|Ahead of print publication
Comparison of ultrasound-guided transversus abdominis plane block with sub-arachnoid block for open inguinal hernia repair
Ashita Mowar, Vishwadeep Singh, Akhilesh Pahade, Geeta Karki
Department of Anesthesiology, Shri Ram Murti Smarak Institute of Medical Sciences, Bareilly, Uttar Pradesh, India
|Date of Submission||20-Aug-2021|
|Date of Acceptance||09-Nov-2021|
|Date of Web Publication||16-Dec-2021|
Department of Anesthesiology, Shri Ram Murti Smarak Institute of Medical Sciences, Bareilly - 243 202, Uttar Pradesh
Source of Support: None, Conflict of Interest: None
| Abstract|| |
Background: Open inguinal hernia repair is one of the routine day-care procedures performed across the world. A multitude of anesthetic techniques have been outlined for painless inguinal hernia repair, comprising general anesthesia and regional anesthesia such as spinal, epidural, and nerve blocks; with regional anesthetic techniques often favored for uncomplicated open inguinal hernia repair. Ultrasound-guided peripheral nerve blocks have made rapid strides and are gaining popularity because of the reduced incidence of adverse events. Aims: We aim to compare the efficacy of two regional anesthesia techniques to compare the adequacy of surgical anesthesia and their efficacy to ease postoperative pain with least potential side effects. Settings and Design: This prospective, interventional, single-centric, double-blind, randomized, parallel-group, active-controlled, Helsinki protocol-compliant clinical study was registered with the Clinical Trial Registry of India (CTRI/2021/04/033109). It was conducted after obtaining written informed consent from all patients and approval from the institutional review board. Materials and Methods: Sixty patients of American Society of Anesthesiologists physical status classes I/II, in the age group of 18–60 years of either sex, scheduled for elective open inguinal hernia repair, were enrolled into two groups of 30 patients each according to the anesthetic technique used. Group T comprised patients receiving ultrasound-guided transversus abdominis plane block (TAP block), whereas the Group S comprised patients administered spinal anesthesia for elective open inguinal hernia repair. The primary end points of this study were to assess the adequacy of surgical anesthesia and duration of postoperative analgesia, whereas the secondary end points included assessment of patients' hemodynamic profile post institution of the block and comparing the incidence of adverse events associated with the two techniques. Statistical Analysis: SPSS version 20.0 was used for analysis. Frequency, mean distribution, standard deviation, Chi Square test and student t Test were calculated to p value. P < 0.05 was considered statistically significant. Continuous variables were expressed as mean + SD, whereas categorical variables were expressed as absolute numbers and percentages. Intergroup nominal categorical data were compared by Chi-square test. Results: The visual analog scale score was found significantly lower in Group T at all time points except immediate postsurgery (3, 6, 12, 24, and 48 h) as compared to Group S (0.357 ± 0.4880 vs. 1.393 ± 1.8527; P = 0.006, 1.393 ± 0.4973 vs. 2.893 ± 2.3148; P = 0.001, 2.429 ± 0.9201 vs. 3.321 ± 2.0377; P = 0.039, 1.214 ± 0.4179 vs. 2.286 ± 1.9217; P = 0.006, and 1.143 ± 0.3563 vs. 1.643 ± 1.5685; P = 0.106, respectively), and the duration of postoperative analgesia was highly significant (P < 0.001) in Group T (724.00 ± 103.2914 min) as compared to Group S (256.643 ± 73.4218 min). Difference in the number of rescue analgesics administered over the first 24 and 24–48 h was significantly higher in the spinal group which comprised patients administered with the TAP block. Conclusion: Ultrasound-guided TAP block provides better intra-operative and postoperative analgesia as compared to subarachnoid block especially in respiratory and cardiovascular cripples without any significant adverse events and hemodynamic changes.
