Direct costs of blood drawings with pre-analytical errors in tertiary paediatric hospital care

BACKGROUND

Blood drawings is a common hospital procedure involving laboratory and clinical disciplines that is important for the diagnosis and management of illnesses in children. Blood drawings with pre-analytical error (PAE) can lead to increased costs for hospitals and healthcare organisations. The direct cost of blood drawings after a PAE is not fully understood in paediatric hospital care.

AIM

The aim of this study was to estimate the average direct cost of PAE per year and per 10,000 blood drawings in tertiary paediatric care.

METHODS

A cost analysis using a bottom-up approach was conducted on the basis of combined information from the hospital's laboratory register for the period 2013-2014 and clinical in-ward observations at a tertiary children's referral hospital in Sweden, the Astrid Lindgren Children's Hospital. For the analysis, we hypothesised the re-collection of all blood drawings with PAE and included the average costs of the sampling materials, the time of the healthcare personnel, the laboratory analyses, and in-ward premises based on the time spent on the blood sampling procedure.

RESULTS

The annual cost of PAE was estimated to be 74,267 euros per 54,040 blood drawings, which corresponds to 13,756 euros per 10,000 blood drawings or 1.5 euros per draw. The personnel cost represented 60.1% (45,261 euros per year) of the cost due to PAE, followed by costs for hospitalisation (25.2%), laboratory analyses (8.1%), and materials (5.7%).

CONCLUSION

PAEs lead to substantial increases in the costs in tertiary paediatric hospital care. If these PAEs can be avoided, costs related to the re-collection of blood drawings with PAE may be re-allocated to other health-promoting activities for children visiting hospital institutions.

Reducing blood sample hemolysis in the emergency department using S-Monovette® in aspiration mode

Background

Blood sample hemolysis continues to be a significant problem in clinical practice. In vitro hemolysis rates up to 77% have been reported in literature. The use of manual aspiration techniques for blood sampling has previously been shown to reduce the burden of erythrocyte injury in the pre-analytical phase compared to the vacuum collection technique. This study compares the hemolysis rates between two blood sampling methods: 5.0 ml BD Vacutainer® SST™ (BDV) and 4.9 ml S-Monovette® serum gel tubes in aspiration mode (SMA).

Methods

This was a prospective randomised controlled study conducted in an Emergency department (ED). A convenience sample of 191 adult patients, aged 18-90 years old, presenting at the ED and requiring blood samples for serum electrolyte was included in the study. Paired blood samples were obtained through an intravenous cannula from each patient with randomised order of blood draw using SMA or BDV. Patient data was obtained and hemolysis index (HI), serum lactate dehydrogenase (LDH), and serum potassium (K) levels measured.

Results

The adjusted mean HI (35.2 vs 21.5 mg/dL, p < 0.001), serum K (4.38 vs 4.16 mmol/L, p < 0.001) and LDH levels (259.6 vs 228.4 U/L, p < 0.001) were significantly higher in blood samples taken using BDV compared to SMA. The frequency of severely hemolyzed (>150 mg/dL) samples was also higher in blood collected using BDV (16.2%) compared to SMA (0%).

Conclusions

The burden of hemolysis in blood samples taken from IV cannulae can be effectively reduced with the use of manual aspiration using the S-Monovette® blood collection system as compared to BD-Vacutainer.

The effect of hemolysis on quality control metrics for noninvasive prenatal testing

Background

Noninvasive prenatal testing (NIPT) is the testing of blood samples from pregnant women to screen for fetal risk of chromosomal disorders. Even though in vitro hemolysis of blood specimens is common in clinical laboratories, its influence on NIPT has not been well investigated.

Methods

Peripheral blood samples were collected from 205 pregnant women and categorized according to the concentration of free hemoglobin in the plasma. After performing NIPT using massively parallel sequencing, the quality control metrics were analyzed and compared with samples that did not undergo hemolysis or samples redrawn from the same women.

Results

The specimens were divided into four groups based on the concentration of free hemoglobin: Group I (0–1 g/L, n = 53), Group II (1–2 g/L, n = 97), Group III (2–4 g/L, n = 30), and Group IV (> 4 g/L, n = 25). There was no significant difference in the quality control metrics of clinical samples with slight or moderate hemolysis (Group II and III). However, samples with severe hemolysis (Group IV) showed a significantly increased rate of duplicated reads (duplication rate) and fetal fraction, as well as decreased library concentration compared with samples without hemolysis. Moreover, the increase in fetal fraction caused by hemolysis was confirmed by redrawing blood samples in Group IV.

