Applicable To Employees of the Gundersen Tri-County Hospital clinical laboratory and Gundersen Palmer Lutheran Hospitals and Clinics laboratories.

Transcription

1 Subject BACTEC 9050 Index Number Lab-8681 Section Laboratory Subsection Regional Clinic/Affiliate Hospital Laboratories Category Departmental Contact Blum, Rachel Last Revised 2/13/2017 References Required document for Laboratory Accreditation by the College of American Pathologists (CAP), Centers for Medicare and Medicaid Services (CMS), and/or COLA. Applicable To Employees of the Gundersen Tri-County Hospital clinical laboratory and Gundersen Palmer Lutheran Hospitals and Clinics laboratories. Detail PRINCIPLE: The detection of microorganisms in a patient s blood has diagnostic and prognostic importance. Blood cultures are essential in the diagnosis and treatment of the etiologic agents of sepsis. Bacterial sepsis constitutes one of the most serious infectious diseases and, therefore, the expeditious detection and identification of bloodborne bacterial pathogens is an important function in the diagnostic microbiology laboratory. The Bactec 9050 series of blood culture instruments are designed for the rapid detection of microorganisms in clinical specimens. The sample to be tested is inoculated into the vial which is entered into the Bactec instrument for incubation and periodic reading. Each vial contains a sensor which responds to the concentration of CO2 produced by the metabolism of microorganisms or the consumption of oxygen needed for the growth of microorganisms. The sensor is monitored by the instrument every ten minutes for an increase in its fluorescence, which is proportional to the increasing amount of CO2 or the decreasing amount of O2 present in the vial. A positive reading indicates the presumptive presence of viable microorganisms in the vial. CLINICAL SIGNIFICANCE: INSTRUMENT Microorganisms, if present in the blood samples, metabolize nutrients in the Bactec culture vial release CO2 into the medium or utilize the oxygen in the medium. The instrument monitors the fluorescence of the vial sensor which increases as CO2 is produced or oxygen is utilized. Analysis of the rate and amount of CO2 produced or O2 utilized enables the instrument to determine if the vial is positive; i.e., the presumptive presence of viable organisms. COMPUTER AND PERIPHERALS The system computer stores all the system software, including the application software which controls instrument operations and the user interface, which enables the user to enter patient information, view results, identify errors, etc. Page 1 of 7

2 BARCODE SCANNER The barcode scanner is located on the outside of the instrument to provide the ability to activate barcode commands and to scan vial labels for specimen identification. When the door is opened and the activity is initiated, the scanner is activated and is ready to read the vial barcode. The barcode scanner for the Bactec 9050 is located on the front of the instrument and is activated when the door is opened and the vial entry or vial removal soft keys are pushed. SPECIMEN: COLLECTION 1. SITE SELECTION a. Select a different site for each culture drawn. b. Avoid drawing blood from arms with indwelling intravascular catheters (i.e. fistulas) unless blood cannot be obtained by venipuncture and you have the physician s permission to do so. If this happens, document on the chart that blood was drawn from such a site with Doctor ABC s permission. This would apply to a patient with a double mastectomy. 2. SITE PREPARATION (ChloraPrep One Step) a. Open the ChloraPrep applicator. b. Pinch the wings on the applicator to break the ampule and release the antiseptic. Do not touch the sponge. Wet the sponge by repeatedly pressing and releasing the sponge against the treatment area until the liquid is visible on the skin. c. Use repeated back-and-forth strokes of the applicator for approximately 30 seconds making sure to completely wet the treatment area with antiseptic. d. Allow the area to air dry for approximately 30 seconds. e. Do not touch or palpate the area after cleansing. 3. DISINFECTING BLOOD CULTURE VIALS a. Remove the flip-off caps from BACTEC culture vials. b. Wipe top of each vial with a separate 70% isopropyl alcohol pad and allow to dry. c. Do not use iodine to disinfect tops of vials. 4. VENIPUNTURE a. Avoid touching the venipuncture site. If it is necessary to touch the site after it has been cleansed, wipe your fingers with the ChloraPrep before touching the site. b. When using the Blood Collection Set ( butterfly ) the phlebotomist MUST carefully monitor the volume collected by using the 5 ml graduation marks on the vial label. If the volume is not monitored, the stated maximum amount collected may be exceeded. This condition may adversely create a false positive result, due to high blood background. c. If using a needle and syringe, typically a 20 ml syringe is used for adults. Draw 16 to 20 ml of blood for one blood culture set (aerobic and anaerobic). Aseptically inject 8 to 10 ml of specimen into each vial. d. For pediatric patients, Draw 1 to 3 ml of blood and transfer the entire amount into BACTEC PEDS PLUS/F vial. e. Continue to care for the venipuncture site following recommended guidelines. f. The inoculated BACTEC vials should be transported as quickly as possible to the laboratory. VOLUME Page 2 of 7

