
==== Front
Lab Med
Lab Med
labmed
Laboratory Medicine
0007-5027
1943-7730
Oxford University Press US

38431798
10.1093/labmed/lmae011
lmae011
Science
AcademicSubjects/MED00690
Rainbow phlebotomy collection and urine aliquots for emergency department add-on testing in the era of pandemic-driven supply shortages
Potter Scott MD Department of Pathology, University of Utah School of Medicine, Salt Lake City, UT, US
ARUP Laboratories, University of Utah, Salt Lake City, UT, US

Rudolf Joseph W MD Department of Pathology, University of Utah School of Medicine, Salt Lake City, UT, US
ARUP Laboratories, University of Utah, Salt Lake City, UT, US

Pearson Lauren N DO, MPH Department of Pathology, University of Utah School of Medicine, Salt Lake City, UT, US
ARUP Laboratories, University of Utah, Salt Lake City, UT, US

Corresponding author: Lauren N. Pearson; lauren.pearson@aruplab.com
Joseph W. Rudolf and Lauren N. Pearson Contributed equally.

9 2024
02 3 2024
02 3 2024
55 5 585589
© The Author(s) 2024. Published by Oxford University Press on behalf of American Society for Clinical Pathology.
2024
https://creativecommons.org/licenses/by-nc/4.0/ This is an Open Access article distributed under the terms of the Creative Commons Attribution-NonCommercial License (https://creativecommons.org/licenses/by-nc/4.0/), which permits non-commercial re-use, distribution, and reproduction in any medium, provided the original work is properly cited. For commercial re-use, please contact journals.permissions@oup.com.

Abstract

Background

Rainbow blood draws for add-on testing in the emergency department (ED) are a common practice at our institution. We sought to determine the prevalence of this practice among reference laboratory clients and characterize the impact of pandemic-driven supply shortages.

Methods

This cross-sectional study surveyed 354 client laboratories to understand specimen collection practices in specific clinical environments and how these practices may have been affected by supply chain shortages. Data analysis by descriptive statistics was performed in Qualtrics.

Results

A total of 138 laboratories took the survey (39% response rate) with 57% indicating that their ED performed rainbow draws. Of these, 16% have a formal policy regarding rainbow draws, and 76% of respondents indicated that their institution was required to modify practices due to pandemic-driven supply shortages. A total of 19% indicated they routinely collect multiple urine aliquots for add-on testing.

Conclusion

Rainbow draws and collection of urine aliquots in the ED for add-on testing are relatively common practices, with few institutions maintaining formal policies regarding the practice. Pandemic-driven supply chain shortages affected a majority of respondent laboratories and local cost-benefit analysis regarding extra specimen collection is recommended to limit waste of laboratory resources.

rainbow
rainbow draw
supply chain
urine aliquot
rainbow phlebotomy
emergency department add-on testing
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pmcIntroduction

A rainbow draw, named for the colors of the outer protective caps of blood specimen vacutainer tubes collected, is often perceived as an essential part of operations workflows in certain clinical settings, such as emergency department (ED) care. Theoretically, this allows for the full spectrum of add-on testing without the harm of a second venipuncture “poke” and perceived subsequent delay associated with specimen collection and processing. Limitations in laboratory operations imposed by integrating a new laboratory information system (LIS) in our hospital-based clinical laboratory necessitated discussion at our institution regarding the practice of rainbow draws and urine aliquots collected at ED admission. These discussions prompted the following questions: Is this the standard of care at other institutions? Given recent supply chain limitations, is this practice sustainable? What are the benefits of this practice? What are the risks and unintended consequences? To inform discussions at our institution, a survey regarding collection of rainbow draws and urine aliquots in the ED was distributed to our reference laboratory clients. We sought to understand the prevalence of this practice in the context of recent supply shortages affecting laboratories and health care systems.

Methods

The goal of the cross-sectional survey was to determine whether and how institutions perform rainbow draws (defined as the practice of collecting a predefined set of blood tubes) and urine aliquot collections. The survey questions were intended to understand specimen collection practices in specific clinical environments and how these practices may have been affected by supply chain shortages. A total of 354 ARUP Laboratories clients who previously completed the 2021 Client Satisfaction Survey (distributed October 2021) were invited electronically by email to participate in the survey on March 24, 2022. ARUP Laboratories is a national nonprofit academic clinical reference laboratory based in Salt Lake City, UT. Survey questions (Supplement 1) were administered in the English language in Qualtrics. The survey was open for 3 weeks until April 15, 2022. Reminder emails were sent out each week (March 31, April 6, and April 13). The survey invitation stated that the survey findings may be published but that individual responses would be analyzed in aggregate and remain confidential. Data analysis by descriptive statistics was performed in Qualtrics.

