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Year : 2018  |  Volume : 21  |  Issue : 4  |  Page : 218-221

Turnaround time for electrolytes, urea, and creatinine in a clinical laboratory

Department of Chemical Pathology, University of Benin Teaching Hospital, Benin City, Edo State, Nigeria

Date of Web Publication31-Dec-2018

Correspondence Address:
Dr. Ekiye Ayinbuomwan
Department of Chemical Pathology, University of Benin Teaching Hospital, Benin City, Edo State
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Source of Support: None, Conflict of Interest: None

DOI: 10.4103/smj.smj_36_17

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Background: Timeliness is expressed as the turnaround time and is often used by the clinician as a benchmark for laboratory performance. Clinicians depend on fast turnaround time to achieve early diagnosis and treatment of their patients and early patient discharge from emergency departments or hospital in-patient services. Determination of the turnaround time would enable a critical self- appraisal of our laboratory services and improve our turnaround time. Objective: This study assessed the turnaround time for electrolytes, urea and creatinine tests from the emergency departments of the hospital. Materials and Methods: An observational study was conducted between September and October 2016 amongst patients from the Intensive Care Unit, Accident and Emergency Department and Children Emergency Room, whose blood specimens were received at the Chemical Pathology Department for emergency electrolytes, urea and creatinine tests. A total of 122 specimens were randomly selected and the average time taken to complete each phase was measured and the overall turnaround time calculated. Data was analysed using statistics software SPSS (version 13.5). Results: Audited cases consisted of 20 (16.4%) specimens from the Intensive Care Unit, 40 (32.8%) from the Children Emergency Room and 62 (50.8%) from the Accident and Emergency Department. The average turnaround time for the Accident and Emergency Department, Intensive Care Unit, and Children Emergency room were 6.5hours, 4.2hours and 5.2hours respectively. Conclusion: This study revealed that the turnaround time for electrolytes, urea and creatinine for patients in the emergency units is quite long and requires some improvement which could be done with the use of Laboratory Information System to track specimens from the various emergency units of the hospital.

Keywords: Creatinine, electrolytes, emergency unit, turnaround time, urea

How to cite this article:
Ayinbuomwan E, Adaja TM. Turnaround time for electrolytes, urea, and creatinine in a clinical laboratory. Sahel Med J 2018;21:218-21

How to cite this URL:
Ayinbuomwan E, Adaja TM. Turnaround time for electrolytes, urea, and creatinine in a clinical laboratory. Sahel Med J [serial online] 2018 [cited 2023 Sep 24];21:218-21. Available from: https://www.smjonline.org/text.asp?2018/21/4/218/249079

  Introduction Top

The four pillars of efficient laboratory services are accuracy, precision, timeliness, and authenticity, but sometimes, laboratory technologists overlook timeliness and concentrate on improving analytical variables. To improve patient care, it is important that we consider how much time every process involved in this activity takes. There are different approaches to the definition of turnaround time (TAT). TAT can be classified by test (e.g., potassium), priority (e.g., urgent or routine), population service (e.g., in-patient and out-patient, emergency department [ED]), and the activities included. The steps in performing a laboratory test were outlined by Lundberg, who described the brain to brain of TAT as a series of nine steps: ordering, identification, collection, transportation, preparation, analysis, reporting, interpretation, and action.[1] Delayed and misplaced requisitions, specimens and reports contribute to unacceptable TATs.[2] In the ED, delay in the review of results by clinicians is the greatest component of perceived TAT.[3]

There are also differences between clinicians and laboratories in their definitions of TAT. In the 1998 College of American Pathologist (CAP) Q-Probes program, 41% of laboratories defined ED TAT as time of receipt in the laboratory until the time of the report; 27% as the ordering of test to result reporting and 18% as specimen collection to reporting.[4] However, over 40% of physicians defined ED TAT as starting at the physician request and only 9% at laboratory receipt. There was a better agreement between laboratories and physicians in the choice of the endpoint with over 40% of physicians choosing when the physician gets the result as the end point and 50% when the ED gets the result. Howanitz has published widely on the CAP survey results and he has suggested that TAT be defined from the time the test is ordered to the time that results are available to the caregiver and that TAT goals be expressed as a percentage within the time interval (90% or 95% of results completed within the time interval).[5]

A general benchmark for laboratory TAT as stated in a study by Hawkins is for 90% of tests to be completed within 60 min.[6] This goal tends to vary from laboratory to laboratory as processing equipment, and volume of specimen vary. With a high paced demand placed on these activities, the technicians experience stress which contributes to a prolonged TAT and low turnover rate. The term “therapeutic TAT” is sometimes used to describe the interval between when a test is requested to the time a treatment decision is made.[7] There is yet another classification of time periods which separates the steps into the preanalytical (order to preparation), analytical (analysis), and postanalytical (reporting to action) phases[8] and this classification was adopted in this study. The variety of different approaches in literature creates difficulties when searching for benchmarking or state-of-the-art data. Inspection of journal abstracts is sometimes insufficient to allow clear identification of how TAT was measured and study of original text does not always clarify details. Laboratories without electronic order entry systems may have difficulty collecting accurate ordering time and may find intra-laboratory TAT a more feasible option at present. The chemical pathology laboratory in the University of Benin Teaching Hospital is one of such centers. However, the total TAT for electrolytes, urea, and creatinine (E/U/Cr) specimens was estimated in this study.