Conclusion

For NIPT using massively parallel sequencing, samples with slight or moderate hemolysis (≤ 4 g/L) are acceptable. However, careful consideration should be taken regarding the use of severely hemolyzed samples (> 4 g/L), since they might increase the risk of test failure.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12920-022-01280-2.

The "EPiQ"-Study (Evaluation of preanalytical quality): S-Monovette® in manual aspiration mode drastically reduces hemolytic samples in head-to-head study

Background

Hemolytic blood samples are the number one cause for specimen rejection at emergency departments. Triggered by unsuitable blood sampling material or incorrect handling and a related strong vacuum force, hemolytic samples often must be retaken. The objective of this study was to assess whether correct manual aspiration using S-Monovette® could reduce the number of hemolytic samples.

Methods

Between January and April 2019, a head-to-head study was conducted. Whereas in the first eight weeks, all specimens were collected using Vacutainer®, in the second eight weeks, blood was taken using S-Monovette® in aspiration mode. Specimens were categorized into five classes (0–30, 31–50, 51–75, 76–100, and 101+ mg/dl of cell-free hemoglobin) and for the statistical analyses, all samples exceeding 30 mg/dl were classified as hemolytic.

Results

Data were collected on 4794 blood specimens (Vacutainer®: 2634 samples, S-Monovette®: 2160 samples). While the percentage of non-hemolytic samples (HI of 0–30 mg/dl) was substantially higher for specimens drawn by S-Monovette® (95.7 %) than Vacutainer® (83.0 %), the opposite was true for all HI categories above 30 mg/dl. Importantly, the reduction of hemolytic samples took place immediately following the imposition of S-Monovette® and remained stable at a low level until the end of the study.

Conclusions

Based on our results, we conclude that switching to S-Monovette® in manual aspiration mode in the blood sampling process could be highly beneficial, not only from a financial point of view, but also with regards to reducing unnecessary tasks and stress for nursing staff and improving patient outcome overall.

•

S-Monovette® in aspiration mode reduces hemolytic samples by a factor of four at emergency departments.

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Various stakeholders affected by poor quality blood samples could benefit.

•

The inconvenience due to redundant blood samples could be significantly reduced.

Evaluation of processes, outcomes, and use of midline peripheral catheters for the purpose of blood collection

HIGHLIGHTS

Results added knowledge on use of midline catheters (MCs) for blood sampling. Using MCs for blood withdrawal resulted in low rates of hemolysis (0.69%). Dwell time was longer in those who had blood drawn from their MC. Nurse practices for blood sampling from MCs varied and learned from other nurses.

BACKGROUND

Blood withdrawal from midline catheters (MCs) is done clinically, but no studies were found evaluating outcomes from this procedure, nor were clinical guidelines found. Drawing blood samples from short peripheral catheters is associated with higher hemolysis rates.

METHODS

A prospective, observational, mixed methods study was used to evaluate outcomes from using MCs for blood withdrawal. Focus group sessions were held to evaluate nurses' practices for this procedure.

RESULTS

Data were collected over 3 months on 397 MCs in 378 patients. Hemolysis rates when the MC was used for blood withdrawal was 0.69% in 1021 tests. More than half had blood specimens drawn through the MC, and the time known for the successful withdrawal was on average 64 ± 85 hours. Mean dwell time for all MCs was 108.5 ± 98 hours, and when MCs were used for blood withdrawal, mean dwell time was 127.19 ± 109.13 hours and for MCs not used for blood withdrawal, 88.34 ± 79.86 hours (P < 0.001). In 338 patients who received therapy through their MC (n = 338), 87% completed intended therapy: 88% with blood withdrawal and 81% without blood withdrawal. Qualitative analysis from focus groups demonstrated wide variation in practice for blood sampling from MCs, and most learned techniques from their preceptors, other nurses, or patients.

