To the Editor:
The case report titled "Profound, Reversible Myopathy with Severe Hypophosphatemia in a Patient with Diabetic Ketoacidosis"(June 2005) warrants a comment. The authors note that phosphate is routinely depleted in uncontrolled diabetes (both in diabetic ketoacidosis [DKA] and in the hyperglycemic hyperosmolar syndrome [HHS]). Routine replacement is not recommended by most physicians, but some disagree,1 precisely because of patients similar to this case. Before the 1950s, potassium replacement was not done routinely in patients with DKA or HHS. It became standard when rapid, accurate measurements demonstrated the risks of not doing so. My colleague and I have described routine replacement of phosphate and magnesium in uncontrolled diabetes and have shown it to be safe as part of a standard treatment regimen, resulting in the lowest reported mortality in hyperglycemic hyperosmolarity.1,2
The present case describes the progressive development of a high cardiac output, speculatively attributed to sepsis, which is very unlikely by days 4 and 5. The authors do not mention the administration of thiamine or B-complex vitamins, which should have been administered in an alcoholic, malnourished, uncontrolled diabetic now being given insulin—a classic scenario for the development of a refeeding syndrome.3 To avoid the potential complications seen in this patient, we have advocated routine administration of B-complex vitamins, thiamine, phosphate, magnesium, and potassium in uncontrolled diabetes. The full manifestations of the refeeding syndrome may not be present in this setting. Just as magnesium level was normal in this patient, different combinations of deficiencies may not be evident until treatment has progressed for some time. This patient's high-output state may have been a manifestation of thiamine deficiency, even if thiamine supplements were administered initially.
Robert Matz, MD
Professor of Medicine, Mount Sinai School of Medicine, New York
1. Carroll P, Matz R. Uncontrolled diabetes mellitus in adults: experience in the treatmentof diabetic ketoacidosis and hyperosmolar nonketotic "coma" with low dose insulin and a uniform treatment regimen (1976-1982). 1983;6:579-584.
Ellenberg & Rifkind's Diabetes Mellitus.
2. Matz R. Hyperglycemic hyperosmolar syndrome. In: Porte D, Sherwin RS, Baron A, eds. 6th ed. New York, NY: McGraw-Hill; 2003:587-599.
3. Matz R. Parallels between uncontrolled diabetes and the refeeding syndrome with emphasis on fluid and electrolyte abnormalities. 1994;17:1209-1213.