Summary & Overview
CPT 82638: Dibucaine Number (Serum Cholinesterase Assay)
CPT code 82638 covers the laboratory assay that determines the dibucaine number, a measure of serum cholinesterase (pseudocholinesterase) activity. The dibucaine number is clinically important for evaluating pesticide toxicity and for assessing patient risk related to use of certain anesthetic agents metabolized by cholinesterase. Nationally, this test supports perioperative safety and toxicology evaluation in acute care, outpatient, and preoperative settings.
Key payers in the market analysis include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. Readers will find a concise overview of clinical context, common sites of service, and the role of the test in anesthetic risk assessment and pesticide exposure evaluation. The publication summarizes reimbursement and coverage benchmarks, typical billing considerations, and relevant policy updates affecting laboratory services. It also outlines operational implications for laboratories and clinical teams ordering the test.
This summary is intended for laboratory managers, billing professionals, and clinicians seeking a national perspective on clinical use, billing classification, and payer coverage landscape for CPT code 82638. Data not available in the input is noted where applicable.
Billing Code Overview
CPT code 82638 describes a laboratory measurement used to determine the dibucaine number, which assesses cholinesterase (pseudocholinesterase) activity in serum. The dibucaine number helps clinicians evaluate pesticide exposure and assess patient risk for certain anesthetic agents that are metabolized by cholinesterase.
Service type: Clinical laboratory testing — specialty chemistry/enzymology
Typical site of service: Clinical laboratory or hospital laboratory
Clinical & Coding Specifications
Clinical Context
A typical patient is an adult scheduled for preoperative evaluation prior to planned administration of succinylcholine or other short-acting depolarizing neuromuscular blockers, or a patient with suspected organophosphate pesticide exposure presenting to an occupational medicine clinic or emergency department. The clinician orders 82638 (dibucaine number / serum cholinesterase activity) when there is concern for atypical pseudocholinesterase activity that increases risk for prolonged apnea after succinylcholine or when evaluating cholinesterase inhibition from pesticide exposure. Workflow: the provider documents indication and obtains informed consent for blood draw; a phlebotomist collects serum sample; the specimen is sent to the clinical laboratory with test order 82638; the laboratory analyst performs the dibucaine inhibition assay and reports the dibucaine number and serum cholinesterase activity in the result; the ordering clinician reviews results for perioperative risk assessment or toxicologic interpretation and documents clinical implications and any anesthesia plan modifications or occupational exposure management in the medical record.
Coding Specifications
| Modifier | Description | When to Use |
|---|---|---|
26 | Professional component | When only the laboratory professional interprets or reports the test and the technical component is billed separately. |