Lithium intoxication: manifestations and management

Extracorporeal Treatment for Lithium Poisoning: Systematic Review and Recommendations from the EXTRIP Workgroup

The Extracorporeal Treatments in Poisoning Workgroup was created to provide evidence-based recommendations on the use of extracorporeal treatments in poisoning. Here, the EXTRIP workgroup presents its recommendations for lithium poisoning. After a systematic literature search, clinical and toxicokinetic data were extracted and summarized following a predetermined format. The entire workgroup voted through a two-round modified Delphi method to reach a consensus on voting statements. A RAND/UCLA Appropriateness Method was used to quantify disagreement, and anonymous votes were compiled and discussed in person. A second vote was conducted to determine the final workgroup recommendations. In total, 166 articles met inclusion criteria, which were mostly case reports, yielding a very low quality of evidence for all recommendations. A total of 418 patients were reviewed, 228 of which allowed extraction of patient-level data. The workgroup concluded that lithium is dialyzable (Level of evidence=A) and made the following recommendations: Extracorporeal treatment is recommended in severe lithium poisoning (1D). Extracorporeal treatment is recommended if kidney function is impaired and the [Li(+)] is >4.0 mEq/L, or in the presence of a decreased level of consciousness, seizures, or life-threatening dysrhythmias irrespective of the [Li(+)] (1D). Extracorporeal treatment is suggested if the [Li(+)] is >5.0 mEq/L, significant confusion is present, or the expected time to reduce the [Li(+)] to <1.0 mEq/L is >36 hours (2D). Extracorporeal treatment should be continued until clinical improvement is apparent or [Li(+)] is <1.0 mEq/L (1D). Extracorporeal treatments should be continued for a minimum of 6 hours if the [Li(+)] is not readily measurable (1D). Hemodialysis is the preferred extracorporeal treatment (1D), but continuous RRT is an acceptable alternative (1D). The workgroup supported the use of extracorporeal treatment in severe lithium poisoning. Clinical decisions on when to use extracorporeal treatment should take into account the [Li(+)], kidney function, pattern of lithium toxicity, patient's clinical status, and availability of extracorporeal treatments.

Evaluation of available treatment guidelines for the management of lithium intoxication

Intoxications with lithium carry considerable risk for long-term morbidity and even mortality. Consequently, any patient suspected of lithium intoxication requires immediate and appropriate care. The objectives of this study were to assess the completeness and the applicability of generally available treatment guidelines for the management of patients with a lithium intoxication and, hence, to provide general recommendations for improvement of existing treatment guidelines. Nineteen treatment guidelines originating from 7 different countries were gathered by searching the Internet, online databases, and textbooks and by contacting different poison information centers and university medical centers. A list of items was composed from the retrieved treatment guidelines and a further literature search. Most relevant items were present in the various guidelines. However, in some guidelines, essential information was missing or potentially hazardous information was provided. Clarity, presentation, and applicability of the guidelines, as assessed using parts of the Appraisal of Guidelines Research and Evaluation instrument, were relatively poor. Regular updates of treatment guidelines should be performed to incorporate new essential information. To improve applicability of guidelines, unambiguous key recommendations, alternative treatments, and special care requirements should be provided and authors are recommended to test treatment guidelines using a panel of less experienced caregivers in a hypothetical case scenario.

Hemodialysis followed by continuous hemofiltration for treatment of lithium intoxication in children

Hemodialysis is the usual recommended treatment for severe lithium intoxication; however, rebound of lithium levels may require repeated hemodialysis treatments. We proposed that the addition of continuous hemofiltration after hemodialysis would prevent rebound by providing ongoing clearance of lithium. We report two pediatric patients with lithium intoxication treated by hemodialysis followed by continuous venovenous hemofiltration with dialysis (CVVHD). Both patients were symptomatic at presentation and had initial lithium levels more than three times the usual therapeutic range. Hemodialysis followed by CVVHD resulted in rapid resolution of symptoms, followed by continuous clearance of lithium without requiring repeated hemodialysis sessions. Both patients had return of normal mental status during CVVHD treatment, and neither patient experienced complications of hemodialysis or CVVHD. Total duration of treatment with hemodialysis followed by CVVHD was 34.5 hours for the first patient and 26 hours for the second patient. We conclude that hemodialysis followed by CVVHD is a safe and effective approach to the management of lithium intoxication in children.

