Influenza prevalence fluctuates seasonally with the onset of “flu season” typically beginning its upswing in the month of December. It is important for providers to have an awareness of influenza prevalence (in addition to other respiratory viruses) to help guide when influenza testing should be pursued.
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Emergency Medicine
Emergency, Inpatient, Test Utilization, West Michigan
Hypercoagulation/Thrombophilia Tests No Longer Available for Adult Emergency Room (ED) and Inpatient
Effective 10/29/2025, hypercoagulation/thrombophilia test ordering will no longer be available in the adult inpatient and emergency department settings at Corewell Health West.
This change aligns the hospital system with the American Society of Hematology Choosing Wisely initiative. This will decrease unnecessary costly testing in the inpatient setting and help to prevent inappropriate diagnoses.
Effective Date: September 3, 2025
The MRSA Screen PCR [LAB1231076] detects the presence or absence of colonization with methicillin-resistant Staphylococcus aureus (MRSA) and may be used to guide antimicrobial prophylaxis decisions. To improve and standardize test utilization across all Corewell Health regions, the following restrictions will be added to this test order:
- Ordering will be restricted to one test every 7 days.
- An indication for ordering must be provided for each order. Acceptable indications are:
- Pneumonia
- Skin and soft tissue (use for non-purulent infections)
- Surgical prophylaxis
Studies have shown that there is minimal utility in re-testing within 2 weeks as MRSA conversion rates are low and the PCR negative predictive values remain high for at least 14 days after initial testing.
Absence of nasal colonization with MRSA cannot be used to reliably rule out MRSA infection in scenarios other than those listed above.
Test Information
Effective June 4, 2025, Corewell Health Laboratories will include a preliminary result of >10000 mIU/mL for Beta Human Chorionic Gonadotropin (hCG + β) (LAB142) specimens that require dilution. The preliminary result will provide a quick insight on the status of the βhCG quantification analysis. It is important to remember that these results are not definitive, therefore final interpretation should be made alongside the fully validated results.
Influenza prevalence fluctuates seasonally, and case numbers are currently increasing throughout West Michigan. The onset of “flu season” varies year-to-year though typically begins its upswing in the month of December. It is important for providers to have an awareness of influenza prevalence (in addition to other respiratory viruses) to help guide when influenza testing should be pursued.
The use of point of care (POC) antigen testing reduces both the cost to the patient and turn-around-time as compared to lab-based molecular methods. POC antigen tests are typically available for COVID-19, influenza A/B, and as a COVID-19/influenza A/B combination test. During warmer months when influenza prevalence is negligible yet COVID-19 may be circulating, a COVID-only antigen test may be helpful for diagnosis. As influenza increases into colder months, a COVID-19/Influenza A/B combo test would act as a screen for both viruses.
POC tests generally have high analytical specificity but lack the sensitivity of nucleic acid amplification methods (e.g. PCR). For this reason, PCR testing is still recommended for hospitalized patients and for outpatients with a negative POC result if influenza is still suspected and if the result will impact clinical decision making. Influenza PCR may be ordered as a standalone test (LAB3255) or as a part of a panel alongside COVID-19 and RSV (LAB1230746).
Test Information
- Influenza PCR Epic Code: LAB3255, Interface EMR Code: 11594, CPT Code 87502
- COVID-19, Influenza A/B, RSV PCR Epic Code: LAB1230746, Interface EMR Code: 1230746, CPT: 0241U
Contact/Resources
Local Infection Prevention Team
Michigan Department of Health and Human Services
- Resources: https://www.michigan.gov/flu/resources
- Surveillance information: https://www.michigan.gov/flu/surveillance
Effective December 2, 2024 at 08:00 AM, Corewell Health West Laboratory Coagulation Department will be updating the reference range for several assays. The following will be impacted by these changes:
APTT testing for the BCS XP analyzers will be updating to 22.0 – 27.0 seconds.
This will include the following tests:
- aPTT Direct Thrombin Inhibitor (LAB1230880) (APTT-DTI)
- Mixing Studies, aPTT (LAB326)
- APTT (LAB325)
- APTT Heparin Neutralization (LAB3377)
Effective December 2, 2024 at 08:00 AM, the Corewell Health West and South Coagulation Departments will be updating the reference range of the Fibrinogen Level (LAB 314) to 190-450 mg/ dL.
Questions may be directed to the Coagulation Laboratory using the Contact Us link above.
This winter, West Michigan influenza infections peaked in February 2024 and significantly declined throughout March and April 2024. Now with a low prevalence of circulating influenza, using the most sensitive diagnostic test is recommended in order to obtain accurate and actionable results. Influenza antigen testing (e.g. Sofia instrument) is no longer appropriate at this time and Influenza PCR testing should be ordered when clinically indicated.
| Low Influenza Prevalence |
High Influenza Prevalence |
|
| Recommended Order | Influenza PCR (LAB3255) | Influenza antigen testing (e.g. Sofia instrument) or Influenza PCR (LAB3255) |
More detailed information can be found as published by the CDC:
Effective February 7, 2024, at 7:30 AM, Corewell Health West Laboratories will go live with a new reference range for the calculated Anion Gap (AG). The AG reference range will be adjusted to align with recent reference range studies.
The following will be the new normal reference ranges for AG:
Anion Gap: 5 – 14 mmol/L