The impact of pneumatic tube transport on whole blood coagulation and platelet function assays

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.

Effects of centrifugation prior to pneumatic tube system transport on routine biochemical and immunological tests of susceptibility to hemolysis

BACKGROUND

Pneumatic tube system (PTS) may be associated with preanalytical hemolysis. The objective of this study was to evaluate the effects of PTS on biochemical and immunological tests susceptible to hemolysis and try to find ways to reduce the result bias caused by PTS.

METHODS

Laboratory parameters were compared between PTS without centrifuging group, PTS after centrifuging group, PTS with serum group, and hand-delivered (HD) group. Studies were performed to access the influence of different PTS transport frequencies on laboratory assays.

RESULTS

PTS transportation resulted in obviously increase in LDH (lactate dehydrogenase) and NSE (neuron-specific enolase) results (LDH: Bias = 17.95%, 95% confidence interval (CI) = -3.13-39.02; p < 0.001; NSE: Bias = 64.26%, 95% CI = -21.29-149.82; p < 0.001; respectively). After pre-centrifugation, no statistical difference was observed in LDH results (Bias = 2.83%, 95% CI = -13.00-18.65; p = 0.737). However, the bias of NSE still reach 19.16% (95% CI = -41.78-80.11), which exceeded the clinical acceptable range (p = 0.017). Both LDH(p = 0.931) and NSE(p > 0.999) show no statistical difference between PTS with serum group and HD group (LDH: Bias = -1.60%, 95% CI = -6.00-2.81; NSE: Bias = -3.68%, 95% CI = -11.35-3.99).

CONCLUSION

PTS can lead to falsely increased LDH and NSE test results. Only loading the centrifuged upper serum in new tubes during PTS transport can eliminate the results bias of NSE.

Relationship between Hypercoagulable State and Circulating Tumor Cells in Peripheral Blood, Pathological Characteristics, and Prognosis of Lung Cancer Patients

Objective

To analyze the relationship between hypercoagulable state and circulating tumor cells (CTCs) in peripheral blood, pathological characteristics, and prognosis of lung cancer patients.

Method

A total of 148 patients with primary lung cancer diagnosed and treated in our hospital from January 2017 to January 2019 were selected as the research objects. According to the CTC test results, the patients were divided into CTC-positive group and CTC-negative group. Also, the coagulation index of patients was tested. According to the blood coagulation index test results, patients were divided into hypercoagulable group and non-hypercoagulable group. The relationship between hypercoagulable state and pathological characteristics of lung cancer patients was analyzed by single factor analysis and multiple logistic regression model. Kaplan–Meier survival curve was applied to analyze the relationship between hypercoagulable state and the prognosis of lung cancer patients.

Results

The platelets (PLTs), fibrinogen (FIB), D-dimer (D-D), and prothrombin time (PT) in CTC-positive group were significantly higher than those in CTC-negative group. There was no significant relationship between the patient's gender, smoking history, pathological type, and the hypercoagulable state of the patients. The proportion of patients aged 60 years or older, with TMN stage III or IV and lymph node metastasis, in the hypercoagulable group was significantly higher than that in the non-hypercoagulable group. Logistic regression analysis showed that there was an independent relationship between the patient's age, lymph node metastasis, and hypercoagulable state. As of January 2020, among the 148 patients with lung cancer follow-up, 5 patients were lost and 52 died. The median survival time of patients in the hypercoagulable group was 82 weeks, which was significantly lower than the 104 weeks in the nonhypercoagulable group.

Conclusion

There is a certain relationship between hypercoagulable state and CTC positive in lung cancer patients. There is an independent relationship between the patient's age, lymph node metastasis, and the hypercoagulable state. The median survival time of patients in the hypercoagulable group was significantly lower than that in the non-hypercoagulable group.

Impact of centrifugation time and pneumatic tube transport on plasma concentrations of direct oral anticoagulants

INTRODUCTION

Rapid results are needed when plasma concentrations of direct oral anticoagulants (DOACs) are required in acute clinical settings. We evaluated the impact of centrifugation time and pneumatic tube transport on DOAC plasma concentrations with the overall aim of reducing turnaround time.