Keywords: Inguinal hernia, spinal anesthesia, transversus abdominis plane block, ultrasound-guided
|How to cite this URL:|
Mowar A, Singh V, Pahade A, Karki G. Comparison of ultrasound-guided transversus abdominis plane block with sub-arachnoid block for open inguinal hernia repair. Anesth Essays Res [Epub ahead of print] [cited 2022 Jan 22]. Available from: https://www.aeronline.org/preprintarticle.asp?id=332710
| Introduction|| |
Inguinal hernia repair is a day-care procedure routinely performed across the world. Associated with moderate-to-severe postoperative pain, return to routine day-to-day activities is delayed. Rarely, it advances into persistent chronic postsurgical pain, affecting 0% to 43% of patients.,
A multitude of anesthetic techniques have been outlined for painless inguinal hernia repair, comprising general and regional anesthesia (RA); with RA favored for uncomplicated open inguinal hernia repair; being safer, cheaper, and easy to administer while providing better surgical conditions and improved intra/postoperative pain profile. Despite the advent of truncal nerve blocks, the age-old subarachnoid block (SAB) is frequently employed and often preferred by surgical and anesthesiology teams in a vast majority of operating rooms for lower abdominal surgeries. With each technique claiming supremacy, anesthesia of choice for these surgeries has become a subject of debate. It has been a problem of plenty with anesthesiologist spoilt for choices with a bouquet of techniques available and newer ones staking their claims at every opportunity.
In trained hands, ultrasound-guided (US-guided) transversus abdominis plane block (TAP-block) has made rapid strides and has gained popularity owing to enhanced reliability, reproducibility, and safety profile because of the ease with which it can be performed under the direct visualization of needle and spread of local anesthetics (LA).
A successful TAP-block involves depositing LA between the internal oblique (IO) and transversus abdominis (TA) muscles, targeting the spinal nerves in this plane. TAP-block provides analgesia to the parietal peritoneum along with skin and muscles of the anterior abdominal wall from the T7 to L1 dermatomes. It has been demonstrated reduction in perioperative opioid consumption following a lower abdominal surgery.
We aim to compare the efficacy of two RA techniques to assess the adequacy of surgical anesthesia and efficacy to ease postoperative pain with least possible side effects. With the paucity of studies comparing TAP-block (alone or as a piggyback with other anesthetic techniques) with a popular central neuraxial blockade technique, i.e., SAB, a prospective randomized study was planned to analyze our aims in open inguinal hernia repair.
| Materials and Methods|| |
This prospective, interventional, single-centric, double-blind, randomized, parallel-group, Helsinki protocol-compliant clinical study was registered with the Clinical Trial Registry of India (CTRI No. REF/2021/04/042772). It was conducted after obtaining written informed consent from all patients and approval from the institutional review board. Sixty patients of American Society of Anesthesiologists (ASA) physical status classes I/II, age group 18–60 years of either sex, scheduled for elective open inguinal hernia repair from April 2021 to August 2021, were enrolled into two groups of 30 patients each according to the anesthetic technique used. Patients refusing consent to participation, those who fall under ASA class III and above, patients with body mass index (BMI) ≥30 kg/m2, patients with bleeding disorders, patients with poorly regulated systemic diseases (diabetes mellitus, hypertension, coronary artery disease, and chronic/acute renal disease), patients with contraindications to RA, patients with irreducible/strangulated/recurrent inguinal hernia, patients with preoperative chronic opioid use, and patients with hypersensitivity to LA were excluded from the study. Patients were randomized into two groups using computer-generated randomization technique. The method of concealment comprised sequentially numbered sealed, opaque envelopes. Group T comprised patients receiving US-guided TAP-block, whereas Group S comprised patients who were administered spinal anesthesia (SAB) for elective open inguinal hernia repair.
Patients were familiarized in the preanesthetic visit an evening before the scheduled elective surgery regarding a visual analog scale (VAS) (0–10) for assessing postoperative pain score, where 0 indicated no pain and 10 indicated the worst pain experienced. All patients were premedicated with oral tablet ranitidine 150 mg and tablet alprazolam 0.5 mg night before the surgery.
