From the Guidelines
Routine coagulation studies are not typically required for preoperative workup before shoulder arthroscopy in healthy patients with no bleeding history. For most patients, a thorough history and physical examination focusing on bleeding risk factors is sufficient 1. If the patient has a history of bleeding disorders, liver disease, is on anticoagulant therapy, or has other risk factors for coagulopathy, then selective coagulation studies may be warranted, including prothrombin time (PT), partial thromboplastin time (PTT), and platelet count.
Key Considerations
- Patients on anticoagulants like warfarin should have their INR checked and typically hold their medication according to established protocols
- For patients on direct oral anticoagulants (DOACs) like apixaban or rivaroxaban, these should generally be stopped 48-72 hours before surgery
- Low molecular weight heparin should be stopped 24 hours preoperatively
- Antiplatelet agents like aspirin and clopidogrel typically require 5-7 days of discontinuation before surgery The rationale for selective rather than routine coagulation testing is that abnormal results are rare in asymptomatic patients without risk factors, and routine testing has not been shown to predict or reduce perioperative bleeding complications in low-risk procedures like shoulder arthroscopy 1.
From the Research
Coagulation Studies for Shoulder Arthroscopy
- Coagulation screens, including prothrombin time (PT) and activated partial thromboplastin time (APTT), are commonly performed pre-operatively to assess bleeding risk 2.
- However, the clinical significance of isolated prolongation of PT or APTT is often limited, and abnormal clotting screens may not always be associated with clinically significant decreases in coagulation factors 2.
- The international normalized ratio (INR) scale, which is used to report PT results, has limitations and may not be suitable for all clinical settings 3.
Routine Pre-Operative Coagulation Screening
- Routine pre-operative coagulation screening tests, including PT and APTT, may not be necessary for healthy patients undergoing elective surgery, as they have low sensitivity and low bleeding predictive value 4.
- The decision to perform coagulation studies should be based on the patient's medical history and the presence of bleeding tendencies 4.
Interpretation of Coagulation Studies
- The interpretation of PT and APTT results can be complex, and different calculation methods may be used to determine correction or noncorrection of plasma mixing tests 5.
- Percentage correction is a suitable calculation method for interpreting PT mixing test results, while APTT mixing tests require additional confirmation with the subtraction III calculation 5.
- Coagulation studies, including PT, APTT, and bleeding time, can provide valuable information in the assessment of bleeding patients, but their results must be interpreted in the context of the patient's clinical presentation 6.