Policy/Principle: | Certification: | Testing Prerequisites: | Materials: | Specimen: | Testing Procedure: | Results Derivation: | Expected and/or | Quality Control: | Infection Control: | References:
This test is performed as a rapid screen in the Emergency Department to ascertain if “occult” (not grossly visible) blood is passing from the gastrointestinal tract. If blood is present in the fecal specimen, the peroxidase-like activity of its heme moiety will catalyze oxidation of the guaiaconic acid impregnated into the paper of the slide by the H2O2 developer solution creating a distinctly blue colored conjugate.
1. Hemoccult screening is supported in these specific locations Mercy Dubuque, Finley and Mercy Dyersville Emergency Departments, Cascade Immediate Care and Crescent Community Health Center. Fecal specimen will be collected by the physician and applied to the Hemoccult Card. The Hemoccult Card will then be handed off to a nurse, who will perform the test and document the results.
2. Orientation, authorization and competency of staff and licensed practitioners performing POCT are provided by the director’s (named on the CLIA certificate) designee as indicated in the “Point of Care (POCT) Program” procedure.
3. Hemoccult screening will be performed by Nursing Service personnel who have been specifically certified:
A. To be certified, the requirements of the Hemoccult screening; POCT Self-Instructional/Competency documentation packet must be completed. The primary goal here is to make sure that the materials are properly managed, test timing is correct and documentation is in order.
B. If the individual seeking certification is unable to demonstrate acceptable performance of Quality Control, he/she must be retrained and successfully re-tested for authorization to perform Hemoccult testing.
C. Re-certification is required annually:
a. Re-certification for an individual may be required more often if deemed necessary. When an instructor observes improper technique, he/she may decertify the operator on the spot. Arrangements for re-certification of that individual must then be made through their immediate supervisor.
b. Re-certification requires an operator to successfully complete the Hemoccult, POCT Self-Instructional Competency documentation packet.
D. The certification record for operators and instructors will be maintained on the unit.
5. This test requires blue-spectrum differentiation; it should not be attempted by individuals with blue colorblindness. (Records available from Employee Health.)
1. The Hemoccult test cannot be run on gastric contents.
2 The only laboratory-sanctioned fecal occult blood screen is the Beckman/Coulter Hemoccult brand with on-slide controls.
1. The three Hemoccult components, slides, applicator sticks and developing solution, are obtained from the hospital central supply department.
2. Hemoccult reagent components are to be stored out of the light and at room temperature. Do not store near ammonia or halogen compounds (iodine, chlorine, bromine).
1. Fecal specimens will be collected by the physician and applied to the Hemoccult Card. The Hemoccult Card will then be handed off to a nurse, who will perform the test and document patient results, control results and the lot # of the Hemoccult Card on the Hemoccult Log.
2. Feces, applied as a THIN SMEAR with the applicator stick provided, is the only acceptable specimen for this test.
3. Fecal specimens for occult blood should not be collected if obvious rectal bleeding is present.
4. In the hospital setting, the Hemoccult slides should be developed within 3-15 minutes of preparation.
DO NOT prepare the specimen and let it set for longer periods of time.
DO NOT prepare Hemoccult slides on more than one patient at time.
DO NOT prepare a Hemoccult slide and walk away from it before it is developed and the results recorded.
5. Red meat and liver can cause false positive results. Horseradish, turnips, melons, radishes and other vegetables and fruits high in peroxidase can cause false positive results as well.
Aspirin, non-steroidal anti-inflammatory drugs, corticosteroids, indomethacin, phenylbutazone, reserpine, anticoagulants, antimetabolites, cancer chemotherapeutic drugs, and alcohol in excess can all cause false positives.
Acetaminophen is not expected to affect test results significantly.
6. Large amounts of Ascorbic Acid (vitamin C), greater than 250mg/day either taken directly or as a food additive can depress the reaction and cause false negative results.
1. Make sure you have properly identified the patient according to established protocol.
2. Obtain a Hemoccult slide from its storage space on the unit; check to make sure the testing materials are within the open-expiration dating.
3. Collect a small feces sample.
4. Open the slide cover and apply a THIN smear inside Box “A” & “B”.
5. Close the slide cover.
1. Wait 3 minutes for the sample to penetrate the paper but no longer than 15 minutes before developing.
2. Open the back of the slide and apply two (2) drops of the developer solution directly over each smear in the “A” and “B” boxes.
