Approach Considerations
Perform a fingerstick glucose test, because beta-blockers may be associated with hypoglycemia, especially in patients with diabetes and in children. Also measure serum electrolytes, because hypokalemia may contribute to cardiac arrhythmias. Co-ingestions or concomitant medical conditions may alter other serum electrolytes, so these should be monitored closely, especially in patients with seizures or altered mental status. Measure cardiac enzymes to rule out myocardial infarction in any hemodynamically unstable patient.
Blood gas (arterial or venous) analysis may be helpful for managing metabolic acidosis from seizures or cardiogenic shock or rare cases of severe bronchospasm, respiratory acidosis, or hypoxia. Acidosis from poor cardiac perfusion may be manifested by low serum bicarbonate.
In a severe overdose that impairs myocardial contraction, chest radiographs may show evidence of pulmonary edema.
Electrocardiographic (ECG) results after beta-blocker overdose may include the following:
- Progressively worsening sinus bradycardia
- Increased PR intervals
- Loss of atrial activity
- Atrioventricular junctional rhythm
- Widening of the QRS complex
- Atrioventricular block
- Idioventricular rhythm
- Asystole
A prolonged QT interval has been observed after sotalol overdose. Ventricular fibrillation and ventricular tachycardia are uncommon because of the antidysrhythmic effects of most beta-blockers, with the exception of sotalol.
Bronstein AC, Spyker DA, Cantilena LR Jr, Green JL, Rumack BH, Heard SE. 2007 Annual Report of the American Association of Poison Control Centers' National Poison Data System (NPDS): 25th Annual Report. Clin Toxicol (Phila). Dec 2008;46(10):927-1057. [Medline].
Watson WA, Litovitz TL, Rodgers GC Jr, et al. 2004 Annual report of the American Association of Poison Control Centers Toxic Exposure Surveillance System. Am J Emerg Med. Sep 2005;23(5):589-666. [Medline].
Wax PM, Erdman AR, Chyka PA, et al. beta-blocker ingestion: an evidence-based consensus guideline for out-of-hospital management. Clin Toxicol (Phila). 2005;43(3):131-46. [Medline].
Position statement and practice guidelines on the use of multi-dose activated charcoal in the treatment of acute poisoning. American Academy of Clinical Toxicology; European Association of Poisons Centres and Clinical Toxicologists. J Toxicol Clin Toxicol. 1999;37(6):731-51.
Engebretsen KM, Kaczmarek KM, Morgan J, Holger JS. High-dose insulin therapy in beta-blocker and calcium channel-blocker poisoning. Clin Toxicol (Phila). Apr 2011;49(4):277-83. [Medline].
Weinberg GL, VadeBoncouer T, Ramaraju GA, Garcia-Amaro MF, Cwik MJ. Pretreatment or resuscitation with a lipid infusion shifts the dose-response to bupivacaine-induced asystole in rats. Anesthesiology. Apr 1998;88(4):1071-5. [Medline].
Weinberg G, Ripper R, Feinstein DL, Hoffman W. Lipid emulsion infusion rescues dogs from bupivacaine-induced cardiac toxicity. Reg Anesth Pain Med. May-Jun 2003;28(3):198-202. [Medline].
Rosenblatt MA, Abel M, Fischer GW, Itzkovich CJ, Eisenkraft JB. Successful use of a 20% lipid emulsion to resuscitate a patient after a presumed bupivacaine-related cardiac arrest. Anesthesiology. Jul 2006;105(1):217-8. [Medline].
Litz RJ, Popp M, Stehr SN, Koch T. Successful resuscitation of a patient with ropivacaine-induced asystole after axillary plexus block using lipid infusion. Anaesthesia. Aug 2006;61(8):800-1. [Medline].
Foxall G, McCahon R, Lamb J, Hardman JG, Bedforth NM. Levobupivacaine-induced seizures and cardiovascular collapse treated with Intralipid. Anaesthesia. May 2007;62(5):516-8. [Medline].
Cave G, Harvey MG, Castle CD. The role of fat emulsion therapy in a rodent model of propranolol toxicity: a preliminary study. J Med Toxicol. Mar 2006;2(1):4-7. [Medline].
Bania TC, Chu J, Perez E, Su M, Hahn IH. Hemodynamic effects of intravenous fat emulsion in an animal model of severe verapamil toxicity resuscitated with atropine, calcium, and saline. Acad Emerg Med. Feb 2007;14(2):105-11. [Medline].
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