From the Guidelines
Prior to endoscopic evaluation, patients should ideally have an INR <1.5, with stricter thresholds for high-risk interventions, and a glomerular filtration rate (GFR) >30 mL/min, while other laboratory parameters such as White Blood Cell (WBC) count, Absolute Neutrophil Count (ANC), Hemoglobin (Hgb)/Hematocrit (Hct), and Platelet (Plt) count should be within normal limits or near-normal limits to minimize procedural risks, as recommended by the most recent guidelines 1.
Ideal Laboratory Parameters
The following are the ideal laboratory parameters prior to endoscopic evaluation:
- White Blood Cell (WBC) count: within normal limits (4,000-11,000/μL) to rule out active infection
- Absolute Neutrophil Count (ANC): >1,000/μL for neutropenic patients, though procedures may proceed with caution at lower levels with appropriate prophylaxis
- Hemoglobin (Hgb): >8 g/dL and Hematocrit (Hct): >24% to ensure adequate oxygen-carrying capacity, particularly for procedures with risk of bleeding
- Platelet (Plt) count: >50,000/μL for diagnostic procedures and >75,000-100,000/μL for therapeutic interventions with higher bleeding risk
- International Normalized Ratio (INR): <1.5 for most procedures, with stricter thresholds (<1.3) for high-risk interventions, as recommended by the British Society of Gastroenterology (BSG) and European Society of Gastrointestinal Endoscopy (ESGE) guidelines 1
- Glomerular Filtration Rate (GFR): >30 mL/min, particularly when using contrast agents, as recommended by the most recent guidelines 1
Rationale
These parameters help ensure patient safety by minimizing risks of bleeding, infection, and cardiopulmonary complications during endoscopic procedures. Individual risk assessment should guide decisions for patients with values outside these ranges. The most recent guidelines from the BSG and ESCE provide recommendations for the management of anticoagulation and antiplatelet therapy in patients undergoing endoscopy, including the use of warfarin, direct oral anticoagulants (DOACs), and low molecular weight heparin (LMWH) 1.
From the Research
Ideal Laboratory Parameters for Endoscopic Evaluation
The ideal laboratory parameters prior to endoscopic evaluation are not explicitly stated in the provided studies. However, the following parameters are mentioned as being relevant in various contexts:
- White Blood Cell (WBC) count:
- A study on the effect of clopidogrel plus aspirin and aspirin monotherapy on hematological parameters found that combination therapy with clopidogrel plus aspirin resulted in significantly greater reductions in WBC counts compared to aspirin alone 2.
- Absolute Neutrophil Count (ANC):
- No specific information is available on ANC in the provided studies.
- Hemoglobin (Hgb)/Hematocrit (Hct):
- A study on the screening for anemia in patients on warfarin found that regular measurement of complete blood count (CBC) with INR led to the detection of otherwise asymptomatic diseases, including gastrointestinal malignancies and pre-malignant lesions 3.
- Another study found that reductions in hemoglobin levels and hematocrit in users of clopidogrel plus aspirin were significantly greater than those in users of aspirin alone 2.
- Platelet (Plt) count:
- A study on the effect of clopidogrel plus aspirin and aspirin monotherapy on hematological parameters found that combination therapy with clopidogrel plus aspirin resulted in significantly greater reductions in platelet counts compared to aspirin alone 2.
- Thrombocytopenia was associated with cardiovascular depression caused by sedation in patients undergoing endoscopic retrograde cholangiopancreatography 4.
- International Normalized Ratio (INR):
- A study on the screening for anemia in patients on warfarin found that regular measurement of CBC with INR led to the detection of otherwise asymptomatic diseases, including gastrointestinal malignancies and pre-malignant lesions 3.
- Glomerular Filtration Rate (GFR):
- No specific information is available on GFR in the provided studies.
Preoperative Laboratory Testing for Endoscopic Procedures
The utility of preoperative laboratory testing for endoscopic procedures is debated:
- A study on the effect and predictive value of routine preoperative laboratory testing for endoscopic retrograde cholangiopancreatography found that routine universal preoperative lab testing was not successful in predicting adverse effects in endoscopic retrograde cholangiopancreatography procedures 4.
- Another study suggested that endoscopic evaluation of liver transplant candidates often identifies important gastrointestinal pathology and frequently impacts patient selection and management before orthotopic liver transplantation (OLT) 5.