Recommendations for blood sampling in emergency departments from the European Society for Emergency Medicine (EUSEM), European Society for Emergency Nursing (EuSEN), and European Federation of Clinical Chemistry and Laboratory Medicine (EFLM) Working Group for the Preanalytical Phase. Executive summary

AIM

Blood Sampling Guidelines have been developed to target European emergency medicine-related professionals involved in the blood sampling process (e.g. physicians, nurses, phlebotomists working in the ED), as well as laboratory physicians and other related professionals. The guidelines population focus on adult patients. The development of these blood sampling guidelines for the ED setting is based on the collaboration of three European scientific societies that have a role to play in the preanalytical phase process: EuSEN, EFLM, and EUSEM. The elaboration of the questions was done using the PICO procedure, literature search and appraisal was based on the GRADE methodology. The final recommendations were reviewed by an international multidisciplinary external review group.

RESULTS

The document includes the elaborated recommendations for the selected sixteen questions. Three in pre-sampling, eight regarding sampling, three post-sampling, and two focus on quality assurance. In general, the quality of the evidence is very low, and the strength of the recommendation in all the questions has been rated as weak. The working group in four questions elaborate the recommendations, based mainly on group experience, rating as good practice.

CONCLUSIONS

The multidisciplinary working group was considered one of the major contributors to this guideline. The lack of quality information highlights the need for research in this area of the patient care process. The peculiarities of the emergency medical areas need specific considerations to minimise the possibility of errors in the preanalytical phase.

Comparison of the speed and quality of innovative and traditional pneumatic tube system transport outside of an emergency laboratory

Background

Ensuring the rapidity and accuracy of emergency laboratory test results is especially important to save the lives of patients with acute and critical conditions. To better meet the needs of clinicians and patients, detection efficiency can be improved by reducing extra-laboratory sample turnaround times (TATs) through the use of innovative pneumatic tube system (PTS) transport for sample transport. However, concerns remain regarding the potential compromise of sample quality during PTS transit relative to that occurring with manual transportation. This study was performed to evaluate the efficacy of an innovative PTS (Tempus600 PTS) relative to a traditional PTS in terms of sample transit time, sample quality, and the concordance of analytical results with those obtained from manually transported samples.

Methods

In total, 30 healthy volunteers aged >18 years were recruited for this study, conducted for five consecutive days. Venous blood samples were collected from six volunteers per day at fixed timepoints. From each volunteer, nine blood samples were collected into tubes with tripotassium ethylene diamine tetraacetic acid anticoagulant, tubes with 3.2 % sodium citrate, and serum tubes with separation gel (n = 3 each) and subjected to all tests conducted in the emergency laboratory in our hospital. 270 blood samples from 30 healthy volunteers were transported and analyzed, yielding 6300 test results. The blood samples were divided randomly into three groups (each containing one tube of each type) and transported to the emergency laboratory manually and with Tempus600 PTS and conventional Swisslog PTS, respectively. The extra-laboratory TATs, sample quality, and test results of the transported blood samples were compared.

Results

The sample quality and test results did not differ according to the delivery method. The TAT was much shorter with the Tempus600 than with the other two transport modes (58.40 ± 1.52 s vs. 1711.20 ± 77.56 s for manual delivery and 146.60 ± 1.82 s for the Swisslog PTS; P = 0.002).

Conclusion

Blood sample transport with the Tempus600 PTS significantly reduced the extra-laboratory TAT without compromising sample quality or test result accuracy, thereby improving the efficiency of sample analysis and the services provided to clinicians and patients.

Diagnostic sample transport via pneumatic tube systems: data logger and their algorithms are sensitive to transport effects

OBJECTIVES

Many hospitals use pneumatic tube systems (PTS) for transport of diagnostic samples. Continuous monitoring of PTS and evaluation prior to clinical use is recommended. Data loggers with specifically developed algorithms have been suggested as an additional tool in PTS evaluation. We compared two different data loggers.

METHODS

Transport types - courier, conventional (cPTS) and innovative PTS (iPTS) - were monitored using two data loggers (MSR145® logger, CiK Solutions GmbH, Karlsruhe, Germany, and a prototype developed at the University Medicine Greifswald). Data loggers differ in algorithm, recording frequencies and limit of acceleration detection. Samples from apparently healthy volunteers were split among the transport types and results for 37 laboratory measurands were compared.

