Comprehensive Metabolic Panel (Definition) The comprehensive metabolic panel (cmp) is a panel of blood tests that serves as an initial broad medical screening tool. The cmp provides a rough check of kidney function, liver function, and electrolyte and fluid balance. The cmp is an expanded version of the basic metabolic panel (bmp), which does not include liver tests. A cmp (or bmp) is usually ordered as part of a routine physical exam.