RESUMEN
Aim of the work: studies mentioning etiological distribution of tetany are rare and responsiveness concerning it is poor among physicians so, we tried to describe different causes of tetany beyond the decrease in total serum calcium level
Methods: patients with overt or latent tetany were assessed clinically and from laboratory investigations. Initial examinations completed were serum calcium, potassium and arterial blood gas analysis. Both ionized and total calcium were evaluated and corrected according to serum albumin level. Depending on initial reports, additional tests were completed for example, alkaline phosphatase, serum phosphate, parathyroid hormone and magnesium levels; and urine potassium, calcium and chloride levels
Results: Gitelman's syndrome [GS], Bartter's syndrome [BS], recurrent vomiting, anxiety hyperventilation, vitamin D3 deficiency [VDD], idiopathic hypoparathyroidism [IHP], postoperative hypoparathyroidism [PHP], acute pancreatitis, tumor lysis syndrome [TLS] and hypomagnesemia were the different causes of tetany identified. Out of 106 patients, total serum calcium was normal in 82 patients with metabolic or respiratory alkalosis [GS, BS, recurrent vomiting, and anxiety hyperventilation]. Total calcium was low only in 24 patients [in VDD, IHP, PHP, acute pancreatitis, TLS and hypomagnesemia]. Ionized calcium was low in all patients. GS was the most common [38%]. Recurrent vomiting [19%], anxiety hyperventilation [13%], and VDD [11%] were also common. PHP was less common [4%]; acute pancreatitis, TLS, hypomagnesemia and IHP were uncommon
Conclusion: tetany has diverse etiologies. Both metabolic and respiratory alkalosis caused a decrease in ionized calcium and are responsible for the majority of cases of tetany. Causes other than decreased total calcium should be kept in mind for early etiological diagnosis of tetany