Inside the operating room, standard monitors were applied and vascular access was secured. The patients were positioned for the procedure as per the group allotted. Intervertebral L3/L4 or L4/L5 spaces were identified according to surface anatomical landmarks. Under all aseptic conditions, subcutaneous plane and projected spinal needle path were infiltrated with 2% lidocaine. A 25-G Quincke spinal needle was introduced in the subarachnoid space through the lidocaine-infiltrated interspace. After confirming the free flow of cerebrospinal fluid, 3 mL of hyperbaric bupivacaine 0.5% was injected intrathecally. After achieving block level (assessed by segmental sensory [pin prick] method) of T8, surgery was commenced. Motor block at the beginning and end of surgery using the Modified Bromage scale was recorded. Patients with inadequate block quality or level were given general anesthesia (GA) and were excluded from the study.
In Group T patients, US-guided TAP block was performed in supine position. Under all aseptic precautions, TAP-block was given with portable ultrasound machine (SonoSite MTurbo; FUJIFILM Sonosite, Bothell, WA, USA) with high-frequency, 38 × 136 MHz 40-mm broadband linear array probe that was placed on the lateral abdominal wall cephalad to the iliac crest and caudal to the costal margin.
An anesthesiologist proficient in USG-guided nerve blocks was assigned the task to perform TAP-block. The probe was tilted in cephalad or caudal direction as required to obtain a clear image of the three lateral abdominal muscles, and TAP was obtained. Blocks were instituted with an 8-cm/22-G echogenic needle (Pajunk; Sonoplex stim cannula; Geisingen, Germany) in supine position. The needle was then targeted in TAP so as to place the needle tip between the IO and TA muscles using in-plane technique. Saline (2 mL) was injected to confirm correct needle placement; thereafter, 20 mL of 0.5% bupivacaine was injected after negative aspiration for blood while ensuring safe dosage for bupivacaine. To assess the level of the sensory block, pin-prick method was used every 5 min to a total duration of 30 min. Achieving T10-L1 level was considered to be a successful block. For those patients who failed to achieve the desired level/those requiring recurrent analgesic boluses, GA was administered and they were excluded from the study.
All patients were monitored for inadequacies in blocks performed or adverse events. The patients underwent noninvasive hemodynamic monitoring: electrocardiography, heart rate (HR), mean arterial pressure (MAP), respiratory rate, and pulse oximetry subsequent to successfully performing subarachnoid or TAP-blocks. Data were recorded at 10-min interval till the end of surgery. Postoperative pain was assessed immediately at the end of surgery and then till the first rescue analgesic (FRA) was administered. VAS score was monitored at 0, 3, 6, 12, 24, and 48 h post procedure. Injection paracetamol 15 mg.kg−1 intravenously (i.v.) was administered 8th hourly following FRA. Inj. tramadol 1.5 mg.kg−1 i.v. was given as a rescue analgesic whenever VAS was ≥4. The number of rescue analgesics required by participants of both groups was monitored in the first 24 h and 24–48 h. Intergroup total tramadol consumption as rescue analgesic in the 48-h period was analyzed.
Bradycardia, hypotension, nausea and vomiting, urinary retention, headache, or other neurological sequelae were recorded.
Quality of sensory block was assessed by a using 4-point numeric scale as follows: Gr-IV: no discomfort, Gr-III: mild discomfort not requiring supplemental analgesics/sedation, Gr-II: discomfort requiring supplemental analgesics/sedation, and Gr-I: inadequate block requiring GA.
Hypotension was defined as more than 20% decrease in mean baseline MAP and was treated with 100-mL aliquots RL and inj. mephenteramine 6 mg i.v., if no response for fluid boluses was observed. Bradycardia (defined fall in HR <50/min) was treated with Inj. atropine 0.6 mg i.v.
Assessing the adequacy of surgical anesthesia and duration of postoperative analgesia were the primary end points. Secondary end points included assessing hemodynamic profile post institution of block and comparing the incidence of adverse events associated with the two techniques.
Referencing a study by Sharma et al., a sample size of 28 was obtained, according to the standard normal distribution theory and fixing Type 1 error (α) at 0.05 and the power of study (1 − β) at 0.8. Considering procedure failure/conversion to GA, 30 patients were enrolled in the study.
