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ORIGINAL ARTICLE
Year : 2022 | Volume
: 23
| Issue : 2 | Page : 91-97
Comparison of ultrasound-guided transversus abdominis plane block and quadratus lumborum block for postoperative analgesia following laparoscopic living donor nephrectomy: A prospective randomized, double-blind study
Kaushik Sengupta1, Jitendra Ladhania1, Amit Kundu1, Titisa Sarkar Mitra1, Tuhin Mistry2
1 Department of Anaesthesiology and Critical Care, Rabindranath Tagore International Institute of Cardiac Sciences, Kolkata, West Bengal, India
2 Department of Anaesthesiology and Perioperative Care, Ganga Medical Centre and Hospitals Pvt Ltd, Coimbatore, Tamil Nadu, India
Correspondence Address:
Dr. Tuhin Mistry
Department of Anaesthesiology and Perioperative Care, Ganga Medical Centre and Hospitals Pvt Ltd, Coimbatore, Tamil Nadu
India
Source of Support: None, Conflict of Interest: None
CheckDOI: 10.4103/TheIAForum.TheIAForum_34_22
Background and Aims: The application of ultrasound (USG)-guided interfascial plane blocks in transplant anesthesia is expanding. This study evaluates and compares the postoperative analgesic efficacy of USG-guided transversus abdominis plane block (TAPB) and quadratus lumborum block (QLB) in adult individuals undergoing laparoscopic living donor nephrectomy (LLDN).
Materials and Methods: A hundred donors of either sex, aged 30–60 years, scheduled to undergo LLDN were randomly allocated into two groups. After completion of the LLDN, USG-guided unilateral TAPB and QLB were performed in lateral position in Groups A (n = 48) and B (n = 48), respectively. A volume of 20 ml of 0.375% ropivacaine was administered in both groups. Postextubation donors were shifted to the postanesthesia care unit (PACU). Heart rate, systolic blood pressure, diastolic blood pressure, and numeric rating scale (NRS) scores were recorded on arrival at PACU at the time of discharge from PACU. Subsequently, the donor was shifted to the intensive care unit, and the vitals and NRS scores (static and dynamic) were monitored postoperatively on the 2nd, 6th, 12th, 18th, and 24th h. Duration of analgesia and the number of donors who needed rescue analgesia were also noted. All the donors were observed for any side effects and complications. P <0.05 was considered statistically significant.
Results: The NRS score was significantly lower in Group B (QLB) than in Group A (TAPB). Duration of analgesia was significantly prolonged in Group B (11.34 ± 1.53 h) compared to Group A (9.05 ± 1.58 min). (P < 0.001)
Conclusion: The QLB effectively prolonged the duration of analgesia, lowers pain scores, and decreases the requirement of rescue analgesia compared to the TAPB. Hence, the donors remain comfortable in the postoperative period without any potential side effects.
Keywords: Acute pain management, laparoscopy, nephrectomy, postoperative analgesia, quadratus lumborum block, transversus abdominis plane block, ultrasonography
The laparoscopic living-donor nephrectomy (LLDN) is now the standard operation for kidney donation. Pain following the LLDN is multifactorial, and optimal pain management is the key to the early recovery of the donor. Although laparoscopic surgery is less painful than open surgery, donors still require more opioids than other laparoscopic nephrectomy patients.[1] Factors include port-site pain, lower abdominal incisions (to retrieve the kidney), pelvic organ nociception, diaphragmatic irritation (shoulder tip discomfort from residual pneumoperitoneum), ureteric colic, and urinary catheter discomfort add up, and contribute to the total pain experience.[2] A multimodal approach to postoperative pain management provides optimal pain relief and minimizes opioid use and opioid-related adverse events.[3] Various regional anesthesia/analgesia (RA) techniques have been used as a component of multimodal analgesia for LLDN patients. Recent research revealed that RA could be safely used for renal surgeries, including donor nephrectomy and renal transplantation.[4] It provides better hemodynamic stability, minimal blood loss, good postoperative pain relief, and fewer postoperative complications.[5] Continuous epidural analgesia is the time-tested and widely used technique for postoperative pain management after donor nephrectomy. However, it often causes hypotension, numbness or tingling of lower limbs, and urinary retention that may delay the mobilization of donors.[6]
With the advent of ultrasonography in RA practice, various interfacial plane blocks have been described for pain management in patients undergoing nephrectomy. Ultrasound (USG)-guided transversus abdominis plane block (TAPB) provided opioids-sparing postoperative analgesia, comparable to a continuous epidural following transperitoneal laparoscopic nephrectomy.[7],[8] However, TAPB was also found ineffective in reducing pain or opioid consumption following laparoscopic nephrectomy in a different clinical setting.[9] Moreover, continuous TAPB provided no additional benefit over a single injection.[10] The TAPB provides analgesia to the skin, anterior abdominal wall muscles, and parietal peritoneum. Hence, systemic analgesics are required to cover the visceral component of pain.
