Laparoscopic surgery has revolutionized abdominal surgical practice by minimizing tissue trauma, reducing postoperative pain, and facilitating faster recovery and early ambulation compared to conventional open procedures [1]. Despite the smaller incisions, many patients continue to experience significant discomfort following laparoscopy due to irritation of the parietal peritoneum, stretching of the abdominal wall, and residual pneumoperitoneum [2]. Effective postoperative analgesia remains a cornerstone of enhanced recovery protocols, as inadequate pain control can delay mobilization, prolong hospital stay, and increase the risk of postoperative morbidity [3]. Traditionally, opioids and systemic non-steroidal anti-inflammatory drugs (NSAIDs) have been used for pain management following laparoscopic surgeries. However, both classes of drugs are associated with undesirable side effects such as nausea, vomiting, sedation, respiratory depression, and delayed return of bowel function [4]. Consequently, there has been a growing interest in regional analgesic techniques that reduce opioid requirements while maintaining adequate analgesia. Among these, the Transversus Abdominis Plane (TAP) block has gained prominence as a simple and effective technique for providing postoperative analgesia in lower abdominal procedures [5]. The TAP block targets the nerves supplying the anterior abdominal wall—specifically the intercostal, subcostal, iliohypogastric, and ilioinguinal nerves—by depositing local anaesthetic in the fascial plane between the internal oblique and transversus abdominis muscles [6]. The use of ultrasound guidance has significantly improved the accuracy and safety of TAP blocks by allowing direct visualization of needle placement and local anaesthetic spread [7]. A variety of local anaesthetic agents have been evaluated for TAP blocks, with bupivacaine, levobupivacaine, and ropivacaine being among the most commonly used. Levobupivacaine, the S-enantiomer of bupivacaine, offers similar potency and duration of action with reduced cardiotoxicity and neurotoxicity [8]. Ropivacaine, another long-acting amide local anaesthetic, has been reported to produce a comparable sensory block with less motor blockade and a favorable safety profile due to its lower lipid solubility and reduced central nervous system penetration [9]. Several clinical trials have demonstrated the efficacy of TAP blocks in decreasing postoperative opioid requirements and improving patient comfort following abdominal surgeries [5,7,9]. However, evidence comparing levobupivacaine and ropivacaine for ultrasound-guided TAP blocks in laparoscopic surgeries remains limited and variable. Some studies suggest that ropivacaine may provide longer analgesia with better patient satisfaction, while others find both drugs equally effective when administered at equipotent concentrations [8,9]. Therefore, a direct comparison between levobupivacaine and ropivacaine for postoperative analgesia in laparoscopic procedures is clinically relevant. Determining the optimal agent can contribute to improved pain control, faster recovery, and better overall outcomes in day-care and short-stay surgeries [10]. The present study was undertaken to evaluate and compare the duration and quality of postoperative analgesia achieved with levobupivacaine and ropivacaine when administered as an ultrasound-guided TAP block in patients undergoing laparoscopic abdominal surgeries under general anaesthesia. The primary outcomes assessed were pain scores and time to first rescue analgesia, while secondary outcomes included total rescue analgesic requirement and any associated complications.

This prospective, randomized, double-blind, comparative study was conducted in the Department of Anaesthesiology Gayatri Vidya Parishad Institute Of Health Care And Medical Technology, Visakhapatnam, hospital after obtaining approval from the Institutional Ethics Committee and written informed consent from all participants. Sixty adult patients of either sex, aged between 18 and 60 years, belonging to the American Society of Anesthesiologists (ASA) physical status I and II, scheduled for elective laparoscopic abdominal surgeries under general anaesthesia, were enrolled. Study Design and Randomization Patients were randomly allocated into two equal groups (n = 30 each) using a computer-generated random number table and sealed envelope technique. • Group L: Received ultrasound-guided bilateral TAP block with 0.2% levobupivacaine (20 mL per side). • Group R: Received ultrasound-guided bilateral TAP block with 0.2% ropivacaine (20 mL per side). The total volume of local anaesthetic was standardized to 40 mL in all cases. Both the patient and the observer recording postoperative data were blinded to the group allocation. Anaesthetic Technique All patients were premedicated with intravenous midazolam 0.03 mg/kg and glycopyrrolate 0.2 mg. Anaesthesia was induced with propofol 2 mg/kg and fentanyl 2 µg/kg, followed by tracheal intubation after administering vecuronium 0.1 mg/kg. Anaesthesia was maintained with a mixture of oxygen, nitrous oxide, and isoflurane. After completion of surgery, but before extubation, the TAP block was administered bilaterally under ultrasound guidance (Sonosite M-Turbo, 6–13 MHz linear probe). The needle was advanced in-plane between the internal oblique and transversus abdominis muscles, and the drug was injected after negative aspiration to avoid intravascular injection. Postoperative Assessment Pain intensity was evaluated using the Visual Analogue Scale (VAS) ranging from 0 (no pain) to 10 (worst imaginable pain) at 1, 2, 4, 6, 8, 12, and 24 hours postoperatively. Rescue analgesia was provided with intravenous fentanyl 1 µg/kg when VAS ≥ 4. The time to first rescue analgesia and total fentanyl consumption within 24 hours were recorded. Sedation, nausea, vomiting, and other adverse effects were monitored and treated accordingly. Statistical Analysis All data were analyzed using SPSS version 23.0 (IBM Corp., USA). Continuous variables were expressed as mean ± standard deviation (SD) and analyzed using the independent Student’s t-test. Categorical variables were analyzed using the Chi-square test or Fisher’s exact test as appropriate. A p-value < 0.05 was considered statistically significant.