Patient information was collected through a structured pro forma, tabulated in a master chart, and analyzed using Statistical Package for the Social Sciences (SPSS Inc., IBM, Chicago, Illinois, United States). Frequency, mean distribution, standard deviation (SD), Chi-square test, and Student's t-test were calculated to obtain P value. P < 0.05 was considered statistically significant. Continuous variables were expressed as mean ± SD, whereas categorical variables were expressed as absolute numbers and percentages. Intergroup nominal categorical data were compared by Chi-square test.
| Results|| |
The consort flowchart depicts the participant flow in both groups [Figure 1].
The demographic parameters (age, BMI, and ASA-class), duration of surgery, and baseline hemodynamic were statistically comparable in both the groups (P = 0.242, 0.204, 0.573, and 0.789) [Table 1].
The average time taken to perform the block (TPB) was greater in Group T (12.93 ± 2.53 min) when compared to that of Group S (5.32 ± 0.476 min) and was highly significant (P < 0.000) [Table 2]. The highest level of sensory block (HSB) in Group T was T10 and in Group S it was T6, which was highly statistically significant (P < 0.000). The time to achieve this HSB was greater in Group T (22.07 ± 3.126 min) when compared to Group S (10.89 ± 2.26), which was statistically highly significant (P < 0.000). Intraoperatively, distribution of patients on the basis of TAP-block grading was 1/18/9/0 patients corresponding to Grade 4/3/2/1.
While participants of both groups were hemodynamically similar at baseline (P = 0.640), there was a significant reduction in terms of HR and MAP at 10, 20, and 30 min (P < 0.000) (86 ± 6.150 vs. 72.18 ± 11.854; 80 ± 7.211 vs. 65.82 ± 8.538; 79.36 ± 6.881 vs. 67.50 ± 6.345, respectively) and (74.04 ± 8.754 vs. 68 ± 8.808, 73.21 ± 8.757 vs. 64.71 ± 8.480, 72.57 ± 8.452 vs. 63.54 ± 8.750, respectively) (P = 0.020, 0.001, and 0.000, respectively). Intergroup hemodynamic comparisons (HR and MAP) attained nonsignificance 40 min onward (P = 0.649). HR attained baseline after peaking at 40 and 50 min. MAP baseline values were attained at 50 min [Figure 2].
VAS scores were significantly lower in Group T at 3, 6, 12, 24, and 48 h compared to that of Group S (0.357 ± 0.4880 vs. 1.393 ± 1.8527; P = 0.006, 1.393 ± 0.4973 vs. 2.893 ± 2.3148; P = 0.001, 2.429 ± 0.9201 vs. 3.321 ± 2.0377; P = 0.039, 1.214 ± 0.4179 vs. 2.286 ± 1.9217; P = 0.006, and 1.143 ± 0.3563 vs. 1.643 ± 1.5685; P = 0.106, respectively) [Figure 3], with the duration of postoperative analgesia being highly significant (P < 0.000) in Group T (724.00 ± 103.2914 min) compared to that of Group S (256.643 ± 73.4218 min) [Table 3].
The total number of rescue analgesics was recorded in the first 24 h and 24–48 h postsurgery along with cumulative tramadol consumption over 48 h postoperatively. Difference in the number of rescue analgesics administered was significantly higher in Group S versus TAP-block. In the first 24-h, patients in the TAP group were administered fewer tramadol rescues (1.071 ± 0.2623 vs. 2.071 ± 1.0157) (P < 0.000). From 24 to 48 h, the number of rescue analgesic in two groups, Group T and Group S, was 0.107 ± 0.3150 versus 0.250 ± 0.4410 (P = 0.169). The total tramadol consumption over the 48-h period was also significantly higher in the spinal group (238.689 ± 139.2910 vs. 112.946 ± 33.9117) (P < 0.000) [Table 3].
