Pneumatic Tube System Transport Research Articles

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

BackgroundEnsuring 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. MethodsIn 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. ResultsThe 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). ConclusionBlood 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.

Transportation of mAb Dosing Solution in Intravenous Bag: Impact of Manual, Vehicle, and Pneumatic Tube System Transportation Methods on Product Quality.

Monoclonal antibody (mAb) products for intravenous (IV) administration generally require aseptic compounding with a commercial diluent within a pharmacy. The prepared dosing solution in the IV bag may be transported to the dosing location via manual, vehicular, pneumatic tube system (PTS), or a combination of these methods. In this study, the type and level of physical stresses associated with these three methods and their product quality impact for relatively sensitive and stable mAbs were assessed. Vibration was found to be the main stress associated with manual and vehicle transportation methods, although this was at a relatively low level (<1 GRMS/Root-Mean-Square Acceleration). Shock and drop events, at relatively low levels, were also observed with these methods. PTS transportation showed substantially more intense shock, vibration, and drop stresses and the measured levels were up to 91 G/force of acceleration or deceleration, 3.7 GRMS and 39 G, respectively. Using a foam padding insert for PTS transportation reduced the shock level considerably (91 G to 59 G). Transportation of mAb dosing solutions in IV bags via different methods including PTS transportation variables caused a small increase in the subvisible particle counts and there was no change in submicrometer particle distribution. No visible particles and no significant change to soluble aggregate levels were observed after transportation. Strategies such as removal of IV bag headspace prior to transport and in-line filtration poststress reduced the subvisible particles counts. All tested transportation conditions showed negligible impact on other product quality attributes tested. Removal of IV bag headspace prior to PTS transport prevented formation of micro air bubbles and foaming compared to the unaltered IV bag. This study shows examples where manual, vehicle, and PTS transport methods did not significantly impact product quality, and provides evidence that mAb products that are appropriately stabilized in the dosing solution (e.g., with a surfactant) can be transported via a PTS.

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

BackgroundPneumatic 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. MethodsLaboratory 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. ResultsPTS 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). ConclusionPTS 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.

Triple apheresis platelet concentrate quality after pneumatic tube system, conveyor box, and courier transport: An observational study.

Background and AimsPlatelets are prone to activation from handling; they are therefore transported as gently as possible, most commonly by courier. Speedier methods like pneumatic tube system (PTS) transport could improve patient care but may subject platelets to mechanical stress. To test the impact of mechanical stress caused by transport, we compared a PTS with a conveyor box and courier transport on apheresis platelet function.MethodsFourteen apheresis platelet concentrate triple donations were analyzed by light transmission aggregometry (LTA), rotational thrombelastometry (ROTEM), and flow cytometry before and after indoor transport over 800 m by PTS, conveyor, and courier, respectively, while recording shocks and vibrations with a high‐frequency acceleration data logger. Shock index scores were calculated as shock intensity (g‐force) times frequency.ResultsThe shock index was 81 for courier, 6279 for conveyor, and 9075 for PTS. Flow cytometry revealed no significant difference in platelet surface expression of CD62p before (16%) and after transport via courier (15%), conveyor (14%), or PTS (16%). LTA with adenosine phosphate and thrombin receptor‐activating peptide‐6 resulted in comparable platelet aggregation for courier, conveyor, and PTS. ROTEM assays showed no relevant differences in coagulation time, clot formation time, and maximum clot firmness between transport modes.ConclusionThough the mechanical challenge was smallest with courier transport, there were no significant differences in platelet activation or aggregation between the three transport modes. These data contradict restrictions on the use of PTSs for platelet concentrate transport.

The comparison of blood gas analysis (BGA) parameters in samples transported by the pneumatic tube system and manual transport at Dr. Soetomo Hospital, Surabaya, Indonesia

Background: Pneumatic Tube System (PTS) can reduce the time needed to transport laboratory samples, thus resulting in faster turn-around time. Blood gas analysis (BGA) is a critical laboratory examination, and it would benefit from sending the sample using PTS. Some studies showed the effect of PTS on BGA’s parameters, so the laboratory should validate the usage of PTS before delivering the samples. This study aims to determine the comparison of BGA parameters in Sample Transported by Pneumatic Tube System and Manual Transport at Dr. Soetomo Hospital, Surabaya, Indonesia.Method: A cross sectional analytic study was conducted among 31 blood patients and divided into two syringes. One syringe was delivered by PTS as well as the other was transported by courier. The delivery distance was 250 meters for both transportations. Both samples then were examined by qualified laboratory analyst. The pH, pCO2, and pO2 were compared. Data were analyzed using SPSS version 17 for windows.Result: The result of pH, pO2 and pCO2 in PTS samples was not significantly different compared to manual transportation (p=0,799; p=0,955 and p=0,856 respectively). Bland-Altman plot was found a good agreement between both types of transportation method.Conclusion: The result of this study showed no significant difference in BGA’s parameters sent by PTS or manual transportation. PTS can be used to replace manual transportation in delivering blood gas samples to the central laboratory.

