Management of sodium-channel blocker poisoning: the role of hypertonic sodium salts

Sodium-channel blockers act by slowing sodium influx into myocytes through voltage gated channels. Many substances have sodium-channel blocking properties and many others show this effect when taken in overdose. Sodium-channel blocker poisoning, associated with a high death rate, is characterized by a variety of clinical presentation, depending on the pharmaceutical agent involved. Sodium bicarbonate or lactate, increasing serum pH and extracellular concentration of the ion, displace the drug from its receptor sites and can be used for the treatment of cardiac toxicity in the setting of sodium-channel blocker poisoning. In spite of this theoretical assumption, the role played by hypertonic sodium salts is not well elucidated and conflicting results have been reported. Authors review the pathophysiologic mechanisms of sodium-channel blocker poisoning and the evidences in literature concerning the efficacy of hypertonic sodium salts in the treatment of the related toxicity.

Hypokalemic rhabdomyolysis in a patient with a laparoscopic adjustable gastric banding

Rhabdomyolysis is an acute skeletal muscle disorder characterized by altered integrity of the cell membranes of muscle fiber cells. It can be related to a variety of factors: muscular trauma, muscle enzyme deficiencies, infections, drugs, toxins, alcohol ingestion, endocrinopathies and electrolyte imbalances such as hypokalemia. We report the case of a 46-year-old woman admitted to the Emergency Department for frequent episodes of vomiting associated with food intake in the last two weeks, general muscular weakness and myalgia. Physical examination on admission was unremarkable, except for a symmetrical and dominantly proximal muscular weakness of all four extremities. Blood pressure was 116/70 mmHg with a sinus bradycardia (53 beats/min) on the electrocardiogram. Laboratory tests showed a metabolic alkalosis with marked hypokalemia (K+= 1.9 mEq/l) and elevation of muscular enzymes (myglobin= 993 ng/ml, troponin T= 0,10 ng/ml e CK= 1113 U/l). No symptoms of recurrent rhabdomyolysis were reported, patient denied alcohol consumption and there was not clinical evidence of hyperthyroidism. A iatrogenic etiology could not be excluded for certain because patient was in therapy with lansoprazole (Naranjo algorithm 3/13) but, revealing medical history that she underwent a laparoscopic adjustable gastric banding for the treatment of a severe obesity, we focused our attention on hypokalemia, due to persistent vomiting. Fasting, administration of metoclopramide and infusion of potassium chloride resulted in steady improvement of clinical conditions and normalization of electrolyte imbalance. At the clinical follow-up of three months, after partial deflation of the gastric banding, the patient was asymptomatic with muscular enzymes and potassium levels in the normal range. Authors discuss the pathophysiologic mechanisms of these alterations.

[A rare case of juvenile diabetes mellitus associated with APECED (autoimmune poly-endocrinopathy, candidiasis and ectodermal dystrophy) with strong X-linked familial inheritance]

The polyglandular autoimmune syndromes (PGA) are well known and are distinguished into type I, type II and type III. PGAI, also called APECED (autoimmune polyendocrinopathy, candidiasis and ectodermal dystrophy), is an autosomal recessive disorder, appearing in childhood and typically characterized by hypoparathyroidism (unusual in PGAII and PGAIII) and adrenal insufficiency. In APECED, autoimmune destruction of the pancreatic beta cells with development of insulin-dependent type 1 diabetes is possible, but less frequent than in the other PGAs, especially PGAII. The pathogenesis of this unique autoimmune disease is unknown. No HLA association seems to exist and genetic studies have assigned the autosomal APECED locus to chromosome 21. The case of a 28-years-old female suggesting the diagnosis of APECED, is presented, characterized by psycho-somatic abnormal development, teeth alterations, post-puberal gonadal failure with dystrophic hypoplasia of external genitalia, previous vaginal candidiasis, a slowly developing juvenile brittle diabetes. Intestinal malabsorption induced by Giardia lamblia occurred (probably resulting, like candidiasis, from immunological anergy). A strong familiarity linked to female sex was noticed (the mother, a sister, the little nice and some maternal female cousins being affected) while the father and a brother were healthy. Diabetes seems to be characterized by early onset and severe complications. In this patient no organo-specific antibodies were detected and the only immunologic disorder was a small decrease of CD3 and CD4/CD8 ratio, both CD4 and CD8 being at the lower normal range. This patient (and her female maternal relatives) needs a long-term follow-up in order to evaluate the function of endocrine glands and to initiate early treatment for hormonal deficits, as well as to detect the non-endocrine components of disease.