients undergoing radical hysterectomy with pelvic lymph node dissection where the incision was below the umbilicus.

 

METHODS

 This is a prospective randomized controlled study. After obtaining approval by institutional ethical committee 100 patients of ASA grade 1 and 2 were enrolled to the study 2017 to 2018. All the patients were posted for radical hysterectomy with pelvic lymph node dissection with pfannenstiel or vertical incision below the umbilicus were included in the study. Written informed consent was obtained Patients refusing the block, history of any relevant drug allergy, history of chronic pain, blood coagulation pathology local sepsis and any deviation from the proposed surgery were excluded. Patients were randomly allocated to TAP block group and non block group. Randomization was done by computer generated table n=50. All patients were premedicated with inj glycopyrrolate 0.02mg /kg and inj midazolam 0.03mg/kg 30 mins before the surgery. Standard monitoring were included like electrocardiogram, non-invasive blood pressure arterial oxygen saturation and end tidal carbon dioxide monitoring. General Anesthesia was induced with inj fentanyl 1.5 mic/k.g, propofol 1-2mg/kg and rocuronium 0.6 to 0.9 mg/kg. and maintained with oxygen and nitrous oxide and relaxant technique. Isoflurane 0.8-1.2 volume percent throughout the surgery was used. Ultrasound guided TAP Block was performed in the block group after induction of anaesthesia by one of the investigators. Asepsis precaution was taken. Ultrasound probe was placed transversely on the anterolateral abdominal wall. Three muscles of anterior abdominal wall( external oblique, internal oblique, transversus abdominis) identified. After identifying the neuro facial plane between internal oblique and transversus abdominis. 23 g needle is introduced anteriorly in the plane of ultrasound beam. on entering the plane . 20 ml of 0.25%bupivacaine injected in to the plane on each side maximum dose being 2mg/kg .The block was performed on the opposite side using the same technique.⁴ After the recovery from anesthesia, As soon as the patients were adequately oriented in post anaesthsia care unit (considered as zero hour) pain was assessed at rest and on movement using numeric visual analogue scale every 2hours till 8hours then every 4 hours till 24hours. We followed standardized post operative analgesia regimen. (refer table no-1)Nausea and vomiting were assessed simultaneously using categorical scale ( none=0, mild=1, moderate=2 severe=3) for 24 hrs ⁴patients with score more than 0 were given rescue antiemetics irrespective of the score. Sedation was assessed using sedation scale(awake and alert=0, quietly awake=1 , asleep but easily roused =2, deep sedation =3) ⁴ We estimated our sample size on the basis of 24hrs VAS pain scores, we calculated that 20 patients per group are required for experimental design incorporating two equal size groups using alfa= 0.0 5 and beta =0.2. To minimize any effect of data loss and to increase power we elected to recruit 50 samples for each group, hence the power test became(1-beta )0.9²⁶ The primary outcome measure in the study is total opioid consumption in 24 hours and time to first request of analgesia. The secondary outcomes assessed were side effects of opioids like nausea and vomiting and sedation

 

STASTICAL ANALYSIS STATISTICAL METHODS

Descriptive and inferential statistical analysis has been carried out in the present study. Results on continuous measurements are presented on Mean ± SD (Min-Max) and results on categorical measurements are presented in Number (%). Significance is assessed at 5 % level of significance. The following assumptions on data is made, Assumptions: 1.Dependent variables should be normally distributed, 2.Samples drawn from the population should be random, Cases of the samples should be independent. Student t test ( two tailed, independent) has been used to find the significance of study parameters on continuous scale between two groups( Inter group analysis) on metric parameters. Chi-square/ Fisher Exact test has been used to find the significance of study parameters on categorical scale between two or more groups.

RESULTS

Hundred and two patients were enrolled in to the study. Two patients, one from each group were excluded from the study as the surgical plan changed intra operatively. Of the remaining 100 patients ,50 patients were randomized for TAP block and 50 patients were randomized for non block group. The groups were comparable in terms of age and weight. Surgical interval was not comparable. Post operatively VAS scores were significantly less in block group at rest and on movement at zero and 2 hours(picture no1and2)As per our protocol time to first request of analgesia was recorded. In the block group 22% patients requested at 0 hours. 52% patients requested analgesic between 2-4hours. 26% of patients requested for analgesics later than 4 hours. Where as in non block group74% patients requested at 0 hours, and 26% patients requested later than 4 hours .(picture no3) Total requirement of analgesics for 24hours were measured. Block group patients consumed less opioid compared to non block group. 38% patients of block group had satisfactory analgesia with non opioids (i.v.paracetamol) and did not require any opioids at all.. 36% required 100 mg(2mg /kg )of tramadol only .14% patients had good pain relief with 100mg of tramadol and fentanyl less than 50 mic.g .8% patients needed tramadol 100 mg with fentanyl >50 mic.g. In the non block group 68%patients consumed tramadol 200mg and fentanyl <50micg. 28% patients required tramadol 200 mg and fentanyl>50 mic.g . and 4% patients were comfortable with 150mg of tramadol and fentanyl< 50mg.(table number 2) Incidence of nausea and vomiting were assessed using categorical scoring method. It was comparable between the two groups at zero and 2 hours. but it became significantly lower in block group at 4 hours, 8 hours, 12hours. p value being 0.001.(picture number 4). We compared sedation using sedation score ⁴between the two groups. At 0and 2 hours non block group patients were less sedated probably due to pain. At 4 hours in the block group patients were less sedated as they required less dose of opioids for effective pain control.(table no 3).

