Brief report
Profound alkalemia during treatment of tricyclic antidepressant overdose: A potential Hazard of combined hyperventilation and intravenous bicarbonate

https://doi.org/10.1016/0735-6757(92)90183-XGet rights and content

Abstract

Two patients with cardiovascular and neurologic toxicity from intentional tricyclic antidepressant overdose received bicarbonate infusions in association with hyperventilation for alkalinization. Both patients developed profound alkalemia. One patient died, and the other patient's alkalemia resolved prior to her death. Bicarbonate infusions have become the standard of care for symptomatic tricyclic antidepressant toxicity. Severe alkalemia (pH greater than 7.60) in other settings has been reported to correlate with higher rates of mortality. Careful monitoring of the pH is imperative when bicarbonate therapy is used. It is probably prudent to keep the pH level in the range 7.45 to 7.60. Capnography may also be useful in monitoring patients during alkalinization.

References (34)

  • J Strom et al.

    Acute self-poisoning with tricyclic antidepressants in 295 consecutive patients treated in an ICU

    Acta Anesthesiol Scand

    (1984)
  • LE Hollister

    Tricyclic antidepressants

    N Engl J Med

    (1978)
    LE Hollister

    Tricyclic antidepressants

    N Engl J Med

    (1978)
  • DW Ellison et al.

    Clinical features and consequences of seizures due to cyclic antidepressant overdose

    Am J Emerg Med

    (1989)
  • JR Hedges et al.

    Bicarbonate therapy for the cardiovascular toxicity of amitriptylline in an animal model

    J Emerg Med

    (1985)
  • JR Hoffman et al.

    Bicarbonate therapy for dysrhythmia and hypotension in tricyclic antidepressant overdose

    West J Med

    (1981)
  • PR Pentel et al.

    Effect of hypertonic sodium bicarbonate on encainide overdose

    Am J Cardiol

    (1986)
  • DM Walsh

    Cyclic antidepressant overdose in children: A proposed treatment protocol

    Pediatr Emerg Care

    (1986)
  • Cited by (31)

    • Reversal of severe tricyclic antidepressant-induced cardiotoxicity with intravenous hypertonic saline solution

      2003, Annals of Emergency Medicine
      Citation Excerpt :

      Serum alkalinization by means of intravenous bolus therapy with sodium bicarbonate, as well as hyperventilation, resulted in pH values in the target range of 7.5 to 7.55. Further therapy with sodium bicarbonate was avoided in our patient because of concerns over potentially harmful effects of excessive alkalization.5 Because of continued deterioration in the form of worsening hypotension, ectopy, and QRS interval widening despite maximal standard therapy, hypertonic saline solution was administered to optimize extracellular sodium concentrations without the additional pH increase that would accompany sodium bicarbonate.

    • Acute lung failure induced by tricyclic antidepressants

      1997, Toxicology and Applied Pharmacology
    • Interfacility Critical Care Transport of an Elderly Patient With Confirmed Tricyclic Antidepressant Toxicity and Hemodynamic Collapse

      2019, Air Medical Journal
      Citation Excerpt :

      Current recommendations related to respiratory therapies include compliance with ARDSnet lung protective guidelines such as maintenance of low tidal volumes, physiologic respiratory rates, and the application of positive end-expiratory pressure to avoid lung derecruitment and atelectasis.1,2 A combined strategy of induced respiratory alkalosis and serum alkalization has been linked to profound metabolic alkalosis and increased mortality.7 Case studies and review articles highlight other potential therapies.

    View all citing articles on Scopus
    View full text