  Materials and Methods Top

This is an observational study of the TAT for emergency electrolytes, urea and creatinine tests ordered from the Accident and ED (A and E), Intensive Care Unit (ICU) and the Children Emergency Room (CHER) which were received between 8 am and 4 pm at the Department of Chemical Pathology from September 16, to October 12, 2016. Patients admitted into the emergency units are in critical conditions and thus require urgent attention. Systematic sampling technique was used to select cases. The procedure for data collection was an observation of the process from the various departments to the laboratory and what happened within the laboratory until the result was ready for the physician. Various instruments are used in the chemical pathology laboratory for analysis of E/U/Cr such as the flame photometer, spectrophotometer, ion selective electrode, and autoanalyzers all of which can be used to determine the TAT. In this study, the spectrophotometer and ion selective electrode were used for biochemical analysis.

A program was developed to record the time taken to complete each phase of the testing cycle. The TAT was classified into 3 phases: preanalytical, analytical, and postanalytical phase. The preanalytical phase involved phlebotomy, transport of specimen from blood collection site to the laboratory, centrifuge, and separation of the specimen. The analytical phase involved the analysis of the specimen for E/U/Cr, whereas the postanalytical phase involved documentation of results, and then receipt of the result by either the nurses or other team members managing the patient. The mean TAT and proportion of acceptable tests (% of TAT within 60 min, 90 min, and after 90 min) were recorded. The average time taken to complete each phase was measured, and the contribution of each phase to the TAT was calculated. Statistics software SPSS (version 13.5, SPSS Inc. Chicago IL.) was used for data analysis and presentation. Ethical approval for the study was obtained on the 20th of march 2017 from the University of Benin Teaching Hospital Ethics and research committee. ADM/E22/A/Vol. VII/1462.

  Results Top

A total of 62 specimens for E/U/Cr from the A and E were analyzed for TAT, and none of these results were ready within 2 h of order. Only 2 (3.2%) results were ready in 3 h, 8 (12.9%) were ready in 4 h while 52 (83.9%) were ready after 4 h of order. Of the 20 specimens analyzed from the ICU, no result was ready within 1 h 30 min of order. Only 2 (10%) was ready in 2 h, 6 (30%) were ready in 3 h, 2 (10%) were ready in 4 h, and 10 (50%) of the results were ready after 4 h. From the CHER, 40 specimens were analysed out of which no result was ready until 2 h after order when only 4 (10%) were ready. Within 3 h of order, 6 (15%) were ready; 1 (2.5%) of the results were ready in 4 h, whereas 29 (72.5%) were ready after 4 h of order [Table 1].
Table 1: Proportion of electrolytes, urea and creatinine versus turnaround time from different units

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The average TAT for E/U/Cr tests from the A and E was 393 min (6.5 h), and 254 min (4.2 h) for those from the ICU, whereas the average TAT was 312 min (5.2 h) for the requests from CHER [Figure 1]. The TAT for E/U/Cr at different phases of the testing cycle was discovered to be the highest at the analytical phase. The mean TAT for the preanalytical phase was 99.4 min (1.7 h) for A and E, 29.2 min (0.49 h) for ICU, and 94.3 min (1.6 h) for CHER. For the analytical phase, it was 296 min (4.9 h) for the A and E, 171 min (2.85 h) for the ICU, and 214 min (3.6 h) for CHER [Table 2].
Figure 1: Average turnaround time for E/U/R in minutes from different units in the hospital. A and E: Accident and emergency, ICU: Intensive Care Unit, CHER: Children emergenccy

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Table 2: Turnaround times at different phases in the testing cycle

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  Discussion Top

Clinicians depend on the TAT to achieve early diagnosis and treatment of patients. A total of 122 E/U/Cr specimens were analysed from the ICU (20) and CHER (40), whereas 62 specimens were analyzed from the A and E for their TATs. The study revealed an analytical phase delay in the testing cycle of E/U/Cr. The average TATs obtained in this study for A and E, ICU, and CHER were 393 (6.5 h), 254 (4.2 h), and 312 (5.2 h) min, respectively [Figure 1]. No laboratory result was generated for the specimens coming from A and E, ICU, and CHER within 90 min of specimen collection. The percentage of specimens which yielded results after 4h of specimen collection were 83.9% from A and E, 50% from ICU and 72.5% from CHER [Table 1].

