LifeBridge Health - Department of Pathology Clinical Pathology

CLINICAL PATHOLOGY
TABLE OF CONTENTS

Medical and Technical Staff

Order Entry: STAT and routine tests may be requested using the hospital information system. Stat blood requests should be entered into the hospital information system with the priority code of STAT. The sample is to be collected and immediately transported to the laboratory specimen receiving department for processing. If the hospital information system is not operational, use the downtime form and list all the tests needed. The downtime procedure is at all nursing stations. If a test is not listed in this manual, please call the specimen processing area for more information.

Tests requests - Outpatient areas: STAT and routine tests may be requested using a paper requisition available from Belvedere Pathology Associates (BPA). For STAT test requests, the sample is to be collected and immediately transported to the laboratory specimen receiving department for processing. Call 410.601.8338 for a courier to pick up the sample. Routine tests may be bundled and transported together. Refer to this manual for test collection and transportation information. If a test is not listed in this manual, please call BPA area for more information.

Patient Identification: This is the most important aspect of laboratory testing To assure proper patient identification, match the name and number on the armband to the name and number on the order each time a specimen is obtained. The initial and clock number of the employee drawing the blood should be written on the label and attached to the sample. The label should also have the test codes, and the date and time of collection.

Add-On Tests: Tests that are to be added to a sample already sent to the lab are to ordered on a "Downtime / Add-On" requistion and tubed to the lab. Do not add tests to an accession number via Cerner order entry.

Downtime Testing: During periods of computer downtime, tests can still be ordered by means of the "Downtime / Add-On" requisition and tubed with the specimen to the lab. Do not use the Cerner order entry system during announced downtime as duplicate orders could be produced.

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Hours of Service:

CLINICAL PATHOLOGY:
Automation - Hematology; Chemistry; Coagulation; Microbiology; Blood Bank; and Blood Gas Laboratory is open 24/7. Telephone 601-5116.

Flow Cytometry: Open from 7:00am to 6:00pm Monday through Thursday, and 07:00am to 8:00pm Friday. No Weekends or Holidays. Telephone 601 - 9003.

Manual Procedures – Special Chemistry; Immunology Laboratory is open from 07:00 to 17:00 Monday through Friday, and 07:00 to 15:30 PM Saturday and Sunday. Telephone 601 - 5935.

Pathologist-on-call - 24 hours per day, seven days per week. The on call list is posted in the main laboratory and available through the Sinai operator.

BPA - Outpatient phlebotomy is available in Suite 11 of the Hoffberger Building. Hours and days of operation are 07:00 to 17:00 Monday through Friday. Telephone 601- 8338.

Laboratory specimens: To insure the accuracy of results, we insist on your cooperation in the proper labeling of specimens.

Specimen Rejection Policy: Specimen integrity is crucial in laboratory testing. The physical condition of the specimen has a direct impact on the validity of certain types of analyses. A new specimen must be requested for testing if the specimen in hand is unacceptable for testing.

QNS: Quantity varies with test ordered.

1. The lab will notify the caregiver that a new specimen is required.

2. The order will be canceled with a coded comment (quantity not sufficient).

3. The name of the person notified and the time will be appended to the comment.

HEMOLYSIS: May not affect all tests ordered.

1. If all of the tests ordered are affected, the care giver will be notified that a new specimen is required.

2. The order will be canceled with a coded comment (Unable to test due to hemolysis).

3. The name of the person notified and the time will be appended to the comment.

4. If not all of the tests are affected, the tests unaffected by hemolysis will be run. The test(s) that are affected by hemolysis will be canceled as in 2 & 3 above.

LIPEMIA: May not affect all tests ordered.

1. The steps above will be followed using a coded comment (Unable to test due to lipemia).

ICTERIC: May not affect all tests ordered.

1. The steps above for hemolysis and lipemia will be followed using a coded comment (Unable to test due to icteric interference).

CLOTTED: Affects all tests.

1. The steps for QNS (above) will be followed, substituting a coded comment (Specimen Clotted).

BUBBLES: For Blood gases and whole blood analyzers.