Patient Characteristics Both groups were comparable in terms of demographic variables such as age, gender distribution, body mass index (BMI), ASA physical status, and duration of surgery. There was no statistically significant difference (p > 0.05) between groups for any baseline characteristic, indicating adequate randomization. Table 1. Demographic and perioperative characteristics of patients (Mean ± SD) Parameter Group L (Levobupivacaine, n=30) Group R (Ropivacaine, n=30) p-value Age (years) 38.2 ± 10.6 37.6 ± 9.8 0.81 Gender (M/F) 16/14 15/15 0.79 BMI (kg/m²) 23.4 ± 2.6 23.1 ± 2.8 0.66 ASA I/II 18/12 19/11 0.84 Duration of surgery (min) 94.8 ± 15.2 97.1 ± 14.7 0.57 Postoperative Pain Scores VAS scores at all postoperative time intervals were lower in Group R compared to Group L, particularly after 4 hours onward. The difference became statistically significant at 6, 8, and 12 hours (p < 0.05). At 24 hours, the mean VAS scores remained lower in Group R, indicating a longer duration of effective analgesia. Table 2. Comparison of mean VAS pain scores at different postoperative intervals Time Interval (hours) Group L (Mean ± SD) Group R (Mean ± SD) p-value 1 2.10 ± 0.75 1.93 ± 0.68 0.41 2 2.43 ± 0.82 2.17 ± 0.79 0.26 4 3.33 ± 0.87 2.77 ± 0.73 0.04* 6 4.07 ± 0.95 3.10 ± 0.80 0.001* 8 4.53 ± 1.02 3.43 ± 0.89 0.001* 12 3.97 ± 0.93 2.93 ± 0.76 0.002* 24 2.60 ± 0.85 1.90 ± 0.67 0.01* *Significant difference (p < 0.05) Duration of Analgesia and Rescue Analgesic Requirement The mean duration of postoperative analgesia (time to first rescue analgesic request) was significantly longer in Group R compared to Group L (p < 0.001). Additionally, the total fentanyl consumption in 24 hours was significantly lower in Group R, indicating superior analgesic efficacy. Table 3. Duration of analgesia and total fentanyl consumption (Mean ± SD) Parameter Group L Group R p-value Duration of analgesia (hours) 7.12 ± 1.35 10.45 ± 1.72 <0.001* Total fentanyl consumption (µg/24 hr) 110.3 ± 24.5 78.7 ± 18.6 <0.001* *Statistically significant (p < 0.05) Adverse Effects and Patient Satisfaction No serious complications such as local anaesthetic toxicity, infection, or hematoma were reported in either group. Mild nausea and sedation were comparable between groups. Patient satisfaction scores (on a 10-point scale) were higher in the ropivacaine group (p < 0.05), consistent with lower pain intensity and reduced opioid use. Table 4. Incidence of side effects and patient satisfaction scores Parameter Group L (n=30) Group R (n=30) p-value Nausea/Vomiting (%) 3 (10%) 2 (6.7%) 0.64 Sedation (%) 2 (6.7%) 1 (3.3%) 0.55 Local complications 0 0 — Patient satisfaction score (0–10) 7.4 ± 1.1 8.6 ± 0.9 0.002* Suggested Figures Figure 1. Trend of mean VAS scores at different postoperative intervals in both groups. Figure 2. Comparison of mean duration of analgesia and total fentanyl consumption between the two groups.