CONCLUSIONS

Findings indicated that blood withdrawal from one specific type of MC had low rates of hemolysis, increased dwell time, and completion of therapy. More studies are needed to determine best practices for blood sampling through various types of MCs and outcomes.

Influence of exogenous and endogenous factors on the quality of the preanalytical stage of laboratory tests (review of literature)

A literature review in the article presents an analysis of the influence of endogenous and exogenous factors on quality of preanalytical phase of laboratory testing. The review shows significance of external and internal factors influencing blood samples at preanalytical phase of laboratory testing. Among the exogenous factors considered: phlebotomy, test tubes for samples, transportation and storage. A number of factors exist at this phase that significantly affect test results. We examined these aspects of phlebotomy process: staff training, disinfectant contamination, needle diameter, needle material contamination. The review considers possible contamination with tube components and the importance of choosing the right anticoagulants and excipients. Transportation and storage of biological samples can be a source of errors at the preanalytical phase of laboratory testing. We analyzed the problem of determining the stability of analytes during storage and aspects of transportation samples by modern means. Among the endogenous factors considered: hemolysis, lipemia, icterricity, cell metabolism.. Hemolysis is one of the most frequent consequences of errors at the preanalytical phase. We analyzed importance of choosing a method for identifying hemolized tubes and the heterogeneity of bias results on different analytical systems. The review shows contribution of various classes of lipoproteins to turbidity of sample, possible preanalytical errors and impact on analytical tests. We examined possible effects of high bilirubin concentrations on analyte measurements. In the review, we also examined metabolism of some cells and its effect on samples.

Hemolytic specimens in complete blood cell count: Red cell parameters could be revised by plasma free hemoglobin

Introduction

Hemolysis is the main cause of unqualified clinical samples. In this study, we established a method for detecting and evaluating hemolysis in whole blood test. We used a mathematical formula for correcting the influence of hemolysis on complete blood cell count (CBC) so as to avoid re‐venipuncture and obtain more accurate parameters of red blood cell detection, reduce the burden of patients, and improve the efficiency of diagnosis and treatment.

Methods

Hemolytic samples were selected and then corrected using the new formula. Plasma free hemoglobin (fHB) was used as the criterion to determine the degree of hemolysis; the uncertainty of measurement is acceptable as the limit value of deviation between the measured value and the revised value. Hemolysis simulation analysis in vitro and continuous monitoring of clinical patients were used to verify the correction effect.

Results

A total of 83 clinical samples with hemolysis were collected and analyzed; fHB 1.4 g/L was selected as the unacceptable value for clinical hemolysis detection. In hemolytic samples, the red blood cell parameters corrected by formula are significantly different from those uncorrected and had a good consistency with those before hemolysis.

Conclusion

The results show that the hemolysis phenomenon of CBC has a significant impact on routine blood testing. By using the new formula, the influence of hemolysis on erythrocyte and related parameters can be quickly and easily corrected, thus avoiding venipuncture again for re‐examination, reducing diagnostic errors, and saving medical resources.

Managing hemolyzed samples in clinical laboratories

Hemolysis is conventionally defined as membrane disruption of red blood cells and other blood cells that is accompanied by subsequent release of intracellular components into the serum or plasma. It accounts for over 60% of blood sample rejections in the laboratory and is the most common preanalytical error in laboratory medicine. Hemolysis can occur both in vivo and in vitro. Intravascular hemolysis (in vivo) is always associated with an underlying pathological condition or disease, and thus careful steps should always be taken by the laboratory to exclude in vivo hemolysis with confidence. In vitro hemolysis, on the other hand, is highly preventable. It may occur at all stages of the preanalytical phase (i.e. sample collection, transport, handling and storage), and may lead to clinically relevant, yet spurious, changes in patient results by interfering with laboratory measurements. Hemolysis interference is exerted through several mechanisms: (1) spectrophotometric interference, (2) release of intracellular components, (3) sample dilution and (4) chemical interference. The degree of interference observed depends on the level of hemolysis and also on the assay methodology. Recent evidence shows that preanalytical practices related to detection and management of hemolyzed samples are highly heterogeneous and need to be standardized. The Working Group for Preanalytical Phase (WG-PRE) of the European Federation of Clinical Chemistry and Laboratory Medicine (EFLM) has published many recommendations for facilitating standardization and improvement of this important preanalytical issue. Some key EFLM WG-PRE publications related to hemolysis involve: (i) a call for more transparency and some practical recommendations for improving the harmonization of the automatic assessment of serum indices and their clinical usefulness, specifically the hemolysis index (H-index), (ii) recommendations on how to manage local quality assurance of serum or plasma hemolysis/icterus/lipemia-indices (HIL-indices) and (iii) recommendations on how to detect and manage hemolyzed samples in clinical chemistry testing. In this review we provide a comprehensive overview of hemolysis, including its causes and effects on clinical laboratory assays. Furthermore, we list and discuss the most recent recommendations aimed at managing hemolyzed samples in everyday practice. Given the high prevalence of hemolyzed blood samples, the associated costs, the great heterogeneity in how hemolysis is handled across healthcare settings, countries and continents, and increasing patient cross-border mobility, standardization and quality improvement processes aimed at combatting this important preanalytical problem are clearly warranted.

