Letters to the Editor: Letters & Announcements
To the Editor:
We read with interest the report of Bhatia et al. (1) on hypoglycemia and cardiac arrest in a patient on tight glycemic control. However, I would like to clarify a few points. First, the patient should have been excluded from the study because she was a patient with renal failure requiring dialysis. Second, it seems the patient had been underfed. She received only 1160 kcal/day (unless the patient's weight is <40 kg, this low caloric intake is, by itself, a risk factor for hypoglycemia). Third, the algorithm itself is problematic. It does not describe the plan of action when there is hypoglycemia in terms of providing calories and the frequency of checking the blood glucose. More importantly, an algorithm for tight glycemic control should mandate more frequent checks of blood glucose; (i.e., every 30 min instead of every 60 min). Fourth, why was this patient's arterial blood gas and potassium checked 4 times in the 6 h before the arrest? Finally, the potassium level before arrest was 3.2, but the potassium level before that was 6.2. Perhaps the 3.2 is an error, and the potassium before the arrest was increased by the patient's renal failure. If so, the hyperkalemic cardiac arrest had as much do to with renal failure as with the rapid administration of glucose.
If the authors could address these points, it would help explain the arrest of this patient during tight glycemic control.
Mariam A. Al-Ansari, MD, FRCSI
Intensive Care Unit
Salmaniya Medical Complex
Ministry of Health
Manama, Kingdom of Bahrain
1. Bhatia A, Cadman B, Mackenzie I. Hypoglycemia and cardiac arrest in a critically ill patient on strict glycemic control. Anesth Analg 2006;102:549–51.