Laparoscopic cholecystectomy is now regarded as the gold standard surgical management of the symptomatic gallstone disease and other benign gall bladder disorders. Laparoscopic surgery has many advantages compared to open cholecystectomy, such as less post-operative pain, shorter hospital stay, earlier mobilization, faster recovery and better cosmetic results¹. Postoperative pain is a major clinical problem after the laparoscopic cholecystectomy, although this procedure is performed in a minimally invasive manner. Surgical pain can be caused by several mechanisms, such as pain from trocar insertion, stretching of the peritoneum caused by the pneumoperitoneum, irritation of the diaphragm with surgery, and visceral manipulation during surgery². Failure to provide adequate postoperative pain management may prolong recovery, lengthen hospital stay, effect patient satisfaction and contribute to higher health care costs³.

Then postoperative pain management becomes a critical part of “perioperative care”. Traditionally, opioids have been the mainstay of postoperative analgesia; however, their use is frequently associated with adverse effects such as nausea, vomiting, respiratory depression, urinary retention, sedation, and delayed gastrointestinal recovery⁴. These complications have led to the pursuit of safer and more effective strategies for analgesia that reduce the use of opioids and yet provide effective pain relief. In modern surgical practice, multimodal analgesia has become a preferred method that involves using a combination of analgesics and their mechanisms of action to achieve optimal pain control and minimize adverse effects of opioids⁵.

 

Pre-emptive analgesia is one of the important concepts in multimodal analgesia. Pre-emptive analgesia involves using an analgesic procedure prior to the occurrence of surgical injury to prevent development of central sensitization and postoperative pain (POP) intensity⁶. Nociceptors in the periphery become excited during surgery, leading to an increase in excitability of central nervous system neurons. This is called central sensitization and can increase the perception of pain after surgery and increase the need for analgesia⁷. Pre-emptive analgesic techniques may reduce the transmission of nociceptive information and enhance the post-operative response⁸ by giving analgesic prior to the onset of a painful stimulus.

 

There are several agents being studied for pre-emptive analgesia, of which paracetamol is the one that has attracted a great amount of interest due to its efficacy, safety, availability, and the fact that it has little side effects. In the world, Paracetamol (acetaminophen) is one of the most frequently used non-opioid analgesics and antipyretics.⁹. Paracetamol's analgesic activity mechanism is not completely understood, but it is thought that it acts by inhibiting cyclooxygenase enzymes in the central nervous system, modulating serotonergic pathways, and possibly acting on cannabinoid receptors in the central nervous system that regulate pain.¹⁰ Paracetamol also does not significantly alter the function of platelets, gastric mucosa or renal blood flow, as is the case with the nonsteroidal anti-inflammatory drugs (NSAIDs), and hence is a safer choice in many surgical patients.¹¹

 

An IV formulation of Paracetamol has increased its use in perioperative medicine. Compared with oral formulations, intravenous administration offers immediate onset of action, a predictable plasma concentration, and 100% bioavailability.¹² Thus, IV paracetamol has gained increasing prominence in the perioperative analgesia regimes of many surgical specialties. Intravenous paracetamol has been shown to be effective for reducing postoperative pain scores and be able to decrease the amount of opioids required when combined with multimodal analgesia.¹³ These benefits could be vital to a better recovery, fewer opioid side effects, and greater satisfaction.

 

Laparoscopic cholecystectomy may have the most severe pain for the first 24 hours after surgery. Intravenous Paracetamol as an early pre-emptive analgesic can be an effective way of controlling pain early and may help to minimise rescue analgesics during this important post-operative period. Studies have shown that paracetamol given preoperatively intravenously, leads to reduced pain scores, reduced need for rescue analgesics and reduced opioid requirements.¹⁴ The size of these benefits, however, has been reported differently in studies, and variations in patient population, delivery time, and analgesic treatments have been responsible for inconsistent results.