Elevated lithium level: a case and brief overview of lithium poisoning

INTRODUCTION

We present the case of a minimally symptomatic patient found to have an elevated lithium level after a blood sample was inadvertently obtained in a green-top tube containing lithium heparin.

CASE REPORT

A 33-year-old woman presented 8 hours after ingesting an unknown quantity of sustained-release lithium carbonate, venlafaxine, clonazepam, and valproic acid. The patient was noted to be slightly drowsy but could be easily aroused. No gastrointestinal symptoms or electrocardiographic changes were observed. The patient was admitted to the intensive care unit for observation. The patient's lithium level 21 hours after ingestion was 5.6 mEq/liter, but she was clinically asymptomatic. The disagreement between symptoms and lithium level led to the discovery that this blood sample had been collected in a lithium heparin tube, thereby falsely elevating the level.

CONCLUSIONS

This case illustrates the wisdom of the old adage to "treat the patient, not the levels." Caution should be used by physicians, nurses, technicians, and other personnel when obtaining blood samples.

In-vivo binding of lithium using the cation exchange resin sodium polystyrene sulfonate

The purpose of this study was to determine if the exchange resin sodium polystyrene sulfonate increases the clearance of lithium in a healthy volunteer. A single healthy volunteer received 900 mg lithium for each of three study phases. A sodium polystyrene sulfonate dose of either 0, 20, or 40 grams was administered one half hour after each lithium dose to assess the effect on lithium clearance. Multiple blood samples were obtained for serum lithium concentrations over a 36- to 48-hour time period. Pharmacokinetic parameter estimates were calculated and compared. Sodium polystyrene sulfonate was found to increase the clearance of lithium in a single volunteer. Sodium polystyrene sulfonate may be useful in the treatment of lithium intoxication by increasing the clearance of lithium.

In vitro binding of lithium using the cation exchange resin sodium polystyrene sulfonate

Sodium polystyrene sulfonate, a cation exchange resin, should be useful in the treatment of lithium overdosage. This in vitro study was conducted to assess the ability of sodium polystyrene sulfonate to bind lithium, effects of pH on binding, binding efficacy in comparison to charcoal, and affinity for lithium versus potassium. Stock solutions of lithium were added to fixed amounts of sodium polystyrene sulfonate and charcoal. Lithium and potassium concentrations in supernatant were measured by flame photometry. Increasing concentrations of sodium polystyrene sulfonate bound more lithium. Changes in pH had little effect on lithium binding. Lithium is bound to sodium polystyrene sulfonate more readily than to charcoal. Potassium is preferentially bound to sodium polystyrene sulfonate over lithium. Sodium polystyrene sulfonate may provide a useful therapeutic modality in the treatment of lithium overdosage.

Objectives to direct the training of emergency medicine residents of off-service rotations: toxicology

Toxicology is an integral component in the training of the emergency physician. This is the 27th article in a continuing series of goals and objectives. The article provides basic guidelines for the organization of the toxicology elective with specific goals and objectives and a list of the contents of the toxicology briefcase. This information should aid in providing a comprehensive experience in toxicology for emergency medicine residents.

Use of sodium polystyrene sulfonate in a lithium overdose

A 23-year-old woman with an acute-on-chronic lithium overdose received multiple oral doses of sodium polystyrene sulfonate totaling 150 g over a 24-hour period. During the 33 hours after the institution of therapy, the serum lithium level decreased from 4.20 to 0.68 mEq/L. The calculated serum lithium elimination half-life of 12 hours is significantly shorter than that previously noted in other similar overdoses, and the patient suffered no adverse effects of therapy. Multiple-dose sodium polystyrene sulfonate may be useful in lowering the serum lithium level of select patients with acute lithium overdoses but is not a substitute for hemodialysis in severely ill patients.