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

Abstract EN

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 fi eld, 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 μg/kg before induction of anesthesia for over 10 min followed by 0.2–0.5 μg/kg/h infusion during maintenance (DEX group; n = 35 patients) or SNP 0.25 μg / kg / min infusion after induction of anesthesia (SNP group; n = 35 patients) to maintain mean arterial blood pressure (MAP) betwee n 50 and 65 mmHg.

Hemodynamic variables and end-tidal isofl urane concentration were recorded, quality of surgical fi eld 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 signifi cantly 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 signifi cantly shorter in the SNP group than in the DEX group.

End-tidal isofl urane concentration and intraoperative fentanyl consumption were signifi cantly lower in the DEX group than in the SNP group, and the quality of the surgical fi eld was better in the DEX group compared with the SNP group, but the time for recovery was signifi cantly longer in the DEX group than in the SNP group.

Conclusion We concluded that DEX is an effective and safe agent with anesthetic benefi ts for controlled hypotension, and that compared with SNP DEX offers the advantage of better quality of the surgical fi eld and decreased anesthetic and fentanyl requirements intraoperatively.

However, DEX was associated with signifi cantly longer time to reach the target MAP and delayed recovery from anesthesia compared with SNP.