Effect of Midazolam Premedication on Mask Ventilation Difficulty

Effect of Midazolam Premedication on Mask Ventilation Difficulty During General Anesthesia Induction in Children: A Randomized Clinical Study

Mask ventilation has great importance during anesthesia induction because it is the only way to oxygenate patients who have lost consciousness and spontaneous breathing. Adequate muscle relaxation and depth of anesthesia may assist with mask ventilation. It is known that premedication to reduce anxiety has a relaxing effect on airway muscles. Midazolam is frequently used in premedication because it has a rapid onset of action and does not cause hemodynamic changes. In addition, midazolam may relax the airway by acting directly on the airway smooth muscle and thus facilitate mask ventilation during anesthesia induction. In this study, we will conduct a randomized controlled trial to evaluate the effect of midazolam premedication on facilitating mask ventilation in children.

American Society of Anesthesiologists (ASA) class I and II patients aged 2-10 years who are scheduled for any elective surgery under general anesthesia will be enrolled. Patients in midazolam group will be treated with midazolam premedication (3 cc mixture of 0.1 mg/kg midazolam and normal saline; maximum midazolam dose, 3 mg) intravenously at waiting area 3 minutes before transportation to an operating room, while 3 cc normal saline will be administered to control group patients. Difficulty of mask ventilation during induction of general anesthesia will be evaluated with the Han Mask Scale. Muscle relaxants will be given for intubation after evaluation. The anxiety and sedation level of patients will be estimated one minute before the intervention and one minute before anesthetic induction in an operating room.

Interventıon descriptıon Patients enrolled in this study are randomly allocated to midazolam group or control group. Total 120 patients will be enrolled. Each group consists of 60 patients. Patients of midazolam group will be treated with midazolam premedication (3 cc mixture of 0.1 mg/kg midazolam and normal saline; maximum midazolam dose, 3 mg) intravenously at waiting area 3 minutes before transportation to an operating room. Control group patients are treated with 3 cc normal saline at waiting area 3 minutes before transportation to an operating room. In anesthesia induction, propofol 2 mg/kg will be given. Before the patients were given muscle relaxants, the patients were evaluated with the Han's mask scale.

Inclusion Criteria:

• age 2< and <10 children
• American Society of Anesthesiologists (ASA) class I and II
• Children who are scheduled for any elective surgery under general anesthesia

Exclusion Criteria:

• age <2 or >10 years;
• obesity (body mass index, ≥35 kg/m2);
• craniofacial anomaly;
• allergic reaction to midazolam;
• presence of muscle weakness or dyspnea.
• children posted for any emergency procedure,
• above ASA class II
• children with abnormal airway anatomy,
• children with active respiratory infection in the last 3 weeks,
• children with a past history of chronic respiratory disorder,
• children who are being treated with sedative or anticonvulsive agents