What is the approach to pre-operative examination clearance for an adult or older adult patient with a possible history of chronic medical conditions, such as diabetes, and taking medications like anticoagulant or antiplatelet agents, prior to surgery?

Preoperative Examination Clearance Approach

Core Principle: History and Physical Drive Testing, Not Routine Protocols

The preoperative evaluation must be driven by targeted history and physical examination findings, patient comorbidities, and surgical risk—not by routine testing protocols applied to all patients. 1, 2

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Step 1: Structured History and Physical Examination

Focus your assessment on these specific elements:

• Cardiovascular symptoms: chest pain, dyspnea, palpitations, syncope, orthopnea, paroxysmal nocturnal dyspnea 3, 4
• Functional capacity: ability to climb ≥2 flights of stairs or walk 4 blocks (≥4 METs) without cardiac symptoms 3, 2
• Active cardiac conditions requiring delay: unstable angina, recent MI (<30 days), decompensated heart failure, significant arrhythmias, severe valvular disease 3, 2
• Bleeding history: spontaneous bruising, excessive surgical bleeding, family history of coagulopathy 1, 2
• Medication review: anticoagulants, antiplatelets, diuretics, ACE inhibitors, ARBs, NSAIDs, insulin, SGLT2 inhibitors 1
• Chronic conditions: diabetes, hypertension, heart failure, chronic kidney disease, liver disease, COPD 1, 2

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Step 2: Risk Stratification

Surgical Risk Classification 2

• Low-risk surgery: cataract, minor dermatologic procedures (no routine testing needed) 1, 5
• Intermediate-risk surgery: intraperitoneal, orthopedic, urologic procedures
• High-risk surgery: vascular, prolonged procedures with substantial blood loss anticipated 1

Cardiac Risk Assessment 3, 2

Use the Lee Risk Index (1 point each):

• High-risk surgery
• History of ischemic heart disease
• History of congestive heart failure
• History of cerebrovascular disease
• Insulin-dependent diabetes
• Preoperative creatinine >2.0 mg/dL

Patients with ≥2 risk factors AND poor functional capacity (<4 METs) require stress testing only if results will change management. 3

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Step 3: Selective Laboratory Testing

Electrocardiography 1, 3, 2

Order ECG for:

• Patients with cardiovascular risk factors (diabetes, hypertension, coronary disease, heart failure, cerebrovascular disease, renal impairment) undergoing intermediate- or high-risk surgery 1, 2
• Patients with recent chest pain or ischemic symptoms 2
• Do NOT order for asymptomatic patients undergoing low-risk surgery 1, 2

Complete Blood Count 1, 2

Order CBC for:

• Diseases increasing anemia risk: liver disease, hematologic disorders, chronic kidney disease 2
• History of anemia or recent blood loss 1
• Anticipated significant perioperative blood loss 1
• Cardiovascular surgery or specific high-risk procedures 2

Electrolytes and Creatinine 1, 2

Order for:

• Patients taking diuretics, ACE inhibitors, ARBs, NSAIDs, or digoxin 2
• Chronic kidney disease, hypertension, heart failure, complicated diabetes, or liver disease 2
• All neurosurgery or cardiovascular surgery patients 2

Glucose and Hemoglobin A1C 1, 2

Order random glucose for patients at high risk of undiagnosed diabetes 2

For known diabetics:

• Target A1C <8% for elective surgeries whenever possible 1
• Order A1C only if results will change perioperative management 2

Coagulation Studies 1, 2

Order PT/aPTT/platelet count for:

• Personal or family history of bleeding disorders 1, 2
• Liver disease or conditions predisposing to coagulopathy 1, 2
• Patients taking anticoagulants 1, 2
• Do NOT order routinely—prevalence of inherited coagulopathies is low 1

Cardiac Biomarkers 2

Consider BNP/NT-proBNP for high-risk patients undergoing major surgery for prognostic information 2

Consider troponin testing for high-risk patients before and 48-72 hours after major surgery 2

Chest Radiography 1, 2

Order only for:

• New or unstable cardiopulmonary signs or symptoms 1, 2
• Patients at risk of postoperative pulmonary complications if results would change management 2

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Step 4: Perioperative Medication Management

Diabetes Medications 1

Day of Surgery:

• Metformin: Hold on day of surgery 1
• SGLT2 inhibitors: Discontinue 3-4 days before surgery 1
• Other oral agents: Hold morning of surgery 1
• NPH insulin: Give half of usual dose 1
• Long-acting insulin analogs: Give 75-80% of usual dose 1
• Insulin pumps: Continue basal rate at 75-80% 1

Perioperative glucose targets: 100-180 mg/dL 1

Monitor blood glucose every 2-4 hours while NPO and dose with short- or rapid-acting insulin as needed 1

Anticoagulation Management 1

Direct Oral Anticoagulants (DOACs):

For high-bleed-risk surgery (intracranial, spinal):

• Apixaban, rivaroxaban, edoxaban: Hold for 2 full days (60-68 hours) before surgery 1
• Dabigatran with normal renal function (CrCl ≥50): Hold for 2 full days 1
• Dabigatran with impaired renal function (CrCl <50): Hold for 3-4 full days 1

For low-to-moderate-bleed-risk surgery:

• Apixaban, rivaroxaban, edoxaban: Hold for 1 full day (30-36 hours) before surgery 1
• Dabigatran with normal renal function: Hold for 1 full day 1

No DOAC on day of surgery 1

Warfarin:

• Obtain PT/INR just prior to procedure 6
• For minimal invasive procedures: adjust dosage to maintain INR at low end of therapeutic range 6
• For procedures requiring interruption: timing depends on target INR and bleeding risk 6

Cardiovascular Medications 3

Continue through surgery:

• ACE inhibitors: Continue through morning of surgery with sip of water 3
• Statins: Continue throughout perioperative period; ideally started ≥30 days before surgery 3

Beta-blockers:

• If started ≥1 month before surgery, titrate to heart rate <70 bpm and systolic BP ≥120 mmHg 3

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Step 5: Special Populations

Patients with Renal Impairment (eGFR <45 mL/min/1.73 m²) 2

• Check CBC (anemia risk >50% when eGFR <30) 2
• Check calcium, phosphate, PTH, alkaline phosphatase 2
• Adjust DOAC interruption intervals for dabigatran 1

Patients Undergoing Spine Surgery 1

Inform patients that these conditions increase POVL risk:

• Preoperative anemia 1
• Vascular risk factors: hypertension, diabetes, peripheral vascular disease, coronary artery disease, previous stroke, carotid stenosis 1
• Obesity and tobacco use 1
• Male sex 1
• Prolonged procedures with substantial blood loss 1

Healthy Patients Undergoing Minor Surgery 2

No routine testing is indicated for ASA Class 1 patients undergoing low-risk surgery 2

Consider pregnancy testing for all females of childbearing age 2

Cataract Surgery 5

No routine preoperative laboratory testing is indicated 5

Consider preoperative medical evaluation only for patients with poorly controlled COPD, hypertension, recent MI, unstable angina, poorly controlled heart failure, or poorly controlled diabetes 5

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Common Pitfalls to Avoid

• Do not order tests "just to be safe" or based on arbitrary age cutoffs 2
• Do not order tests that will not change perioperative management 2
• Do not use routine testing protocols applied to all patients regardless of risk 2
• Do not fail to assess functional capacity—it is the single most important predictor of perioperative risk 3
• Do not forget to hold SGLT2 inhibitors 3-4 days before surgery (newer requirement) 1
• Do not use correction-only insulin in diabetic patients perioperatively—basal-bolus coverage reduces complications 1