3 The volume of blood cultured is critical because the number of organisms per ml of blood in most cases of bacteremia is low, especially if the patient is on antimicrobial therapy. In infants and children, the number of organisms per ml of blood during bacteremia is higher than adults, so less blood is required for culture. 1. Children: 1 to 5 ml of blood per venipuncture. Transfer the entire amount to a BACTEC PEDS PLUS/F vial. 2. Adults: 16 to 20 ml of blood per venipuncture. It is impossible to draw the required amount, aliquot as follows: Amount per venipuncture Amount in BACTEC Plus Aerobic Vial Amount in BACTEC Plus Anaerobic Vial ml Split equally between aerobic and anaerobic vials ml 8 ml 5-8 ml ml 5-7 ml 5 ml 5-9 ml Entire blood amount 0 Note: Optimum recovery of isolates will be achieved by adding 8 to 10 ml of blood. BACTEC PEDS PLUS/F: 1 3 ml. The use of higher volumes may adversely affect recovery and/or detection times. SPECIMEN LABELING Each vial should be labeled with appropriate patient information: 1. Patient s name 2. HIM # 3. Date and time of collection 4. Collector s initials REAGENTS/MATERIALS: MEDIA 1. Bactec Lytic/10 Anaerobic/F Culture Vial Optimum blood volume for each vial is 8 to 10 ml; 3 to 10 ml of blood is acceptable. a. Each vial contains: i. 40 ml Enriched Soybean-Casein Digest broth (TSB)\ ii % SPS iii. Carbon Dioxide (CO2) iv. Oxygen (O2) v. Sensor for the detection of fluorescence b. Store at 2 to 25 C 2. Bactec Plus Aerobic/F Culture Vial Optimum blood volume for each vial is 8 to 10 ml; 3 to 10 ml is acceptable. a. Each vial contains: i. 30 ml Enriched Soybean-Casein Digest broth ii. 0.25% Yeast extract iii. 0.05% Amino acids iv. 0.05% SPS v. Resins Page 3 of 7

4 vi. CO2 and Nitrogen gas (N2) vii. Sensor for the detection of fluorescence. b. Store at 2 to 25 C 3. Bactec Peds Plus/F Culture Vial Optimum blood vial for each vial is 1 to 3mL; 0.5 to 5 ml of blood is acceptable. a. Each vial contains: i. 40 ml Enriched Soybean-Casein Digest Broth ii. 0.02% SPS iii. Resins iv. CO2 v. O2 vi. Sensor for the detection of fluorescence b. Store at 2 to 25 C. EQUIPMENT/INSTRUMENTATION OPERATION: ENTERING NEW VIALS 1. After specimens have been prepared, they should be scanned and placed in the instrument as soon as possible. The Bactec 9050 has a delayed vial positivity criteria that provide for routine delays caused by vial transport. The system accommodates the following delay conditions: a. Up to 20 hours if vials are incubated prior to entry in the instrument, or b. Up to 48 hours if vials are not incubated (i.e. held at room temperature) 2. There are two ways to enter new vials into the instrument: By scanning the vial barcode when the barcode scanner ready icon appears a. Open Bactec 9050 door b. Press vial entry soft key c. Scan vial barcode d. Place vial in specified station e. Default protocol is for 5 days f. If protocol needs to be adjusted press change protocol. g. Press UP ARROW or DOWN ARROW keys until desired protocol appears. h. Confirm that information is correct and press OK soft key. i. If you do not place the vial in the station, or need to change something else, press the cancel soft key. j. Repeat the steps in this box until all vials are entered. Then press exit soft key. By manually selecting the medium type if the vial barcode cannot be scanned by pressing the no barcode soft key. 1. Press no barcode soft key 2. System will ask media type 3. Select media type with UP or DOWN ARROW key. 4. Press OK soft key POSITIVE and NEGATIVE SPECIMENS: 1. The system will notify you of new positive cultures in several ways: a. New Positive indicator lamp on the front of the instrument flashes Page 4 of 7

