Preoperative Evaluation for Endoscopy

Introduction to Preoperative Evaluation

The American Society of Anesthesiologists (ASA) physical status classification is the standard recommended scale for preoperative evaluation before endoscopic procedures, which divides patients into five classes based on their physical status 1, 2, 3, 4.

The ASA classification is a widely used and validated risk stratification system for endoscopic procedures, with classes including: Class I (no organic, physiological, biochemical, or psychiatric disturbances), Class II (mild to moderate systemic disturbance), Class III (severe systemic disturbance), Class IV (severe systemic disturbance that is a constant threat to life), and Class V (moribund patient with little chance of survival) 1, 2, 3, 4.
A structured preendoscopic questionnaire should include evaluation of general health status, specific medical conditions (such as myocardial infarction, stroke, pulmonary problems, hepatic problems, hypertension, diabetes mellitus, coagulation disorders, seizures, and rheumatic fever), medication review (including aspirin, oral contraceptives, and over-the-counter medications), and history of allergies and anesthesia problems 1, 2, 3, 4, 5.

The American Society of Anesthesiologists recommends that the timing of preoperative evaluation be guided by the combination of the invasiveness of the procedure and the severity of the patient's disease, with high-risk patients requiring a complete evaluation before the day of surgery 6, 7, 8.

A directed physical examination should include evaluation of airway, lungs, and heart, with documentation of vital signs, and may also include examination of other systems based on the patient's history and the type of procedure 6, 7, 8, 9.

High-risk patients include those with severe systemic disease (ASA ≥3), those undergoing difficult or prolonged procedures, emergencies, procedures requiring large-diameter instruments, and those requiring combination benzodiazepine/opioid therapy 1, 4.

Preoperative tests should be selective, not routine, and ordered only after considering specific information from the patient's history, physical examination, and type of procedure, including hemoglobin/hematocrit, coagulation studies, electrolytes, and renal function tests 7, 8, 10.
Indications for specific tests include history of anemia, bleeding, liver disease, hematologic disorders, extreme age, and type and invasiveness of the procedure 8, 10, 9.