What is the recommended pre-operative examination protocol for patients undergoing surgery?

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Last updated: November 25, 2025View editorial policy

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Preoperative Examination Protocol

Base preoperative testing decisions on the patient's clinical history, physical examination findings, and perioperative risk assessment rather than ordering routine tests for all surgical patients. 1, 2

Core Principle: History and Physical Examination Drive Testing

The foundation of preoperative evaluation is a targeted clinical assessment, not blanket laboratory orders. 1, 2 Testing should only be performed when specific clinical indications exist—global designations like "preop status" or "surgical screening" do not constitute valid indications. 1

Cardiovascular Assessment

When to Order ECG:

  • Obtain ECG for patients with known cardiovascular disease (coronary artery disease, heart failure, arrhythmias, valvular disease) or active cardiovascular symptoms. 1, 2
  • Obtain ECG for patients undergoing high-risk surgery regardless of cardiac history. 1, 2
  • Obtain ECG for patients undergoing intermediate-risk surgery who have cardiac risk factors (diabetes, renal impairment, cerebrovascular disease, structural heart disease). 1, 2
  • Do not order ECG for asymptomatic patients undergoing low-risk surgery. 1, 2

Risk Stratification:

  • Identify active cardiac conditions requiring preoperative evaluation: unstable coronary syndromes, decompensated heart failure, significant arrhythmias, or severe valvular disease. 2
  • Patients with good functional capacity (≥4 METs or ability to climb ≥2 flights of stairs) can proceed to surgery without further cardiac testing. 2

Pulmonary Assessment

  • Order chest radiography only for patients with new or unstable cardiopulmonary signs or symptoms. 1, 2
  • Do not perform routine chest radiography in asymptomatic, otherwise healthy patients. 1, 2

Laboratory Testing

Complete Blood Count (CBC):

  • Order CBC for patients at risk of anemia based on history (liver disease, hematologic disorders, recent blood loss). 1, 2
  • Order CBC when significant perioperative blood loss is anticipated. 1, 2
  • Order CBC for patients undergoing cardiovascular surgery or other high-risk procedures. 2
  • Do not order routine CBC for healthy patients undergoing low-risk surgery. 1

Electrolytes and Renal Function:

  • Order electrolytes and creatinine for patients taking medications that affect electrolyte balance (diuretics, ACE inhibitors, ARBs, NSAIDs, digoxin). 1, 2
  • Order testing for patients with hypertension, heart failure, chronic kidney disease, complicated diabetes, or liver disease. 2
  • Order testing for patients undergoing neurosurgery or cardiovascular surgery. 2
  • Do not order routine electrolytes for healthy patients without risk factors. 1

Glucose Testing:

  • Consider random glucose or A1C only if an abnormal result would change perioperative management. 1, 2
  • Order testing for patients at high risk of undiagnosed diabetes. 2
  • The incidence of occult diabetes in presurgical populations is only 0.5%, making universal screening unjustified. 2

Coagulation Studies:

  • Order coagulation testing for patients taking anticoagulants. 1, 2
  • Order testing for patients with history of bleeding disorders or medical conditions predisposing to coagulopathy (liver disease, hematologic disorders). 1, 2
  • Do not order routine coagulation studies for patients without these risk factors. 1, 2

Urinalysis:

  • Order urinalysis only for patients undergoing urologic procedures or implantation of foreign material (prosthetic joints, heart valves). 1, 2
  • Do not perform routine urinalysis for asymptomatic patients. 1, 2

Timing of Preoperative Assessment

  • Perform assessment prior to day of surgery for patients with high severity of disease or undergoing high surgical invasiveness procedures. 1
  • Assessment may occur on day of surgery for patients with low severity of disease undergoing low or medium surgical invasiveness procedures. 1
  • At minimum, focused physical examination should assess airway, lungs, heart, and vital signs. 1

Surgery-Specific Considerations

Cataract Surgery:

  • Do not order any preoperative testing for patients in their usual state of health undergoing cataract surgery. 1, 2
  • A large randomized trial of over 19,000 patients demonstrated no difference in outcomes between patients who received preoperative testing versus no testing. 1
  • Routine medical evaluation, history, and physical examination have failed to reduce systemic or ocular complications in three randomized trials. 1

Thyroid Surgery:

  • Perform preoperative laryngeal examination for all patients undergoing thyroidectomy to establish baseline vocal fold mobility. 1
  • Preoperative vocal fold paralysis occurs in 1% of patients with benign disease and up to 8% with malignant disease. 1
  • Finding vocal fold paralysis preoperatively strongly suggests invasive malignancy (>70% rate in invasive disease versus 0.3% in noninvasive disease). 1

Common Pitfalls to Avoid

  • Avoid ordering tests "just to be safe" without specific clinical indications—this increases costs without improving outcomes. 1, 2
  • Avoid delaying surgery for minor laboratory abnormalities that do not change management. 1
  • Avoid routine medical evaluations for patients with well-controlled chronic conditions undergoing low-risk procedures. 1
  • Consider directed medical evaluation only for patients with severe systemic diseases (poorly controlled hypertension, recent myocardial infarction, unstable angina, poorly controlled heart failure or diabetes, chronic obstructive pulmonary disease). 1

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References

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Guideline

Preoperative Screening Guidelines

Praxis Medical Insights: Practical Summaries of Clinical Guidelines, 2025

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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