Comparison between intravenous dexmedetomidine and nitroglycerin infusions for induced hypotension in patients undergoing vertebral fixation surgeries

Abstract

Background In vertebral fixation surgeries, patients lose a lot of blood during the course of surgery. This could result in severe patient complications during and after surgery. This also makes surgical visualization in the bloody field difficult and the duration of surgery more prolonged. With the new anesthetic agents, drugs, and monitoring techniques, this problem has been addressed. Controlled hypotension is defined as a reduction in systolic blood pressure to 80–90 mmHg, a reduction of mean arterial pressure (MAP) to 60–70 mmHg or by 30% of the baseline. Controlled hypotension is a commonly used technique to limit blood loss and improve visualization of the operative field during vertebral fixation surgery. Objective To compare the effects of intravenous infusion of dexmedetomidine (DEX) and nitroglycerin (NTG) on intraoperative hemodynamics, amount of blood loss, speed of recovery from hypotension after cessation of infusion, and postoperative complications. Subjective This study was carried out on 50 adult patients of both sexes, American Society of Anesthesiologists I and II, admitted to Alexandria Main University Hospital, Department of Neurosurgery for elective spinal fixation surgeries (by the same surgical team) under general anesthesia. Results The results of the present study showed that arterial blood pressure in group I DEX at baseline (before induction of anesthesia) was 87.32±6.11 and increases significantly after 10 min from 20 to 80 min. The MAP was significantly decreased in group I at 90 min till the end of follow-up; there was no significant change in MAP from the baseline, while in group II ‘NTG.’ Comparing the two studied groups regarding MAP at different periods of follow-up, it was found that there was no significant difference between the two groups regarding MAP all over the period of follow-up. Conclusion NTG and DEX could induce hypotension, but DEX showed a more favorable hemodynamic profile as regards blood pressure and heart rate. DEX also showed a shorter duration of surgery with less blood loss and less blood transfusion.