Preoperative Screening Guidelines

Introduction to Preoperative Screening

• The American Academy of Family Physicians recommends that preoperative testing should be based on the patient's clinical history, comorbidities, physical examination findings, and perioperative risk assessment rather than performed routinely for all patients 1, 2, 3

Cardiovascular Assessment

• The American Academy of Family Physicians recommends Electrocardiography (ECG) for patients with signs or symptoms of cardiovascular disease 1, 2, 3
• ECG is indicated for patients undergoing high-risk surgery and those undergoing intermediate-risk surgery who have additional risk factors (coronary heart disease, structural heart disease, heart failure, cerebrovascular disease, diabetes, or renal impairment) 4
• Patients undergoing low-risk surgery do not require ECG 2, 3
• Risk stratification should identify active cardiac conditions requiring evaluation before surgery (unstable coronary syndromes, decompensated heart failure, significant arrhythmias, severe valvular disease) 4
• Patients with good functional capacity (≥4 METs or ability to climb ≥2 flights of stairs) can generally proceed to surgery without further cardiac testing 4

Pulmonary Assessment

• The American Academy of Family Physicians recommends that chest radiography is not performed routinely for asymptomatic, otherwise healthy patients 3, 5
• Chest radiography is indicated for patients with new or unstable cardiopulmonary signs or symptoms 1, 3
• Consider chest radiography for patients at risk of postoperative pulmonary complications if results would change perioperative management 2, 3

Laboratory Testing

Complete Blood Count (CBC)

• The American Academy of Family Physicians recommends CBC for patients with diseases that increase risk of anemia (liver disease, hematologic disorders) 6
• CBC is recommended for patients with history of anemia or recent blood loss 6
• CBC should be performed when significant perioperative blood loss is anticipated 1, 2
• CBC is indicated for patients undergoing cardiovascular surgery and specific high-risk procedures 6

Electrolytes and Renal Function

• The American Academy of Family Physicians recommends that electrolyte and creatinine testing should be reserved for patients at risk of electrolyte abnormalities or renal impairment 1, 2, 3
• Testing is recommended for patients taking medications that predispose to electrolyte abnormalities (diuretics, ACE inhibitors, ARBs, NSAIDs, digoxin) 5, 6
• Patients with hypertension, heart failure, chronic kidney disease, complicated diabetes mellitus, or liver disease should have electrolyte and creatinine testing 5
• Electrolyte measurement is recommended for all patients with known renal conditions and those undergoing neurosurgery or cardiovascular surgery 6

Glucose and A1C Testing

• The American Academy of Family Physicians recommends random glucose testing for patients at high risk of undiagnosed diabetes mellitus 2, 5
• In patients with diagnosed diabetes, A1C testing is recommended only if results would change perioperative management 5, 7
• The incidence of occult diabetes in the presurgical population is low (0.5%), so universal screening is not justified 5

Coagulation Studies

• The American Academy of Family Physicians recommends that coagulation testing (prothrombin time, activated partial thromboplastin time, platelet count) should be reserved for patients with history of bleeding or medical conditions predisposing to coagulopathy (e.g., liver disease) 1, 2, 5
• Testing is indicated for patients taking anticoagulants 1, 3
• Indiscriminate preoperative coagulation testing is not warranted due to low prevalence of inherited coagulopathies 5

Urinalysis

• The American Academy of Family Physicians recommends that routine urinalysis is not performed for asymptomatic patients 5, 8
• Urinalysis is indicated for patients undergoing urologic procedures or implantation of foreign material (e.g., prosthetic joint, heart valve) 2, 8

Special Considerations

• The American Academy of Family Physicians recommends that patients in their usual state of health undergoing cataract surgery do not require preoperative testing 3

Preoperative Evaluation of Patients with Moderate Renal Impairment

Risk Stratification and Baseline Assessment

• Patients with eGFR 45 mL/min/1.73 m² fall into the moderate renal impairment category (CKD Stage 3a-3b) and require comprehensive preoperative evaluation to minimize perioperative acute kidney injury and optimize outcomes, as recommended by the American Journal of Kidney Diseases 9
• Obtain complete blood count as patients with eGFR <60 mL/min/1.73 m² have increased risk of anemia, which occurs in >50% of patients with eGFR <30 mL/min/1.73 m², according to the American Journal of Kidney Diseases 9