3. Read the test results within 60 seconds of applying the developer solution. Wait a full 60 seconds on specimens that appear negative. Do NOT attempt to read after 60 seconds.
Any trace of blue color on or at the edge of a smear is positive for occult blood.
4. Place the patient identification label or record the patient name and birthdate on the Hemoccult Log. Record Patient and Control results and the Hemoccult Card lot # on the Hemoccult Log.
1. Within 60 seconds of applying the developing solution, positive specimens will show a blue color around the smear(s). Wait a full 60 seconds on specimens that appear negative. Do NOT attempt to read after 60 seconds.
2. Any trace of blue on or at the edge of the smear(s) is positive for occult blood.
3. Some blue discoloration may be noticed on the test paper of the slide. It does not affect the performance of the test when the test is properly performed in accordance with the written procedure above. This blue-tinged background will recede to the edge of the wetted area following addition of the developer solution directly over the fecal smear(s). The area around the actual smear(s) will then be off-white. Any blue that then develops at the edge of the smear(s) indicates presence of occult blood.
4. Once the patient test has been read, apply one drop of the developer solution between the positive and negative spots marked on the bottom back of the slide. Read the results within 10 seconds. (Refer to the Quality Control section following.)
5. If the on-board controls are satisfactory, record the result on the patient’s chart as either “Positive for occult blood” or “Negative for occult blood”.
6. If the on-board controls are not satisfactory, do not report the patient results at all. See the Q.C. section that follows.
1. Asymptomatic people will generate a positive result about 2-5% of the time. 1-2% are falsely positive.
2. Less than 2ml of whole blood gastrointestinal loss daily is within normal limits. The Hemoccult test will give positive results about 50% of the time when the daily blood loss to the G.I. tract is 2-3 ml. Virtually all tests will be positive when the daily blood loss is 10ml and greater.
1. As specified in the written procedure above, for each and every test, the person running the test will check the control spots on the slide and record results on the Hemoccult Log:
A. Once the patient test has been read, one drop of the developer solution is applied between the positive and negative spots marked on the bottom back of the slide. The results are read within 10 seconds.
B. The integral control spots provide assurance that the guaiac paper and developer are functional. The spot marked (+) contains a hemoglobin derivative and will turn blue within 10 seconds when exposed to the H202 of the developer.
The spot marked (-) contains no hemoglobin derivative and will not turn blue in the face of peroxide.
2. If the on-board controls are satisfactory, record the result on the patient’s chart as either “Positive for occult blood” or “Negative for occult blood”.
3. If the on-board controls are not satisfactory, do not report the patient results at all.
Note: The fact that the Q.C. was not satisfactory is important and must be recorded in the Hemoccult Test Log. Fill in all the fields of the log except the “Hemoccult Result” field, which will be left blank. Enter “not satisfactory” in the “Internal Q.C.” field AND report the failure to the department supervisor.
1. Staff will wear a fresh pair of gloves while performing the Hemoccult test and will wash their hands after the procedure using established protocol.
2. Residual fecal specimen may be flushed down the toilet. The testing slide, applicator and gloves will be disposed of in accordance with the hospital’s approved waste management policy.
1. December 2000. S. Raymond; Technical Director, Dubuque Pathology Associates
2. Beckman/Coulter Hemoccult pkg insert; 19990301
i. April 2001 S. Raymond/L. McGovern
ii. November 2001 L. McGovern (Revised: IV.3.)
iii. January 2006 L. McGovern (Revised: IX.2.)
iv. July 2006 L. McGovern (Revised: IX.2.)
v. June 2008 L. McGovern (Revised: for physician use in the Emergency Department)
vi. September 2008 L. McGovern (Revised: removed laboratory information)
vii. November 2009 L. McGovern/S. Raymond (Revised: II., V.; VI.; IX.1., 3.Note)
Medical Director; P.A.:
Technical Director; P.A.:
Mercy Nursing Service
Finley Nursing Service
January 2011 L. McGovern (Revised:II.6.removed; XI.3.removed)
October 2011 L. McGovern (Revised: II.1.locs specified; IV.1.; exp/storage removed; VI.2.developer removed)