8 Reasons why we decided to move to PCR for our UTI’s
- Better Pathogen Identification
- Better Turn Around Times (TAT)
- Week-day TAT Goal: Same day Results of receipt of sample
- Week-end TAT Goal: Two day Results of receipt of sample
- Better Patient Care (faster targeted antibiotic)
- Able to prescribe a targeted antibiotic within the 1st 24 hrs of sample collection
- Able to de-prescribe the broad spectrum antibiotic sooner
- Better Antibiotic Stewardship Compliance
- Better Diagnostic Stewardship
- Able to tailor the UTI by PCR+ process to better meet the needs of LTC
- By developing a “comprehensive” diagnostic product combining the strengths of both PCR and traditional C&S micro
- Able to correct and improve the drawbacks and failures of the early UTI by PCR
- Able to better correlate the UTI PCR+ Results with C&S 2 days sooner
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TLM Diagnostics, LLC dba Doctors Lab-9441 Stevens Road, Ste 100, Shreveport, LA 70815 Rev 1.1 051523
In order to improve the Negative Predictive Value of our Urinalysis Reflex to UTI-ID by PCR
Panel, we have added the Catalase test to strengthen our final determination of calling a urine
“negative” and therefore would not reflex it to a UTI-ID by PCR. This was done to minimize the
number of “Negative-Not Detected” urines being reflexed for UTI-ID by PCR analysis.
By the addition of the Catalase to our Reflex to our UA Reflex Panel we have significantly
improved our Negative Predictive Value of a potential UTI to nearly 100% and therefore we can
more confidently rule out the reflex to a UTI-ID by PCR analysis.
Catalase is found in both WBCs and Bacteria. The best Positive Predictive Value of a potential
UTI that would indicate a reflex to a UTI-ID by PCR is the presence of both WBCs (pyuria) and
Bacteria (bacteriuria). Normal, clean urine has no significant Catalase activity.
A UTI-ID by PCR will be reflexively ordered when 1 or more of the following triggers
occurs:
- Clarity- Cloudy (very)
- Blood- Positive
- Nitrite- Positive
- Leukocyte Esterase- Positive
- Catalase- Positive
Ordering Instructions:
- Order the Urinalysis+Catalase w/ Reflex to UTI-ID by PCR panel
- If a UTI by C&S is desired, please write “Do Not Perform UTI-PCR" in the Comments Box
Executive Summary
Reasons and Advantages for Developing and Implementing our LTC tailored UTI-ID by
PCR
- Superior Turnaround Times (TATs). Traditional microbiology typically takes 3-5 days TAT whereas PCR turnaround time is usually same day results, once the specimen is received (except weekends). This can be a significant advantage for the provider and resident to begin a targeted antibiotic treatment much sooner.
- Superior Pathogen Detection especially on complex multi-organism samples. We have found PCR to be to be much more sensitive and specific at detecting pathogens than traditional cultured micro especially with multi-organism samples. With PCR if there is a small amount of DNA, we can clearly “see” and ID the pathogen or pathogens whereas traditional micro may “miss” a slow growing obscured pathogen.
- Improved Validations. We validated our PCR method and results against the “goldstandard” traditional microbiology lab which is different than most PCR laboratories that typically validate their methods and results against other PCR assays. Validating against the “gold-standard” allowed us to discover analytical issues that typically would not show up in a PCR-PCR Validation. We believe that this has improved the accuracy of our LTC tailored UTI-ID assay.
- Superior Antibiotic Stewardship Compliance.
- Faster Results make it possible to more quickly and appropriately treat your residents providing the opportunity for an improved outcome by:
- Deprescribing initial broad-spectrum antibiotic treatments sooner
- Prescribing targeted antibiotics sooner
- Faster Results make it possible to more quickly and appropriately treat your residents providing the opportunity for an improved outcome by:
- Superior Result Interpretation and Reporting. At Victoria Healthcare PCR we approach result interpretation and reporting differently than most PCR labs which tend to report whatever they find, which can make it difficult for the provider to decide what to do with 4,5 or 6 organisms (poly-microbial). Consistent with traditional microbiology, our policy is to only report a maximum of (3) potebtial pathogens, as anything over (3) is considered a “contaminated specimen” that should be recollected. If a specimen is collected properly, there should be very few recollects. All UTI by PCR reports are reviewed, interpreted and reported by our licensed Microbiologists and not just analytical PCR techs.