Results

A total of 138 clients took the survey (39% response rate) from a variety of facilities across 3 geographical regions (TABLE 1). Of these, 78 participants (57%) selected “yes” to their ED performing “rainbow draws” and were asked additional questions about rainbow draws. A total of 60 participants (43%) selected “no” (36%) or “don’t know” (8%) and were then directed to questions about urine aliquot collections. A total of 16% of the institutions have a formal policy governing the use of rainbow draws (46% did not and 38% of respondents did not know).

TABLE 1. Rainbow draw respondent demographics (n = 138)

Facility type	No. (%) of respondents	United States region	
East	Central	West	
Community 1 (0-100 beds)	31(22.5)	7	16	8	
Community 2 (101-250 beds)	32 (23.2)	8	14	10	
Community 3 (251-500 beds)	33 (23.9)	10	11	12	
Community 4 (>500 beds)	4 (2.9)	0	3	1	
Reference lab: regional	4 (2.9)	1	0	3	
Reference lab: specialty	2 (1.4)	0	0	2	
Reference lab: national	1 (0.7)	0	0	1	
Reference lab: research	1 (0.7)	0	0	1	
Academic	18 (13.0)	6	7	5	
Veterans Affairs/federal	2 (1.4)	0	1	1	
Pathology group or clinic	3 (2.2)	0	3	0	
Children's	7 (5.1)	2	5	0	

Most institutions (>70%) who collect rainbow draws include purple/lavender EDTA, light blue sodium citrate, light green lithium heparin, and gold/tiger top serum tubes in the collection set (FIGURE 1). Approximately one-third also include a red top with no additive. A small minority of institutions include the remaining types of tubes queried in the survey types. Most institutions collect blood into 1 tube of each tube type in the set, although a few collect multiple tubes of each type.

FIGURE 1. Tubes included in the “rainbow” at surveyed institutions. The percentages in the chart do not add up to 100% because participants could select more than 1 option.

A total of 78% of respondents indicated that their facility was required to modify tubes included in the rainbow draws due to supply chain shortages. A total of 13% did not make modifications and 9% did not know. Light green lithium heparin, light blue sodium citrate, blue top, and purple/lavender EDTA tubes were most affected by supply chain issues (FIGURE 2). Free response comments showed that for many who have changed their practices regarding rainbow draws, nationwide vacutainer shortage, limited number of “extra” tubes actually being used for add-on testing, and a desire to decrease cost, medical waste, and iatrogenic anemia were reasons driving policy change. Respondents also mentioned conversion to a new LIS as a driving factor in discontinuing the practice due to limited informatics capability to support the practice safely.

FIGURE 2. Impacts of supply chain limitations on the practice of rainbow draws (A) and venipuncture blood collection tubes (B).

Approximately one-third of institutions use rainbow draws in specific clinical scenarios (FIGURE 3A), with facilitation of add-on testing and trauma workflows being the most indicated reasons to default to rainbow collection (FIGURE 3B).

FIGURE 3. Clinical scenarios in which rainbow collections are performed (A) and why (B). Respondents could select more than 1 reason. Of the 26% who selected “other” (A), 80% said they perform rainbow collections for emergency department (ED) patients. TAT, turnaround time.

Of 135 total, 26 participants (19%) who answered questions about urine aliquot practice indicated that their ED routinely collects multiple aliquots of urine in case of unanticipated testing and were asked additional questions about urine aliquots (3 participants omitted the question). A total of 109 participants (81%) selected no (61%) or didn’t know (20%) and were directed to the end of the survey. Gray top (preservative), yellow top (no additive), sterile cups, and clear tubes were used to collect urine aliquots in the ED (FIGURE 4A). FIGURE 4B shows the clinical laboratory tests for which urine aliquots are collected; urine culture, toxicology testing, and urinalysis were the most frequently utilized tests.

FIGURE 4. Tubes included in urine aliquots (A) and specific clinical laboratory tests for which urine aliquots are collected in the ED (B). aOf those 42% who selected “other (please specify),” 50% said they use sterile cups for urine aliquots and 20% said clear tubes.