1. The steps for QNS (above) will be followed, using a coded comment (air bubbles present).

NEEDLES: Must be removed and replaced with a dead-end cap. Syringes are acceptable only for blood gas whole blood electrolyte samples. Recapping by hand is prohibited. Needles must be removed using a Kelly or other instrument. Transfer all other specimens obtained in a syringe into appropriate containers.
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Biohazard and Infectious Specimens: All specimens are treated with universal precautions when received in the laboratory. We suggest double bags and leak proof containers be used when transporting samples to the laboratory. All samples in transport must be contained.

Clinical Pathology Reports: Laboratory results are available in the hospital information system as soon as laboratory verification occurs. Written laboratory reports are printed by the hospital information system each day and distributed to the appropriate areas.

General Result Inquiry: The laboratory is required not to release results to patients. If patients inquire the laboratory for results, they will be referred to the physician of record. Results are stored in the hospital information system. Archive results may be obtained from medical records or the hospital information system. Specimen processing will release results to the proper health care giver upon request, this method should be used when the hospital information system is not operational.

Critical Value Reporting: The laboratory will call critical value results to the health care giver, the physician of record, or the service/nursing station.

Cardiac Marker Testing:

MYOCARP
(Myocardial Panel)
LABORATORY MARKERS OF
MYOCARDIAL INJURY

Notes:

1. Serial measurements are necessary. Single measurements do not r/o MI so panel must be ordered every 4 hours. Extend q 4 hr draws as long as there is suspicion of MI.
2. Available-7 days/24 hours.
   

3. Turnaround- 30 minutes from receipt in Lab.

4. Collection-Dark green top-heparinized vacuum tube with 5mL of blood.

5. Do not use tests to measure size of infarction.

Characterization of Myocardial Infarction with MYOCARP

RE Wenk MD, J Quartner MD, D Meyers MD, M Goldstein MD,
C Cummings MD, B Dubois MD and D Dembo MD

     Historically, myocardial infarction (MI) has been marked by characteristic release of myocardial proteins into plasma. The proteins showed an early increase above the normal range, an apex or peak, and a late decreased concentration over time. Even when proteins (e.g., enzyme activities such as total LDH) were not specific to myocardial tissue, the time-concentration sequence curve was considered diagnostic. When more specific markers of cardiac tissue became available (e.g., creatine kinase), the time-concentration paradigm did not change: the rise and fall of cardiac markers denote the acute injury that occurs in MI. The same paradigm applies to the most recent and most specific markers. Myoglobin and Troponin I all show increases, peaks and decreases following heart injury.

     After myocardial infarction, myoglobin reaches its peak concentration first, probably because it is a small, abundant protein that is readily released from heart muscle. Myoglobin is a sensitive but nonspecific marker that is found in all striated muscle. It demonstrates small, extended and reinfarctions better than the other markers. The apex of its increase occurs at a mean of 3.4 hours from the time of the first blood sample collected from a MI case. Caution is warranted because it is possible to fail to observe the myoglobin curve when the patient’s visit to the Chest Pain Emergency Room (CPER) is delayed after the MI or if there is delay in collecting blood samples.

     The apex of CK-MB occurs at a mean of 8.6 hours, but is more heart-specific. The CK MB mass measurement analyzes the antigenic structure of the enzyme instead of its catalytic activity (measured with an assay that is now obsolete). The new CK MB mass test avoids the problem of interference by "macro CK", an autoantibody-CK BB complex found in 1-2% of hospital patients.

     Troponin I, the most specific test of cardiac muscle damage, will peak at an average of 8.9 hours after collection of the first blood sample. Despite its specificity for cardiac muscle, troponin I can be released in other disorders affecting myocardium (cardiac trauma, cardiomyopathies, following therapeutic interventions, unstable angina, etc.) Troponin I tends to remain elevated for hours to days after MI. The slow decline of troponin I concentration allows the test to replace the total LDH and LDH isoenzyme tests as late indicators of MI.

     Diagnosis of MI is most certain after observing typical time sequences of the curves of all three MYOCARP markers. Although there is evidence to suggest that the peak values of the three markers’ results indicate size of infarction, the tests should not be used for this purpose. The MYOCARP order should be used for diagnosis or to rule out MI. Rarely, a patient with MI may show a late rise in values (myoglobin first) or atypical time sequences of the expected curves. This is apt to occur when there are therapeutic interventions or complicating diseases. Clinical and laboratory observations (q 4 hours) should be extended for as long as there is suspicion of MI.