- Personalized Result Support. By doing the UTI-ID by PCR in-house we are able to give the caregivers more detailed information from our testing especially on confusing and problematic samples when needed. We have a consultant Microbiologist with 30 years’ experience that is available for any consultations and a Molecular PhD available to explain any PCR questions that you may have.
Background: Process and Development of our LTC Tailored UTI-ID by PCR
Doctors Lab has historically utilized the traditional microbiology model of culture, ID, and sensitivity
for the diagnosis and treatment of suspected UTI cases. However, the drawback of this “goldstandard” model was and is the 48-72 hr turn-around times (TATs).
With the troubling increase of multi-resistant organisms and the impending implementation of the
Antibiotic Stewardship program in the LTCF arena, Doctors Lab began exploring newer technologies
to better address these needs and requirements. We looked for a technology with a better TAT that
identified potential pathogens and provided suitable treatment options. We reviewed several
technologies in this area to meet our requirements. While no technology is “perfect”, we determined
after a lengthy review that UTI-ID by PCR came the closest to achieving our goals for meeting the
expressed needs of the LTC community
We decided in 2020, just before Covid, to begin sending our UTI samples out for analysis by PCR.
Ours and our clients responses were positive especially with the superior turn-around times even
with the extra shipping day.
However, over time, we began to have realize that UTI-ID by PCR in general did not necessarily
meet the needs of the LTC resident population. After much review and discussions we decided to
put together a team to develop a UTI-ID by PCR better tailored to meet the needs of the LTC
community.
Our goal was to develop a “hybrid” UTI by PCR analysis by combing the superior PCR technology
for identification and quick TAT with the traditional microbiology interpretations for review and
reporting. Again, knowing that no “test” is perfect, We believe that we have taken significant and
necessary steps towards a UTI-ID by PCR better suited for the LTC needs.
On October 6, 2022, after a long and successful development and validation process Doctors Lab
began doing the LTC tailored UTI-ID by PCR in-house. By doing it in-house we were able to adjust
and improve the end product as well as improve the TATs by eliminating the previous “extra
shipping day”. While our “tailored” UTI-ID by PCR has gone live, we remain in a “responsive mode”
as we listen to and welcome your feedback.
UTI-ID by PCR Molecular Development and Analytical Team
- Jeanne Rhea-McManus, PhD ABCC Clinical Chemistry
- Steve Finkbeiner, PhD Molecular Biology
- Laurene LeCoq, MT(ASCP) Microbiologist
- Mickey Chance, MT(ASCP) Microbiologist, Molecular
- Donna Poimboeuf, BSMT(ASCP)
- Andy Gill, BSMT (ASCP)
At Doctors Lab, we are continually reviewing and evaluating new and emerging
technologies so that we can provide the best diagnostic tools with the best turnaround
times to better serve you and your residents.
It is with these goals in mind, that we have decided to pursue a new technology to
provide more accurate and faster results for the diagnosis of UTI (urinary tract
infections) when compared to the traditional Culture-ID-Sensitivity model. We have
decided, for most samples, to move away from the traditional microbiology model of
Culture-ID-Sensitivity that usually takes 1-2 days for No Growth Negatives and 2-4 days
to complete the ID and Sensitivity and to move to UTI diagnosis by PCR (polymerase
chain reaction).
Polymerase chain reaction (PCR) is a method used widely in molecular biology to make
several copies of a specific DNA segment. Using PCR, copies of DNA sequences are
exponentially amplified to generate thousands to millions more copies of that particular
DNA segment. This allows the assay to quickly ID (genetically) bacteria found in urine
samples without the need to culture the urine thereby saving 18-24 hours. The PCR
assay can also detect the presence or absence of specific genes that can influence or
determine the bacteria’s sensitivity or resistance to specific antibiotics.