This shows that physicians face a lot of difficulties in making quick assessment and diagnosis at various emergency units in the hospital. These TATs are in clear contrast with 40–60 min reported for emergency specimens by Goswani et al.[9] However, Bolodeoku et al., in 2017 reported average TAT of 5.12 h and 7.32 h for the A and E and ICU, respectively, in a multicenter study in Nigeria[10] which is consistent with the findings of this study. Cox[11] in 2001 reported a standard TAT for acute care laboratory testing in tertiary care institution as <15 min for blood gases and electrolytes. This is also in contrast to TAT obtained in this study.

Different phases in the total testing cycle have been documented as possible points of delay. The common points of delay being pre- and post-analytical phases in the testing cycle.[12] However, this study revealed that the delay encountered in the testing cycle was mainly analytical. According to Steindel and Novis, 15 min is required for the order to specimen collection and collection to receipt while 30 min for receipt to verification time for urgent specimens from EDs.[13] This study revealed delays at the preanalytical (86.2 min) and analytical (257.7 min) phases of the testing cycle [Table 2]. Delay at the postanalytical phase was not documented due to the absence of data as a result of the lack of functioning laboratory information system (LIS) to keep track of the laboratory activities.

Delay in the analytical phase of the testing cycle E/U/Cr could be from the use of obsolete laboratory equipment, poor power supply, poor attitude of laboratory staff to work, batching of emergency specimens, and poor laboratory policies affecting efficiency, and productivity.

  Conclusion Top

This study reveals that our laboratory is functioning below capacity with a TAT of over 4 h for most of the emergency specimens. Establishment of a LIS to track specimens from the emergency units and a good working relationship between all the stakeholders in the laboratory (pathologists, technicians, support staff, and hospital management) will enhance laboratory effectiveness and efficiency in meeting the needs of these emergency units. It is important that specimens marked urgent should be analysed as such and results sent immediately to the requesting clinicians.

Financial support and sponsorship


Conflicts of interest

There are no conflicts of interest.

  References Top

Lundberg GD. Acting on significant laboratory results. JAMA 1981;245:1762-3.  Back to cited text no. 1
Holland LL, Smith LL, Blick KE. Reducing laboratory turnaround time outliers can reduce emergency department patient length of stay: An 11-hospital study. Am J Clin Pathol 2005;124:672-4.  Back to cited text no. 2
Saxena S, Wong ET. Does the emergency department need a dedicated stat laboratory? Continuous quality improvement as a management tool for the clinical laboratory. Am J Clin Pathol 1993;100:606-10.  Back to cited text no. 3
Steindel SJ, Howanitz PJ. Physician satisfaction and emergency department laboratory test turnaround time. Arch Pathol Lab Med 2001;125:863-71.  Back to cited text no. 4
Howanitz PJ. Errors in laboratory medicine: Practical lessons to improve patient safety. Arch Pathol Lab Med 2005;129:1252-61.  Back to cited text no. 5
Hawkins RC. Laboratory turnaround time. Clin Biochem Rev 2007;28:179-94.  Back to cited text no. 6
Fermann GJ, Suyama J. Point of care testing in the emergency department. J Emerg Med 2002;22:393-404.  Back to cited text no. 7
Truchaud A, Le Neel T, Brochard H, Malvaux S, Moyon M, Cazaubiel M, et al. New tools for laboratory design and management. Clin Chem 1997;43:1709-15.  Back to cited text no. 8
Goswani B, Singh B, Chawla B, Gupta VK, Mallika V. Turnaround time (TAT) as a benchmark of laboratory performance. Indian J Clin Biochem 2010;25:376-9.  Back to cited text no. 9
Bolodeoku J, Ogbeiwi O, Kuti MA, Adebisi SA. Laboratory tests turnaround time in outpatient and emergency patients in Nigeria: Results of a physician survey on point of care testing. Int J Med Res Health Sci 2017;6:76-81.  Back to cited text no. 10
Cox CJ. Acute care testing. Blood gases and electrolytes at the point of care. Clin Lab Med 2001;21:321-35.  Back to cited text no. 11
Wanker AD. Study of determination of laboratory turnaround time in tertiary care hospital in India. Int J Res Med Sci 2014;2:1396-401.  Back to cited text no. 12
Steindel SJ, Novis DA. Using outlier events to monitor test turnaround time. Arch Pathol Lab Med 1999;123:607-14.  Back to cited text no. 13


  [Figure 1]

  [Table 1], [Table 2]


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