To the Editor:
The article by Seger et al. entitled “Variability of recommendations for serum alkalinization in tricyclic antidepressant overdose: A survey of U.S. poison center medical directors” Citation1 raises an interesting dilemma. Although the authors present persuasive evidence that there are a lack of outcomes data regarding the use of sodium bicarbonate therapy in tricyclic antidepressant (TCA) poisoned patients, their arguments are complicated by their call for a consensus practice guideline to direct care. The question arises whether it is better to create something imperfect based on available evidence, or to spend the time acquiring information to formulate an evidence‐based practice recommendation.
The wide variability in practice recommendations illustrates how little research exists regarding the management of TCA poisoning. Based on the limited data available, there has been a general approach to treatment of this poisoning since 1986 Citation2Citation7. Although as shown by Seger et al., application of sodium bicarbonate therapy is highly variable.
After convincingly citing the lack of evidence, the authors make a call for consensus guidelines. However, they themselves make the most eloquent argument against such consensus. In their conclusion they state, “There are no well‐designed clinical studies that delineate the indications or methods for alkalinization. Recommendations are based on anecdotal clinical experience, tradition, animal and in vitro research, and observational studies” Citation1. In order to make recommendations for therapy in any condition, there should be strong evidence to support such practices. In “Consensus doesn't equal correctness” Citation3, Hoffman reiterates that an “evidence‐based approach is only as good as the evidence.” Rather than continuing to try to create position statements and consensus guidelines that will lack conviction, the financial support and time of astute clinicians would better be utilized through participation in rigorous scientific endeavors designed to answer such questions as “when is it best to stop bicarbonate therapy.”
In 2000, Juurlink and McGuigan published “Gastrointestinal Decontamination for Enteric‐Coated Aspirin Overdose: What to Do Depends on Who You Ask” Citation4. Using a hypothetical case of a potentially severe salicylate overdose, they polled the North American poison control centers as well as the physicians who drafted the AACT/EAPCCT position statements on gastrointestinal decontamination and found 36 different courses of action. This observation has resonance in the current study. In tricyclic antidepressant poisoning, experimental evidence convincingly demonstrates the utility of hypertonic sodium bicarbonate Citation5&6. Why then oppose the creation of position statements for the management of this overdose? Every clinical situation is different, and the creation of guidelines for practice based on limited evidence eliminates the variability of response that is necessary to react to changes in a particular individual's presentation and the healthcare setting in which care is rendered. Additionally, the creation of practice guidelines has implicit interpretation as a standard of care in both clinical and medico‐legal arenas. When the experts can't agree, as demonstrated by both Juurlink and Seger, any consensus will be a compromise. Care, even if based on consensus, should never be compromised.
In conclusion, without the evidence‐based data to support an evidence‐based consensus, attempts to standardize therapy are difficult at best. Therapy guided by experience, intuition, and limited experimental data should not be abandoned, lest medicine be returned to a less enlightened era. In order to ensure that we as a medical subspecialty continue to provide the best care to our patients, we should continue to treat each case uniquely. The only position that we should agree on is that more information is needed and that together we can find the evidence to form a consensus. Perhaps with continued progress we can shift our focus from doing what we agree is right to practicing what we know is right.
Howard A. Greller, M.D.
Fellow—Medical Toxicology
New York City Poison Control Center
455 First Avenue—Room 123
New York, NY 10016, USA
References
- Seger D L, Hantsch C, Zavoral T, Wrenn K. Variability of recommendations for serum alkalinization in tricyclic antidepressant overdose: a survey of U.S. Poison Center Medical Directors. J Toxicol Clin Toxicol 2003; 41(4)331–338, [PUBMED], [INFOTRIEVE]
- Sasyniuk B I, Jhamandas V, Valois M. Experimental amitriptyline intoxication: treatment of cardiac toxicity with sodium bicarbonate. Ann Emerg Med 1986; 15(9)1052–1059, [PUBMED], [INFOTRIEVE]
- Hoffman R S. Does consensus equal correctness?. J Toxicol Clin Toxicol 2000; 38(7)689–690, [PUBMED], [INFOTRIEVE], [CROSSREF]
- Juurlink D N, McGuigan M A. Gastrointestinal decontamination for enteric‐coated aspirin overdose: what to do depends on who you ask. J Toxicol Clin Toxicol 2000; 38(5)465–470, [PUBMED], [INFOTRIEVE], [CROSSREF]
- Sasyniuk B I, Jhamandas V. Mechanism of reversal of toxic effects of amitriptyline on cardiac Purkinje fibers by sodium bicarbonate. J Pharmacol Exp Ther 1984; 231(2)387–394, [PUBMED], [INFOTRIEVE]
- Hedges J R, Baker P B, Tasset J J, Otten E J, Dalsey W C, Syverud S A. Bicarbonate therapy for the cardiovascular toxicity of amitriptyline in an animal model. J Emerg Med 1985; 3(4)253–260, [PUBMED], [INFOTRIEVE], [CROSSREF]
- Boehnert M T, Lovejoy F H. Value of the QRS duration versus the serum drug level in predicting seizures and ventricular arrhythmias after an acute overdose of tricyclic antidepressants. New Engl J Med 1985; 313(8)474–479, [PUBMED], [INFOTRIEVE]