Plasma chemistry in nesting leatherback sea turtles (Dermochelys coriacea) from Florida: Understanding the importance of sample hemolysis effects on blood analytes

Plasma chemistry is widely used in diagnostic and research settings in sea turtles. However, plasma discolorations such as hemolysis are often not considered in data interpretation. The objectives of this study were to (1) evaluate the effects of moderate hemolysis on plasma electrolytes, minerals, and proteins using dry chemistry analysis (DCA) and protein electrophoresis from nesting leatherback sea turtles (Dermochelys coriacea) from Florida and to (2) establish blood analyte reference intervals. Twenty-six plasma samples with absence of hemolysis were selected and sub-divided into one non-hemolytic aliquot and an aliquot that was experimentally manipulated to mimic moderate hemolysis. Plasma samples were analyzed for hemoglobin using a handheld photometer; sodium, potassium, chloride, magnesium, calcium, phosphorus, and total protein using DCA; and protein electrophoresis. Packed cell volume and hemoglobin were measured in corresponding whole blood samples. Reference intervals were established. All analytes except calcium and pre-albumin were significantly higher and the calcium:phosphorus and albumin:globulin ratios were significantly lower in hemolytic plasma compared to non-hemolytic plasma. Alpha2-globulins and potassium were the analytes most impacted by hemolysis, averaging 3.3- and 2.0-fold higher in hemolyzed samples, respectively, indicating that (1) hemoglobin migrates into the alpha2-globulin region in this species and (2) notable intracellular potassium is released into plasma with hemolysis. Attempted conversion factors for compensation of hemolysis were considered inaccurate for 4 of 16 analytes due to non-significant regression lines. We also report that PCV provides an estimate of hemoglobin (g/L) using the formula: (2.59 × PCV) + 24.59. Given the spurious effects of hemolysis, the degree of this artifact should be reported with biochemistry data, and samples with moderate to severe hemolysis should be excluded from datasets when interpreting electrolyte, mineral, and protein results. This will ensure accurate data interpretation for individual turtles in rehabilitation or research settings and population-level data relevant to conservation-focused projects.

Using the hemoglobin-binding Staphylococcus aureus protein IsdH to enable plasma analysis of hemolyzed blood samples

Background

Intravascular hemolysis and in vitro hemolysis are prevalent contributors to failed blood sample analysis in the routine hospital laboratory. Interferences by hemoglobin in spectrophotometric and certain enzyme activity assays is the major causative factor.

Methods

By exploiting the hemoglobin-binding properties of the iron-regulated surface determinant H (IsdH) protein from Staphylococcus aureus we have developed a new method to instantly remove hemoglobin and hemoglobin-haptoglobin complexes from plasma in vitro thereby enabling the measurement of hemoglobin-sensitive analytes in hemolyzed plasma. In the present study we used an engineered IsdH mutant form conjugated to Sepharose for the efficient removal of plasma hemoglobin in concentrations up to 15 mg/mL. The high abundance of haptoglobin, which forms a tight complex with hemoglobin in plasma, did not affect the hemoglobin removal by IsdH Sepharose.

Results

Applying the method on plasma samples that beforehand were spiked with blood hemolysate re-enabled measurement of the hemolysis sensitive parameters: alkaline phosphatase, conjugated bilirubin, iron, ferritin, γ-glutamyltransferase, total thyroxine and troponin T. IsdH Sepharose-mediated hemoglobin removal also enabled measurement of hemolysis sensitive parameters in hemolyzed samples from anonymized patients.