The need for the visceral analgesia to provide better postoperative pain relief led to adopting a more posterior approach that involves injecting the local anesthetic (LA) adjacent to the quadratus lumborum (QL) muscle. The QL block (QLB) described by Børglum et al. was a transmuscular or anterior QLB, where the LA is injected in the plane between the psoas major and QL muscles.[11] Clinical trials of QLB in LLDN are still limited, but evidence has shown its efficacy in reducing postoperative pain and opioid use to promote recovery after cesarean section, laparoscopic or laparotomy procedures, and hip surgery.[12] The QLB was found to have a similar analgesic efficacy to the continuous epidural analgesia following transperitoneal laparoscopic nephrectomy.[1]
To date, no trials have compared the analgesic efficacy of USG-guided TAPB with QLB following LLDN. Hence, the present study was conceived to assess and compare the USG-guided TAPB and QLB for postoperative analgesia in donors. We hypothesized that USG-guided QLB does not significantly affect postoperative pain score, duration of analgesia requirement of rescue analgesia, and side effects compared to TAPB. The primary objective was to compare the postoperative pain scores at different time intervals, and the secondary objectives were to compare the duration of analgesia, rescue analgesic consumption, and incidence of side effects.
Materials and MethodsThis prospective, randomized, double-blind, comparative study was conducted in the department of anesthesiology at a tertiary care center over 1 year (August 2019 to July 2020). The ethical permission was taken from the institutional committee and review board (Ref No. NRRTIICSEC/Acad/DNB-Anes/2019/003, Approval No: NHRTIICSEC/AP/014/2019 dated July 15, 2019). After a detailed explanation, consent was obtained from each donor fulfilling the eligibility criteria. The numeric rating scale (NRS) scores of 0–10 were also explained during the preanesthetic assessment.
Our study included 98 subjects of either sex, aged 30–60 years, belonging to the American Society of Anesthesiologists physical status Grade I and II, scheduled for elective LLDN under general anesthesia (GA). Subjects with a history of systemic diseases, opioid dependence, and hypersensitivity to the study drugs were excluded from the study. Donors on more than one antihypertensives medicine, required conversion to open nephrectomy, had local pathology at the injection site, altered abdominal wall anatomy, and those who refused to participate in the study were also excluded from the study.
The donors were randomly allocated into one of the two predefined Groups, A or B, with 48 patients using the computer-generated random numbers. An experienced anesthesiologist prepared the study drugs and performed the blocks. The other investigators who had collected the postblock data were blinded to the group allocation and blocks performed. Thus, the patient and the data collector were unaware of the group distribution.
GA was induced with intravenous (IV) fentanyl, propofol, and atracurium, and the trachea was intubated with an appropriate endotracheal tube for each donor. Anesthesia was maintained with oxygen, titrated isoflurane, atracurium, and positive pressure ventilation. All donors received IV paracetamol 15 mg/kg and additional doses of 1 μg/kg/hr fentanyl intraoperatively. Heart rate (HR), hemoglobin oxygen saturation (SpO2), systolic blood pressure (SBP), diastolic blood pressure (DBP), end-tidal carbon dioxide, and temperature were monitored throughout surgery.
At the end of the surgery, USG-guided unilateral TAPB or QLB was performed by an experienced regional anesthesiologist in the lateral position under all aseptic precautions. A volume of 20 ml of 0.375% ropivacaine was administered in both groups. The study drug was prepared in a sterile 20 ml syringe with 10 ml of 0.75% ropivacaine (Ropin, Neon Laboratories Ltd., Mumbai) and 10 ml of 0.9% saline (Sodium Chloride Injection, Aculife Healthcare Pvt. Ltd., Gujarat).
