Life-threatening Torsades de Pointes resulting from "natural" cancer treatment.

INTRODUCTION: Nonradioactive cesium chloride (CsCl) is used by some alternative medicine advocates as a treatment for cancer. The therapy was proven to be neither safe nor effective. Chronic use of CsCl has resulted in cases with severe cardiotoxicity. CASE REPORT: A 65-year-old lady presented to our hospital's accident and emergency department with recurrent syncope attacks. Electrocardiogram monitoring showed QT prolongation and transient Torsades de Pointes (TDP) ventricular tachycardia. She was taking anticancer naturopathic drugs for 6 weeks before admission. One of her naturopathic drugs was subsequently confirmed containing 89% CsCl by weight. Besides conventional treatment of QT prolongation and TDP, the patient was given a 4-week course of oral Prussian blue to enhance gastrointestinal elimination of cesium. The serum half-life of cesium was reduced from 61.7 to 29.4 days after the use of Prussian blue. QT prolongation was normalized in 27 days. DISCUSSION: To our knowledge, this is the first published case of nonradioactive cesium poisoning treated with Prussian blue. A transient rise in serum cesium level was observed during Prussian blue therapy. Possible explanations for this observation include poor drug compliance during outpatient treatment and redistribution of cesium from body stores. CONCLUSION: Nonradioactive CsCl poisoning can result in severe cardiotoxicity with QT prolongation and TDP ventricular tachycardia. The key points in the management of nonradioactive cesium poisoning include cessation of cesium exposure, vigorous electrolytes replacement, and oral Prussian blue therapy.

Electrospray ionisation mass spectrometry: principles and clinical applications.

This mini-review provides a general understanding of electrospray ionisation mass spectrometry (ESI-MS) which has become an increasingly important technique in the clinical laboratory for structural study or quantitative measurement of metabolites in a complex biological sample. The first part of the review explains the electrospray ionisation process, design of mass spectrometers with separation capability, characteristics of the mass spectrum, and practical considerations in quantitative analysis. The second part then focuses on some clinical applications. The capability of ESI-tandem-MS in measuring bio-molecules sharing similar molecular structures makes it particularly useful in screening for inborn errors of amino acid, fatty acid, purine, pyrimidine metabolism and diagnosis of galactosaemia and peroxisomal disorders. Electrospray ionisation is also efficient in generating cluster ions for structural elucidation of macromolecules. This has fostered a new and improved approach (vs electrophoresis) for identification and quantification of haemoglobin variants. With the understanding of glycohaemoglobin structure, an IFCC reference method for glycohaemoglobin assay has been established using ESI-MS. It represents a significant advancement for the standardisation of HbA1c in diabetic monitoring. With its other applications such as in therapeutic drug monitoring, ESI-MS will continue to exert an important influence in the future development and organisation of the clinical laboratory service.