The Effectiveness of Intravenous Dexmedetomidine on Perioperative Hemodynamics, Analgesic Requirement, and Side Effects Profile in Patients Undergoing Laparoscopic Surgery Under General Anesthesia.

Abstract

Background: There is an upward surge in the use of laparoscopic surgeries due to various advantages when compared to open surgeries. Major advantages are, due to small incisions which are cosmetically acceptable and most of them are now daycare procedures. Problem of economic burden and hospital bed occupancy has been overcome with laparoscopic surgeries. All these advantages are not free from disadvantages, as hemodynamic changes such as hypertension; tachycardia and other surgical-related complications are commonly observed intraoperatively. Dexmedetomidine is one of the α₂ agonist drugs which acts at both supraspinal and spinal level and modulate the transmission of nociceptive signals in the central nervous system. The basic effect of dexmedetomidine on the cardiovascular system is to decrease the heart rate and systemic vascular resistance with additional feature of opioid sparing effect. This drug has become an ideal adjuvant during general anesthesia, especially when stress is expected. Hence, the drug was studied in laparoscopic surgeries.

Aims and objectives: (a) To study the effect of dexmedetomidine on hemodynamic parameters during perioperative period in patients undergoing laparoscopic surgery. (b) To study the postoperative sedation score and analgesic requirement. (c) To study the side effect profile of dexmedetomidine.

Settings and design: Randomized double blind controlled trial.

Subjects and methods: After obtaining the Institutional Ethical Clearance, the study was conducted. Forty patients of American Society of Anesthesiologists Class I and II were enrolled in this randomized study. The patients were randomly divided into two groups; group normal saline (NS) and group dexmedetomidine. Patient received either NS or dexmedetomidine in group NS and group dexmedetomidine, respectively, depending upon the allocation. The infusion rate was adjusted according to; loading dose (1 μg/kg) over 10 min and maintenance dose (0.5 μg/kg/h) and perioperative hemodynamics was recorded. Routine general anesthesia was administered in all the patients with conventional technique without deviating from institutional protocols. Postoperatively, Rasmsay sedation score, time taken for request of first analgesic dose, and side effects if any were recorded.

Statistical analysis used: The categorical factors are represented by the number and frequency (%) of cases. The continuous variables are represented by measures of central frequency and standard deviation. The statistical analysis was done by using unpaired t-test and Chi-square. P < 0.05 was considered statistically significant.

Results: Significant hemodynamic changes are observed in NS group during laryngoscopy, intubation, during pneumoperitoneum formation, and during extubation. Hemodynamic stress response in dexmedetomidine group was significantly attenuated. Analgesic requirement during postoperative 24 h were much less in dexmedetomidine group when compared to NS group. No significant side effects were noted except for bradycardia; which was observed in two cases of dexmedetomidine group.

Conclusion: Dexmedetomidine infusion in the dose of 1 μg/kg body weight as bolus over 10 min and 0.5 μg/kg/h intraoperatively as maintenance dose controlled the hemodynamic stress response in patients undergoing laparoscopic surgery. Use of dexmedetomidine extends the pain free period postoperatively and thereby reducing total analgesic requirement. Thus, dexmedetomidine can be utilized as an ideal anesthetic adjuvant during laparoscopic surgeries.