RESULTS

For each logger specific arbitrary units were calculated. Area-under-the-curve (AUC)-values (MSR145®) were lowest for courier and highest for iPTS and increased with increasing recording frequencies. Stress (St)-values (prototype logger) were obtained in kmsu (1,000*mechanical stress unit) and were highest for iPTS as well. Statistical differences between laboratory measurement results of transport types were observed for three measurands sensitive for hemolysis.

CONCLUSIONS

The statistical, but not clinical, differences in the results for hemolysis sensitive measurands may be regarded as an early sign of preanalytical impairment. Both data loggers record this important interval of beginning mechanical stress with a high resolution indicating their potential to facilitate early detection of preanalytical impairment. Further studies should identify suitable recording frequencies. Currently, evaluation and monitoring of diagnostic sample transport should not only rely on data loggers but also include diagnostic samples.

POCT urine dipstick versus central laboratory analyses: Diagnostic performance and logistics in the medical emergency department

OBJECTIVES

The aim of this study was to evaluate the logistics and diagnostic performances of dipstick analyses compared to their counterpart central laboratory analyses for detection of bacteriuria, proteinuria, hyperglycemia, ketosis and hematuria.

DESIGN AND METHODS

Urine dipstick results, urine culture results, flow cytometric cell counts, U-albumin-to-creatinine ratio, P-glucose and P-beta-hydroxybutyrate were retrospectively reviewed in a cohort of consecutive patients admitted to the medical emergency departments of two Danish hospitals. Sensitivity, specificity and predictive values of traditional dipstick analysis were estimated and dipstick was compared to flow cytometry for detection of significant bacteriuria using logistic regression. Turn-around-time for central laboratory analyses were assessed.

RESULTS

For each comparison, 1,997 patients or more were included. Traditional dipstick analyses for proteinuria, bacteriuria and ketosis reached sensitivities of up to 90%, while sensitivity for hyperglycemia was 59%. Flow cytometry outperformed traditional dipstick analysis for detection of bacteriuria with a difference in the area under the ROC-curve of 0.07. Turn-around-times for 95% delivery of central laboratory analysis results ranged from approximately 1½ to 2 h.

CONCLUSIONS

For the detection of bacteriuria and albuminuria, central laboratory analyses reach better performance than dipstick analysis while achieving acceptable turn-around-times and are thus viable alternatives to dipstick analysis. For detection of ketosis and hyperglycemia, dipstick analysis does not perform adequately, but as very short turn-around-time is often required, these conditions may be best diagnosed by point-of-care blood test rather than dipstick or central laboratory analyses. Dipstick hemoglobin analysis, flow cytometry and microscopic evaluation may serve each their distinct purposes, and thus are relevant in the emergency department.

Impact of Pneumatic Transport System on Preanalytical Phase Affecting Clinical Biochemistry Results

Introduction PTS (pneumatic transport system) is extensively being used in modern hospitals for rapid transportation of blood samples and other specimens. However, it has a potential impact on blood components, which should be investigated and nullified accordingly. This study was part of a correction program aimed at reducing hemolysis. It was done by comparing paired samples transported manually and by PTS.

Materials and Methods This study was initiated to monitor the impact of PTS on hemolysis of clinical biochemistry blood samples. It was performed in two phases—before and after the corrective action taken. Phase I: done after PTS installation but before the corrective action was taken. Duplicate samples from 100 healthy individuals were collected, one set transported by PTS and the other by human carriers. Both sets were assessed for 25 biochemistry analytes, hemolysis index (HI), and acceleration profiles using a data logger. Corrective measures were then taken, followed by phase II of the study. In phase II, the sample size and study design remained the same as phase I. All the test results of PTS and hand-carried samples were statistically analyzed for any significant difference.

Result In phase I, all the hemolysis-manifesting parameters, LDH (lactate dehydrogenase), potassium, AST (aspartate transaminase), and phosphorus, were raised in PTS samples as compared with the manual samples. Their differences were significant as the p-values were 0.001, 0.000, 0.025, and 0.047, respectively. The differences for LDH and potassium were clinically significant as well. HI (9%) and peak acceleration (15.7 g) were high in PTS samples.