In Group S, two patients (2/28) had bradycardia, one (1/28) patient had hypotension, two (2/28) patients complained of nausea, and one (1/28) experienced vomiting, but none in Group T. Three (3/28) patients complained of headache and two (2/28) patients had urinary retention in Group S. None of the side effects were statistically significant [Table 2].
| Discussion|| |
Approximately 800,000 mesh hernioplasties are performed each year in the USA. Acute postoperative pain may transcend into chronic pain, which can be debilitating and equally distressing for the patient. Conventionally, postoperative pain management heavily relies on opioids and Non-Steroidal Anti-inflammatory drugs (NSAIDs), translating into significant side effects. Various RA techniques have claimed their share of the pie in multimodal analgesia regimes. Though addition of adjuvants can prolong the SAB, the patient and the anesthesiologist have to deal with the associated side effects. Our study also explored the dream of an opioid-free anesthesia world by assessing postoperative opioid consumption and the hurdles faced.
The TPB was significantly higher in Group T, as US-guided TAP-block needs time for accurate visualization of muscle planes to administer the drug safely and accurately as compared to SAB which is an age-old, easy-to-perform procedure, not requiring imaging/radiological techniques or workforce while having a precise end point. The TAP-block provides good-quality analgesia of the anterior abdominal wall with duration and level of block depending on the site of injection, drug type, and amount of LA administered.
As spinal nerves exit the spinal cord, total nerve volume increases, but epineurium density decreases. Near the nerve origin, the nonneural: neural tissue ratio is 1:1, while as the nerve goes farther, the ratio is modified to 2:1, resulting into early and dense sensory and motor blockade in SAB and delayed onset of block in TAP-block. This may also prove as a drawback where time constraint is a factor.
TAP-block provides localized surgical analgesia without adverse effects commonly associated with SAB and hence, may well prove as an alternative where the SAB is not possible or contraindicated. Our findings were consistent with those of Jankovic who evaluated the efficacy of TAP-block in (lower) abdominal surgery and found that TAP-block was devoid of any motor/sympathetic block. However, the intraoperative quality of TAP-block obtained can be explained on the basis of TAP-block not affecting visceral pain. Inguinal hernia repair being a superficial surgery, TAP-block provided adequate postoperative analgesia.
There was no difference in VAS score between the two groups during the intraoperative and immediate postoperative period. Total postoperative analgesic duration as shown by time for FRA in patients administered TAP-block was significantly higher than that in SAB. The supremacy of TAP-block was also highlighted by favorable VAS scores in TAP group patients at all monitoring time frames postoperatively. Even though mean VAS scores were sub-4 in both groups at major monitoring time points, interpreting the equivalence of SAB to TAP-block based on mean VAS scores can mislead because most patients demanded analgesic rescue between the specified time points, which resulted in lower VAS scores at the monitoring time frames. A hidden picture also gets highlighted upon analyzing the difference in the number of rescue analgesics administered in 48 postoperative hours along with total tramadol consumption, which were significantly higher in patients of SAB. Cumulatively, 28 tramadol rescue doses were administered in 24 h postoperatively in TAP group compared to almost double, 58 in SAB group. In addition, if we classify our patients based on mild/no pain, moderate, and severe pain categories on the lines of the three-pain cluster model used for post mastectomy patients, patients administered with TAP-block, cumulatively 4 recordings (VAS 4) were in moderate and no recording in severe pain cluster in 48 h. In Group S, cumulatively, 11 recordings were in severe (VAS 7–10) and 39 (VAS 4–6) in moderate pain category over 48-h period, a stark contrast over the TAP group. The VAS score trajectory showed a downward trend with only 3/28 patients in the TAP group and 7/28 patients in Group S needing rescue analgesics in the 24–48-h period. The significant difference in pain scores and early requirement of rescue analgesics in Group S can be attributed to the regression of spinal Anesthesia. Literature search on acute postoperative pain in inguinal hernia repair revealed that the pain, especially the superficial incisional somatic pain, was maximum on day 0 and regressed over the next 3 days, reaching preoperative levels on day 3. In our case, though the requirements of rescue analgesic requirement were reduced in the 24–48 h period, baseline pain management was done with Inj. paracetamol i.v. administered 8th hourly with the provision of rescue analgesic available.