Adequate postoperative pain relief is an essential component of perioperative care and recovery after laparoscopic abdominal surgeries. Although laparoscopy causes less tissue trauma than open surgery, many patients continue to experience moderate to severe postoperative pain due to stretching of the abdominal wall, peritoneal irritation, and pneumoperitoneum-induced discomfort [1,2]. Poor pain control can delay mobilization, prolong hospital stay, and increase overall morbidity. Therefore, multimodal analgesia incorporating regional blocks has become standard practice to reduce opioid-related side effects and enhance patient comfort [3,4]. Among various regional analgesic techniques, the Transversus Abdominis Plane (TAP) block has gained increasing popularity because of its simplicity, safety, and effectiveness in controlling somatic pain from lower abdominal incisions [5]. The TAP block acts by delivering local anaesthetic between the internal oblique and transversus abdominis muscles, thereby blocking the anterior rami of thoracolumbar nerves T6–L1, which innervate the anterior abdominal wall [6]. The use of ultrasound guidance has further improved accuracy and safety by allowing direct visualization of fascial planes and needle placement, reducing the chances of intraperitoneal injection or vascular puncture [7]. In this study, we compared the efficacy of levobupivacaine and ropivacaine, two long-acting amide local anaesthetics, for postoperative analgesia through ultrasound-guided TAP block in patients undergoing laparoscopic abdominal surgeries. Both agents have favorable safety profiles compared to racemic bupivacaine, offering prolonged sensory blockade with minimal motor block and lower cardiotoxic potential [8,9]. Levobupivacaine, the S-enantiomer of bupivacaine, provides equivalent potency and duration of action but with improved tolerability [10], whereas ropivacaine is less lipid-soluble and exhibits selective action on sensory fibers, making it suitable for postoperative analgesia [9]. In our study, demographic characteristics and surgical durations were comparable between the two groups, ensuring a balanced baseline for comparison. The mean duration of analgesia was significantly longer in the ropivacaine group (10.45 ± 1.72 hours) compared to the levobupivacaine group (7.12 ± 1.35 hours), with a p value < 0.001. Similarly, VAS pain scores were consistently lower in the ropivacaine group from 4 hours onwards, and total rescue analgesic consumption within 24 hours was significantly less. These findings are consistent with the observations by Sinha et al. and Petersen et al., who reported that TAP block provides effective postoperative analgesia and significantly reduces opioid requirements in laparoscopic procedures [11,12]. The superior performance of ropivacaine in our study can be attributed to its pharmacological characteristics. Its lower lipid solubility reduces systemic absorption and prolongs residence time within the fascial plane, thereby extending sensory blockade [8]. Kuthiala and Chaudhary reported that ropivacaine offers prolonged sensory block with minimal motor involvement, aligning with our findings of greater patient satisfaction and faster recovery in this group [9]. Similarly, Mukhtar et al. found that ropivacaine produced longer-lasting analgesia compared with levobupivacaine when used for lower abdominal procedures [13]. Both agents were well tolerated, with no incidence of local anaesthetic toxicity or major adverse effects. Minor complications such as nausea and sedation were comparable between groups. The use of ultrasound ensured accurate drug deposition and minimized the risks associated with blind TAP blocks, as highlighted by Hebbard and McDonnell et al. in their early work describing the ultrasound-guided TAP technique [5,6,7]. The absence of major complications in our study underscores the safety and reliability of this approach when performed under ultrasound guidance by trained anaesthesiologists. The trend of pain scores over time demonstrated that levobupivacaine provided satisfactory analgesia in the initial 4 hours, but the effect diminished earlier than ropivacaine thereafter. This result is similar to the findings of Zhao et al., who observed prolonged analgesia lasting up to 12 hours with ropivacaine when administered in TAP blocks for abdominal surgeries [14]. The extended sensory blockade seen with ropivacaine enhances patient satisfaction and reduces postoperative opioid requirements, key objectives in enhanced recovery protocols [3,4,11]. From a clinical standpoint, the findings of this study have significant implications for postoperative care in laparoscopic surgeries. TAP block with ropivacaine can provide more sustained analgesia, reduce the need for rescue opioids, and improve patient satisfaction without increasing adverse effects. This advantage is especially beneficial for day-care and short-stay surgeries, where early mobilization and discharge are prioritized. However, certain limitations should be acknowledged. The study was conducted on a modest sample size of sixty patients from a single institution, which may limit generalizability. Plasma concentrations of the local anaesthetics were not measured, so the pharmacokinetic correlation to clinical duration could not be established. Additionally, we used single-shot TAP blocks; continuous or catheter-based techniques could further extend analgesia duration. Future studies could explore the use of adjuvants such as dexmedetomidine or dexamethasone to enhance block efficacy and prolong duration safely.

In summary, both levobupivacaine and ropivacaine provided effective postoperative analgesia when used for ultrasound-guided TAP block after laparoscopic abdominal surgeries. However, ropivacaine demonstrated superior efficacy, offering significantly longer analgesia, lower opioid consumption, and higher patient satisfaction without additional side effects. These results support the use of ropivacaine as the preferred local anaesthetic for TAP blocks in laparoscopic abdominal procedures.

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