Experts from the National Institutes of Health say pre-op blood work helps medical professionals determine if a patient is healthy enough to undergo a surgical procedure. Some pre-operative blood tests are ordered for every patient scheduled for surgery, while other tests are only ordered if a patient is at risk for certain medical conditions, according to the MedlinePlus website.
The blood tests performed before surgery include the complete blood count (CBC) and comprehensive metabolic panel. The complete blood count determines the number and type of certain cells in the blood, according to WebMD. According to WebMD, these cells include white blood cells, red blood cells and platelets. The CBC blood test also measures the amount of hemoglobin in the blood. Hemoglobin carries oxygen, so measuring the amount of hemoglobin present helps determine if the blood is able to carry enough oxygen throughout the body.
According to the University of Rochester Medical Center, the comprehensive metabolic panel helps determine how well the liver and kidneys are working. This test also measures the amount of glucose in the blood; determines if a patient's blood has the right acid/base balance; and measures the amount of electrolytes in the blood. These electrolytes include potassium, sodium and calcium, as stated by the University of Rochester Medical Center website.