In phase II, no statistically significant difference between paired samples was found for all biochemistry parameters except for a few which were clinically nonsignificant. For PTS samples, HI was 2.5% and the peak acceleration was 11.2 g, whereas for manual samples, HI was 2%.

Conclusion Evidence of hemolysis was found in PTS samples as compared with handheld samples, which was resolved after several corrective actions were taken. Thereafter, PTS became reliable for sample delivery in a routine biochemistry laboratory. Hence, each hospital should scrutinize their PTS for its effects on sample integrity to get rid of PTS-induced preanalytical errors.

Evaluation of a pneumatic tube system carrier prototype with fixing mechanism allowing for automated unloading

OBJECTIVES

A carrier prototype by Aerocom^® (Schwäbisch Gmünd, Germany) for pneumatic tube systems (PTS) is able to transport 9 blood tubes which are automatically fixed by closing the lid. In this study, we examined the influence of the transport on blood sample quality using the carrier prototype comparing to courier transport and a conventional carrier (AD160, Aerocom^®).

METHODS

Triplicate blood samples sets (1 lithium heparin, 1 EDTA, 1 sodium citrate) of 35 probands were split among the transportation methods: 1. courier, 2. conventional carrier, and 3. carrier prototype. After transport 51 measurands from clinical chemistry, hematology and coagulation were measured and compared.

RESULTS

Overall, 49 of the investigated 51 measurands showed a good concordance among the three transport types, especially between the conventional carrier and the carrier prototype. Focusing on well-known hemolysis sensitive measurands, potassium showed no statistically significant differences. However, between courier and both carrier types lactate dehydrogenase (LDH) and free hemoglobin (fHb) showed statistically significant shifts, whereas the clinical impact of the identified differences was neglectable. The median concentration of fHb, for example, was 0.29 g/L (18 µmol/L), 0.31 g/L (19 µmol/L) and 0.32 g/L (20 µmol/L) for courier transport, conventional carrier and carrier prototype, respectively. These differences cannot be resolved analytically since the minimal difference (MD) for fHb is 0.052 g/L (3.23 µmol/L), at this concentration.

CONCLUSIONS

The carrier prototype by Aerocom^® is suitable for transportation of diagnostic blood samples. The overall workflow is improved by decreasing hands-on-time on the ward and laboratory while minimizing the risk of incorrectly packed carriers.

Investigation of the effects of pneumatic tube transport system on routine biochemistry, hematology, and coagulation tests in Ankara City Hospital

OBJECTIVES

Academics are far from a consensus regarding the effects of pneumatic tube system (PTS) delivery on sample integrity and laboratory test results. As for the reasons for conflicting opinions, each PTS is uniquely designed, sample tubes and patient characteristics differ among studies. This study aims to validate the PTS utilized in Ankara City Hospital for routine chemistry, coagulation, and hematology tests by comparing samples delivered via PTS and porter.

METHODS

The study comprises 50 healthy volunteers. Blood samples were drawn into three biochemistry, two coagulation, and two hemogram tubes from each participant. Each of the duplicate samples was transferred to the emergency laboratory via Swiss log PTS (aka PTS-immediately) or by a porter. The last of the biochemistry tubes were delivered via the PTS, upon completion of coagulation of the blood (aka PTS-after). The results of the analysis in these groups were compared with multiple statistical analyses.

RESULTS

The study did not reveal any correlation between the PTS and serum hemolysis index. There were statistically significant differences in several biochemistry tests. However, none of them reached the clinical significance threshold. Basophil and large unidentified cell (LUC) tests had poor correlations (r=0.47 and r=0.60; respectively) and reached clinical significance threshold (the average percentages of bias, 10.2%, and 15.4%, respectively). The remainder of the hematology and coagulation parameters did not reach clinical significance level either.

CONCLUSIONS

The modern PTS validated in this study is safe for sample transportation for routine chemistry, coagulation, and hematology tests frequently requested in healthy individuals except for basophil and LUC.

