Midazolam Use in the Emergency Department 三軍總醫院

Conscious sedation Minimally depressed level of consciousness Independently and continuously maintain an airway and adequate cardiorespiratory function. Respond to tactile stimulation and/or verbal command. Tolerate the unpleasant procedures.

Conscious sedation (Procedural sedation) in the ED Alleviate anxiety Provide amnesia * Pain : not adequately addressed.

Clinical indications for sedation in the ED Orthopedic reduction. Cardioversion. Wound debridement. Pediatric laceration repair. Lumbar puncture. Abscess incision and drainage. Chest tube insertion. Burn care. CT scans and other diagnostic procedures in children. Peritoneal lavage. Removal of vaginal or rectal foreign body.

Drugs for conscious sedation Benzodiazepines: Midazolam Opioids: Fentanyl, Meperidine. Hypnotics agents: Barbiturates, Propofol, Ketamine.

Midazolam Rapid onset. (i.v. 1-3 min, i.m. 5 min) Shorter duration. No injection pain. Existence of antagonist- Flumazenil

Pharmacology of midazolam Anxiolytic Muscle relaxant Anticonvulsant Sedative Hypnotic Amnesic

Side effects of midazolam Respiratory depression * Short-lived. * Respond to verbal stimulation and oxygen alone. * Injection rate-related. (slowly injection) Rare: * Hiccups. * Cough. * Nausea/Vomiting.

Antagonist (Flumazenil, Anexate) Reverse hypnotic-sedative effect. Reverse respiratory depression? (dose) Overdose: CNS symptoms occurred. Suggest: Given by incremental dose (0.2 mg) Short duration of action.

Other use of midazolam in the ED Anticonvulsant: i.v.: 0.15-0.2 mg/kg  0.75mg/kg/min infusion. i.m.: 5-15 mg. Rapid sequence induction (intubation) Combined with opioids (fentanyl, meperidine): Respiratory depression, hypoxemia, prolonged duration.

Equipment for conscious sedation monitoring Oxygen and mask. Pulse oximeter. ECG monitor. Suction. Orotracheal tube. Laryngoscope. Ambu bag.

Summary Midazolam: Safe for sedation in ED “Titration”: the principle of administration of midazolam and flumazenil.

NPO for conscious sedation No evidence-based guideline for optimal fasting duration prior to sedation in the ED. ASA recommend: 6 hr for solids. 2 hr for liquids. Balance between urgency and associated risk.

Drug interaction * Ranitidine * Omeprazole * Macrolide antibiotics Drugs that inhibit the metabolism of midazolam * Cimetidine * Ranitidine * Omeprazole * Macrolide antibiotics * Oral contraceptives Drug that enhance the metabolism of midazolam * Rifampin