In Group A donors, a high-frequency linear array transducer (8–13 MHz) of the USG machine (SonoSite, MicroMaxx) was placed posterior to the midaxillary line between the costal margin and iliac crest. The tip of a 22-G Quincke's spinal needle was advanced from anterior to posterior and placed in the plane between the internal oblique fascia and the transversus abdominis muscles. Then, the study drug was injected in 5 ml increments after negative aspiration for blood. An echolucent lens-shaped space (Kayak sign) between the two muscles was considered a successful injection. In Group B donors, a low-frequency curvilinear transducer (2–5 MHz) was placed in the mid-axillary line cranial to the iliac crest and moved posteriorly to visualize the “shamrock sign.” The tip of a 22-G Quincke's spinal needle was advanced from posterior to anterior and positioned in the plane between the QL and psoas major muscles. Then, the study drug was administered in 5 ml aliquots following negative aspiration for blood.
At the end of the block, subjects were extubated following the reversal of residual neuromuscular blockade and shifted to the postanesthesia care unit (PACU). The pain was assessed using NRS scores as static (at rest) and dynamic (on movement, the donor was asked to flex their knees maximally). Postoperatively, HR, SBP, DBP, SpO2, and NRS scores were recorded on arrival at PACU, at the time of discharge from PACU. The donor was shifted to the intensive care unit (ICU) for observation and monitoring for 24 h. Hence, the vitals and NRS score were monitored in ICU on the 2nd, 6th, 12th, 18th, and 24th h postoperatively.
Rescue analgesic IV tramadol 100 mg along with ondansetron 4 mg was administered at NRS score ≥ 4, and the time was noted. The total duration of analgesia was defined as the time from the study drug administration to the rescue analgesic administration. All the donors were observed for side effects such as nausea, vomiting, and complications like hematoma and last during the 24-h postoperative period.
The sample size was calculated from the pilot study's findings on 10 patients with the statistical formula.[13] The difference in mean NRS score at 6 h after surgery (2.5 in TAPB and 1.5 in QLB groups) between the two groups was 1. Assuming P < 0.05, the standard deviation of 1.48, and the power of the study 90%, we got n = 48 for each group. Considering the potential dropouts, 100 subjects were included in our study.
Raw data were filled into a Microsoft Excel spreadsheet and analyzed using the Statistical Package for the Social Sciences software (SPSS® Statistics for Windows, version 27.0.1, IBM Corp., Armonk, New York, USA). Categorical variables such as the number and percentage of donors were compared across the groups using Pearson's Chi-square test for Independence of Attributes/Fisher's exact test as appropriate. Continuous variables are expressed as mean, median, and standard deviation and compared across the groups using the Mann–Whitney U-test. An alpha level of 5% has been taken, i.e. if any P < 0.05, it has been considered significant.
ResultsWe recruited 100 donors, and four were excluded from the final analysis. The consort diagram of our study indicating enrollment and progress is shown in [Figure 1]. Both the study groups were comparable in terms of demographic profiles [P > 0.05, [Table 1]]. Most donors were from the mean age group of 30–40 years.
[Table 2] shows the postoperative vitals at various time points, and the differences were comparable between the groups.
The static and dynamic NRS scores at different time points are depicted in [Figure 2] and [Figure 3], respectively. The difference in mean static and dynamic NRS scores at 12th, 18th, and 24th h postoperatively were statistically significant between the groups.
Figure 2: Static pain scores. PACU: Postanesthesia care unit, TAP: Transverse abdominis plane, QL: Quadratus lumborum
Figure 3: Dynamic pain scores. PACU: Postanesthesia care unit, TAP: Transverse abdominis plane, QL: Quadratus lumborumGroup B patients had a prolonged duration of analgesia than Group A (11.34 ± 1.53 h vs. 9.05 ± 1.58 h). The difference was statistically significant.
The difference was statistically significant [P < 0.001, [Table 3]]. Forty-four donors required rescue analgesia in Group A, almost three times more than Group B (15 donors, P < 0.001).