Essential Laboratory Testing

• Check serum calcium, phosphate, PTH, and alkaline phosphatase at least once in patients with eGFR <45 mL/min/1.73 m² to assess for metabolic bone disease, as suggested by the American Journal of Kidney Diseases 9

Preoperative Evaluation for Healthy Young Females Undergoing Minor Surgery

Direct Recommendations

• The American Academy of Family Physicians and the American Society of Anesthesiologists recommend that for a healthy young female undergoing minor surgery with no cardiovascular risk factors or comorbidities, no routine preoperative laboratory testing is indicated 10, 11, 12

Evidence-Based Approach

When Testing is NOT Required

• Healthy patients (ASA Class 1) undergoing low-risk/minor surgery do not require any routine preoperative testing, according to the American Academy of Family Physicians and the American Society of Anesthesiologists 10, 11, 12
• No ECG is needed for asymptomatic patients without cardiovascular risk factors undergoing minor procedures, as stated by the American Academy of Family Physicians 10
• No coagulation studies are required unless there is a personal or family history of bleeding disorders or current anticoagulant use, as recommended by the American Society of Anesthesiologists 11, 12
• No urinalysis is necessary unless undergoing urologic procedures or prosthesis implantation, according to the American Society of Anesthesiologists 11, 12

Clinical Rationale

• Routine testing identifies abnormalities in only 0.8-22% of cases, with changes in clinical management occurring in only 1.1-4% of abnormal results, as reported by the American Society of Anesthesiologists 12

What Actually Matters: History and Physical Examination

• Testing should be driven by specific clinical characteristics identified during history and physical examination, not by routine protocols, as recommended by the American Society of Anesthesiologists 11, 12
• Focus your preoperative assessment on cardiovascular symptoms, bleeding history, medication review, chronic diseases, and anemia symptoms, according to the American Academy of Family Physicians and the American Society of Anesthesiologists 10, 11, 12

Special Considerations for Young Females

• Pregnancy testing may be considered for all females of childbearing age, as history and physical examination may be insufficient to identify early pregnancy, as recommended by the American Society of Anesthesiologists 11

Common Pitfalls to Avoid

• Do not order tests "just to be safe" or because "it's always been done", and do not rely on arbitrary age cutoffs, as stated by the American Society of Anesthesiologists 11, 12
• Only order tests that would alter perioperative care, according to the American Society of Anesthesiologists 11, 12

Preoperative Laboratory Testing for Noncardiac Surgery

Introduction to Preoperative Testing

• The European Society of Cardiology recommends ordering preoperative labs selectively based on patient risk factors, surgical risk, and whether results will change perioperative management, as routine testing for all patients is not recommended and should be avoided 13, 14, 15

Risk Stratification

• The American College of Cardiology recommends using clinical risk indices, such as the Lee Risk Index or NSQIP model, to identify cardiac risk 13, 14

Electrocardiography

• The American College of Cardiology recommends ordering a 12-lead electrocardiogram for patients with recent chest pain or ischemic symptoms who are undergoing intermediate- or high-risk surgery, as well as for asymptomatic patients with diabetes mellitus 16, 17, 18
• The European Society of Cardiology recommends ordering a 12-lead electrocardiogram for patients with cardiovascular risk factors undergoing intermediate- or high-risk surgery 13, 14

Biomarker Testing

• The European Society of Cardiology recommends considering Pro-BNP/NT-proBNP testing for high-risk patients undergoing major noncardiac surgery for independent prognostic information regarding perioperative and late cardiac events 19
• The European Society of Cardiology recommends against routine biomarker sampling for all patients, as it is not recommended and does not change immediate management 13, 14, 19

Cardiac Troponins

• The European Society of Cardiology recommends considering cardiac troponin testing for high-risk patients both before and 48-72 hours after major surgery 13, 14

Complete Blood Count

• The American Academy of Family Physicians recommends ordering a complete blood count for patients with diseases increasing anemia risk, such as liver disease, hematologic disorders, or chronic kidney disease 15

Electrolytes and Creatinine

• The American Academy of Family Physicians recommends ordering electrolytes and creatinine for patients with chronic kidney disease, hypertension, heart failure, complicated diabetes, or liver disease 15

Glucose and Hemoglobin A1C

• The American Academy of Family Physicians recommends ordering random glucose for patients at high risk of undiagnosed diabetes, and ordering hemoglobin A1C for patients with diagnosed diabetes if results would change perioperative management 15

