Spontaneous haematomas and haematochezia due to vitamin C deficiency in a haemodialysis patient.

A man in his 50s with dialysis-dependent end-stage renal disease, several weeks history of progressive skin bruising and acute-onset gastrointestinal bleeding presented to the emergency department following a syncopal event during routine haemodialysis owing to profound hypotension. He was found to have a severe normocytic, normochromic anaemia requiring several blood transfusions. He followed a diet lacking fruits and vegetables and stopped taking renal multivitamins. All parameters of coagulation were unremarkable, but serum vitamin C level was undetectable, supporting a diagnosis of scurvy. Although typically associated with individuals who are at risk of malnourishment, such as those with alcohol use disorder, malabsorption, and those who experience homelessness, scurvy should be considered in patients receiving renal replacement therapy as vitamin C is removed during haemodialysis.

A case of chronic hypomagnesemia in a cancer survivor.

OBJECTIVES: Hypomagnesemia is common among hospitalized patients, particularly those who are critically ill. It can be associated with a number of potentially life-threatening cardiovascular, neurological and behavioral manifestations. As opposed to acute, chronic hypomagnesemia is often underdiagnosed and underreported and as such may pose a diagnostic and therapeutic problem. CASE PRESENTATION: We describe a case of magnesium wasting in a middle-aged woman with head and neck cancer who presented with recurrent syncopal episodes complicated by a femur fracture 4 months after completing a course of carboplatin-containing chemotherapy. Fractional excretion of magnesium of 16% was consistent with renal wasting of magnesium. After ruling out all common causes of hypomagnesemia, it was concluded that she sustained carboplatin-induced renal tubular damage making her relatively resistant to magnesium supplementation. CONCLUSION: Several antineoplastic agents have been linked to chronic hypomagnesemia including anti-epidermal growth factor receptor agents such as cetuximab and panitumumab, cyclosporine, and the platinum-based agents cisplatin and carboplatin. The example case presented here illustrates the importance of chronic hypomagnesemia and its possible debilitating effects following carboplatin-containing chemotherapy. A growing numbers of cancer survivors are treated with these antineoplastic agents, and are hospitalized for non-cancer-related problems. These patients may have prolonged hypomagnesemia, and hence pose a diagnostic dilemma. We review the pathophysiology, etiology, diagnosis, clinical manifestations, monitoring and treatment of hypomagnesemia, with special attention to mechanisms of renal damage caused by platinum-containing chemotherapeutic agents.