Effects of a pneumatic tube system on the hemolysis of blood samples: a PRISMA-compliant meta-analysis

Many studies have explored how using a pneumatic tube system (PTS) is related to the hemolysis of blood samples, but their conclusions have been inconsistent. This meta-analysis was to clarify whether using a PTS induces the hemolysis of blood samples. The PubMed, Embase, Scopus, CNKI, CqVip, SinoMed and WanFang databases were searched for studies published between January 1970 and August 2019. The primary outcomes were the hemolysis rate and hemolysis index of blood samples after applying a PTS and manual transportation. We estimated the pooled risk ratio (RR) and the standardized mean difference (SMD), using random-effects models. This meta-analysis included 29 studies covering 3121 blood samples. No significant differences were found between the PTS and manual-transportation groups in the hemolysis rate [RR: 0.99, 95% confidence interval (CI): 0.57 to 1.70], hemolysis index (SMD: 0.19, 95% CI: -0.00 to 0.38), or level of potassium (SMD: 0.05, 95% CI: -0.03 to 0.12), alanine aminotransferase (SMD: 0.00, 95% CI: -0.10 to 0.11), or aspartate aminotransferase (SMD: 0.04, 95% CI: -0.08 to 0.17). However, lactate dehydrogenase (LDH) level was significantly higher in the PTS group than in the manual-transportation group (SMD: 0.20, 95% CI: 0.06 to 0.34). Subgroup analysis revealed that the LDH level was clearly higher in the PTS group than in the manual-transportation group only when the PTS speed was ≥6 m/s or when the PTS distance was ≥250 m. According to this meta-analysis, PTSs were associated with alterations in LDH measurements, so it is sensible that each hospital validates and monitors their PTSs.

Pneumatic tube validation: Reducing the need for donor samples by integrating a vial-embedded data logger

BACKGROUND

The most common way to validate a pneumatic tube system is to compare pneumatic tube system-transported blood samples to blood samples carried by hand. The importance of measuring the forces inside the pneumatic tube system has also been emphasized. The aim of this study was to define a validation protocol using a mini data logger (VitalVial, Motryx Inc., Canada) to reduce the need for donor samples in pneumatic tube system validation.

METHODS

As an indicator of the total vibration, the blood samples are exposed to under pneumatic tube system transportation; the area under the curve was determined by a VitalVial for all hospital Tempus600 lines using a five-day validation protocol. Only the three lines with the highest area under the curves were clinically validated by analysing potassium, lactate dehydrogenase and aspartate aminotransferase. A month after pneumatic tube system commissioning, a follow-up on laboratory data was performed.

RESULTS

Mean area under the curve of the six lines ranged between 347 and 581. The variability of the area under the curve was between 1.51 and 11.55%. In the laboratory data follow-up, an increase in lactate dehydrogenase haemolysis was seen from the three lines with the highest area under the curve and the emergency department, which was not detected in the clinical validation. When the Tempus600 system was in commission, a higher mean area under the curve was measured.

CONCLUSION

A three-day validation protocol using VitalVials is enough to determine the stability of a Tempus600 system and can greatly reduce the need for donor samples. When in commission, the stability of the pneumatic tube system should be verified and lactate dehydrogenase haemolysis should be routinely checked.

Pneumatic tube transportation of urine samples

Objectives

Pneumatic tube transportation of samples is an effective way of reducing turn-around-time, but evidence of the effect of pneumatic tube transportation on urine samples is lacking. We thus wished to investigate the effect of pneumatic tube transportation on various components in urine, in order to determine if pneumatic tube transportation of these samples is feasible.

Methods

One-hundred fresh urine samples were collected in outpatient clinics and partitioned with one partition being carried by courier to the laboratory, while the other was sent by pneumatic tube system (Tempus600). Both partitions were then analysed for soluble components and particles, and the resulting mean difference and limits of agreement were calculated.

Results

Albumin, urea nitrogen, creatinine, protein and squamous epithelial cells were unaffected by transportation in the Tempus600 system, while bacteria, renal tubular epithelial cells, white blood cells and red blood cells were affected and potassium and sodium may have been affected.

Conclusions

Though pneumatic tube transportation did affect some of the investigated components, in most cases the changes induced were clinically acceptable, and hence samples could be safely transported by the Tempus600 pneumatic tube system. For bacteria, white blood cells and red blood cells local quality demands will determine if pneumatic tube transportation is appropriate.