Similar results were reported by Sharma et al. where the duration of analgesia (the time for FRA) was more in Group T (941 ± 235.68 min) as compared to that of Group S (240.75 ± 5.44 min). Group T did not require any rescue analgesia in the first 24 h.
Venkatraman et al. compared the efficacy of US-guided TAP-block for postoperative analgesia in patients undergoing inguinal hernia repair and reported reduced VAS score at 0, 2, and 24 h by TAP-block patients as compared to control group. The total duration of analgesia for TAP-block with ropivacaine was 390 min. Total analgesic consumptions were also significantly reduced in the TAP group.
Aveline et al. compared two different truncal blocks for hernia repair. Patients received either US-guided TAP-Bl or ilioinguinal/iliohypogastric nerve blocks. The patients were monitored for VAS scores at rest (in the postanaesthesia care unit, at 4, and at 12 h) and during movement (at 24 h, 48 h, at 3 months, and at 6 months). Median VAS scores at rest were lower in the USG-guided TAP group at 4, 12, and 24 h. We found similar results in our study with significant difference in pain scores at 3, 6, and 12 h.
In our study, Group T patients showed hemodynamic stability throughout the procedure with no significant intragroup tachycardia or hypotension. Group S patients showed an initial decline in HR and MAP followed by significant reduction at 10, 20, and 30 min with values attaining preoperative levels at 60 min. This is due to LA-induced lumbar preganglionic sympathetic fibers blockade, resulting in decrease in systemic vascular resistance, with unopposed parasympathetic tone causing bradycardia. Decreased preload results into activation of reflexes that respond to a stretch of intracardiac volume and/or pacemaker receptors. The level of sympathetic block induced by SAB determines the extent of cardiovascular instability. In our study, hemodynamic pattern displayed by both groups spanning intra/postoperative period was similar to the findings of Sharma et al. where the HR was lower in spinal group at all time intervals compared to those of TAP group but returned to preprocedure values at 20 min.
In terms of side effects, TAP-block displayed fewer adverse events. The advantage of TAP block is its safety profile. Leeladharan et al. assessed analgesic efficacy and safety of US-guided TAP-block in postcesarean section patients and found higher incidence of nausea and vomiting in the control group without block. They also concluded that USG guidance provides precision and evades procedure-related complications.
Kahsay et al. evaluated TAP-block in parturient following cesarean section. Patients were allocated in TAP and control groups. The investigators found significantly lower VAS scores in TAP group patients, hence lower analgesic consumption. Similar results were found in our study wherein the requirement of rescue analgesics was greatly reduced in patients receiving TAP-block.
Despite TAP-block being efficacious, certain issues need attention as follows: US-guided TAP-block requires training, expensive equipment, and technical expertise. This is in addition to the extra time for instituting the block, which can be reduced by regular practice. With POCUS becoming the norm in operating rooms across the world, cost factor is likely to come down in the near future, with cost-effective multi-use ultrasound equipment already making their presence felt.
No research is without limitations and so was ours; firstly, a small sample size which was decided based on the previous literature available. The authors feel that the study or its modifications can be conducted with a higher sample size. Secondly, even though the blocks in our case were performed by experienced operators, when performed by operators with limited experience, the block characteristics may vary.
| Conclusion|| |
US-guided TAP-block provides better intraoperative/postoperative analgesia as compared to SAB in cardiovascular and respiratory cripples. The limitations experienced were the time for instituting the block, large volume of LA required, and absence of dense block. Training and regular use of USG can easily overcome this limitation. Furthermore, placing in-plane catheters shall make 24–48 h pain-free postoperative phase a realistic possibility. We recommend US-guided TAP-block in conjunction with SAB for effective management of patients undergoing hernia/lower abdominal surgery for enhanced postoperative pain control with stable hemodynamic to achieve superadded cum synergistic advantages of both RA techniques.