Pneumatic tube system transport and false hyperkalemia related to leukocytosis: a retrospective analysis

Uncentrifuged blood samples are sent to the local laboratory through PTS. Data were retrospectively collected from routine testing carried out on all specimens arrived in the laboratory between September 2017 and March 2018. Clinical chemistry testing is routinely performed using lithium-heparin tubes. When false hyperkalemia induced by leukocytosis is suspected, potassium measurement is then performed in serum (clotting activator tubes) or whole blood samples. The analysis was focused on samples with both leukocytosis (i.e., >15×109/L) and plasma potassium >5.0 mmol/L, before any corrective therapeutic measure to lower potassium levels was established. A total number of 18 samples were included in our analysis, 9 drawn from patients with hematologic malignancies and 9 without. In the 9patients without hematologic malignancies (median leukocyte count, 20.4×109/L), the median potassium value was 5.4 mmol/L in plasma and 4.5 mmol/L in serum or whole blood. In the 9 patients with hematologic malignancies (median leukocyte count, 151.9×109/L; p <0.001), the median potassium value was 7.7 mmol/L in plasma and 4.3 mmol/L in serum or whole blood (median difference, 2.9 mmol/L; p <0.001). The results of our study suggest that even modest leukocytosis (i.e., around 15x109/L), which can be frequently encountered in clinical practice, may be associated with a significant variation of plasma potassium. This would lead us to conclude that plasma samples transportation by PTS should be avoided in patients with even mild leukocytosis.

Smartphone Application Monitoring of Acceleration Forces During Pneumatic Tube System Transport of Emergency Department Patient Samples.

The use of pneumatic tube system (PTS) transport has gained considerable popularity in modern hospitals but is also associated with sample hemolysis. The potential contribution of PTS-associated acceleration forces to high hemolysis rates observed in the emergency department (ED) has not been investigated before and can be easily examined nowadays using smartphone applications. The first aim of our study was to investigate whether our PTS induces hemolysis of patient samples obtained from our ED. We also explored a potential correlation between hemolysis index (HI) on the one hand and acceleration forces during PTS transport or other potential causes of hemolysis related to patient characteristics on the other for two different blood sampling techniques. Blood samples from 100 ED patients were collected in one Sarstedt S-Monovette® serum tube (PTStransported to laboratory) and two BD Vacutainer® serum tubes (one PTS-transported and one hand-carried). For all serum samples HI was measured. A smartphone was sent along with the samples in order to register accelerations during transport. Patient's erythrocyte sedimentation rate (ESR), mean corpuscular volume (MCV), hematocrit, total cholesterol, low density lipoprotein (LDL), and high-density lipoprotein (HDL) concentration were determined as well. Hemolysis rate was only 1 - 4% and 5% for PTS and hand-carried transport, respectively. Calculated acceleration vector sums for PTS transport from the ED to laboratory reached up to 131.49 m/second2 (13.40 g). No correlation could be demonstrated between HI on the one hand and acceleration forces acting on the samples during PTS transport or ESR, MCV, hematocrit, and HDL concentration on the other. However, an inverse correlation was noted between HI and cholesterol (total and LDL) concentration in serum tubes transported via PTS, though not in those carried by hand. We demonstrated that our PTS does not induce or contribute to hemolysis of ED patient samples, even at high acceleration vector sums up to 13 g. Technological advancements such as the development of smartphone applications offer the ability to regularly monitor acceleration forces during PTS transport of patient samples. Low total cholesterol and LDL concentrations may affect the erythrocyte membrane fluidity, making erythrocytes more prone to hemolysis.

The impact of pneumatic tube system on routine laboratory parameters: a systematic review and meta-analysis.