The Modern Pneumatic Tube System Transports with Reduced Speed Does Not Affect Special Coagulation Tests

Pneumatic tube transport systems (PTS) for delivery of patient samples to a hemostasis laboratory are often used to reduce turnaround time for vital analyses. PTS in our hospital has the ability to regulate the transport speed in the range of 3-6 m/s with acceleration control technology. We evaluated the effects of PTS transport for routine coagulation tests, platelet function tests and special global coagulation tests. Duplicate samples were collected from 29 patients and 40 healthy individuals. One sample was sent using PTS and the other was carried by personnel to the lab for determination of protrombin time, activated partial thromboplastin time, trombin time, fibrinogen, antitrombin and thrombin generation test. Platelet function was measured by means of a Apact 4004® analyzer using the inductors (ADP, Arachidonic acid and Epinephrine). Samples transported using PTS with normal transport speed 6 m/s does not affect basic coagulation tests (PT, aPTT, FIB, TT and AT), but TGT has significantly altered. The use of PTS with controlled acceleration regulated the increase in thrombin generation from 10% to 3%, which is not statistically signifiant. The use of PTS with controlled acceleration did not show a significant difference even with the highly sensitive method of platelet aggregation. We conclude that PTS with acceleration control with transport speed from 3 to 6 m/s does not affect to platelet activity as measured by LTA and also global coagulation test - TGT. The advantage of PTS transport is very rapid assessment laboratory testing. From the above validation study, it is clear that PTS should always be validated for specialized laboratory methods and appropriately adapted to specific transport conditions.

Use of clinical data and acceleration profiles to validate pneumatic transportation systems

Background

Modern pneumatic transportation systems (PTSs) are widely used in hospitals for rapid blood sample transportation. The use of PTS may affect sample integrity. Impact on sample integrity in relation to hemolysis and platelet assays was investigated and also, we wish to outline a process-based and outcome-based validation model for this preanalytical component.

Methods

The effect of PTS was evaluated by drawing duplicate blood samples from healthy volunteers, one sent by PTS and the other transported manually to the core laboratory. Markers of hemolysis (potassium, lactate dehydrogenase [LD] and hemolysis index [HI]) and platelet function and activation were assessed. Historic laboratory test results of hemolysis markers measured before and after implementation of PTS were compared. Furthermore, acceleration profiles during PTS and manual transportation were obtained from a mini g logger in a sample tube.

Results

Hand-carried samples experienced a maximum peak acceleration of 5 g, while peaks at almost 15 g were observed for PTS. No differences were detected in results of potassium, LD, platelet function and activation between PTS and manual transport. Using past laboratory data, differences in potassium and LD significantly differed before and after PTS installation for all three lines evaluated. However, these estimated differences were not clinically significant.

Conclusions

In this study, we found no evidence of PTS-induced hemolysis or impact on platelet function or activation assays. Further, we did not find any clinically significant changes indicating an acceleration-dependent impact on blood sample quality. Quality assurance of PTS can be performed by surveilling outcome markers such as HI, potassium and LD.

Blood Sample Transportation by Pneumatic Transportation Systems: A Systematic Literature Review

BACKGROUND

Pneumatic transportation systems (PTSs) are increasingly used for transportation of blood samples to the core laboratory. Many studies have investigated the impact of these systems on different types of analyses, but to elucidate whether PTSs in general are safe for transportation of blood samples, existing literature on the subject was systematically assessed.

METHODS

A systematic literature review was conducted following the preferred reporting items for systematic reviews and metaanalyses (PRISMA) Statement guidelines to gather studies investigating the impact of PTS on analyses in blood samples. Studies were extracted from PubMed and Embase. The search period ended November 2016.

RESULTS

A total of 39 studies were retrieved. Of these, only 12 studies were conducted on inpatients, mainly intensive care unit patients. Blood gases, hematology, and clinical chemistry were well investigated, whereas coagulation, rotational thromboelastometry, and platelet function in acutely ill patients were addressed by only 1 study each. Only a few parameters were affected in a clinically significant way (clotting time parameter in extrinsic system thromboelastometry, pO2 in blood gas, multiplate analysis, and the hemolysis index).

CONCLUSIONS

Owing to their high degree of heterogeneity, the retrieved studies were unable to supply evidence for the safety of using PTSs for blood sample transportation. In consequence, laboratories need to measure and document the actual acceleration forces in their existing PTS, instituting quality target thresholds for these measurements such as acceleration vector sums. Computer modeling might be applied to the evaluation of future PTS installations. With the increasing use of PTS, a harmonized, international recommendation on this topic is warranted.