Pediatric Digitalis Toxicity Workup

  • Author: Kenneth T Kwon, MD; Chief Editor: Timothy E Corden, MD   more...
 
Updated: Jul 9, 2010
 

Laboratory Studies

Laboratory studies in patients with digitalis toxicity are as follows:

  • Determination of electrolyte, BUN and creatinine, magnesium, and calcium levels
    • Hyperkalemia is the major electrolytic complication in acute massive digitoxin poisoning.
    • Initial potassium levels are better correlated with the prognosis than either ECG changes or the initial serum digoxin level. In one series, all patients with an initial potassium level greater than 5.5 died, whereas 50% of patients with a serum digoxin level of 5-5.5 died.[13]
    • Hypomagnesemia and hypercalcemia worsen digitalis toxicity.
  • Determination of serum digoxin level
    • The recent development of sensitive and accurate radioimmunoassays has improved the diagnosis and management of digitalis toxicity.
    • The therapeutic range is 0.5-2 ng/mL, but significant levels in patients with toxicity and levels in those without toxicity overlap significantly. Digoxin levels cannot be used as the sole indicator of toxicity. Neonates and small infants rarely develop toxic symptoms or ECG abnormalities with serum levels less than 4-5 ng/mL. Children without cardiovascular disease may tolerate levels as high as 10 ng/mL without serious toxicity, but they may have bradyarrhythmias or conduction delays on ECG. The general rule is this: The smaller the infant, the higher the levels may be before toxic effects are observed.
    • Levels determined less than 6-8 hours after an acute ingestion reflect the initial distribution of the drug but not the actual tissue levels, and they are not necessarily predictors of toxicity. The plasma half-life of digoxin is shortened to 10-25 hours with acute massive ingestions, compared with a mean value of 36 hours in nontoxic ingestions.
    • Endogenous digoxinlike immunoreactive substance (DLIS) can cause a false-positive result or an elevated digoxin level. DLIS is observed in neonates and in patients with renal insufficiency, liver disease or hyperbilirubinemia, subarachnoid hemorrhage, congestive heart failure, diabetes mellitus, or acromegaly; it may also be present in those who are pregnant or using spironolactone. In some studies, premature infants had levels as high as 4 ng/mL, with peaks at age 6 days, and positive assay results until they were aged 3 months. Most authors agree that serum digoxin levels due to DLIS are usually less than 2 ng/mL and that the interference is assay dependent and may vary with the lot of the reagent. Some laboratories use ultrafiltration techniques to eliminate the contribution of DLIS.
    • Because most digoxin assays measure total rather than free digoxin levels, serum digoxin levels are no longer useful after Fab fragment administration.
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Procedures

  • Sinus bradycardia and atrioventricular (AV) conduction blocks are the most common ECG changes in the pediatric population.[4]
  • Almost any dysrhythmia may occur, but rapid atrial fibrillation or flutter is rare.
  • Sinus bradycardia and first-degree or second-degree AV blocks are more common in pediatric patients than in adults, whereas ventricular ectopy is more common in adults.[4]
  • Nonparoxysmal atrial tachycardia with a block and bidirectional ventricular tachycardia are particularly characteristic of severe digitalis toxicity.
  • Suspect digitalis toxicity when the evidence suggests increased automaticity and depressed conduction.
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Contributor Information and Disclosures
Author

Kenneth T Kwon, MD  Director of Pediatric Emergency Medicine, Associate Clinical Professor, Department of Emergency Medicine, University of California at Irvine Medical Center, Co-Director, Pediatric Emergency Services, Mission Regional Medical Center/Children's Hospital of Orange County at Mission

Kenneth T Kwon, MD is a member of the following medical societies: American Academy of Emergency Medicine, American Academy of Pediatrics, American College of Emergency Physicians, and Society for Academic Emergency Medicine

Disclosure: Nothing to disclose.