Pneumatic tube system (PTS) is a widely used method of transporting blood samples in hospitals. The aim of this study was to evaluate the effects of the PTS transport in certain routine laboratory parameters as it has been implicated with hemolysis. A systematic review and a meta-analysis were conducted. PubMed and Scopus databases were searched (up until November 2016) to identify prospective studies evaluating the impact of PTS transport in hematological, biochemical and coagulation measurements. The random-effects model was used in the meta-analysis utilizing the mean difference (MD). Heterogeneity was quantitatively assessed using the Cohran's Q and the I2 index. Subgroup analysis, meta-regression analysis, sensitivity analysis, cumulative meta-analysis and assessment of publication bias were performed for all outcomes. From a total of 282 studies identified by the searching procedure, 24 were finally included in the meta-analysis. The meta-analysis yielded statistically significant results for potassium (K) [MD=0.04 mmol/L; 95% confidence interval (CI)=0.015-0.065; p=0.002], lactate dehydrogenase (LDH) (MD=10.343 U/L; 95% CI=6.132-14.554; p<10-4) and aspartate aminotransferase (AST) (MD=1.023 IU/L; 95% CI=0.344-1.702; p=0.003). Subgroup analysis and random-effects meta-regression analysis according to the speed and distance of the samples traveled via the PTS revealed that there is relation between the rate and the distance of PTS with the measurements of K, LDH, white blood cells and red blood cells. This meta-analysis suggests that PTS may be associated with alterations in K, LDH and AST measurements. Although these findings may not have any significant clinical effect on laboratory results, it is wise that each hospital validates their PTS.

Pneumatic tube system transport does not alter platelet function in optical and whole blood aggregometry, prothrombin time, activated partial thromboplastin time, platelet count and fibrinogen in patients on anti-platelet drug therapy.

IntroductionThe aim of this study was to assess pneumatic tube system (PTS) alteration on platelet function by the light transmission aggregometry (LTA) and whole blood aggregometry (WBA) method, and on the results of platelet count, prothrombin time (PT), activated partial thromboplastin time (APTT), and fibrinogen.Materials and methodsVenous blood was collected into six 4.5 mL VACUETTE® 9NC coagulation sodium citrate 3.8% tubes (Greiner Bio-One International GmbH, Kremsmünster, Austria) from 49 intensive care unit (ICU) patients on dual anti-platelet therapy and immediately hand carried to the central laboratory. Blood samples were divided into 2 Groups: Group 1 samples (N = 49) underwent PTS (4 m/s) transport from the central laboratory to the distant laboratory and back to the central laboratory, whereas Group 2 samples (N = 49) were excluded from PTS forces. In both groups, LTA and WBA stimulated with collagen, adenosine-5’-diphosphate (ADP), arachidonic acid (AA) and thrombin-receptor-activated-peptide 6 (TRAP-6) as well as platelet count, PT, APTT, and fibrinogen were performed.ResultsNo statistically significant differences were observed between blood samples with (Group 1) and without (Group 2) PTS transport (P values from 0.064 – 0.968). The AA-induced LTA (bias: 68.57%) exceeded the bias acceptance limit of ≤ 25%.ConclusionsBlood sample transportation with computer controlled PTS in our hospital had no statistically significant effects on platelet aggregation determined in patients with anti-platelet therapy. Although AA induced LTA showed a significant bias, the diagnostic accuracy was not influenced.

Pre-analytical effects of pneumatic tube system transport on routine haematology and coagulation tests, global coagulation assays and platelet function assays

IntroductionPneumatic tube system (PTS) in hospitals is commonly used for the transport of blood samples to clinical laboratories, as it is rapid and cost-effective. The aim was to compare the effects on haematology samples of a newly acquired ~2km-long PTS that links 2 hospitals with usual transport (non-pneumatic tube system, NPTS). MethodsComplete blood cell count, routine coagulation assays, platelet function tests (PFT) with light-transmission aggregometry and global coagulation assays including ROTEM® and thrombin generation assay (TGA) were performed on blood samples from 30 healthy volunteers and 9 healthy volunteers who agreed to take aspirin prior to blood sampling. ResultsThe turnaround time was reduced by 31% (p<0.001) with the use of PTS. No statistically significant difference was observed for most routine haematology assays including PFT, and ROTEM® analysis. A statistically significant, but not clinically relevant, shortening of the APTT after sample transport by PTS was found (mean±SD: 30s±1.8 vs. 29.5s±2.1 for NPTS). D-dimer levels were 7.4% higher after transport through PTS but were not discordant. A statistically significant increase of thrombin generation was found in both platelet poor- and platelet rich- plasma samples after PTS transport compared to NPTS transport. ConclusionPTS is suitable for the transport of samples prior to routine haematology assays including PFT, but should not be used for samples intended for thrombin generation measurement.