The difference in postoperative nausea and vomiting (PONV) between groups was statistically significant [Table 4].
DiscussionOur results showed that the QLB is a superior analgesic technique to TAPB in donors following LLDN. It helped significantly reduce consumption and demands of rescue analgesics in the first 24 h compared to those with TAPB.
QLB has recently gained popularity as a novel truncal block in various abdominal surgeries.[14] Among the four described types, we chose transmuscular or anterior QLB during this study because it was reported to offer better analgesia than other approaches.[15] The actual mechanism of analgesia has not yet been fully explained. It is believed that the LA spread along the thoracolumbar fascia and the endothoracic fascia is responsible for the analgesia. The latest anatomical evidence shows that LA also extends into the thoracic paravertebral space.[16] The visceral analgesia may result from the distribution of LA toward the celiac ganglion or sympathetic trunk through splanchnic nerves.[17] The ongoing comparative trial between the transmuscular QLB and thoracic paravertebral block for laparoscopic renal surgery would probably provide substantial clinical evidence regarding the analgesic mechanism of transmuscular QLB.[18]
Our study showed a comparable pain score (both at rest and on movement) between the groups in the early postoperative period up to 6 h. Later, at 12, 18, and 24 h following the performance of the block, the static and dynamic NRS scores were significantly less in the QLB group. These observations are similar to a study on patients undergoing total abdominal hysterectomy.[19] Kumar et al. also observed a significant difference in postoperative pain scores between TAPB and QLB groups at the 1st, 2nd, 4th, 6th, 8th, 10th, 12th, and 16th h.[20] However, Blanco et al.[12] and Deng et al.[21] did not observe any significant differences in static and dynamic pain scores between the TAPB and QLB groups in patients after cesarean delivery and laparoscopic colorectal surgery, respectively. This difference could be due to the spread of LA in the thoracolumbar fascial plane or into the paravertebral space and dermatomal area involved in the surgery.
We observed a significantly longer mean duration of analgesia in the QLB group than in TAPB. According to Blanco et al.,[12] the median duration of analgesia after bilateral QLB exceeds 24 h with 0.125% bupivacaine at 0.4 mL/kg in patients after cesarean delivery. In another study by Murouchi et al.,[22] the mean duration of analgesia in the QLB group (>24 h) was much longer than in the TAPB group (7.0 h) after laparoscopic ovarian surgery. In our study, the difference in duration of analgesia was statistically significant but shorter than in the published trials. This disparity could be due to the use of bilateral blocks and a higher volume of LA in the studies mentioned above.
In our study, more donors required rescue analgesics in the TAPB group. This observation matches the analysis performed by Blanco et al.;[12] individuals in the QLB group needed significantly less morphine than the TAPB group at 12, 24, and 48 h after cesarean delivery.
We did not notice any significant hemodynamic alteration following the block in the first 24-h postoperative period. This finding was similar to Blanco et al.[12] and Baytar et al.[23] Out of 48 donors, three had Grade 1 and three had Grade 2 PONV in the TAPB group. None of the donors in the QLB group had PONV. Baytar et al.[23] observed nausea and vomiting in patients undergoing laparoscopic cholecystectomy in TAPB and QLB groups. These gastrointestinal side effects could be due to higher pain scores or use of IV tramadol as rescue analgesia.
Our study has a few limitations. We did not assess dermatomal levels of blocks, as we focused on pain score and rescue analgesic consumption. We also did not measure the blood ropivacaine levels following blocks and correlation with NRS scores at different time intervals. The efficacy of TAPB or QLB was not compared with the standard technique like epidural analgesia. Further studies are recommended for transmuscular QLB regarding optimal dosing schemes (i.e. single-shot vs. catheter, intermittent vs. continuous catheter infusions, type of LA and different doses, concentration and volumes of LA), the addition of various adjuvants, and comparison with other approaches.
ConclusionUSG-guided unilateral QLB and TAPB can be safely performed in a lateral position for postoperative analgesia in donors following elective LLDN. The QLB is highly effective in prolonging the duration of analgesia, lower pain scores, and lesser requirement of rescue analgesia than the TAPB. Hence, the donors remain comfortable in the postoperative period without any potential side effects.
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Conflicts of interest
There are no conflicts of interest.
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