Table 1: Post operative analgesia regimen

inj=injection, mic=micrograms VAS=visual analogue score

 

Table 2: Total requirement of opioids in 24 hours in two study groups

 

Control is more sedated compared to cases with grade 2 (76%) at 0hrs and( 86%) at 2hrs where as in block group it is less( 38% and 62%) at 0 and 2 hours-- ( SED= sedation, #=number, awake and alert=0, quietly awake=1 , asleep but easily roused =2, deep sedation =3) ⁴

Table 3: Sedation frequencies between cases and controls

 

Picture 1: VAS score at rest to 24 hours          

Picture 2: VAS score on movement from 0 to 24 hours

 

stastically analysed with continuous measurements and are presented on Mean ± SD (Min-Max) VAS is more in control group (p<0.001at 0 hours,p=0.001at 2hrs,p0.46 at 6hrs,at 12 and 16hours0.002) VAS=visual analogue score

 

   

 

Picture 3: 74% pts of control group requested analgesia at 0 hours Picture 4: NV is more associated with control at between 4 to 8 hours (NV= nausea vomiting ) Picture 5: opoid requirement

 

DISCUSSION

Radical hysterectomy among the Gyenecological surgeries results in more acute pain post operatively compare to other surgeries due to extensive dissection and tissue handling. Effective post operative pain control is crucial for reduction in stress response which results in lesser morbidity and better surgical out come. Data available indicate that afferent neural blockade with local anaesthetics is most effective analgesic technique. There are various studies on TAP block as a part of multimodal analgesia. The efficacy of the TAP block in reducing opoid consumption in radical hysterectomy is not widely studied. Griffith et al.⁷ conducted study on benefits of TAP block in women undergoing major gynecological cancer surgeries where they concluded that the block conferred no benefit in addition to multimodal analgesia. They also concluded that the lack of benefit may be due to heterogeneity of patient population receiving multimodal analgesia for midline laporotomy. Recent evidence in literature shows reduction in pain scores and opioids consumption with TAP blockade ¹⁰ In our prospective randomized control trial on the efficacy of TAP block in radical hysterectomy in reducing opoid consumption , demonstrated that complementing the standard multimodal analgesic regimen with TAP block resulted in statistically significant reduction in opoid consumption post operatively. Total requirement for 24 hours as well as first request of opioids was significantly less in block group. In our institute on an average 130 to 150 radical hysterectomies with pelvic lymph node dissection are being performed per year. Our institutional currant multimodal analgesic regimen comprises epidural analgesia and of inj fentanyl 1.5to2 mcg/k.g i.v. intraoperatively at time of induction and intermittent bolus doses of 0.5 mcg /kg as assessed by the anaesthesiologist. Postoperatively inj paracetamol 1gm followed by inj tramadol 2mg/k.g. which may be supplemented with inj fentanyl 0.5mcg/k.g depending on the pain scores (ref table no 1) .some times epidural catheter placement will be deferred because of contraindicatond, pt refusal or difficulty in placing, then only opoids become the main source of analgesia .Though the currant regimen provides optimal analgesia it is associated with side effects like nausea vomiting and sedation. delirium . In our study patients requiring identical surgical procedure where incision is below the umbilicus either pfannenstiel or vertical were included, So that there is homogeneity in the patient population and surgical insult. Intra abdominal surgery causes moderate to severe pain due to incision(parietal pain) and by the trauma to the intra abdominal structures(visceral pain).therefore a multimodal approach is required to block the nociceptive transmission from both the abdominal wall incision and from pelvic abdominal visceral structures.^3,14,12 Regional analgesia techniques are beneficial as a part of multimodal analgesia for decreasing the intensity of pain and incidence of side effects, there by improving the patient comfort and surgical out come. TAP block has been demonstrated to provide excellent analgesia to the skin and anterior abdominal wall musculature. which can be part of multimodal analgesia^17,20. “As described by Mukhtar .K in his article on TAP BLOCK in the journal of New York school of regional anesthesia Antero lateral abdominal wall is innervated by the anterior rami of spinal nerves T7 to L1. These include the intercostal nerves (T7-T11), the subcostal nerve (T12), and the iliohypogastric and ilioinguinal nerves (L1). The anterior divisions of T7-T11 continue from the intercostal space to enter the abdominal wall between the internal oblique and transversus abdominis muscles until they reach the rectus abdominis, which they perforate and supply, ending as anterior cutaneous branches supplying the skin of the front of the abdomen. In their course they pierce the external oblique muscle giving off the lateral cutaneous branch which divides into anterior and posterior branches that supply the external oblique muscle and latissmus dorsi respectively⁵. The anterior branch of T12 communicates with the iliohypogastric nerve and gives a branch to the pyramidalis. Its lateral cutaneous branch perforates the internal and external oblique muscles and descends over the iliac crest and supplies sensation to the front part of the gluteal region. The iliohypogastric nerve (L1) divides between the internal oblique and transversus abdominis near the iliac crest into lateral and anterior cutaneous branches, the former supplying part of the skin of the gluteal region while the latter supplies the hypogastric region. The ilioinguinal nerve (L1) communicates with the iliohypogastric nerve between the internal oblique and transversus abdominis near the anterior part of the iliac crest. It supplies the upper and medial part of the thigh and part of the skin covering the genitalia.(3)The transverus abdominis plane thus provides a space in to which local anesthetic can be deposited to achieve myocutaneous sensory blockade^14,15” The dose of the drug used was bupivacaine 0.25% 20ml on each side, maximum dose being 2mg/k.g. higher recommended dose of bupivacaine was used to provide prolonged analgesia with single shot technique. Though the dose is within the recommended range, potential for systemic toxicity has to be borne in mind.^6,20.

