Timing of Laboratory Testing:

Laboratory tests should be considered valid for up to 3 months before surgery, unless there has been an interim change in clinical status.


Specific tests                                                      Indications

Complete Blood Count                                  Patients 65 years or older undergoing major surgery

Patients undergoing major surgery that is expected to result in significant blood loss

History of fatigue, dyspnea on exertion, liver disease, blood loss

Signs of coagulopathy, tachycardia


Consider a response for the following abnormal values:

Hb < 10.0% for patients with active CAD

Hb < 8.0% for patients undergoing surgery with significant expected blood loss


Serum Creatinine (renal function)            Patients over 50 undergoing intermediate or high risk surgery Perioperative  hypotension is expected

Nephrotoxic medications are to be used

History of hypertension, cardiac disease


Abnormal values which require a response:

Cr > 2.0: Review medications and formulate plan to reduce risk of medication nephrotoxicity


Electrolytes                                                        Current use of a diuretic, ACE-Inhibitor, ARB, or other medications that affect electrolytes

                                                                                Chronic renal insufficiency/CKD


                                                                                Consider a response for the following abnormal values:

sK+ < 3.2: consider potassium supplementation

sK+ > 5.8: consider medications to reduce potassium level then recheck the  potassium level


Blood Glucose                                                   Patients with diabetes mellitus


                                                                                Abnormal values which require a response: Patient-dependent


Liver function tests                                         Consider albumin measurement for patients undergoing major surgery or with a history of chronic illness.

Otherwise not recommended


Be aware that serum albumin levels < 3.5 are associated with an increased risk of perioperative complications


Prothrombin Time                                           History of bleeding diathesis, chronic liver disease, warfarin use, malnutrition, recent or long-term antibiotic use


Partial Thromboplastin Time (aPTT)         History of bleeding diathesis


Urinalysis                                                             Signs of cystitis, patients undergoing genito-urologic procedure


Electrocardiogram                                           Men > 45 years old, Women > 50 years old

                                                                                History of CAD, HTN, or DM


ACC/AHA 2007 guideline summary: Preoperative 12-lead rest electrocardiogram (ECG) prior to noncardiac surgery

Class I - There is evidence and/or general agreement that a preoperative rest ECG should be obtained in the following setting

• Patients with a least one clinical risk factor who require vascular surgical procedures

• Patients with atherosclerotic cardiovascular disease scheduled for intermediate-risk procedures

Class IIa - The evidence or opinion is in favor of usefulness of a preoperative rest ECG in the following setting

• Patients with no clinical risk factors who require vascular surgical procedures

Class IIb - The evidence or opinion is less well established for the usefulness of a preoperative rest ECG in the following settings

• Patients with at least one clinical risk factor scheduled to undergo intermediate-risk procedures

Class III - There is evidence and/or general agreement that preoperative rest and postoperative ECGs are not useful in the following setting

• Asymptomatic patients who are scheduled for a low-risk operative procedures.

J Am Coll Cardiol. 2007 Oct 23;50(17):e159-241.


Chest X-ray                                                         Patients with cardiopulmonary disease and those older than 50 years of age who are undergoing abdominal aortic aneurysm surgery or upper abdominal/thoracic surgery


Pulmonary Function Tests                            Patients who have dyspnea that is unexplained after careful clinical evaluation.  Patients undergoing lung resection surgery.




Michota, FA.  The preoperative evaluation and use of laboratory testing.  Cleveland Clinic Journal of Medicine 2006; 73 Supplement 1: S4-S7.

Smetana GW.  Preoperative Evaluation of the Healthy Patient.  UpToDate Online accessed May 27, 2010.

Smetana GW, Macpherson DS.  The case against routine preoperative laboratory testing.  Medical Clinics of North America 2003; 87: 7-40.