Just how serious is acute lithium overdose and how should it be managed?

Just how serious is acute lithium overdose and how should it be managed?

The Journai of Emergency Medicine, Voi 11, pp 759-764, Printed 1993 m the USA Copyrignt 0 ‘993 ?eryairwn ?ress -la. a treatment for acute li...

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The Journai

of Emergency

Medicine,

Voi 11, pp 759-764,

Printed

1993

m the USA

Copyrignt

0 ‘993 ?eryairwn

?ress -la.

a treatment for acute lithium overdose. .Arm Gmerp Med. 1991; 20:536-9. 3. Tenenbein M. Whole bowel irrigation as a gastrointestinal decontamination procedure after acute drug overdose, Arch Intern Med 198?;147:905-7. 4. Tenenbein M. Whole-bowel irrigation in iron poisoning. J Pediatr. 1987;111:142. 5. Tenenbein M, Cohen S, Sitar II. Wrote bawel irrigation as a gastrointestinal decontamination procedure after acute poisoning. Med Toxicol. 1988;3:77-84.

The case reports and review of “‘Overdose with sustained-release lithium preparations,” by Bosse and Arnold (1) in the November-December 1992 issue of the Journal of Emergency Medicine accurately stated that charcoal is ineffective as an initial measure in the management of acute overdose with sustained-release lithium, unless there are coingestants, because charcoal does not effectively bind lithium. However, they mention only gastric emptying as an alternative method of gastrointestinal decontamination. In May 1991, I published a study (2) showing that whole-bowel irrigation (WBI) begun 1 hour after ingestion of sustained-release lithium and administered at a rate of 2 liters per hour for 5 hours decreased absorption of lithium by 67% f 11% compared to controls, and decreased the time to maximal serum concentration of lithium from 4.4 to 2.8 hours. Based on the results of this study and other reI (3-5) as a gastrointestinal decontaminant in overdose, the Hennepin Poison Center and we in the emergency department use WBI routinely in the management of acute overdose with sustainedrelease lithium. We also use WBI in the management of overdose with iron, another ion that is not absorbed by charcoal.

(2) have stimulated the writing of thi dress two specific issues - 8astr~i~tes nation and prognosis for acute lit e were surprised that a

quent studies of modified rele (one being lithium [4]), decrease 67% (4) and 73% (5) were showy were published well before the s nal manuscript.

Stephen W. Smith, MD epartment of Emergency Medicine IIennepin County Medical Center Emergency Medical Services Minneapolis, Minnesota

of these studies is&on of the fi-

vention (2). Control have been recently p

FERENCES I. Bosse GM, Arnold TC. Overdose with sustained-release lithium preparations. J Emerg Med. 1992;10:719-21. 2. Smith SW, king LJ, Halstenson CE. Whole-bowel irrigation as

15’J70(7) by AUC criteria in c Kayexalate@ would not seem enormous amounts required in In the above studies (6,7

This article was published without the authors’ review as proofs were not received at press time.

uidelines for Letters-Letters will appear at the discretion of the editor as space permits anal .UJJ be subjected to some editing. Three typewritten, double spaced copies should be submitted. ____I. 759

760

The Journal

600 (6) and approximately 1300 mg (7). The volume of Kayexalate@ required for Bosse and Arnold’s patients, who ingested 4500 and 9000 mg of lithium, would be intolerable. Of additional concern would be the potential for hypernatremia, hypokalemia, hypocalcemia, and hypomagnesemia if massive amounts of this cation exchange resin were used. The benign course of these two patients (1) mirrors previously published experience of an amazing lack of significant morbidity and mortality in acute lithium overdose despite the title of the editorial. Bosse and Arnold appropriately indicate that significant morbidity and mortality rests chiefly with chronic lithium toxicity. They cite 4 deaths from the 1989 annual AAPCC report (8). Actually, we found 5. Cases 376 and 377 were chronic toxicities while cases 395 and 539 were polypharmacy overdose pa; tients with therapeutic serum lithium concentrations. Case 373 was an imipramine and lithium overdose with a toxic serum lithium concentration (6.2 mEq/ L). However, it is important to note that values as high as 8.2 mEq/L have been tolerated with negligible symptoms (9). Indeed, the literature is remarkable for the benign nature of acute lithium overdose (9-l 1). While we do not wish to promote a cavalier attitude toward this overdose, knowledge of the facts is the foundation for a rational approach to patient management.

