Beta-blocker toxicity
Background
- Coingestion with Calcium Channel Blockers, Tricyclic Antidepressants, and Antipsychotics increases mortality
- Agents with membrane-stabilizing activity are esp lethal
- Prolongs QT > dysrhythmias
- Propranolol
- Sotalol
- Prolongs QT > dysrhythmias
Clinical Features
- Cardiac
- Bradycardia
- Hypotension
- Ventricular dysrhythmias
- CNS
- Mental status change
- Delirium, coma
- Seizure (esp w/ propranolol)
- Mental status change
- Other
- Hypoglycemia (uncommon in adults)
- Bronchospasm (uncommon)
- Hypothermia
Differential Diagnosis
- Calcium-channel blockers
- Unlikely to cause CNS changes
- Hyperglycemia is more common
- Digoxin
- Nausea/vomiting is more common
- Clonidine
- Miosis, somnolence
- Cholinergic agents
- SLUDGE
Diagnostic Evaluation
- ECG
- PR prolongation
- Bradycardia
- QT Prolongation
- Any bradydysrhythmia
- Glucose
- Chemistry
- Creatinine (esp with atenolol)
Management
- Consider activated charcoal if present within 2 hr of ingestion
- Symptomatic bradycardia
- Atropine 0.5-1mg q3-5min up to 0.04mg/kg
- Hypotension
- IV fluids
- Hypoglycemia
- Adult - D50
- Ped - 2.5mL/kg of D10
- If IV fluid and atropine are not sufficient then consider
Glucagon
- Half-life is 20min
- Consider concurrent administration of ondansetron (causes n/v)
- Adult: 5mg IV bolus over one minute [1] [2]
- Ped: 50mcg/kg
- Rebolus if no response after 10min
- Effects persist for 10-15 min
- If effective start infusion at:
- Adult: 2-5mg/hr
- Ped: 70mcg/kg/hr
High dose insulin and glucose
- Augments myocardial contraction[3]
- Regular Insulin 1 Unit/kg IV Bolus accompanied by 0.5g/kg dextrose
- Regular insulin 1Unit/kg/hr Drip
- D50W drip at 0.1-0.2gram/kg/hr
Vasopressors
- Consider to be added as adjunctive therapy to all other therapies. Toxcity can also be manage vasopressors alone [4]
- Epinephrine
- Adult: Start 1 mcg/min and titrate to MAP=60
- Ped: Start 0.1mcg/kg/min
Intralipid Therapy
Draw all labs prior to infusion Support as an antidote comes from animal studies and case reports[5]
- IV 20% Intralipid at 1.5 mL/kg Bolus[6]
- Bolus could be repeated 1-2 times if persistent asystole
- Followed by infusion of 0.25 mL/kg/min for 30-60 minutes or until hemodynamic stability achieved
- if responsive to bolus initiate infusion at 0.25 mL/kg/min for 1hr (e.g. about 600 mL over 30 minutes in a 70kg adult)
- Infusion rate could be increased if the BP declines
Hemodialysis
- Only effective for Nadolol, sotalol, and atenolol
Sedation
- Consider ketamine as post-intubation sedation for hemodynamics
Disposition
- Admit all symptomatic patients
- Admit all sotalol ingestions (long half-life)
- Observe all others for ~ 6hr
See Also
References
- ↑ Kerns W. Management of beta-adrenergic blocker and calcium channel antagonist toxicity. Emerg Med Clin North Am. 2007;25(2):309-331. (Review)
- ↑ Bailey B (2003). Glucagon in beta-blocker and calcium channel blocker overdoses: a systematic review. Journal of toxicology. Clinical toxicology, 41 (5), 595-602 PMID: 14514004
- ↑ High-dose insulin therapy in beta-blocker and calcium channel-blocker poisoning. Engebretsen KM et al. Clin Toxicol 2011;49:277-283
- ↑ Levine M et al. Critical Care Management of Verapamil and Diltiazem Overdose with a Focus on Vasopressors: A 25-Year Experience at a Single Center. Ann Emerg Med 2013 May 1
- ↑ Rothschild L, Bern S, Oswald, et al. Intravenous lipid emulsion in clinical toxicology. Scand J Trauma Resusc Emerg Med. 2010; 18:51.
- ↑ Cave, G. Intravenous Lipid Emulsion as Antidote Beyond Local Anesthetic Toxicity: A Systematic Review. 2009. 16(9)815–824