We believe that by utilizing the PCR technology to provide the UTI ID-Sensitivity that we
can improve our Accuracy and Turn Around Times (TATs) by 1-3 days. We also believe
that these improvements will allow you and your homes to better comply with the spirit
and “laws” of the Antibiotic Stewardship program.
The transition to UTI ID-Sensitivity by PCR is already underway and we hope to begin
the week of January 20, 2020.
The transition to this more accurate, sensitive and costly technology has necessitated
another change that we want to make you aware of.
Historically, we have had a number of providers consistently order a C&S no matter
what the results of the Urinalysis revealed. This practice is presumably due the
seriousness of a UTI in a long-term patient and the typical extended times to receive the
pertinent UTI results to be able to appropriately treat your residents? However, due the
complexity and cost of the PCR analysis and today’s regulatory environment, our
strategic PCR lab partner requires that we screen out negatives so as to not send a
high volume of “Negative-No Growth” urines to be analyzed by PCR.
In order to comply with our strategic PCR partner’s requirements, to minimize the
number of “Negative-No Growth” urines sent to them for PCR analysis, we have
enhanced our UA w/ Reflex to C&S panel to better identify the highest percentage of
“Negative-No Growth” samples.
We have historically used the following criteria on our UA w/ Reflex to C&S panel to
identify positive urine samples with the highest probability of being a true UTI.
- Clarity: Cloudy, turbid
- Nitrite: Positive reaction on the dipstick
- Leukocyte Esterase: Positive reaction on the dipstick
The above criteria according to the literature provides an 80-90% Negative Predictive
Value (NPV) for a UTI. In order to improve the Negative Predictive Value (NPV) of our
UA w/ Reflex to C&S panel we have added a catalase test to our reflex criteria scheme
that should improve our Negative Predictive Value (NPV) to nearly 100%.
Our request to you as an ordering provider is to order the UA w/ Reflex to C&S
panel and to not order a C&S regardless of the UA results.
Going forward, the “UA w/ Reflex to C&S” order will be performed by PCR.
As we make this transition to better serve you and your residents we look forward to
receiving your questions, concerns and feedback.
We are preparing to add an additional bacteria screening test to our Reflex to C&S panel in
order to improve our Negative Predictive Value and to strengthen our final determination of
calling a urine “negative” and therefore would not reflex it to a C&S (ID & Sensitivity).
The additional test is the UriScreen. We will be adding the UriScreen to our “Urinalysis with
Reflex to C&S Panel”. The UriScreen detects catalase. Catalase is found in both WBCs and
Bacteria. The best Positive Predictive Value of a potential UTI that would indicate a reflex to a
C&S is the presence of both WBCs (pyuria) and Bacteria (bacteriuria). Normal, clean urine has
no significant catalase activity.
By the addition of the UriScreen to our Urinalysis with Reflex to C&S Panel we will be able to
significantly improve our Negative Predictive Value of a potential UTI and therefore more
confidently rule out the reflex to a C&S.
In light of the above addition, we will be making the following ordering adjustments.
Currently we are ordering the following Panels for the UA with reflex to C&S
45 Urinalysis w/ Microscopic (SHV)
50 Urinalysis w/ Microscopic (PH)
Beginning January 2020, we will begin ordering the following Panels for the Urinalysis Reflex to C&S orders.
2702 UR C&S Reflex Panel (PH)
2704 UR C&S Reflex Panel (SHV)
The New C&S Profile to be reflexed to will be UTI-ID & Sensitivity by PCR (MA). It is loaded in Careevolve and in the Labdaq Urine_C&S Ordering Tab if you need to order it individually.
The new Panel # 7503 UTI ID & Sensitivity by PCR (MA) will be reflexively ordered by Labdaq when any of the following triggers occur
- Positive Nitrite
- Positive Leukocyte Esterase
- Positive Catalase
The (MA) at the end of the Panel name is for the new reference lab MedArbor. We do not currently have an interface with MedArbor but have begun working on it.