Discussion

Implementation of a new LIS system was the catalyst for reexamining our institution’s practices; however, patient safety, cost, medical waste, and specimen quality concerns were perceived by the laboratory for many years prior. The laboratory built custom processes and procedures to accommodate the rainbow collection to add-on testing workflow desired by the ED specifically. In our workflow, specimens are received and stored unprocessed as extra specimens and later retrieved from storage after a technician approves add-on testing that is requested. Prior to laboratory automation, this was a manual process and is now partially automated. Specimens are received on the track, centrifuged on the automated line if appropriate, and sent to refrigerated storage. Unpublished internal data at our hospital laboratory showed a low frequency of add-on requests for the stored specimens collected during a rainbow draw. Our anecdotal experience is corroborated by 1 survey respondent who indicated that <10% of stored specimens were being used for add-on testing at their facility. This is similar to reported rates of 4% and 7% in the limited literature addressing rainbow draws.1,2 Snozek et al3 indicate that of 5 standard tubes in their rainbow, the fluoride oxalate, citrate, and serum separator tubes were often discarded unused; however, the rapid serum tube and EDTA were used nearly 100% of the time for initial or add-on testing.

Prior laboratory studies addressed the rainbow process from the standpoint of eliminating waste. They evaluated cost, risk of iatrogenic anemia, human resources burden, laboratory operations burden (staffing, space, and infrastructure), and rate of use of the extra tubes.1-5 The most recent study incorporated rates of tube use compared with staff perception of benefit from the practice to provide insight to encourage systematic change.3 Among all of these studies, the actual prevalence of the practice of rainbow collections has not been estimated. Our survey is unique in that it estimates a prevalence for rainbow collections (57% of our respondents) as well as impact of recent supply chain shortages (78% modified practice) across a spectrum of facility types and in all regions of the United States.

Is This the Standard of Care at Other Institutions?

With just over half of our surveyed clients indicating they perform rainbow collections and only 19% affirming collection of urine aliquots in the ED, it may be argued that these traditional practices do not constitute a standard of care. It was noted that 1 survey respondent shared that trauma level I best practice is to collect all required draws during initial phlebotomy procedure; however, compliance with this purported best practice may not necessarily mean collecting 1 of every tube type at the initial phlebotomy. We were also unable to find a best practice regarding phlebotomy in level I trauma centers. It has been suggested that a chief complaint or specific clinical scenario approach may be appropriate to use rainbow collections and urine aliquots without adding undue burden or increasing the aforementioned sources of waste.3,4 It has also been suggested that future studies should be geared toward identifying appropriate clinical scenarios in which a rainbow collection, and we would add urine aliquot collection, may be appropriate.2

Is This Practice Sustainable?

At our institution, local factors—laboratory resources, LIS limitations, and storage—along with global factors, such as vacutainer shortages and the recent pandemic, have affected discussions about the practice of rainbow and urine aliquot collections. As previously indicated, a majority of those who perform rainbow collections were forced to alter their practices due to supply chain limitations. In their comments, many respondents indicated that the practice of rainbow collections had been tolerated but discouraged at their institution, and the vacutainer shortage was the final push to abandon the practice. With 78% of respondents who perform rainbow draws indicating they had to change or modify their practice due to pandemic-related workflow issues, this suggests that the practice may not be sustainable in the current environment. A few respondents even indicated that a single extra tube was not tolerated in their systems, and others discussed tracking of unused specimens collected as part of their quality and monitoring processes to eliminate waste. With ongoing disruption in global supply chains, extra tubes to be collected, stored, and discarded without use for testing may be unsustainable in some settings.

What Are the Benefits to This Practice?

Perceived benefits of this practice inevitably center on the decreased turnaround time for clinically actionable test results and greater patient satisfaction with avoidance of additional phlebotomy collections.3,4 Snozek et al3 showed a high perceived value of rainbow draws among their surveyed ED staff, and perception of utilization rates of tubes, add-on rates of tests, and averted additional venipunctures was overestimated compared with the true rates of these practices. One example is that averted venipunctures were perceived by staff at a rate of >11 patients/day (79% of staff) vs the calculated rate of averted venipunctures as 7 patients/day.3Although this example could be interpreted to show there is not as much benefit from the practice of rainbow collections as traditionally believed, this does show that our colleagues in the ED place a great deal of importance on these practices to achieve their desired standard of patient care. Individual institutions will potentially need internal studies to elucidate the true value of this practice. Again, further work to determine the appropriate clinical scenarios for add-on testing would be beneficial to the broad community of ED and trauma care. One scenario where rainbow collections could show benefit is in circumstances where there are large numbers of patients in the ED waiting room or triage area awaiting full medical evaluation. Having basic laboratory results reported for these patients could, in theory, expedite diagnosis and disposition.

