Intravenous Lidocaine Infusion Versus Intravenous Dexmedetomidine Infusion During Laparoscopic Sleeve Gastrectomy : the Effect on Recovery Outcomes Variables

Morbid obesity is often linked to conditions such as diabetes, coronary artery disease, hypertension, hyperlipidaemia, and certain types of cancer, all of which negatively affect patients' quality of life, increase mortality risk, and shorten life expectancy. (1) Evidence suggests that medical approaches for weight loss, such as dietary therapy, physical activity, and behavioural modifications, typically do not lead to significant or sustained weight loss. In contrast, bariatric surgery is far more effective when combined with regular exercise and lifestyle changes. It remains the most successful and durable treatment for severe obesity and its related conditions, reducing the risk of 5-year mortality and significantly improving quality of life. (2) Laparoscopic sleeve gastrectomy has become a popular bariatric procedure due to its relative simplicity compared to more complex surgeries, such as gastric bypass or the full biliopancreatic diversion with duodenal switch (BPD/DS). The procedure can be performed laparoscopically, which is minimally invasive, leading to shorter recovery times and fewer complications. (3-5) Although laparoscopic (LAP) bariatric surgery is minimally invasive. Following any laparoscopic procedure, patients typically experience the peak of postoperative pain within the first 24 hours. This intense pain gradually subsides, with significant relief usually occurring by the 2nd or 3rd postoperative day. The initial peak and subsequent decline in pain intensity highlight the importance of effective early pain management strategies to ensure patient comfort and recovery during this critical period. Inadequate management of postoperative pain can result in serious complications, including delayed wound healing, impaired gastrointestinal function, myocardial ischaemia, immunologic changes, pulmonary issues, and an increased risk of thromboembolism due to immobility. (6) Centrally acting opioids have long been the cornerstone for managing severe postoperative pain. However, growing awareness of their side effects has sparked increasing interest in opioid-sparing multimodal analgesic strategies. This approach is particularly important in morbidly obese patients, who often present with multiple co-morbidities and face specific challenges related to anaesthesia and surgery. Opioid-sparing strategies in these patients not only aim to manage pain effectively but also minimise the risks associated with opioid use, improving overall postoperative outcomes. (7) Lidocaine is increasingly recognised as a vital adjunct in managing perioperative pain. Its efficacy extends beyond traditional local anaesthetic applications, as it also demonstrates analgesic, anti-hyperalgesic, and anti-inflammatory properties. By employing intravenous lidocaine infusions during the perioperative period, healthcare providers can enhance pain control, particularly in populations such as bariatric patients. Lidocaine achieves its effects through various mechanisms, including sodium channel blockade and inhibition of G protein-coupled receptors and N-methyl-D-aspartate (NMDA) receptors. This multifaceted action makes lidocaine a valuable component in multimodal analgesic regimens, ultimately improving patient comfort and recovery outcomes. (8,9) Dexmedetomidine is a highly selective alpha-2 adrenergic agonist with hypnotic, sedative, anxiolytic, sympatholytic, and analgesic effects, while causing minimal respiratory depression. Its sympatholytic properties lower mean arterial blood pressure (MAP) and heart rate (HR) by inhibiting the release of norepinephrine. Additionally, dexmedetomidine can reduce the need for both anaesthetic and opioid analgesics during the perioperative period. (10-13) AIM OF THE WORK The present study aims to evaluate the effect of intraoperative intravenous infusion of lidocaine versus intravenous infusion of dexmedetomidine on postoperative analgesia and opioid requirements.

The primary outcomes:

• Quality of pain control assessed by the visual analogue scale (VAS) in the first 24 hours after surgery at rest and at movement.

The secondary outcomes:

• The total amount of rescue opioids administered in the first 24 hours post-operatively. (mg).
• Time until the first analgesic requirement. (hours).
• Duration of stay in the PACU. (hours).
• Patients' satisfaction score.
• The incidence of post-operative complications, such as nausea, vomiting, and hypoxaemia.