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The CPT® Code 80164 refers to a laboratory test specifically designed to measure the total concentration of valproic acid, also known as dipropylacetic acid or depakote. Valproic acid is classified as an anticonvulsant medication, which is commonly utilized in the management of various medical conditions, including seizure disorders, the manic phase of bipolar disorder, and migraine headaches. The mechanism of action for valproic acid involves altering the levels of certain neurotransmitters in the brain, which helps to stabilize mood and prevent seizures. The total valproic acid test is crucial for monitoring the effectiveness of drug therapy, ensuring patient compliance with prescribed treatment regimens, and evaluating the potential for drug toxicity. In cases where the total valproic acid concentration falls within the normal range, a separate test for free valproic acid (CPT® Code 80165) may be conducted to investigate the underlying causes of toxicity, particularly in patients who exhibit altered or unpredictable protein binding capacities. The testing process involves obtaining a blood sample through venipuncture, which is performed just prior to the administration of medication to capture the trough level of the drug. The laboratory analysis for total valproic acid is conducted using fluorescence polarization immunoassay techniques, while the assessment for free valproic acid employs quantitative enzyme multiplied immunoassay methods.
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The test for total valproic acid (CPT® Code 80164) is indicated for the following conditions:
The procedure for testing total valproic acid involves several key steps:
After the procedure, the patient may experience minimal discomfort at the venipuncture site, which typically resolves quickly. There are no specific post-procedure care instructions required for this test. However, it is important for healthcare providers to communicate the results of the test to the patient and adjust the valproic acid dosage as necessary based on the total concentration levels obtained. Regular monitoring may be recommended to ensure ongoing therapeutic effectiveness and to prevent potential toxicity.
| Short Descr | ASSAY DIPROPYLACETIC ACD TOT | Medium Descr | DRUG ASSAY VALPROIC DIPROPYLACETIC ACID TOTAL | Long Descr | Valproic acid (dipropylacetic acid); total | Status Code | Statutory Exclusion (from MPFS, may be paid under other methodologies) | Global Days | XXX - Global Concept Does Not Apply | PC/TC Indicator (26, TC) | 9 - Not Applicable | Multiple Procedures (51) | 9 - Concept does not apply. | Bilateral Surgery (50) | 9 - Concept does not apply. | Physician Supervisions | 09 - Concept does not apply. | Assistant Surgeon (80, 82) | 9 - Concept does not apply. | Co-Surgeons (62) | 9 - Concept does not apply. | Team Surgery (66) | 9 - Concept does not apply. | Diagnostic Imaging Family | 99 - Concept Does Not Apply | CLIA Waived (QW) | No | APC Status Indicator | Conditionally packaged laboratory tests | Type of Service (TOS) | 5 - Diagnostic Laboratory | Berenson-Eggers TOS (BETOS) | T1H - Lab tests - other (non-Medicare fee schedule) | MUE | 2 | CCS Clinical Classification | 235 - Other Laboratory |
| 90 | Reference (outside) laboratory: when laboratory procedures are performed by a party other than the treating or reporting physician or other qualified health care professional, the procedure may be identified by adding modifier 90 to the usual procedure number. | GW | Service not related to the hospice patient's terminal condition | GV | Attending physician not employed or paid under arrangement by the patient's hospice provider | Q4 | Service for ordering/referring physician qualifies as a service exemption | 91 | Repeat clinical diagnostic laboratory test: in the course of treatment of the patient, it may be necessary to repeat the same laboratory test on the same day to obtain subsequent (multiple) test results. under these circumstances, the laboratory test performed can be identified by its usual procedure number and the addition of modifier 91. note: this modifier may not be used when tests are rerun to confirm initial results; due to testing problems with specimens or equipment; or for any other reason when a normal, one-time, reportable result is all that is required. this modifier may not be used when other code(s) describe a series of test results (eg, glucose tolerance tests, evocative/suppression testing). this modifier may only be used for laboratory test(s) performed more than once on the same day on the same patient. | 26 | Professional component: certain procedures are a combination of a physician or other qualified health care professional component and a technical component. when the physician or other qualified health care professional component is reported separately, the service may be identified by adding modifier 26 to the usual procedure number. | 59 | Distinct procedural service: under certain circumstances, it may be necessary to indicate that a procedure or service was distinct or independent from other non-e/m services performed on the same day. modifier 59 is used to identify procedures/services, other than e/m services, that are not normally reported together, but are appropriate under the circumstances. documentation must support a different session, different procedure or surgery, different site or organ system, separate incision/excision, separate lesion, or separate injury (or area of injury in extensive injuries) not ordinarily encountered or performed on the same day by the same individual. however, when another already established modifier is appropriate it should be used rather than modifier 59. only if no more descriptive modifier is available, and the use of modifier 59 best explains the circumstances, should modifier 59 be used. note: modifier 59 should not be appended to an e/m service. to report a separate and distinct e/m service with a non-e/m service performed on the same date, see modifier 25. | 76 | Repeat procedure or service by same physician or other qualified health care professional: it may be necessary to indicate that a procedure or service was repeated by the same physician or other qualified health care professional subsequent to the original procedure or service. this circumstance may be reported by adding modifier 76 to the repeated procedure or service. note: this modifier should not be appended to an e/m service. | 77 | Repeat procedure by another physician or other qualified health care professional: it may be necessary to indicate that a basic procedure or service was repeated by another physician or other qualified health care professional subsequent to the original procedure or service. this circumstance may be reported by adding modifier 77 to the repeated procedure or service. note: this modifier should not be appended to an e/m service. | 95 | Synchronous telemedicine service rendered via a real-time interactive audio and video telecommunications system: synchronous telemedicine service is defined as a real-time interaction between a physician or other qualified health care professional and a patient who is located at a distant site from the physician or other qualified health care professional. the totality of the communication of information exchanged between the physician or other qualified health care professional and the patient during the course of the synchronous telemedicine service must be of an amount and nature that would be sufficient to meet the key components and/or requirements of the same service when rendered via a face-to-face interaction. modifier 95 may only be appended to the services listed in appendix p. appendix p is the list of cpt codes for services that are typically performed face-to-face, but may be rendered via a real-time (synchronous) interactive audio and video telecommunications system. | CC | Procedure code change (use 'cc' when the procedure code submitted was changed either for administrative reasons or because an incorrect code was filed) | GA | Waiver of liability statement issued as required by payer policy, individual case | GC | This service has been performed in part by a resident under the direction of a teaching physician | GY | Item or service statutorily excluded, does not meet the definition of any medicare benefit or, for non-medicare insurers, is not a contract benefit | GZ | Item or service expected to be denied as not reasonable and necessary | X5 | Diagnostic services requested by another clinician: for reporting services by a clinician who furnishes care to the patient only as requested by another clinician or subsequent and related services requested by another clinician; this modifier is reported for patient relationships that may not be adequately captured by the above alternative categories; reporting clinician service examples include but are not limited to, the radiologist's interpretation of an imaging study requested by another clinician | XU | Unusual non-overlapping service, the use of a service that is distinct because it does not overlap usual components of the main service |
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| 2015-01-01 | Changed | Description Changed |
| 2013-01-01 | Changed | Medium description changed per AMA 2013 corrections document dated January 25, 2013. |
| 2011-01-01 | Changed | Short description changed. |
| 1993-01-01 | Added | First appearance in code book in 1993. |
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