Declaration of patient consent
The authors certify that they have obtained all appropriate patient consent forms. In the form, the patient (s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
| References|| |
Kamal K, Jain P, Bansal T, Ahlawat G. A comparative study to evaluate ultrasound-guided transversus abdominis plane block versus ilioinguinal iliohypogastric nerve block for post-operative analgesia in adult patients undergoing inguinal hernia repair. Indian J Anaesth 2018;62:292-7.
] [Full text]
Hosalli V, Ayyanagouda B, Hiremath P, Ambi U, Hulkund SY. Comparative efficacy of postoperative analgesia between ultrasound-guided dual transversus abdominis plane and ilioinguinal/iliohypogastric nerve blocks for open inguinal hernia repair: An open label prospective randomized comparative clinical trial. Indian J Anaesth 2019;63:450-5.
] [Full text]
Kumar A, Dogra N, Gupta A, Aggarwal S. Ultrasound-guided transversus abdominis plane block versus caudal block for postoperative analgesia in children undergoing inguinal hernia surgery: A comparative study. J Anaesthesiol Clin Pharmacol 2020;36:172-6. [Full text]
Venkatraman R, Abhinaya RJ, Sakthivel A, Sivarajan G. Efficacy of ultrasound-guided transversus abdominis plane block for postoperative analgesia in patients undergoing inguinal hernia repair. Local Reg Anesth 2016;9:7-12.
Frassanito L, Pitoni S, Gonnella G, Alfieri S, Del Vicario M, Catarci S, et al.
Utility of ultrasound-guided transversus abdominis plane block for day-case inguinal hernia repair. Korean J Anesthesiol 2017;70:46-51.
Sharma D, Singh VP, Mahajan A. Ultrasound guided transversus abdominis plane block for post-operative analgesia in inguinal hernia repair. Karnataka Anaesth J 2016;2:86-9. [Full text]
Sharma SK, Ahmad S, Kumar S, Khan AP, Dwivedi P, Rani R, et al
. A comparative study of efficacy and safety of ultrasound guided Transversus Abdominis plane(TAP) block with unilateral spinal Anaesthesia for inguinal hernia repair in geriatric patients. J Evolv Med Dent Sci 2016;5:7356-60.
Aveline C, Le Hetet H, Le Roux A, Vautier P, Cognet F, Vinet E, et al.
Comparison between ultrasound-guided transversus abdominis plane and conventional ilioinguinal/iliohypogastric nerve blocks for day-case open inguinal hernia repair. Br J Anaesth 2011;106:380-6.
Vadhanan P, Tripaty DK, Adinarayanan S. Physiological and pharmacologic aspects of peripheral nerve blocks. J Anaesthesiol Clin Pharmacol 2015;31:384-93.
] [Full text]
Jankovic Z. Transversus abdominis plane block: The Holy Grail of anaesthesia for (lower) abdominal surgery. Period Biol 2009;111:203-8.
Okamoto A, Yamasaki M, Yokota I, Mori M, Matsuda M, Yamaguchi Y, et al
. Classification of acute pain trajectory after breast cancer surgery identifies patients at risk for persistent pain: A prospective observational study. J Pain Res 2018;11:2197-206.
Tolver MA, Rosenberg J, Bisgaard T. Early pain after lap. Groin hernia repair. Acta Anaesthesiol Scand 2012;56:549-57.
Neal JM. Hypotension and bradycardia during spinal anesthesia: Significance, prevention, and treatment. Tech Reg Anesth Pain Manage 2000;4:148-54.
Tammam TF. Transversus abdominis plane block: The analgesic efficacy of a new block catheter insertion method. Egypt J Anaesth 2014;30:39-45.
Leeladharan SP, Puthenveettil N, Rakhi B, Nair SS, Kumar L. Analgesic efficacy and safety of ultrasound guided transverse abdominis plane block in post cesarean section patients – A randomized control trial. J Obstet Anaesth Crit Care 2020;10:16-20. [Full text]
Kahsay DT, Elsholz W, Bahta HZ. Transversus abdominis plane block after Caesarean section in an area with limited resources. South Afr J Anaesth Analg 2017;23:90-5.
[Figure 1], [Figure 2], [Figure 3]
[Table 1], [Table 2], [Table 3]