CPT® Code 85175

Official Description

Clot lysis time, whole blood dilution

Common Language Description

The CPT® Code 85175 refers to a laboratory test known as clot lysis time, which utilizes whole blood dilution to evaluate the functionality of the fibrinolytic system. This test is crucial for understanding how effectively the body can break down fibrin, a protein that forms the structural basis of blood clots. The process of fibrin breakdown is primarily mediated by the plasmin serine protease pathway, which is essential for maintaining hemostatic balance. An increase in the activity of this pathway can lead to a heightened risk of bleeding, known as hemorrhage, while a decrease can result in the formation of unwanted blood clots, or thrombosis. To perform this test, a sample of whole blood is collected and placed in a test tube, where it is clotted by the addition of thrombin, a clotting factor. The sample is then incubated at a controlled temperature of 37 degrees Celsius. During the incubation period, the test observes and counts the release of erythrocytes, or red blood cells, from the clot at 30-minute intervals. To enhance the clot lysis reaction, substances such as exogenous tissue plasminogen activator (TPA), activated Protein C, or anti-PAI antibodies may be introduced into the test tube. This laboratory test is particularly useful in diagnosing and monitoring conditions associated with atherosclerosis, assessing the coagulation status in patients who have undergone liver transplants, and managing patients during and after cardiovascular surgical procedures.

1. Indications

The clot lysis time test (CPT® Code 85175) is indicated for several clinical scenarios where assessment of the fibrinolytic system is necessary. The following conditions and situations warrant the performance of this test:

Atherosclerosis Associated Diseases This test may be utilized to diagnose and monitor diseases related to atherosclerosis, which is characterized by the buildup of plaques in the arterial walls, potentially leading to cardiovascular complications.
Coagulation Status in Liver Transplants The test is important for surveying the coagulation status of patients who have undergone liver transplants, as liver function is closely tied to the body’s ability to regulate clotting and fibrinolysis.
Cardiovascular Surgery During and after cardiovascular surgical procedures, this test can help monitor the patient’s fibrinolytic activity, ensuring that any potential bleeding or clotting issues are promptly addressed.

2. Procedure

The procedure for conducting the clot lysis time test involves several key steps that ensure accurate measurement of the fibrinolytic activity in the blood sample. The following steps outline the process:

Step 1: Sample Collection A sample of whole blood is collected from the patient and placed into a test tube. This initial step is critical as it ensures that the sample is representative of the patient’s current fibrinolytic status.
Step 2: Clot Induction Thrombin is added to the collected blood sample to induce clotting. This step is essential for creating a stable clot that can be monitored for lysis over time.
Step 3: Incubation The test tube containing the clotted blood sample is incubated at a temperature of 37 degrees Celsius. This controlled environment is necessary for optimal enzymatic activity during the lysis process.
Step 4: Observation and Counting The release of erythrocytes from the clot is observed and counted at 30-minute intervals. This monitoring allows for the assessment of how quickly the clot is being lysed, providing valuable data on the fibrinolytic activity.
Step 5: Addition of Enhancers (if applicable) To accelerate the clot lysis reaction, exogenous TPA, activated Protein C, or anti-PAI antibodies may be added to the test tube. This step is optional and depends on the specific requirements of the test being conducted.

3. Post-Procedure

After the completion of the clot lysis time test, the results are analyzed to determine the activity of the fibrinolytic system. The findings can provide insights into the patient’s bleeding risk or tendency for thrombosis. It is important for healthcare providers to interpret the results in the context of the patient’s overall clinical picture, including any underlying conditions or recent surgical interventions. Follow-up care may involve additional testing or monitoring based on the results obtained from this test, particularly in patients with a history of atherosclerosis, liver transplants, or those who have undergone cardiovascular surgery.

Short Descr	BLOOD CLOT LYSIS TIME
Medium Descr	CLOT LYSIS TIME WHOLE BLOOD DILUTION
Long Descr	Clot lysis time, whole blood dilution
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	1
CCS Clinical Classification	233 - Laboratory - Chemistry and Hematology

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.