LIMITATION OF THE STUDY

We had limited our analysis to 24 hours although block has been demonstrated to clinically useful levels for up to 48 hrs post operatively as reported in the literature. Local anaesthetic large volume between 30 to 40 ml are administered though we did not come across any complications related to the volume of local anesthetic. Further studies are required to evaluate the optimum volume. We have evaluated in only one type of surgical procedure. Further evaluation is required in cancer surgeries.

 

CONCLUSION

In conclusion TAP block can be a useful complementary modality to multimodal analgesic regimen in radical hysterectomy in gynecology surgeries where the incision is below the umbilicus. Further evaluation of the usefulness of the block is needed in of cancer surgeries.

 

REFERENCES

1. O Donnell BD , Mcdonnell JG, Mcshane AJ, The transversus abdominis plane block in open retro pubic prostectomy. reg anesth pain med 2006;31;91
2. Mcdonnell JG, Donnell OB, Curley G, Heffernan A ,Power C, Laffey JG. The analgesic efficacy of The transversus abdominis plane block after abdominal surgery, A prospective randomized controlled trial.anesth analg 2007;104;193-197
3. Mcdonnell JG, Curley G, carney J ,Benton A, Costello J, Maharaj C et al. . the analgesic efficacy of transversus abdominis plane block after cesarean delivery, A randomised controlled trial. anesth analg 2008;106:189-91
4. carney GJ , Mcdonnell JG, ochana A, Bhinder R, Laffey JG. transversus abdominis plane block provides effective post operative analgesia in patients undergoing total abdominal hysterectomy Anesth analg 2008; 107: 2056-60
5. Mukthar K, transversus abdominis plane block .The journal of new York school of regional anesthesia. may 2009 .vol 12
6. .El-Dawlalty AA,Turkistani A, Ketter SC, Machata AM, Delvi MB, Thallaj A, et al.. Ultrasound guided transverus abdominis plane block: description of new technique and comparison with conventional systemic analgesia during laproscopic cholecystectomy. BJA 2009;102 :763-7.
7. Griffith J, Middle JV, Barron FA, Grout SJ, Popham PA, Royse CF. Transversus abdominis plane block does not provide additional benefit to multimodal analgesia in gynaecological cancer surgery. Anesth Analg 2010;11: 797-801.
8. .TranTMN, Ivanusic JJ, Hebbard P.,and Barrington MJ. Determination of spread of injectate after ultrasound-guided transverses abdominis plane block: a cadaveric study B.J.A 2009;102(1)123-7
9. .Hebbard P, Barrington MJ, Vasey C. Ultra sound guided oblique subcostal transverses abdominis plane blockade; description of anatomy and clinical technique. Reg anesth pain med 2010; 35;616-617
10. Tan PCS, Teo SC, Chen CK. Bilateral ultra sound – guided oblique subcostal transverses abdomonis plane block provides effective intra –and post operative analgesia as intravenous morphine in laproscopic cholecystectomy;BJA 2012;108(52);ii387-ii437
11. McDonnell JG,O’ Donnell BD, Tuite D,. The regional abdominal field infiltration technique computerized tomographic and anatomical identification of a novel approach to the transverses abdominis neuro vascular fascial plane . Anaesthesiology 2004;101;A899
12. Young JM, Gorlin AW, Modest VE, and QuraishiSA,. Clinical Implications of the Transversus Abdominis Plane Block in Adults. Anesthesiology Research and Practice 2012;article ID;73164513.
13. Charlton S, Cyna AM., MiddletonP. and Griffiths J D., “Perioperative transversus abdominis plane (TAP) blocks for analgesia after abdominal surgery,” Cochrane Database of Systematic Reviews, vol. 8, Article ID CD007705, 2010.
