Localized areas of necrotic soft tissue that occur when pressure applied to the skin over time are greater than normal capillary closure pressure, which is about 32 mm Hg. Critically ill patients have a lower capillary closure pressure and a greater risk of pressure ulcers. Brunner & Suddarth, 2010
Hypokalemia is generally defined as a serum potassium level of less than 3.5 mEq/L (3.5 mmol/L). Moderate hypokalemia is a serum level of 2.5-3.0 mEq/L, and severe hypokalemia is a level of less than 2.5 mEq/L.