What Are the Risks and Unintended Consequences?

In 2003 the College of American Pathologists released results from a survey of 140 laboratories addressing the overcollection of blood for routine laboratory testing. They estimated that more than 8.5 times the blood volume necessary for the indicated tests was collected, leading to waste and potentially iatrogenic anemia. It was concluded that most institutions could decrease blood volume while not affecting the reliability and turnaround time for their testing procedures.6 This was a landmark report that showed the potential for systematic change in laboratory practices to improve patient care. In 2010, Loh et al5 were the first to discuss the problem of extra blood tubes from the perspective of waste, including loss of blood from excess phlebotomy and the financial cost of the additional consumables, processing time, and storage of tubes in the laboratory process. Seaver and Gray1 focused on true cost analysis, eliminating waste, and improving staff efficiency as an essential laboratory function due to increasing costs and decreasing reimbursement for laboratory tests. Mullen4 indicated an opportunity for cost savings by focusing on the medical waste reduction alone as well as decreased risk of exposure inherent to all steps of collection, processing, testing, storage, and disposal of potentially hazardous samples. Anecdotal experience as well as comments from respondents suggests that storage of extra tubes often requires a deviation from standard practice compared with specimens drawn with active orders. These deviations can introduce opportunities for error and may lead to suboptimal conditions for testing when add-on requests are made. Additional assessment of risk from the clinical workflow could be enlightening, and a study incorporating ED metrics and viewpoints would add to the body of literature.

When a larger than necessary number of blood specimens is collected, there is a risk of patient specimen labeling and identification errors, which is a patient safety concern. Additionally, failure to follow appropriate collection practices for order of draw can result in spurious results being reported, which, if unrecognized, could result in misdiagnosis and inappropriate treatment. Because some specimens collected during rainbow draws will be stored as extra specimens without consideration for the specimen processing and storage conditions required for the myriad of tests that may be subsequently ordered, there is a risk of spurious, poor quality results being reported for the tests that are done using the stored extra specimen. For example, electrolytes and common enzyme tests are affected by ambient vs cold storage conditions and whether the plasma or serum is separated from cells. Although of perceived benefit, the unintended consequences of potentially spurious results and reduced quality is a risk for patient care that should be carefully considered at every institution.

Conclusion

Our study shows that rainbow draws and urine aliquot collections happen at many institutions in the United States but that there is heterogeneity among institutional practices. Few institutions have a policy governing the use of these workflows. Given the quality, cost, and laboratory operations impacts, each institution should determine local prevalence of the practice, assess benefits vs risks, and quantify waste and the cost of maintaining this process. Variables affecting an institution’s ability to accommodate this workflow include (but are not limited to) availability of phlebotomists to collect specimens from patients in the ED, acuity of care offered in the ED, volume and wait times for ED care, the ability of a laboratory LIS to accommodate rainbows and urine aliquots, laboratory staffing limitations, and the efficiency of manual vs automated processes in the laboratory for receiving, storing and retrieving specimens. This study only determined the prevalence of rainbow draws and urine aliquots in the ED; future studies could examine prevalence in other clinical areas where there may be perceived benefit, such as inpatient acute care and obstetrics. Perceived patient satisfaction associated with reduced venipuncture draws was not included in our study. An additional area for future research includes collaboration with ED physicians and other clinicians to identify potential use-case scenarios where rainbow draws and urine aliquots could be clinically and operationally beneficial. This survey showed many laboratories were affected by pandemic-driven supply constraints, which represent another reason to revisit the practice of rainbow phlebotomy collections and urine aliquots for optimal areas of use.

Acknowledgments

The authors thank Leslie Smith for her expertise in drafting survey questions, facilitating the survey, and providing preliminary data analysis of responses.

Abbreviations:

ED emergency department

LIS laboratory information system

Conflict of Interest Disclosure

The authors have nothing to disclose.
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