Which preoperative laboratory tests are commonly obtained for major surgery?

• A. CBC, electrolytes/creatinine, coagulation studies (PT/INR, aPTT), type and screen
• B. Urinalysis only
• C. Chest X-ray only
• D. None

Answer: (A)

Before major surgery, the goal is to have a baseline picture of blood health, organ function, and bleeding risk, plus the ability to transfuse if needed. A complete blood count checks for anemia, infection, and platelet status, guiding decisions about surgical risk and tolerance to blood loss. A basic metabolic panel with creatinine evaluates electrolytes and kidney function, which influence fluid management, drug dosing, and overall perioperative stability. Coagulation studies (PT/INR and aPTT) reveal how well the blood will clot, helping anticipate bleeding risk and plan any needed interventions. A type and screen confirms the patient’s blood type and screens for antibodies so compatible blood can be available quickly if a transfusion becomes necessary. Taken together, these tests provide essential, actionable information for anesthesia planning, perioperative management, and transfusion readiness.

Relying on urinalysis or chest imaging alone would not give a comprehensive view of these critical domains, and saying none would miss important baseline data, so the full laboratory panel is the most informative choice.