Docstoc

Hemoccult Stool Testing

Document Sample
Hemoccult Stool Testing Powered By Docstoc
					                              Fecal Occult Blood Test - Hemoccult
                                         STUDY MATERIAL

Routine Screening Test for Fecal Occult Blood

The Point of Care Testing (POCT) program at Vanderbilt University Medical Center
(VUMC) is overseen and coordinated by the POCT Steering Committee as chartered by
the Medical Center Medical board. The POCT Steering Committee administers the
program with the primary goal of meeting clinical needs in the most cost-efficient manner
possible. In order to provide for both regulatory compliance and appropriate utilization of
POCT, any clinical area wishing to perform POCT must be approved by the POCT
Steering Committee and must maintain acceptable performance according to criteria set
forth in Hospital Policy 20-23.

I.       PRINCIPLE:

The Hemoccult test is based on the oxidation of guaiac by hydrogen peroxide to a blue-
colored compound. The heme portion of hemoglobin, if present in the fecal specimen,
has peroxidase activity which catalyzes the oxidation of alpha guaiaconic acid (active
component of the guaiac paper) by hydrogen peroxide (active component of the
developer) to form a highly conjugated blue quinone compound.

II.      PURPOSE:

The Beckman Coulter Hemoccult test is a qualitative screening method for detecting fecal
occult blood, which may be indicative of gastrointestinal disease. It is not a test for
specific diseases.

III.     SCOPE OF PRACTICE:

Stool occult blood testing may be performed by RN’s, LPN’s, Patient Care
Partners/Technicians, OR Technicians, and Nursing Externs working in areas/units
approved by the POCT Steering Committee to perform point of care stool occult blood
testing. To maintain this privilege, testing must be performed in accordance with VUMC
hospital POCT policy. All staff performing testing must attend POCT orientation, annual
retraining, read procedure annually and follow established testing protocol.

IV.      SPECIMEN COLLECTION:

         A. Conditions for Patient Preparation
            1. Refer to current package insert for collection procedure and patient
               preparation.
            2. Samples should not be collected during periods of active bleeding (e.g.,
               menstruation, active hemorrhoids, urinary tract infection).
            3. Remove toilet bowl cleaners from toilet tank and flush twice before
               proceeding with sample collection.
            4. For seven days before and during the stool collection period, avoid non-
               steroidal anti-inflammatory drugs such as ibuprofen, naproxen or aspirin
               (more than one adult aspirin a day).

                                     VUMC Point of Care Testing
Hemoccult Procedure revised 2-2006                                               Page 1 of 7
                              Fecal Occult Blood Test - Hemoccult
                                         STUDY MATERIAL

             5. For three days before and during stool collection period, avoid vitamin C in
                excess of 250mg a day from supplements, and citrus fruits and juices.
             6. For three days before and during stool collection period, avoid red meats
                (beef, lamb, and liver).
             7. Eat a well balanced diet including fiber such as bran cereals, fruits and
                vegetables.
             8. Collect samples over a 3 day period.

         B. Specimen Type
            1. Small amount of fecal specimen
            2. Do not test samples containing visible blood
            3. Collect sample in a clean, dry container, before contact with toilet bowl
               water.
            4. Gastric or vomitus specimens are not recommended

         C. Handling Conditions
             Use Standard Precautions
            1. Specimen is applied to guaiac paper of Hemoccult test card as THIN
               SMEAR using provided applicator stick
            2. Apply samples form bowel movements collected on three different days to
               test card.
            3. Separate samples should be taken from two different sections of each fecal
               specimen.
            4. Hemoccult test cards are best developed no sooner than 3 days after
               sample application.
            5. Slides containing samples may be stored up to 14 days at controlled room
               temperature 15-30°C before developing.

V.       REAGENTS AND SUPPLIES:

             1. Hemoccult test cards (guaiac paper)
             2. Hemoccult developer (Stabilized aqueous solution. <5% hydrogen peroxide,
                75% denatured alcohol)
             3. Applicator sticks (optional)
             4. Collection tissues (optional)

VI.      STORAGE AND STABILITY:

           1. Store product at controlled room temperature 15 to 30C (59 to 86F) in
              original packaging. Do not refrigerate or freeze.
           2. Protect from excessive heat and light.
           3. Do not store Hemoccult test cards or developer with volatile chemicals.
           4. Hemoccult slides and developer, stored as recommended, are stable until
              printed expiration dates if quality control is acceptable.
           5. All reagents must be labeled with staff initials, and valid expiration date
              (including box and developer bottles).
VII.     CALIBRATION:
                                     VUMC Point of Care Testing
Hemoccult Procedure revised 2-2006                                                Page 2 of 7
                              Fecal Occult Blood Test - Hemoccult
                                         STUDY MATERIAL



