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A 76-year-old woman with electrolyte abnormalities

Published:December 15, 2016DOI:https://doi.org/10.1016/j.ejim.2016.12.007

      Keywords

      1. Case presentation

      A 76-year-old female was admitted to our hospital because of severe diarrhea and lethargy. Diarrhea persisted since several weeks. Past medical history revealed cholecystectomy, appendectomy, coronary artery bypass surgery, and hypertension. Palpation of the right hemi abdomen was slightly painful. No pathologic findings could be detected with abdominal ultrasound, abdominal X-ray, and computed tomography of the cerebrum. Laboratory tests revealed several electrolyte abnormalities. The clinical chemist, however, suspected that a laboratory error had occurred and suggested to repeat the test. In order to start electrolyte supplementation as soon as possible, we tried to verify the electrolyte abnormality without waiting for the second test. Hence, a blood pressure cuff was placed around her right arm and inflated to a pressure above systolic blood pressure (Video 1).

      2. What is your diagnosis?

      2.1 Diagnosis

      As shown in the video, flection of the wrist, extension of the interphalangeal joints and adduction of the fingers occurred. This phenomenon is known as Trousseau sign, which is typical for hypocalcaemia [
      • Cooper M.S.
      • Gittoes N.J.
      Diagnosis and management of hypocalcaemia.
      ]. The described muscle contraction is the result of increased neural excitability due to hypocalcaemia, enforced by ischemia due to the inflated blood pressure cuff and can be found in 94% of all patients with hypocalcaemia [
      • Urbano F.L.
      Signs of hypocalcemia: Chvostek's and Trousseau's signs.
      ].
      In this case, laboratory tests indeed confirmed a very low total calcium level of 1.36 mmol/l (reference value 2.10–2.55 mmol/l). Serum albumin (37.7 g/l; reference value 32–47 g/l), and parathyroid hormone level (3.3 pmol/l; reference value1.3–6.8 pmol/l) were normal. Presumably, hypocalcaemia was the result of relative hypoparathyroidism caused by severe hypomagnesaemia (0.17 mmol/l; reference value 0.7–1.0 mmol/l) due to fecal loss. Severe hypomagnesaemia interferes with the parathyroid calcium-sensing receptor [
      • Shoback D.M.
      • Bilezikian J.P.
      • Costa A.G.
      • Dempster D.
      • Dralle H.
      • Khan A.A.
      • et al.
      Presentation of hypoparathyroidism: etiologies and clinical features.
      ], resulting in relative hypoparathyroidism, i.e. parathyroid hormone secretion is insufficient to maintain normal serum calcium levels.
      Because of the presence of Trousseau sign, calcium and magnesium supplementation was started immediately. As a result calcium and magnesium levels normalized and parathyroid hormone levels increased to 17.0 pmol/l. After treatment with metronidazole, diarrhea ceased. This case shows how Trousseau sign could be used to verify deviant calcium levels in clinical practice.
      The following is the supplementary data related to this article.

      Conflict of interest/disclosures

      None.

      References

        • Cooper M.S.
        • Gittoes N.J.
        Diagnosis and management of hypocalcaemia.
        BMJ. 2008; 336: 1298-1302
        • Urbano F.L.
        Signs of hypocalcemia: Chvostek's and Trousseau's signs.
        Turner White Communications Inc., Wayne, PA2000 (Hospital Physician)
        • Shoback D.M.
        • Bilezikian J.P.
        • Costa A.G.
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        • Dralle H.
        • Khan A.A.
        • et al.
        Presentation of hypoparathyroidism: etiologies and clinical features.
        J Clin Endocrinol Metab. 2016; 101: 2300-2312