This is a brief synopsis of AFP's Preoperative Testing Before Noncardiac Surgery: Guidelines and Recommendations"

This is a brief synopsis of:

Preoperative Testing Before Noncardiac Surgery: Guidelines and Recommendations  

MOLLY A. FEELY, MD; C. SCOTT COLLINS, MD; PAUL R. DANIELS, MD; ESAYAS B. KEBEDE, MD; AMINAH JATOI, MD; and KAREN F. MAUCK, MD, MSc, Mayo Clinic, Rochester, Minnesota

Am Fam Physician. 2013 Mar 15;87(6):414-418

http://www.aafp.org/afp/2013/0315/

     Pre Op testing is a way to determine if a patient is suitable for surgery, or to see if they can survive it. It is done on almost every patient going to the OR, but it generally has not been proven useful.  Testing is decided by "low level evidence and expert opinion". Nonetheless, it routinely done regardless of it medical necessity.
     The first thing to consider  is the risk of the procedure  An example of high risk procedures are vascular surgeries, such a peripheral or aortic. Intermediate risk procedures are intraperitoneal, intrathoracic, head, neck, prostate, and orthopedic surgeries. Low risk procedures are breast, ambulatory, endoscopic, and cataract surgeries.
     ECG is a test that is almost always performed on all pre op patients. It is not generally recommended in asymptomatic patients undergoing low risk procedures  it is however recommended in high risk procedures.  For intermediate risk procedures, the patient should have at least 1 risk factor, such as CHF, cardiovascular disease, diabetes requiring insulin, ischemic heart disease  creatinine greater than 2mg/dL,  or undergoing intrathoracic, intra-abdominal or suprainguinal vascular surgery.
     Chest x ray is another commonly ordered procedure that is not needed. It is only recommended for those with new or unstable cardiopulmonary signs/symptoms, or in those with increased risk of post op pulmonary complications. Patients with other risk factors such as COPD or CHF will not benefit from the X ray.
     The story is similar with ordering routine lab work  Urinalysis is only recommended in those getting surgical implants or invasive urological procedures  Electrolytes and creatinine need only be tested if your clinical judgement, through the history and physical, warrant it. One guideline recommends testing in patients over 40. Glucose can be checked in patients suspected of undiagnosed diabetes,m  and A1C in diabetics.  A CBC can be ordered if you expect the procedure to have significant blood loss, or you think that the patient may have anemia. Coagulation testing can be -performed if you suspect a possible disorder, impaired hemostasis  or if the patients is on anticoagulants.
     So to make a long story short, there are no standard pre op tests for the asymptomatic patient undergoing a low risk procedure  Once the procedure becomes more risky, or the patient has more issues, the physician must use his clinical decision making skills on a case by case basis to decide what to do and what test to order.