Conclusions

In conclusion, IsdH Sepharose is a simple cost-effective pretreatment of hemolyzed samples correcting and enabling the measurement of several important hemoglobin-sensitive parameters in a way compatible with standard procedures in routine laboratories.

Effect of Blood Cell Subtypes Lysis on Routine Biochemical Tests

BACKGROUND

The aim of this study is to establish the contribution of blood cells subtypes on hemolysis.

METHODS

Separated blood cell subtype suspensions prepared with blood from 10 volunteers were serially diluted to obtain different concentrations of cell suspensions. The cells were fully lysed and cell hemolysates were added (1:20) to aliquots of serum pool. Thus, seven serum pools with different concentrations of interferent were obtained for each blood cell subtype. Biochemical parameters and serum indices were measured by an autoanalyzer. As cell lysis markers, free hemoglobin was measured by spectrophotometry while myeloperoxidase and ᵝ-thromboglobulin were measured by enzyme immunoassay. The percent changes in analyte levels of the serum pools were evaulated by Wilcoxon Signed Rank Test and compared with clinical thresholds defined for each test.

RESULTS

The clinical thresholds were exceeded in lactate dehydrogenase, potassium, aspartate aminotransferase, creatine kinase, magnesium, total protein, total cholesterol, inorganic phosphate, glucose for red blood cells (RBC); lactate dehydrogenase, aspartate aminotransferase, total protein, inorganic phosphate and glucose for platelets (PLT). Free hemoglobin was significantly correlated with RBC (r=0.999; p=0.001), while myeloperoxidase and b thromboglobulin showed no significant correlation to white blood cells (WBC) and PLT, respectively.

CONCLUSIONS

The effect of RBC hemolysis in serum on the routine biochemical tests are clearly established, yet, additional studies are required in order to verify this kind of effects of PLT and WBC hemolysis.

Novel Opportunities for Improving the Quality of Preanalytical Phase. A Glimpse to the Future?

The preanalytical phase is crucial for assuring the quality of in vitro diagnostics. The leading aspects which contribute to enhance the vulnerability of this part of the total testing process include the lack of standardization of different practices for collecting, managing, transporting and processing biological specimens, the insufficient compliance with available guidelines and the still considerable number of preventable human errors. As in heavy industry, road traffic and aeronautics, technological advancement holds great promise for decreasing the risk of medical and diagnostic errors, thus including those occurring in the extra-analytical phases of the total testing process. The aim of this article is to discuss some potentially useful technological advances, which are not yet routine practice, but may be especially suited for improving the quality of the preanalytical phase in the future. These are mainly represented by introduction of needlewielding robotic phlebotomy devices, active blood tubes, drones for biological samples transportation, innovative approaches for detecting spurious hemolysis and preanalytical errors recording software products.

Preanalytical errors in medical laboratories: a review of the available methodologies of data collection and analysis

Preanalytical errors have previously been shown to contribute a significant proportion of errors in laboratory processes and contribute to a number of patient safety risks. Accreditation against ISO 15189:2012 requires that laboratory Quality Management Systems consider the impact of preanalytical processes in areas such as the identification and control of non-conformances, continual improvement, internal audit and quality indicators. Previous studies have shown that there is a wide variation in the definition, repertoire and collection methods for preanalytical quality indicators. The International Federation of Clinical Chemistry Working Group on Laboratory Errors and Patient Safety has defined a number of quality indicators for the preanalytical stage, and the adoption of harmonized definitions will support interlaboratory comparisons and continual improvement. There are a variety of data collection methods, including audit, manual recording processes, incident reporting mechanisms and laboratory information systems. Quality management processes such as benchmarking, statistical process control, Pareto analysis and failure mode and effect analysis can be used to review data and should be incorporated into clinical governance mechanisms. In this paper, The Association for Clinical Biochemistry and Laboratory Medicine PreAnalytical Specialist Interest Group review the various data collection methods available. Our recommendation is the use of the laboratory information management systems as a recording mechanism for preanalytical errors as this provides the easiest and most standardized mechanism of data capture.