5 b. On the Main status display, the station is displayed as a filled circle with a plus sign (+) in it, the positives total in the Summary reflects the number of positives in the instrument. c. When the door is opened, the remove positives soft key appears in the soft key assignment area of the LCD Display. d. Until silenced, the audible alarm sounds. i. Press the SILENCE ALARM key to silence the audible alarm. ii. Open the instrument door. iii. Press remove positives soft key. iv. Remove the vial from the specified station and scan vial barcode, or leave vial in and press DOWN ARROW to skip to next positive station v. Repeat until all positives are removed. The press exit soft key. e. Positive vials will be gram stained and subbed to media for further identification. f. Positive blood cultures are called to the Charge Nurse. Laboratory will document to whom the results were given and time and tech initials. Lab results will be repeated back by person taking results. 2. Negative cultures may exist as ongoing negatives (in protocol) and out-of-protocol negatives. You are notified of these conditions as follows: a. Ongoing Negatives On the Main Status display, the station is displayed as a filled circle with a minus (-) in it. Also the negative in the Summary reflects the number of final negatives in the instrument. No audible alarm sounds for notification. When the door is opened, the remove negatives soft key appears in the soft key assignment area of the LCD Display. i. Open the instrument door. ii. iii. iv. Press remove negatives soft key. Remove vial from specified station and scan vial barcode, or leave vial in and press DOWN ARROW to skip to next negative station Repeat until all negatives are removed. Then press exit soft key. Work-up of positive culture bottles: Positive vials will be subcultured and gram stained. 1. Shake the bottle to mix contents. 2. Disinfect the rubber septum of the bottle with an alcohol wipe. 3. Using a 3 ml syringe pull out 1 ml of blood from the bottles. 4. Place a drop of blood on to BAP, CHOC, and THIO media. Place one drop on a slide for gram stain. 5. Streak plates. Incubate plates and thio at 37 o C. Read gram stain. 6. Call physician or appropriate personnel with positive cultures. Document in the communication log. Refer to Lab-0130 Critical Call Values, Lab Reporting Protocol. 7. Read at 24 hours and work-up organism as follows. a. One bottle only i. Coagulase negative Staph, Corynebacterium, Bacillus, Micrococcus, and Propionibacterium will get finalized with a comment added for the physician to call for further work-up. ii. Alpha strep gets full ID and comment to call for sensitivities. iii. All other organisms get a full ID and sensitivity if appropriate. b. More than one bottle of any organism gets a full work-up. Page 5 of 7

6 8. Streak nutrient or chocolate slant for each organism. These will be held for at least 6 weeks for further work-up or sending to the state lab for surveillance. False Positive Vials: If the Gram stain reveals no organism, the bottle will be reloaded into the instrument via the load bottles function. The bottle must be returned to the instrument within 3 hours of removal. Do not enter the results entry of Epic for a false positive vial. If you do, the autotimer will be turned off and the daily updates will not occur. The autotimer can be turned back on to resume the daily updates. To turn the autotimer back on go to Result Entry, then open up the Actions drop down menu and choose Enable Auto Result. If the subculture grows, edit the bottle s status to positive on the edit test results screen. Unload the positive bottle from the instrument. REPORTING IN EPIC: Positive bloods: 1. Choose the culture tab in edit mode and enter see table below from the pick list. 2. Add an isolate; indicate which bottles were positive in the quantity field. 3. Add descriptive preliminary ID (gram pos cocci in clusters, chains, or pairs, gram neg rod, etc.) 4. Document in the critical call communication log. 5. Choose the workup tab and enter any workup completed. Add sensitivities if appropriate. 6. Preliminary verify. 7. When a final ID and sensitivity are available update the culture and final verify. Negative bloods: Negative blood cultures pulled after the fifth day of incubation are final verified as negative at 5 days. PROCEDURAL NOTES: Do not plate bottles off of the set up bench until ready to place them in the instrument. The automatic timer starts when they are plated off, so not placing them in the machine at that time will make the bottles terminate early. CALIBRATION/MAINTENANCE: DAILY Check the temperature readout on the LCD display on the instrument. Verify the temperature of the instrument and internal temperature vial read 35 C ±1.5 C. MONTHLY Change or clean the air filters on both sides of the instrument. Refer to the User s Manual (Section 6.2). POWER FAILURE The information is stored in memory until a power failure occurs. The BacTec 9050 is on backup generator power. UPDATE SOFTWARE Page 6 of 7

7 1. From time to time, updated versions of the system software may be provided. New software should be installed as soon as it is received, and logged on Micro Log. 2. To install a software update, insert the floppy disc containing the new software into the disk drive, then press the perform action soft key to initiate the update. The system reboots and then immediately begins to update the system software. QUALITY CONTROL: MEDIA Each case of media has a Quality control certificate indicating the organisms tested and the acceptability of those tests. Implementation LIMITATIONS: Due to blood volumes. Overfilling vials may give false positives and under filling may give false negative results. REVIEW AND CHANGES: This procedure and all attached forms will be reviewed optimally on an annual basis, with 2 years as the maximum review date. Review will be done by the Technical Leader, Supervisor, Manager, Medical Director or designated person. Changes require retyping document or form and review by the technical consultant/medical director. REFERENCES: 1. BACTEC PLUS Aerobic/F Culture Vial Insert. Rev. PP-088E BD Biosciences. 2. BACTEC PEDS PLUS/F Culture Vials Insert. Rev. PP-091-I. BD Biosciences. 3. BACTEC LYTIC/ 10 Anaerobic/F Culture Vials Insert. Rev. PP-108JAA. Biosciences. 4. BACTEC 9050 Automated Blood Culture Procedure. Rev. 07/25/01. Page 7 of 7