Coauthor(s)

Megan Boysen, MD  Resident Physician, Department of Emergency Medicine, University of California Irvine Medical Center

Megan Boysen, MD, is a member of the following medical societies: American Academy of Emergency Medicine, American College of Emergency Physicians, and Society for Academic Emergency Medicine

Disclosure: Nothing to disclose.

Specialty Editor Board

William T Zempsky, MD  Associate Director, Assistant Professor, Department of Pediatrics, Division of Pediatric Emergency Medicine, University of Connecticut and Connecticut Children's Medical Center

William T Zempsky, MD is a member of the following medical societies: American Academy of Pediatrics

Disclosure: Nothing to disclose.

Mary L Windle, PharmD  Adjunct Associate Professor, University of Nebraska Medical Center College of Pharmacy; Editor-in-Chief, Medscape Drug Reference

Disclosure: Nothing to disclose.

Jeffrey R Tucker, MD  Assistant Professor, Department of Pediatrics, Division of Emergency Medicine, University of Connecticut and Connecticut Children's Medical Center

Disclosure: Merck Salary Employment

Paul D Petry, DO, FACOP, FAAP  Consulting Staff, Freeman Pediatric Care, Freeman Health System

Paul D Petry, DO, FACOP, FAAP is a member of the following medical societies: American Academy of Osteopathy, American Academy of Pediatrics, American College of Osteopathic Pediatricians, and American Osteopathic Association

Disclosure: Nothing to disclose.

Chief Editor

Timothy E Corden, MD  Associate Professor of Pediatrics, Co-Director, Policy Core, Injury Research Center, Medical College of Wisconsin; Associate Director, PICU, Children's Hospital of Wisconsin

Timothy E Corden, MD is a member of the following medical societies: American Academy of Pediatrics, Phi Beta Kappa, Society of Critical Care Medicine, and Wisconsin Medical Society

Disclosure: Nothing to disclose.

References

  1. Gheorghiade M, van Veldhuisen DJ, Colucci WS. Contemporary use of digoxin in the management of cardiovascular disorders. Circulation. 2006;113:2556-2564. [Medline].

  2. Sulafa Ali KM. Collateral effects of antiarrhythmics in pediatric age. Current Pharmaceutical Design. 2008;14:782-787. [Medline].

  3. Woolf AD, Wenger T, Smith TW, Lovejoy FH Jr. The use of digoxin-specific Fab fragments for severe digitalis intoxication in children. N Engl J Med. Jun 25 1992;326(26):1739-44. [Medline].

  4. Thacker D, Sharma J. Digoxin toxicity. Clin Pediatr (Phila). Apr 2007;46(3):276-9. [Medline].

  5. Brophy JM. Rehabilitating digoxin. Eur Heart J. Jan 2006;27(2):127-9. [Medline].

  6. The Internet Drug Reference Top 300 Prescriptions for 2005. RxList. Available at http://www.rxlist.com/script/main/art.asp?articlekey=79509. Accessed March 4, 2010.

  7. Litovitz TL, Klein-Schwartz W, White S, Cobaugh DJ, Youniss J, Drab A, et al. 1999 annual report of the American Association of Poison Control Centers Toxic Exposure Surveillance System. Am J Emerg Med. Sep 2000;18(5):517-74. [Medline].

  8. Bronstein AC, Spyker DA, Cantilena LR Jr, Green JL, Rumack BH, Giffin SL. 2008 Annual Report of the American Association of Poison Control Centers' National Poison Data System (NPDS): 26th Annual Report. Clin Toxicol (Phila). Dec 2009;47(10):911-1084. [Medline].

  9. Hauptman PJ, Kelly RA. Digitalis. Circulation. Mar 9 1999;99(9):1265-70. [Medline].

  10. Koren G, Parker R. Interpretation of excessive serum concentrations of digoxin in children. Am J Cardiol. Apr 15 1985;55(9):1210-4. [Medline].