         N/A

VIII.    QUALITY CONTROL (QC):

              1. The positive and negative Performance Monitors (quality controls) built into
                 each Hemoccult test card must be developed each time a Hemoccult test
                 card is used for patient testing.
              2. These Performance Monitors (quality controls) check the function and
                 stability of the test card and the developer.
              3. DO NOT apply developer to Performance Monitor areas before interpreting
                 patient test results.
              4. The Positive Performance Monitor area contains a hemoglobin-derived
                 catalyst, which will turn blue within 10 seconds after application of developer.
                 The negative Performance Monitor does not contain the catalyst and should
                 not turn blue after application of developer.

IX.      TEST PROCEDURE:

          Observe Standard Precautions

         A.        Preparing and Developing PATIENT Test

         1. Properly label test card with patient information
         2. Collect sample on applicator stick.
         3. Apply thin smear to card side A.
         4. Obtain another sample from different part of specimen and apply a thin smear to
            card side B.
         5. Close cover and wait 3 to 5 minutes.
         6. Open back flap and apply (2) drops developer over each smear.
         7. Read within 60 seconds. Any trace of blue on or at the edge of the smear is
            positive for occult blood. Any blue color originating from the positive
            Performance Monitor area should be ignored when reading the patient sample
            results.

         B.       Developing Performance Monitors (quality controls):

         1. Apply (1) drop of Hemoccult developer between the positive and negative
            Performance Monitors. They are located in the orange rectangle below the
            patient testing area.
         2. Read the results within 10 seconds.
         3. If the test card and developer are functioning correctly, the positive Performance
            Monitor will turn blue in color (positive result), and the negative Performance
            Monitor will remain white with no blue color visible (negative result).

 If the Performance Monitors do not react as expected after applying the
  developer, regard patient results as invalid. Follow the corrective action steps.
                                     VUMC Point of Care Testing
Hemoccult Procedure revised 2-2006                                                     Page 3 of 7
                              Fecal Occult Blood Test - Hemoccult
                                         STUDY MATERIAL



         B.        Corrective Action:

         1. Check expiration date of Hemoccult test cards and developer being used.
         2. If supplies not expired, retest patient sample using a different test card from the
            kit.
         3. If needed, retest patient sample with test card and developer from a different
            box of Hemoccult supplies. If Performance Monitors yield expected results with
            test card from the second box of supplies, discontinue use of test cards and
            developer from the original box. Notify POCT Support Center for pick-up of bad
            supplies.
         4. If still unable to obtain expected results of the Performance Monitors, notify
            POCT Support Center at phone # 3-5707.

X.       REPORTING RESULTS:

         Patient test results and quality control test results are reported/recorded as positive
         or negative for occult blood

XI.      DOCUMENTATION:

         The following information is required to be documented with patient results in the
         permanent medical record:

         a.   Date and Time of patient testing
         b.   Comments or corrective action taken
         c.   Hemoccult test card lot number and expiration date
         d.   Hemoccult developer lot number and expiration date
         e.   Results of positive and negative performance monitor.
         f.   Identification of staff performing testing

XII.     QUALITY ASSESSMENT:

         The manager or designee has oversight of the following requirements:

             All POCT performed in patient care areas have been approved by the
              Diagnostic Laboratories and the State of Tennessee.
             Testing is performed only by staff approved by the Diagnostic Laboratories and
              the State of Tennessee.
             All staff are trained prior to testing, and assessed for competency annually.
             Individuals responsible for staff training and /or compliance review, (quality
              control and patient documentation); have attended appropriate training sessions
              provided by the POCT Support Center.
             Initial training records, current annual competency records and “designated”
              trainer records must be accessible.
             Notification to the POCT Support Center of any changes or transfer of testing
              personnel.
                                     VUMC Point of Care Testing
Hemoccult Procedure revised 2-2006                                                    Page 4 of 7
                              Fecal Occult Blood Test - Hemoccult
                                          STUDY MATERIAL

            Current testing procedures and accessible to all testing staff.
            Quality control and maintenance procedures are performed, documented and
             reviewed for compliance by the manager or designee at least weekly, and are
             accessible for two years following review. Any corrective action is noted, and
             filed with records.
            Routine review of random patient medical records by manager or designee to
             verify compliance with patient test result documentation as described in testing
             procedures. Examples must be available for inspections.
            All testing supplies are stored and labeled according to instructions found in
             individual testing procedures.
            CAP proficiency testing, as required, is performed according to accompanying
             instructions and results and requested information returned to the POCT
             Support Center within specified time frame.

