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The CPT® Code 85557 refers to a laboratory test known as osmotic fragility of red blood cells (RBCs) that is performed under incubated conditions. This test is designed to assess the fragility of RBCs, which is their tendency to undergo hemolysis, or rupture, when subjected to osmotic stress. In this procedure, RBCs are exposed to a hypotonic saline solution, which causes water to enter the cells. As the cells swell and reach their maximum capacity, they become increasingly susceptible to rupture. This test is particularly useful in diagnosing conditions such as hereditary spherocytic hemolytic anemia, where the RBCs are spherically shaped and have a reduced ability to expand, leading to their rupture under less severe hypotonic conditions. The results of the osmotic fragility test are interpreted based on the degree of hemolysis observed at various concentrations of sodium chloride (NaCl). A positive result is indicated when hemolysis occurs in three or more specific NaCl concentrations, which include 0.50 g/dl, 0.60 g/dl, 0.65 g/dl, and 0.75 g/dl. Additionally, the test can reveal increased fragility in conditions such as immunohemolytic anemia, following recent blood transfusions, and in various hemolytic disorders, including congenital nonspherocytic hemolytic anemia due to glucose-6-phosphate dehydrogenase (G-6-PD) deficiency or pyruvate kinase deficiency. Conversely, decreased fragility may be observed in patients who have undergone splenectomy or those with chronic liver disease, iron deficiency anemia, thalassemia, hyponatremia, polycythemia vera, and sickle cell disease. The test requires a blood sample, which is obtained through a separate venipuncture, and the analysis is conducted using techniques such as spectrophotometry or osmotic lysis-flow cytometry.
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The osmotic fragility test (CPT® Code 85557) is indicated for the evaluation of various hematological conditions. The following are the specific indications for performing this test:
The procedure for conducting the osmotic fragility test involves several key steps that ensure accurate measurement of red blood cell fragility. The following outlines the procedural steps:
Post-procedure care for patients undergoing the osmotic fragility test is generally minimal, as the test is primarily a laboratory evaluation. However, it is important to monitor the patient for any immediate reactions to the venipuncture, such as bleeding or discomfort at the site. The results of the test will be analyzed and reported to the physician, who will interpret the findings in the context of the patient's clinical condition. Follow-up may be necessary depending on the results, particularly if abnormal fragility is noted, which may warrant further investigation or management of underlying hematological disorders.
| Short Descr | RBC OSMOTIC FRAGILITY | Medium Descr | OSMOTIC FRAGILITY RBC INCUBATED | Long Descr | Osmotic fragility, RBC; incubated | 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 |
| 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. | 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. |
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| Pre-1990 | Added | Code added. |
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