14. .Rafi AN Abdominal field block; a new approach via lumbar triangle Anaesthesia 2001;56; 1024-1026.
15. Jankovic ZB, DuFeu FM, McConnell P. “An anatomical study of the transversus abdominis plane block: location of the lumbar triangle of petit and adjacent nerves,” Anesth Analg 2009; 109; ( 3); 981–985.
16. Bharti N, Kumar P, Bala I, Gupta V. “The efficacy of a novel approach to transversus abdominis plane block for postoperative analgesia after colorectal surgery,” AnesthAnalg, 2011;112; (6); 1504–1508.
17. Siddiqui MRS , Sajid MS, Uncles DR, Cheek L,. Baig MK. “A meta-analysis on the clinical effectiveness of transversus abdominis plane block,” Journal of Clinical Anesthesia.2011; 23; (1); 7–14,
18.  McMorrow RCN, Mhuircheartaigh RJN, Ahmed KA,. “Comparison of transversus abdominis plane block vs spinal morphine for pain relief after Caesarean section,” Bri J of Anaesth2011; 106;. (5);. 706–712.

19. Kanazi GE, Aouad MT,. AbdallahFW. “The analgesic efficacy of subarachnoid morphine in comparison with ultrasound-guided transversus abdominis plane block after cesarean delivery: a randomized controlled trial,” Anesth Analg 2010; 111;( 2); 475–481,
20. Niraj G, Searle A, Mathews M ,“Analgesic efficacy of ultrasound-guided transversus abdominis plane block in patients undergoing open appendicectomy,” Bri JAnaesth2009 103;. (4) 601–605,
21. PetersenPL, Mathiesen O, Torup H,. Dahl JB. “The transversus abdominis plane block: a valuable option for postoperative analgesia? A topical review,” Acta Anaesthesiologica Scandinavica 2010. 54;( 5). 529–535, 2010.
22. Rachel A,Ware, John R Radical hysterectomy with pelvic lymphadenectomy;indications, Technique,and complications review article obstetric and gynecology international volume 2010;ID; 587610
23. Bernard R. Fundamentals of Biostatistics, 5^th Edition, Duxbury, 2000; 80-240.
24. Robert H R) , Statistics in Medicine , second edition, Academic press.2005;85-125.
25. .SunderRao PSS, Richard J, An Introduction to Biostatistics, A manual for students in health sciences , New Delhi: Prentice hall of India. 2006;4^th edition, 86-160
26. ManjareeM PrakashSM Transversus abdominis plane block: The new horizon for postoperative analgesia following abdominal surgery review article Egyptian journal of anaesthesia 2016; 32(2) 243-247
27. Hsiao-CT Takayuki Y TaiYC Sheng FY, ⁵ Transversus Abdominis Plane Block: An Updated Review of Anatomy and Techniques Biomed res int 2017 828884363
28. Heidi C, . Rimel BJ, Andrew J. Li, Ilana Cass, Beth Y. Karlan, and Christine Walsh^⁎ Ultrasound guided transversus abdominis plane (TAP) block utilization in multimodal pain management after open gynecologic surgery gyenecol oncol rep 2018 ;26;75-77 .

Policy for Articles with Open Access
Authors who publish with MedPulse International Journal of Anesthesiology (Print ISSN:2579-0900) (Online ISSN: 2636-4654) agree to the following terms:
Authors retain copyright and grant the journal right of first publication with the work simultaneously licensed under a Creative Commons Attribution License that allows others to share the work with an acknowledgement of the work's authorship and initial publication in this journal.
Authors are permitted and encouraged to post links to their work online (e.g., in institutional repositories or on their website) prior to and during the submission process, as it can lead to productive exchanges, as well as earlier and greater citation of published work.