What are the medical reasons to cancel surgery based on abnormal laboratory results?

From the Guidelines

Cancel surgery if lab results indicate any of the following:

• Hemoglobin level below 7 g/dL or hematocrit below 21% for non-anemic patients
• Platelet count below 50,000 cells/μL
• International Normalized Ratio (INR) above 1.5
• Prothrombin Time (PT) or Partial Thromboplastin Time (PTT) significantly elevated
• Electrolyte imbalances such as potassium below 3.5 mmol/L or above 5.5 mmol/L
• Blood urea nitrogen (BUN) above 40 mg/dL or creatinine above 2.0 mg/dL in patients with known kidney disease
• Glucose levels above 200 mg/dL in diabetic patients
• White blood cell count above 15,000 cells/μL or below 3,000 cells/μL
• Aspartate aminotransferase (AST) or alanine aminotransferase (ALT) above 3 times the upper limit of normal as indicated by 1.

Additionally, consider canceling surgery if the patient has unstable coronary disease, decompensated heart failure, or severe arrhythmia or valvular heart disease as stated in 1, or if the patient is taking medications that may increase the risk of bleeding, such as warfarin, aspirin, or clopidogrel, and these medications cannot be safely discontinued before surgery 1. The decision to cancel surgery should be made on a case-by-case basis, taking into account the patient's overall health, the urgency of the surgery, and the potential risks and benefits of proceeding with the operation. It is also important to consider the patient's blood pressure, as deferring surgery may be considered in patients with planned elective major surgery and SBP of 180 mm Hg or higher or DBP of 110 mm Hg or higher as recommended in 1.

Key Considerations

• Cardiovascular risk factors: Patients with active cardiac conditions, such as unstable coronary disease, decompensated heart failure, or severe arrhythmia or valvular heart disease, may require cancellation or delay of surgery until the cardiac problem has been clarified and treated appropriately 1.
• Medication management: Patients taking medications that may increase the risk of bleeding, such as warfarin, aspirin, or clopidogrel, should be carefully evaluated, and the decision to cancel surgery should be made on a case-by-case basis 1.
• Electrolyte and metabolic abnormalities: Patients with significant electrolyte imbalances, such as potassium below 3.5 mmol/L or above 5.5 mmol/L, or glucose levels above 200 mg/dL in diabetic patients, may require cancellation of surgery until these abnormalities are corrected.
• Hematologic abnormalities: Patients with a hemoglobin level below 7 g/dL or hematocrit below 21% for non-anemic patients, or a platelet count below 50,000 cells/μL, may require cancellation of surgery until these abnormalities are corrected.

Laboratory Results

The following laboratory results may indicate a need to cancel surgery:

• Hemoglobin: below 7 g/dL or hematocrit below 21% for non-anemic patients
• Platelet count: below 50,000 cells/μL
• INR: above 1.5
• PT or PTT: significantly elevated
• Electrolytes: potassium below 3.5 mmol/L or above 5.5 mmol/L
• BUN: above 40 mg/dL or creatinine above 2.0 mg/dL in patients with known kidney disease
• Glucose: above 200 mg/dL in diabetic patients
• White blood cell count: above 15,000 cells/μL or below 3,000 cells/μL
• AST or ALT: above 3 times the upper limit of normal

It is essential to consider the patient's overall health, the urgency of the surgery, and the potential risks and benefits of proceeding with the operation when making the decision to cancel surgery.

From the FDA Drug Label

Discontinuation: Premature discontinuation increases risk of cardiovascular events. Discontinue 5 days prior to elective surgery that has a major risk of bleeding.

The medical reason to cancel surgery based on abnormal laboratory results is not explicitly stated in the provided drug labels. However, it can be inferred that abnormal laboratory results indicating a high risk of bleeding may be a reason to cancel surgery, especially if the patient is taking clopidogrel.

• Bleeding risk: Patients taking clopidogrel are at an increased risk of bleeding, and elective surgery with a major risk of bleeding should be avoided.
• Discontinuation of clopidogrel: The drug label recommends discontinuing clopidogrel 5 days prior to elective surgery with a major risk of bleeding. It is essential to note that the decision to cancel surgery should be made on a case-by-case basis, considering the individual patient's risk factors and medical history 2.

From the Research

Medical Reasons to Cancel Surgery Based on Abnormal Laboratory Results

The decision to cancel surgery due to abnormal laboratory results is often based on the patient's overall health and the potential risks associated with the procedure. Some medical reasons to cancel surgery include:

• Low hemoglobin levels: A hemoglobin level below 7 g/dL is generally considered a threshold for transfusion 3, but some studies suggest that even higher levels may be associated with adverse outcomes 4, 5, 6.
• Significant decrease in hemoglobin concentration: A decrease of at least 50% from the preoperative hemoglobin level during surgery is associated with adverse outcomes, even if the absolute hemoglobin level remains above the transfusion threshold of 7 g/dL 5, 6.
• Anemia: Anemia is an independent risk factor for transfusion, postoperative complications, and mortality 4.
• Abnormal coagulation parameters: Abnormal coagulation parameters, such as a high international normalized ratio (INR) or low platelet count, may increase the risk of bleeding during surgery.

Specific Hemoglobin Thresholds

Some studies have investigated specific hemoglobin thresholds for canceling surgery:

• A hemoglobin level below 12 g/dL in women is associated with increased risk of postoperative complications and transfusion 4.
• A hemoglobin level below 10 g/dL may be acceptable for hip fracture surgery without transfusion using a patient blood management protocol 7.
• A decrease of at least 50% from the preoperative hemoglobin level during cardiac surgery is associated with adverse outcomes, even if the absolute hemoglobin level remains above the transfusion threshold of 7 g/dL 6.

Patient-Specific Factors

The decision to cancel surgery due to abnormal laboratory results should take into account patient-specific factors, such as:

• Underlying medical conditions: Patients with underlying medical conditions, such as heart disease or lung disease, may be at higher risk for complications during surgery.
• Age: Older patients may be at higher risk for complications during surgery due to decreased physiological reserve.
• Overall health status: Patients with poor overall health status may be at higher risk for complications during surgery.