METHODS

Blood samples were spiked with rivaroxaban, apixaban or dabigatran in a low and a high concentration prior to centrifugation for 25 minutes (3163 g) or 5 minutes (3000 g) (n = 20 for each DOAC). Both samples spiked with DOACs (n = 20 for each DOAC) and patient samples (n = 25 in total) were transported manually or by pneumatic tube system samples.

RESULTS

For samples spiked with DOAC, statistically significant differences in DOAC plasma concentrations were found between centrifugation times for rivaroxaban in low (P < .05) and high (P < .05) concentrations. Relative bias was below 9% for all DOACs. Statistically significant differences were found between modes of transportation for rivaroxaban (P < .01) and dabigatran (P < .01) in high concentrations. Relative bias was 4%-23% for all DOACs. For patient samples, no statistically significant differences were found between modes of transportation, and relative bias was below 12% for all DOACs.

CONCLUSION

Minor, clinically insignificant, differences regarding centrifugation times were found in DOAC plasma concentrations. Importantly, no significant differences were found according to transportation modes for samples collected from patients. Although statistically significant differences were found depending on mode of transportation of spiked samples, relative bias was clinically acceptable. Thus, reduced centrifugation time and pneumatic tube transport should be considered to reduce turnaround time for rapid measurement of DOAC plasma concentrations.

Management of the thrombotic risk associated with COVID-19: guidance for the hemostasis laboratory

Coronavirus disease 2019 (COVID-19) is associated with extreme inflammatory response, disordered hemostasis and high thrombotic risk. A high incidence of thromboembolic events has been reported despite thromboprophylaxis, raising the question of a more effective anticoagulation. First-line hemostasis tests such as activated partial thromboplastin time, prothrombin time, fibrinogen and D-dimers are proposed for assessing thrombotic risk and monitoring hemostasis, but are vulnerable to many drawbacks affecting their reliability and clinical relevance. Specialized hemostasis-related tests (soluble fibrin complexes, tests assessing fibrinolytic capacity, viscoelastic tests, thrombin generation) may have an interest to assess the thrombotic risk associated with COVID-19. Another challenge for the hemostasis laboratory is the monitoring of heparin treatment, especially unfractionated heparin in the setting of an extreme inflammatory response. This review aimed at evaluating the role of hemostasis tests in the management of COVID-19 and discussing their main limitations.

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.

Alterations in the parameters of classic, global, and innovative assays of hemostasis caused by sample transportation via pneumatic tube system

BACKGROUND

Pneumatic tube system (PTS) is an integral part of large medical facilities providing rapid interconnection between units within the hospital and often used to transport blood samples. The aim of our study was to compare a wide variety of hemostasis assays to identify assays sensitive to this transport method and diagnostic relevance of the alterations.

METHODS

Routine coagulation and platelet tests (APTT, PT, TT, fibrinogen, light transmission aggregometry (LTA) with ADP, collagen, ristomycin and epinephrine), whole blood flow cytometry platelet function test (levels of CD42b, CD61, CD62P, PAC1, annexin V binding and mepacrine release) and global coagulation tests (thromboelastography (TEG), thrombin generation (TGT), thrombodynamics (TD), thrombodynamics-4D (TD-4D)) were determined in PTS- and manually transported samples of 10 healthy volunteers.

RESULTS

There were no significant differences between the values of APTT, PT, TT or fibrinogen between the samples transported by PTS or manually. The results for LTA demonstrated increase in the collagen-induced aggregation (84 ± 7% versus 73 ± 5%), while the response to epinephrine was decreased (58 ± 20% versus 72 ± 7.4%). Flow cytometry-based platelet function test showed a pre-activation of platelets by PTS-transportation while all integral assays of coagulation tested in the present study (TEG, TGT, TD, TD-4D) demonstrated a hypercoagulation shift.

CONCLUSIONS

Transportation by PTS caused significant shifts in parameters of functional and integral assays that exceeded parameter variation values and sometimes even were comparable to normal ranges. The results obtained in this study indicate that using of PTS for such assays may cause sufficient alterations of results and can lead to patient's mistreatment.