Laboratory Medicine Updates - November 8, 2002

 

University of Virginia Health System

Medical Laboratories

“Quality You Expect, Service You Deserve” 

LABORATORY MEDICINE UPDATE

November 8, 2002

 

B-TYPE NATRIURETIC PEPTIDE (BNP) 

Beginning November 12, 2002, the Core Laboratory will offer analysis for B-type Natriuretic Peptide (BNP).  BNP has diagnostic utility in differentiating heart failure from other etiologies of dyspnea (Maisel et al, J Am Coll Cardiol 2001;37:379-85).  BNP is also a strong predictor of outcomes of heart failure [Latini et al. J Card Fail 2002;8:288-99 (review)] and of mortality and subsequent cardiac events in acute coronary syndromes (deLemos et al N Eng J Med 2001;345:1014-21; Sabatine et al. Circulation 2002;105:1760-3).  BNP-guided therapy of heart failure has been reported to improve outcomes (Troughton et al, Lancet 2000;355:1126-30). The test has limited if any utility in screening for heart failure (Vasan et al. JAMA 2002;288:1252-9).

Test Name: B-type Natriuretic Peptide

CPT code: 83520 (will change in January, 2003)

Sample requirements: Lavender tube, whole blood or plasma

Minimum volume: 0.5 mL whole blood or EDTA plasma

Add-on Limitations: Unprocessed samples must be analyzed within 4 hours.  Frozen plasma is stable for up to two weeks.

Availability and Turnaround Time: Daily, 60 minutes

Reference Intervals: <100 pg/mL

 

REQUESTS FOR METHOTREXATE LEVELS

Requests for serum methotrexate levels needed during regular business hours should be directed to the toxicology laboratory (924-2029).  If proper patient management requires immediate specimen analysis and result reporting after regular business hours (between 5 PM and 8 AM or on Sundays), the following steps should be taken the day prior to the drug level determination:

1.      Select one member of the treatment team to communicate the request

2.      Obtain the methotrexate dose, infusion start/stop time, and patient weight

3.      Call the PATH RESIDENT LAB MEDICINE ON CALL (PIC 1383) who will make arrangements for the toxicology technician to return to the hospital at the designated time, perform the assay, and issue the test result

4.      Ensure that the specimen is collected at the designated time in a gold-top tube, placed in a light-protected bag, and sent to central receiving

5.      Inform the pathology resident if the time that the drug level is needed changes

If proper patient management does not require immediate specimen analysis and result reporting, the specimen may be collected at the desired time and sent to central receiving for analysis the next morning without compromising the test results.

 

MEDICAL LABORATORIES STANDING ORDERS

 

Beginning October 15, 2002, the Medical Laboratories began entering requests for standing orders into a computer database.  These orders can now be accessed from any Medical Laboratory outpatient phlebotomy area.  To ensure continued smooth operation of this system, requests must be faxed to Client Services at 434-243-6499.    This enhanced system will notify the ordering physician prior to the expiration date so the order may be renewed if necessary without interruption of service.   All orders must meet the Medical Laboratory Compliance Policy #0022, page 15 of the 2002 Laboratory Handbook.    Please contact Client Services at 434-924-LABS with questions.

 

ANATOMIC PATHOLOGY AND CYTOLOGY RESULTS ON CAS

The Clinical Archive System (CAS) now has Anatomic Pathology and Cytology reports available on cases signed out after 5/20/02.  CAS can be accessed within UVA at the address www.cas.virginia.edu.  To access this data, after entering the appropriate patient, select Pathology at the top of the screen to view the available reports.  For CAS access or assistance in retrieving pathology reports, please contact the HSCS helpdesk at 4-5334.

 

GLOMERULAR BASEMENT MEMBRANE ANTIBODY TESTING

 The analysis for glomerular basement membrane (GBM) antibody testing has changed to EIA.  The new reference interval is 0 – 20 units.  The assay is performed once a week (Thursdays) or by STAT request to the laboratory medicine resident on call (pic 1383).  Specimen requirement remains the same, one gold-top serum tube.

 

PYRUVATE KINASE DEFICIENCY SCREEN

This analysis is now a sendout to our reference laboratory, Quest Diagnostics.

Specimen requirements: one lavender top tube (sodium heparin or ACD solution B also acceptable)

Methodology: Fluorometric spot test

Assay is set up Tuesday and Friday mornings with results available one day after set-up.

 

HEINZ BODY SCREEN

This analysis is now a sendout to our reference laboratory, Quest Diagnostics.

Specimen requirements: one lavender top tube (5 ml minimum volume)

Samples must be submitted Monday through Thursday only.

Methodology: Microscopic evaluation

Turn around time: 3 days after receipt of sample.

 

NEW REFERENCE INTERVALS FOR PTT TESTING 

Due to a change in reagent lot number, the following reference intervals changes have been made effective November 7, 2002.  The appropriate reference interval for the reagents used for any individual test is provided with the test result.

 

Test

Old (s)

New (s)

PTT

24.1 – 33.7

25.0 – 35.3

HEPPTT

63 - 111

61 – 101

HPSORB

24.1 – 33.7

25.0 – 33.7