Comparison of intravenous dexmedetomidine and lignocaine in combination with parasternal intercostal block on postoperative analgesia in adult patients undergoing cardiac surgery- A prospective randomized study

Despite the use of multimodal analgesic regimes, minimally invasive surgical procedures, and better recovery programs, postoperative pain management remains inadequate. Acute postoperative pain impedes patients’ functional recovery and is one of the most important predictors of the shift to chronic postsurgical pain. When compared to other major surgical operations, cardiac surgery is linked with significant pain. Postoperative day (POD) 1 and 2 are the most painful days following heart surgery. In addition to the patients’ experience, postoperative pain following heart surgery has a negative impact on the result. Postoperative tachycardia, hypertension, arrhythmias, and myocardial ischemia are all common. The majority of postoperative pain treatment procedures are based on opioids, which have a dose-dependent analgesic effect.

Although multimodal analgesia was employed in 86% of patients in a recent large cohort trial, practically all patients got an opioid for postoperative pain. High dosages of opioids are well recognized to cause respiratory depression, drowsiness, postoperative nausea and vomiting (PONV), pruritus, urine retention, constipation and ileus , hyperalgesia, and allodynia. All of these factors can hinder patients’ functional recovery, lengthen hospital stays, and raise health-care expenses, as well as result in poor postoperative pain control and the transition to chronic pain. As a result, there is still a need to test adjuvant treatments that might minimize perioperative opioid usage.

In the Enhanced Recovery After Surgery era, parasternal intercostal nerve block has been proposed to improve pain control and reduce opioid use in patients undergoing cardiac surgery. Dexmedetomidine, a highly selective alpha 2 adrenoreceptor agonist, and lidocaine, a well-established local anesthetic, appear potential as adjuvants for this purpose. Dexmedetomidine has a relatively high ratio of α2/α1 activity (1620:1 against 220:1 for clonidine) and is thus regarded a complete agonist of the α2 receptor. This may result in more strong sedative effects without the undesirable cardiovascular consequences associated with α1 receptor activation. Dexmedetomidine, unlike gamma-aminobutyric acid agonists and opiates, has a distinct mode of action. It has sedative, anxiolytic, sympatholytic, anti-delirious, and analgesic sparing actions while causing minimal respiratory depression. Currently, intravenous lidocaine is utilized as a peri-operative analgesic in a variety of settings, including the operating room, recovery room, intensive care unit (ICU), and surgical ward.

The purpose of this study was to see how dexmedetomidine and lidocaine affected postoperative pain and analgesic consumption, as well as important functional recovery characteristics like bowel function, mobilization, sleep quality, and other parameters (like PONV and sedation) in patients undergoing cardiac surgery. A standard anesthesia technique will be followed in all the patients included in the study. Well informed written consent will be taken from the patient included in the study. All the records will be confidential, and the patient identity would be known to the chief investigator and would not be released to anybody else. Participation in the study will be voluntary and refusal to participate will not influence care of the participants in the hospital anyway.