Diagnostic Laboratories POCT Support Center Provides:

                      Technical support
                      Training
                      Content of training materials and testing procedures
                      Validation and implementation of testing methodologies
                      Assistance with request for testing privileges

The POCT Steering Committee is chartered by the VUMC Medical Board and has the
authority to revoke testing privileges.

XIII.    INTERFERING SUBSTANCES:

         A. Some specimens have a high bile content, which causes feces to appear green.
            A distinct green color appearing on or at the edge of the smear within 60
            seconds after adding developer should be interpreted as negative. A blue or
            blue-green color should be interpreted as positive for occult blood.

         B. Substances, which can cause false-positive test results include:
               1. Red meat
               2. Antiseptic preparations containing iodine.
               3. Aspirin (greater than 325 mg/day) and other non-steroidal anti-
                  inflammatory drugs such as ibuprofen, indomethacin and naproxen.
               4. Alcohol in excess
          C. Substances, which can cause false negative test results:
              1. Ascorbic acid in excess of 250 mg/day.
              2. Excessive amounts of vitamin C enriched foods (citrus fruits and juices)
              3. Iron supplements which contain quantities of vitamin C in excess of 250
                 mg per day




                                      VUMC Point of Care Testing
Hemoccult Procedure revised 2-2006                                                 Page 5 of 7
                              Fecal Occult Blood Test - Hemoccult
                                         STUDY MATERIAL

XIV.     SAFETY:

             1. Observe standard precautions.
             2. Treat all patient specimens as potentially infectious and dispose of with
                proper precautions.
             3. Developer is an irritant. Avoid contact with skin and eyes.
             4. Developer is flammable and subject to evaporation.


XV.      LIMITATIONS OF PROCEDURES:

             1. This test is read visually and requires color differentiation. It should not be
                interpreted by staff with blue color blindness.
             2. Hemoccult tests are designed for preliminary screening as an aid to
                diagnosis. They are not intended to replace diagnostic procedures.
             3. Blood, if present, may not be distributed evenly in feces consequently; a test
                result may be negative even when disease is present.
             4. False positives can occur due to low but detectable levels of blood loss
                common to healthy adults.
             5. Positive results can be obtained from patients free of polyps and colorectal
                cancers due to other causes of bleeding.
             6. Negative results can be obtained from patients with polyps and colorectal
                cancers when there is no bleeding, intermittent bleeding and when the blood
                is not distributed uniformly in the fecal specimen.
             7. The Hemoccult test should not be used to test gastric specimens.
             8. Rehydration of guaiac test card with water is not recommended.

XVI.     PROCEDURE NOTES:

             1. Fecal specimen should not be collected if hematuria or obvious rectal
                bleeding, such as from hemorrhoids is present. Pre-menopausal women
                must be instructed to avoid collecting fecal specimens during or in the first
                three days after a menstrual period.
             2. Since bleeding from gastrointestinal lesions may be intermittent, fecal
                specimens for testing should be collected from three bowel movements
                closely spaced in time. To further increase probability of detecting occult
                blood, separate samples should be taken from two different sections of each
                fecal specimen.
             3. Neither the intensity nor the shade of blue from the Positive Performance
                Monitor area should be used as a reference for the appearance of positive
                test results.
             4. Any blue originating from the Positive Performance Monitor area should be
                ignored when reading the sample test results.


XVII. REFERENCES:

                                     VUMC Point of Care Testing
Hemoccult Procedure revised 2-2006                                                   Page 6 of 7
                              Fecal Occult Blood Test - Hemoccult
                                         STUDY MATERIAL



         1.       Hemoccult product insert #462478.D; Beckman Coulter, Inc.; 4300 N. Harbor
                  Blvd., Fullerton, CA 92834-1300. Rev. May 2000.
         2.       VUMC Point of Care Support Center




                                     VUMC Point of Care Testing
Hemoccult Procedure revised 2-2006                                                Page 7 of 7

				
DOCUMENT INFO