Coagulation Studies

• The American Academy of Family Physicians recommends ordering coagulation studies for patients with a personal or family history of bleeding disorders, medical conditions predisposing to coagulopathy, or patients taking anticoagulants 15

Urinalysis

• The American Academy of Family Physicians recommends ordering urinalysis for patients undergoing urologic procedures or implantation of foreign material 15

Chest Radiography

• The American Academy of Family Physicians recommends ordering chest radiography for patients with new or unstable cardiopulmonary signs or symptoms, or for patients at risk of postoperative pulmonary complications if results would change perioperative management 15

Left Ventricular Function Assessment

• The American College of Cardiology recommends ordering left ventricular function assessment for patients with current or poorly controlled heart failure, and considering it for patients with prior heart failure or dyspnea of unknown origin 16, 17, 18

Perioperative Management

• The European Society of Cardiology recommends only ordering tests that would alter perioperative care, and avoiding routine testing protocols applied to all patients 13, 14, 15

Risk‑Based Preoperative Laboratory Testing Guidelines

1. Risk Stratification Framework

• Use validated clinical risk indices (e.g., Lee Risk Index or NSQIP model) to stratify cardiac risk and align laboratory testing with the combination of patient‑specific risk factors and the planned surgical risk level. 20

• Recognize the following major patient‑related risk factors that should trigger targeted testing:

  • Cardiovascular – known coronary artery disease, heart failure, cerebrovascular disease, or structural heart disease. 21
  • Metabolic – diabetes mellitus, chronic kidney disease (eGFR < 60 mL/min/1.73 m²), or chronic liver disease. 21
  • Functional capacity – inability to climb two flights of stairs or achieve < 4 METs. 21
  • Hematologic – personal or family history of bleeding disorders or prior anemia. 22

2. Surgical Risk Categories

• Low‑risk procedures – cataract surgery, endoscopy, and other superficial operations. 23
• Intermediate‑risk procedures – orthopedic, intra‑abdominal, and head/neck surgeries. 23
• High‑risk procedures – vascular, major thoracic, and cardiovascular surgeries. 23

3. General Testing Recommendations

3.1 Healthy Patients (ASA I) Undergoing Low‑Risk Surgery

• No routine preoperative laboratory tests are required, including ECG, CBC, chemistry panel, coagulation studies, or chest radiography.
• Exception: consider pregnancy testing for females of child‑bearing potential. 22
• Evidence strength: routine testing in this group detects abnormalities in only 0.8–22 % of cases, and management changes occur in merely 1.1–4 % of abnormal results; no reduction in peri‑operative complications has been demonstrated. 22

3.2 Electrocardiogram (ECG)

• Order an ECG for any patient with cardiovascular risk factors (e.g., known coronary disease, heart failure, diabetes, renal impairment, cerebrovascular disease) who is scheduled for intermediate‑ or high‑risk surgery. 20
• Order an ECG for all patients undergoing vascular surgery who have ≥ 1 cardiovascular risk factor. [23][21]
• Do not order an ECG for asymptomatic patients without risk factors undergoing low‑risk surgery, or for patients with good functional capacity (≥ 4 METs) even if risk factors are present. 23

3.3 Coagulation Studies (PT/INR, aPTT, Platelet Count)

• Order coagulation testing when there is a personal or family history of bleeding disorders or when liver disease/coagulopathy is present. 22
• Do not order routine coagulation screening in the absence of a bleeding history. 22

3.4 Biomarkers (BNP, Troponin)

• Consider measuring BNP or troponin in high‑risk patients (e.g., undergoing major thoracic or vascular surgery) before surgery and again 48–72 hours post‑operatively for prognostic information. Routine use in all surgical patients is not recommended. 20

4. Additional Cardiac Testing

• For patients with poor functional capacity (< 4 METs) and ≥ 3 clinical risk factors undergoing vascular surgery, non‑invasive stress testing should be considered if the results would influence peri‑operative management. 23
• Patients with adequate functional capacity (≥ 4 METs) can generally proceed without further cardiac testing. 23

5. Clinical Pitfalls & Decision‑Making Principles

• Avoid ordering tests solely “to be safe” or because they have been traditionally performed; such practices generate false‑positive results that lead to unnecessary follow‑up and contribute to substantial healthcare waste. False positives have been identified as a major driver of avoidable costs. 21

• Do not use age alone as an indication for testing; functional capacity and comorbidities are more predictive of peri‑operative risk. 22

• Only order a test when an abnormal result is expected to change peri‑operative management. 22