  11. Aarnoudse AL, Dieleman JP, Stricker BH. Age- and gender-specific incidence of hospitalisation for digoxin intoxication. Drug Saf. 2007;30(5):431-6. [Medline].

  12. Rathore SS, Wang Y, Krumholz HM. Sex-based differences in the effect of digoxin for the treatment of heart failure. N Engl J Med. Oct 31 2002;347(18):1403-11. [Medline].

  13. Bismuth C, Gaultier M, Conso F, Efthymiou ML. Hyperkalemia in acute digitalis poisoning: prognostic significance and therapeutic implications. Clin Toxicol. 1973;6(2):153-62. [Medline].

  14. Smith TW, Butler VP Jr, Haber E, et al. Treatment of life-threatening digitalis intoxication with digoxin- specific Fab antibody fragments: experience in 26 cases. N Engl J Med. Nov 25 1982;307(22):1357-62. [Medline].

  15. Zucker AR, Lacina SJ, DasGupta DS, et al. Fab fragments of digoxin-specific antibodies used to reverse ventricular fibrillation induced by digoxin ingestion in a child. Pediatrics. Sep 1982;70(3):468-71. [Medline].

  16. Kelly RA, Smith TW. Recognition and management of digitalis toxicity. Am J Cardiol. Jun 4 1992;69(18):108G-118G; disc. 118G-119G. [Medline].

  17. Brubacher JR, Ravikumar PR, Bania T, Heller MB, Hoffman RS. Treatment of toad venom poisoning with digoxin-specific Fab fragments. Chest. Nov 1996;110(5):1282-8. [Medline].

  18. Rajapakse S. Management of yellow oleander poisoning. Clin Toxicol (Phila). Mar 2009;47(3):206-12. [Medline].

  19. Antman EM, Wenger TL, Butler VP Jr, et al. Treatment of 150 cases of life-threatening digitalis intoxication with digoxin-specific Fab antibody fragments. Final report of a multicenter study. Circulation. Jun 1990;81(6):1744-52. [Medline].

  20. Beller GA, Smith TW, Abelmann WH, et al. Digitalis intoxication. A prospective clinical study with serum level correlations. N Engl J Med. May 6 1971;284(18):989-97. [Medline].

  21. Ekins BR, Watanabe AS. Acute digoxin poisonings: review of therapy. Am J Hosp Pharm. Mar 1978;35(3):268-77. [Medline].

  22. Fazio A. Fab fragments in the treatment of digoxin overdose: pediatric considerations. South Med J. Dec 1987;80(12):1553-6. [Medline].

  23. Hastreiter AR, van der Horst RL, Chow-Tung E. Digitalis toxicity in infants and children. Pediatr Cardiol. Apr-Jun 1984;5(2):131-48. [Medline].

  24. Husby P, Farstad M, Brock-Utne JG, et al. Immediate control of life-threatening digoxin intoxication in a child by use of digoxin-specific antibody fragments (Fab). Paediatr Anaesth. Jul 2003;13(6):541-9. [Medline].

  25. Kaufman J, Leikin J, Kendzierski D, Polin K. Use of digoxin Fab immune fragments in a seven-day-old infant. Pediatr Emerg Care. Jun 1990;6(2):118-21. [Medline].

  26. Lewander WJ, Gaudreault P, Einhorn A, et al. Acute pediatric digoxin ingestion. A ten-year experience. Am J Dis Child. Aug 1986;140(8):770-3. [Medline].

  27. Ordog GJ, Benaron S, Bhasin V, et al. Serum digoxin levels and mortality in 5,100 patients. Ann Emerg Med. Jan 1987;16(1):32-9. [Medline].

  28. Rutledge J. Digitalis toxicity in infants and plasma digoxin levels. Pediatr Cardiol. 1985;6(1):51-2. [Medline].

  29. Shumaik GM, Wu AW, Ping AC. Oleander poisoning: treatment with digoxin-specific Fab antibody fragments. Ann Emerg Med. Jul 1988;17(7):732-5. [Medline].

 
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