Deliberate hypotensive anesthesia during maxillofacial surgery: A comparative study between dexmedetomidine and sodium nitroprusside

Abstract

Background The aim of the present study was to evaluate the anesthetic properties such as the onset of required hypotension, the quality of the surgical field, the percentage of inhaled anesthesia, intraoperative consumption of fentanyl, time to recovery, and adverse events of dexmedetomidine (DEX) as a hypotensive agent in comparison with sodium nitroprusside (SNP) in maxillofacial surgery. Patients and methods A total of 70 ASA I or II patients, aged 20-60 years, scheduled for maxillofacial surgery were randomly assigned to receive either DEX 1 mg/kg before induction of anesthesia for over 10 min followed by 0.2-0.5 mg/kg/h infusion during maintenance (DEX group; n = 35 patients) or SNP 0.25 mg/kg/min infusion after induction of anesthesia (SNP group; n = 35 patients) to maintain mean arterial blood pressure (MAP) between 50 and 65 mmHg. Hemodynamic variables and end-tidal isoflurane concentration were recorded, quality of surgical field was assessed by the same surgeon who was blinded of the selected hypotensive agent, and intraoperative fentanyl consumption and recovery time were recorded. Results Heart rate was significantly lower (P < 0.05) in DEX group. Both drugs were effective in achieving the desired level of hypotension (MAP: 50-65 mmHg). However, the time needed to reach the target MAP was significantly shorter in the SNP group than in the DEX group. End-tidal isoflurane concentration and intraoperative fentanyl consumption were significantly lower in the DEX group than in the SNP group, and the quality of the surgical field was better in the DEX group compared with the SNP group, but the time for recovery was significantly longer in the DEX group than in the SNP group. Conclusion We concluded that DEX is an effective and safe agent with anesthetic benefits for controlled hypotension, and that compared with SNP DEX offers the advantage of better quality of the surgical field and decreased anesthetic and fentanyl requirements intraoperatively. However, DEX was associated with significantly longer time to reach the target MAP and delayed recovery from anesthesia compared with SNP.