 

Despite the availability of numerous effective pain management techniques, proper postoperative pain management is difficult in developing countries such as Pakistan because of the lack of resources, differences in practice and worries about side effects associated with opioids. Intravenous Paracetamol is an option which is relatively safe, easily administered and cheap. It could enhance patients' recovery and reduce the need for opioid analgesics in perioperative pain management. However, there is limited evidence about its effectiveness as a pre-emptive analgesic in laparoscopic cholecystectomy in the local context. The generation of context-specific data is relevant to evidence based clinical practice and to optimize post-operative pain management strategies in the local healthcare context.¹⁵

 

Hence, the present study was aimed at assessing the effectiveness of pre-emptive intravenous paracetamol prior to surgery in patients with laparoscopic cholecystectomy. The study was conducted to assess the difference in post-operative pain intensity, time to first rescue analgesic and total analgesic consumption for patients who received IV pre-operative paracetamol and those who received standard care. Intravenous Paracetamol was administered preoperatively in an attempt to improve the postoperative pain control, reduce the need for postoperative analgesics and improve recovery after a laparoscopic cholecystectomy. The results of this study could be a part of the accumulating evidence of multimodal analytic therapy and may also be helpful to develop effective, safe and economical analytic management for surgical patients

This randomized controlled trial was conducted in the Department of General Surgery of a tertiary care teaching hospital after obtaining approval from the Institutional Ethical Review Committee (ERC). Written informed consent was obtained from all participants before enrollment. The study was carried out over a period of six months from April 2022 to October 2022. The study population comprised patients undergoing elective laparoscopic cholecystectomy for symptomatic cholelithiasis under general anesthesia. The sample size was calculated using the WHO sample size calculator by considering a 95% confidence level, 80% study power, and a level of significance of 5%. Based on previously published studies reporting differences in postoperative pain scores between intervention and control groups, a minimum sample size of 60 patients (30 in each group) was required to detect a statistically significant difference. To compensate for possible dropouts, all eligible patients presenting during the study period were considered for inclusion. Patients aged 18–65 years of either gender with American Society of Anesthesiologists (ASA) physical status I or II and scheduled for elective laparoscopic cholecystectomy were included in the study. Patients with known hypersensitivity to paracetamol, chronic pain disorders, hepatic or renal impairment, history of opioid dependence, pregnancy or lactation, conversion to open cholecystectomy, or those receiving analgesic medications within 24 hours prior to surgery were excluded from the study. A total of 60 patients fulfilling the eligibility criteria were enrolled through consecutive sampling and randomly allocated into two equal groups using a computer-generated randomization sequence. Patients in Group A received intravenous paracetamol 1 g diluted in 100 mL solution approximately 30 minutes before induction of anesthesia, whereas patients in Group B received 100 mL of normal saline as placebo. Both the patients and the postoperative assessors were blinded to group allocation. Standardized general anesthesia was administered to all participants according to departmental protocols. After completion of surgery, postoperative pain was assessed using the Visual Analog Scale (VAS), where 0 represented no pain and 10 represented the worst imaginable pain. Pain scores were recorded at 1, 4, 8, 12, and 24 hours after surgery. Rescue analgesia in the form of intravenous tramadol was administered when the VAS score was ≥4 or when requested by the patient. The time to first rescue analgesia and total postoperative analgesic consumption during the first 24 hours were documented. Patients were also monitored for adverse events including nausea, vomiting, dizziness, allergic reactions, and any drug-related complications. All collected data were entered and analyzed using Statistical Package for Social Sciences (SPSS) version 26. Quantitative variables such as age, body mass index, VAS pain scores, time to first rescue analgesia, and total analgesic consumption were expressed as mean ± standard deviation. Qualitative variables such as gender and occurrence of adverse effects were presented as frequencies and percentages. Independent sample t-test was used to compare continuous variables between the two groups, while Chi-square test or Fisher’s exact test was applied for categorical variables. A p-value of ≤0.05 was considered statistically significant.