CHAPTER 35: Calcium in Critical Care

Nutrition is an essential part in the care of critically ill patients. Calcium is a major nutritional element, and is acquired mainly through food resources. Calcium is required in the control of many cellular mechanisms. Because of its vital importance, it is under strict control by PTH, other minerals and vitamin D. Any imbalance in its range may cause deleterious implications in many organ systems including arrhythmia, laryngeal spasms and death. As in critical illness the total calcium concentration may be changed by hypoalbuminemia and disorders of acid–base balance, the diagnosis of hypocalcemia should be based on ionized calcium levels. This chapter discusses the importance of calcium in general, with a focus on critical care, and presents the different manifestations and consequences patients may suffer when they are in a hypo- or hypercalcemic status. We also discuss the different treatment options.