The plan is to send each Positive Reflex sample to MedArbor to be analyzed by a new technology known as PCR. The new PCR technology is faster and better and we should be able to cut a day or two off of our turnaround time.
The sample preparation should essentially be the same. The plan is to place a filled (with urine) and labeled Gray top tube with a requisition into a plastic sample bag and send them up to Shreveport for UPS to pick up between 5-6PM.
Rev 1.5 011820
Nursing Home Memo
Re: UA Reflex to C&S (ID & Sensitivity) If Indicated
Medicare regulations prohibit laboratories from automatically ordering additional laboratory tests based on results from prior tests. However, "Reflex" testing may be done if the client specifies this in the original order.
When a client orders "Urinalysis w/Reflex to Culture and Sensitivity (C&S)",
DOCTORS LAB will reflexively order a urine culture if one or more of the following conditions are met:
- Clarity: Cloudy, turbid
- Nitrite: Positive reaction on the dipstick
- Leukocyte Esterase: Positive reaction on the dipstick
- Catalase: Positive
NOTES:
- In the case of the a suspected UTI, we recommend ordering the "Urinalysis w/Reflex to C&S"
- If a doctor wants a C&S ‘no matter what” and orders one, it will be performed
- If a UA is ordered without a C&S order or Reflex to a C&S, regardless of the UA results, a C&S will not be performed
Rev 2.0 01.10.20
Issue: We have received a number of calls consistent with the following scenario: Patient is
drawn in early AM. CBC performed and reports a “critical value” on Hemoglobin and/or
Hematocrit. Patient admitted to hospital for possible transfusion. Hospital draws CBC for
evaluation and finds the Hgb/Hct is now higher and not critical and the patient does not require
a transfusion or receives an unnecessary transfusion.
Review: On each one of these calls, Doctors Lab has reviewed each case to insure that there
were no instrument or system failures. We have reviewed: Correct patient drawn, Instrument
maintenance and QC. We sent split samples to other labs and have re-drawn patients and sent
split samples to other labs for comparison. We contacted the instrument manufacturer. None
of these review processes have satisfactorily identified an “issue” that could or should be
corrected. After each review we felt confident in the accuracy of the results that we provided.
However, we still had no satisfactory explanation for the lower results that we reported.
Note: we were anxious to resolve this issue as the “tendency” is to assume that the laboratory
and its results are always the ones who are wrong.
Conclusion: After our case reviews, we continued to research possible explanations for the
phenomenon that we and you were experiencing. As we have searched the literature, we
believe that we have found a plausible explanation to accurately explain the differences in the
results.
Study Conclusions:
- Our results confirm the theory that a change in posture causes changes in some of the blood indices; posture changes the hydrostatic pressure that leads to a change in the movement of fluid between interstitial space and intravascular space and causes physiologic fluctuations in blood volume.
- It is recommended that healthcare providers consider the postural pseudo-anemia phenomena in the event of a Critical Hgb or Hct prior to admitting for possible transfusion.
- Changes in posture can lead to substantial changes in Hgb/Hct, which may be attributed mistakenly to blood loss or acute anemia and result in a cascade of unnecessary diagnostic costs. In reality, these changes represent postural pseudoanemia, a normal p hysiological response to a change in position from standing to lying (and vice versa).
From our literature reviews and our own in-house study, we believe that the Postural Pseudoanemia phenomena is most likely the reason for most of the differing CBC results between the
early AM and later in the day draws.
Recommendations: We believe that this Postural Pseudo-anemia phenomena is probably
happening on most of our patient results but does not become an “issue” until the results
approach the Critical Values borders.
Our recommendation: Change the position of the patient and call us for a STAT redraw prior to
admission.
Summary: When receiving a Critical Value on a Hgb/Hct on an early AM draw that could
potentially indicate the need for a transfusion (especially in the absence of other clinical
indications of bleeding or anemia), is to get the patient up (change of posture) and redraw the
sample before admitting to the hospital. Call us for STAT redraw.
