Midazolam Use in the Emergency Department 三軍總醫院 Conscious sedation

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.

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

• Drugs that inhibit the metabolism of midazolam

• * Cimetidine

• * Ranitidine

• * Omeprazole

• * Macrolide antibiotics

• * Oral contraceptives

• Drug that enhance the metabolism of midazolam

• * Rifampin