8. 9. 10. 11.

of Emergency

Medicine

Lithium absorption prevented by sodium polystyrene in volunteers. Ann Emerg Med. 1992;21:1308-11. Litovitz TL, Schmitz BF, Bailey KM. 1989 Annual report of the American Association of Poison Control Centers national data collection system. Am J Emerg MEd. 1990;8:394-442. Horowitz LC, Fisher GU. Acute lithium toxicity. New Engl J Med. 1969;281:1369. Gadallah MF, Feinstein EI, Massry SG. Lithium intoxication: clinical course and therapeutic considerations. Miner Electrolyte Metab. 1988;14:146-9. Dyson EH, Simpson D, Prescott LF, Proudfoot AT. Selfpoisoning and therapeutic intoxication with lithium. Human Toxicol. 1987:6:325-g.

q Response From the Authors We thank Dr. Smith and Drs. Palatnick and Tenenbein for their responses to our article and agree with the point they make regarding the use of whole bowel irrigation (WBI). In recent years, the Kentucky Regional Poison Center has been using WBI in selected ingestions of toxic agents not well adsorbed by activated charcoal (for example, iron and lithium), and of sustained-release preparations. Through informal discussions with colleagues at other centers, it appears that such use of WBI is commonplace. Further studies will define its role in the therapy of toxic ingestions.

Department Wes Palatnick, MD, FRCPC"~ Milton Tenenbein, MD, FRCPC',~,~ Departments of ‘Emergency Medicine, ‘Pediatrics, and 3Pharmacology University of Manitoba and the 4Manitoba Poison Control Centre

George M. Bosse, MD of Emergency Medicine University of Louisville Louisville, Kentucky

Thomas C. Arnold, MD Department of Emergency Medicine Louisiana State University Medical Center-Shreveport Shreveport, Louisiana

REFERENCES 1. Bosse GM, Arnold TC. Overdose with sustained-release lithium preparations. J Emerg Med. 1992;10:719-21. 2. Kulig K. All lithium overdoses deserve respect. J Emerg Med. 1992;10:757-8. 3. Tenenbein M, Cohen S, Sitar DS. Whole bowel irrigation as a decontamination procedure after acute drug overdose. Arch Intern Med. 1987;147:905-7. 4. Smith SW, Ling LJ, Halstenson CE. Whole-bowel irrigation as a treatment for acute lithium overdose. Ann Emerg Med. 1991;20:536-9. 5. Kirshenbaum LA, Mathews SC, Sitar DS, Tenenbein M. Wholebowel irrigation versus activated charcoal in sorbitol for the ingestion of modified-release pharmaceuticals. Clin Pharmaco1 Ther. 1989;46:264-71. 6. Belanger DR, Tierney MG, Dickinson G. Effect of sodium polystyrene sulfonate on lithium bioavailability. Ann Emer Med. 1992;21:1312-5. 7. Tomaszewski C, Musso C, Pearson JR, Kulig K, Marx JA.

q To the Editor: Smith (1) recently alerted readers of the Journal of Emergency Medicine to the problem of atlantooccipital dislocation. His case report and discussion was succinct and timely. I agree with him that we are going to be seeing more and more of these types of patients in the emergency department setting. I wish to call attention, though, to one minor (or major) verbal miscue. He describes patients with atlanto-occipital dislocation as “victims of high speed accidents . . . ” who “frequently sustain serious injuries involving multiple organ systems.” As Smith