What should a preoperative evaluation note for a patient with an unspecified medical history and current medications, including anticoagulants (e.g. warfarin) and antiplatelets (e.g. aspirin), undergoing a surgical procedure include?

Preoperative Evaluation Note Structure for Patients on Anticoagulants/Antiplatelets

A preoperative evaluation note must document previous medical records review, physical examination findings, medication reconciliation with specific timing of anticoagulant/antiplatelet discontinuation, coagulation status assessment, bleeding/thrombotic risk stratification, and a clear plan for perioperative anticoagulation management. 1

Essential Documentation Components

Medical History Review

• Document all congenital or acquired blood disorders including factor VIII deficiency, sickle cell anemia, idiopathic thrombocytopenic purpura, and liver disease 1
• Record complete anticoagulant/antiplatelet medication list with specific agents (warfarin, clopidogrel, aspirin), doses, and timing of last administration 1
• Identify risk factors for organ ischemia including cardiorespiratory disease, coronary artery disease, history of congestive heart failure, cerebrovascular disease, diabetes mellitus, and renal insufficiency 1
• Document bleeding history including spontaneous bruising, excessive surgical bleeding, and family history of heritable coagulopathy 1
• Record use of vitamins or herbal supplements that may affect coagulation (garlic, Ginkgo biloba, ginger, ginseng) 1, 2
• Note previous exposure to drugs that may cause allergic reactions upon repeat exposure (e.g., aprotinin) 1

Physical Examination

• Perform focused cardiovascular examination to assess for signs of heart failure, valvular disease, or arrhythmias 1
• Examine for signs of bleeding disorders including petechiae, ecchymoses, or mucosal bleeding 1
• Assess functional capacity using validated tools or clinical assessment of ability to perform activities of daily living 1, 3

Laboratory Testing (Risk-Stratified)

For patients on anticoagulants (warfarin, direct oral anticoagulants):

• Hemoglobin/hematocrit to establish baseline and predict transfusion need 1, 3
• Coagulation profile including PT/INR, aPTT to assess current anticoagulation status 1, 3
• Renal function tests (BUN, creatinine) as warfarin effects may last several days depending on patient response 1, 3
• Electrolytes if patient has heart disease or takes medications affecting electrolyte balance 1, 3

For patients on antiplatelet agents (aspirin, clopidogrel):

• Hemoglobin/hematocrit 1, 3
• Platelet count if history suggests thrombocytopenia or hematologic disorder 1
• Coagulation testing only if medical conditions associated with impaired hemostasis exist (liver disease, diseases of hematopoiesis) or abnormal bleeding history 1

Additional testing based on comorbidities:

• ECG for patients with known heart disease, peripheral vascular disease, cerebrovascular disease, or cardiovascular risk factors undergoing intermediate- or high-risk surgery 1, 3
• Random glucose or HbA1c only if results would alter perioperative management in diabetic patients 1, 3

Anticoagulation Management Plan

For warfarin:

• Document timing of discontinuation: Stop warfarin 5-6 days before surgery to allow INR normalization 1
• Verify INR testing plan: Check INR preoperatively to confirm hemostasis (target INR <1.5 for most procedures) 1
• Document bridging anticoagulation decision: Patients at high risk for perioperative thromboembolism (mechanical heart valves, atrial fibrillation with CHADS₂ ≥5, recent VTE within 3 months) require bridging with therapeutic-dose LMWH or unfractionated heparin 1
• Specify reversal agent availability: Vitamin K, prothrombin complex concentrate, recombinant activated factor VII, or FFP should be available if urgent reversal needed 1, 2
• Plan resumption timing: Resume warfarin 12-24 hours after surgery (evening of or next day) when adequate hemostasis achieved 1

For clopidogrel:

• Document timing of discontinuation: Stop clopidogrel 7-10 days before elective surgery as effects may last approximately one week 1
• Special consideration for coronary stents: Patients with bare-metal stent <6 weeks or drug-eluting stent <6 months should continue antiplatelet therapy or delay surgery if possible 1

For aspirin:

• Document continuation vs. discontinuation decision: Continue aspirin for minor dental, skin, or eye procedures; stop 7-10 days before procedures with high bleeding risk 1
• For CABG surgery: Stop aspirin 7-10 days before surgery unless myocardial ischemia risk outweighs bleeding risk 1

Risk Stratification Documentation

Bleeding risk factors to document:

• High-intensity anticoagulation (INR >4.0) 2
• Age ≥65 years 2
• History of gastrointestinal bleeding 2
• Hypertension, cerebrovascular disease, serious heart disease 2
• Anemia, malignancy, trauma 2
• Renal insufficiency 2
• Concomitant NSAIDs or antiplatelet agents 2

Thrombotic risk factors to document:

• Mechanical prosthetic heart valves 2
• Atrial fibrillation with prior stroke/TIA, age >75, heart failure, hypertension, or diabetes 2
• Recent venous thromboembolism 1
• Hypercoagulable states 1

Surgical Risk Assessment

• Classify procedure bleeding risk: High-risk procedures (intracranial, spinal, cardiac, major vascular) vs. low-risk procedures (cataract, minor dental, skin procedures) 1
• Document expected blood loss: Ensure blood products available when significant blood loss or transfusion expected 1

Patient Counseling Documentation

• Document informed consent discussion regarding potential risks vs. benefits of blood transfusion 1
• Record patient preferences regarding transfusion 1
• Document discussion of bleeding vs. thrombotic risks when altering anticoagulation status 1

Common Pitfalls to Avoid

• Do not delay surgery unnecessarily: If anticoagulation discontinued but insufficient time elapsed, delay surgery until drug effects dissipate rather than proceeding with elevated bleeding risk 1
• Do not order routine coagulation testing: Reserve for patients with specific indications (anticoagulant use, liver disease, bleeding history, hematologic disorders) 1
• Do not assume normal coagulation tests exclude bleeding disorders: Von Willebrand disease may present with normal PT/aPTT 1
• Do not forget genetic considerations: Lower warfarin doses may be needed for patients with CYP2C9 or VKORC1 genetic variations 2
• Do not overlook herbal supplements: Many botanicals have anticoagulant, antiplatelet, or fibrinolytic properties additive to warfarin effects 2
• Do not continue therapeutic anticoagulation without clear indication: Balance thrombotic risk against bleeding risk for each individual case 1

Timing Considerations

The preoperative evaluation should be completed well enough in advance to:

• Allow time for anticoagulation discontinuation (5-10 days depending on agent) 1
• Correct identified medical abnormalities 4
• Arrange bridging anticoagulation if indicated 1
• Ensure blood product availability for high-risk procedures 1