Preanesthesia Evaluation

Preoperative tests should not be ordered routinely.

Preoperative tests may be ordered, required, or performed on a selective basis for purposes of guiding or optimizing perioperative management.

• The indications for such testing should be documented and based on information obtained from medical records, patient interview, physical examination, and type and invasiveness of the planned procedure.

There is insufficient evidence to identify explicit decision parameters or rules for ordering preoperative tests on the basis of specific clinical characteristics.

Consideration of selected clinical characteristics may assist the anesthesiologist when deciding to order, require, or perform preoperative tests. The following clinical characteristics may be of merit, although the anesthesiologist should not limit consideration to the characteristics suggested below.

Electrocardiogram

• Important clinical characteristics may include cardiocirculatory disease, respiratory disease, and type or invasiveness of surgery.

• The Task Force recognizes that ECG abnormalities may be higher in older patients and in patients with multiple cardiac risk factors.

• An ECG may be indicated for patients with known cardiovascular risk factors or for patients with risk factors identified in the course of a preanesthesia evaluation. Age alone may not be an indication for ECG.

Preanesthesia Cardiac Evaluation Other than ECG

• Preanesthesia cardiac evaluation may include consultation with specialists and ordering, requiring, or performing tests that range from noninvasive passive or provocative screening tests (e.g. , stress testing) to noninvasive and invasive assessment of cardiac structure, function, and vascularity (e.g. , echocardiogram, radionucleotide imaging, cardiac catheterization).

• Anesthesiologists should balance the risks and costs of these evaluations against their benefits.

• Clinical characteristics to consider include cardiovascular risk factors and type of surgery.

Preanesthesia Chest Radiographs

• Clinical characteristics to consider include smoking, recent upper respiratory infection, COPD, and cardiac disease.

  • The Task Force recognizes that chest radiographic abnormalities may be higher in such patients but does not believe that extremes of age, smoking, stable COPD, stable cardiac disease, or resolved recent upper respiratory infection should be considered unequivocal indications for chest radiography.

Preanesthesia Pulmonary Evaluation Other than Chest X-ray

• Preanesthesia pulmonary evaluation other than chest x-ray may include consultation with specialists and tests that range from noninvasive passive or provocative screening tests (e.g. , pulmonary function tests, spirometry, pulse oximetry) to invasive assessment of pulmonary function (e.g. , arterial blood gas).

  • Anesthesiologists should balance the risks and costs of these evaluations against their benefits.

  • Clinical characteristics to consider include type and invasiveness of the surgical procedure, interval from previous evaluation, treated or symptomatic asthma, symptomatic COPD, and scoliosis with restrictive function.

Preanesthesia Hemoglobin or Hematocrit

• Routine hemoglobin or hematocrit is not indicated.

• Clinical characteristics to consider as indications for hemoglobin or hematocrit include type and invasiveness of procedure, patients with liver disease, extremes of age, and history of anemia, bleeding, and other hematologic disorders.

Preanesthesia Coagulation Studies

• Clinical characteristics to consider for ordering selected coagulation studies include bleeding disorders, renal dysfunction, liver dysfunction, and type and invasiveness of procedure.

  • The Task Force recognizes that anticoagulant medications and alternative therapies may present an additional perioperative risk.

  • The Task Force believes that there were not enough data to comment on the advisability of coagulation tests before regional anesthesia.

Preanesthesia Serum Chemistries (i.e. , Potassium, Glucose, Sodium, Renal and Liver Function Studies)

• Clinical characteristics to consider before ordering preanesthesia serum chemistries include likely perioperative therapies, endocrine disorders, risk of renal and liver dysfunction, and use of certain medications or alternative therapies.

  • The Task Force recognizes that laboratory values may differ from normal values at extremes of age.

Preanesthesia Urinalysis

• Urinalysis is not indicated except for specific procedures (e.g. , prosthesis implantation, urologic procedures) or when urinary tract symptoms are present.

Preanesthesia Pregnancy Testing

• Patients may present for anesthesia with early undetected pregnancy.

  • The Task Force believes that the literature is inadequate to inform patients or physicians on whether anesthesia causes harmful effects on early pregnancy.

  • Pregnancy testing may be offered to female patients of childbearing age and for whom the result would alter the patient's management.

Timing of Preoperative Testing

• The current literature is not sufficiently rigorous to permit an unambiguous assessment of the clinical benefits or harms of the timing for preoperative tests.

  • There is insufficient evidence to identify explicit decision parameters or “rules” for ordering preoperative tests on the basis of specific patient factors.

• Test results obtained from the medical record within 6 months of surgery generally are acceptable if the patient's medical history has not changed substantially.

  • More recent test results may be desirable when the medical history has changed, or when a test results may play a role in the selection of a specific anesthetic technique (e.g. , regional anesthesia in the setting of anticoagulation therapy).

Limitations in resources available to a specific healthcare system or practice environment may affect the timing of the preanesthetic evaluation.

The healthcare system is obligated to provide pertinent information to the anesthesiologist for the appropriate assessment of the invasiveness of the proposed surgical procedure and the severity of the patient's medical condition well in advance of the anticipated day of procedure for all elective patients.

Specific tests and their timing should be individualized and based upon information obtained from sources such as the patient's medical record, patient interview, physical examination, and the type and invasiveness of the planned procedure.