Comparative study of the effects of dexmedetomidin and midazolam on respiration and hemodynamics used during facial surgery

Abstract

Background: The interventions in facial surgery are specific, short, and very painful. The place of the surgery can compromise a patient’s airway. Surgeons prefer to give local infiltrative anesthetics, but during the surgery patients are nervous, stressed, restless and ask for drugs to be asleep/ask for sleep medication. Dexmedetomidine (Dex) as an agent for analgosedation can meet the needs of those patients. Dex is an alpha 2 adrenergic agonist with sedative, anxiolytic and analgesic properties; Midazolam (Mdz) is the most often used drug for classical sedation, a drug from the benzodiazepine group. Aims: The aim of this study was to compare the effects on circulation and respiration of two drugs, dexmedetomidine (Dex) and midazolam (Mdz). Blood pressure, Puls/min, respiration/min, SpO2, incidents of bradycardia, hypotension, hypoxia, and other complications were measured and compared in the two groups. Material and methods: Sixty patients for facial surgery who met the inclusion criteria were enrolled in the study. Due to a computed choice/option, patients were allocated to be sedated with Dex (n=30) or Mdz (n=30). After signing a written consent for inclusion in the study, prior to surgery all patients got two venous lines and were preoperatively monitored. Patients of Dex group received a bolus of Dex 1 mcg/kg given in 10 minutes. The sedation was maintained with an additional dose of Dex of 0.5 mcg/kg/h, which was disconnected at the end of the surgery. Patients of Mdz group received a bolus of Mdz of 0.03 mg/kg followed by an infusion of Mdz of 0.2 mg/kg/h, which was disconnected at the end of the surgery. The vital signs (ECG, BP, P/min, Res/min, SpO2, ETCO2, BIS) were monitored and noted on 5-minute intervals. Results: The obtained results were statistically analyzed. Demographic data showed homogeneity between the groups. All patients prior to procedural sedation got local infiltrative anesthesia with lidocaine 1%. There was insignificant difference in duration of the surgical procedure between the groups (p>0.05) and prolonged induction to sedation in the Dex group (10.6±2.7* vs. 1.9±1.7); p=0.01. Blood pressure of patients in the Dex group showed a significant decrease and was lower than that in the Mdz group (p=0.05). Also, P/min in the Dex group was lower than in the Mdz group (74.45±14.84*vs. 84.13±12.88) p=0.03. The results from the monitored respiration showed a statistically significant decrease in respiration/minute in the Mdz group (p=0.05) and decrease in SpO2, (p=0.02). Conclusion: We found that Dex, used as an agent for analgosedation for facial surgery, is a safe drug providing hypotension and mild bradycardia which are easy for treatment with vasoconstrictors and a sedation without effects on respiration. Patients in the Dex group were more comfortable, and their satisfaction was higher than in patients in the Mdz group.