Impact of Pneumatic Tube System Transport of Whole Blood Samples on Free DNA Concentration in Human Plasma

To the Editor: During the last decade the interest in using circulating cell-free DNA (ccfDNA)1 as a biomarker for the early diagnosis, prognosis, and monitoring of a variety of clinical conditions has increased rapidly. In daily clinical practice, it has been shown that preanalytical variables such as blood sampling, handling-procedurevariations, and blood storage conditions affect the ccfDNA concentration in human plasma (1). In this respect, optimal handling of blood samples between venipuncture and plasma preparation may be considered essential for downstream processes (1, 2) since time delay and/or agitation could trigger the release of genomic DNA from white blood cells (1). To reduce laboratory turnaround time, sample transport by pneumatic tube systems (PTS) has been established in many hospitals. However, rapid accelerations and decelerations during the PTS transport may cause shear stress and can potentially affect various laboratory measurements for coagulation, clinical chemistry, hematology, or blood gas analyses (3). At present, the literature lacks studies investigating the impact of PTS transport on quantitative ccfDNA measurements. Therefore, we compared ccfDNA plasma concentrations between paired whole …

Does Pneumatic Tube System Transport Contribute to Hemolysis in ED Blood Samples?

IntroductionOur goal was to determine if the hemolysis among blood samples obtained in an emergency department and then sent to the laboratory in a pneumatic tube system was different from those in samples that were hand-carried.MethodsThe hemolysis index is measured on all samples submitted for potassium analysis. We queried our hospital laboratory database system (SunQuest®) for potassium results for specimens obtained between January 2014 and July 2014. From facility maintenance records, we identified periods of system downtime, during which specimens were hand-carried to the laboratory.ResultsDuring the study period, 15,851 blood specimens were transported via our pneumatic tube system and 92 samples were hand delivered. The proportions of hemolyzed specimens in the two groups were not significantly different (13.6% vs. 13.1% [p=0.90]). Results were consistent when the criterion was limited to gross (3.3% vs 3.3% [p=0.99]) or mild (10.3% vs 9.8% [p=0.88]) hemolysis. The hemolysis rate showed minimal variation during the study period (12.6%–14.6%).ConclusionWe found no statistical difference in the percentages of hemolyzed specimens transported by a pneumatic tube system or hand delivered to the laboratory. Certain features of pneumatic tube systems might contribute to hemolysis (e.g., speed, distance, packing material). Since each system is unique in design, we encourage medical facilities to consider whether their method of transport might contribute to hemolysis in samples obtained in the emergency department.

Bank to bedside: A reliable and efficient transportation of blood by pneumatic tube system

Background: Turnaround time (TAT) is an important quality indicator in blood banking. This study evaluated the effectiveness of the pneumatic tube system (PTS) to reduce TAT and its effect on the quality of the blood products. Materials and Methods: The PTS (Swisslog GMBH, Germany) which connects to 29 stations was installed at our 2032-bedded tertiary care referral center. The system transports the carrier at an average speed of 25 feet/s (7.6 m/s). Acknowledgment slips were sent along with the blood components through this carrier system to know the time of receipt. Quality control parameters were checked before and after PTS transport in 10 bags of each of the blood components (packed red blood cells [PRBC], platelet concentrate, and fresh frozen plasma [FFP]). Data were analyzed using IBM SPSS Statistics 20. Results: PTS was used for 220 events to deliver 69% PRBC (n = 152), 15% FFP (n = 34), 14% platelets (n = 30), and 2% cryoprecipitate (n = 4), respectively, to 11 destinations. The average transport time by PTS was 1.36 ± 0.34 min and for human-based transport, it was 7.92 ± 1.40 min and this difference was found to be statistically significant (P Conclusion: PTS is rapid and reliable for the transport of the blood products to bedside.

Response of platelet concentrates to pressure and temperature changes without impairment of the in vitro function

BackgroundRapid platelet concentrate (PC) transfusion is crucial for hemostatic resuscitation. Pressure-aided and warmed transfusion combined with pneumatic tube system (PTS) transport from the laboratory to the operating theatre offers a potentially rapid delivery technique. The aim of this study is a quantitative assessment of in vitro platelet function after PTS transport followed by warmed and/or pressure-aided mock transfusions. MethodsTen PC samples entered a single PTS run and were subsequently aliquoted for testing. PCs were warmed in a blood warmer and/or subjected to pressure-aided mock transfusion at 300mm Hg on day 2 or day 7 after collection. Platelet function was assessed using light-transmission aggregometry and multiple-electrode aggregometry to measure the response to ADP, arachidonic acid, collagen, and thrombin-receptor activating peptide. Data were analyzed with non-parametric testing; P<0.05 was considered statistically significant. ResultsSingle PTS transport markedly reduced ADP response in fresh PCs. Seven-day storage had a pronounced effect on both ADP and collagen response. All other tested platelet agonists revealed preserved function. Subsequent warming and/or application of pressure did not significantly compromise platelet function. ConclusionsPressure-aided plus warmed transfusion and PTS transport was not found to be detrimental to the PC. Further clinical studies are required to determine safety and efficacy of the product.

Evaluation of the pneumatic tube system for transportation of packed red cell units.

Background:Pneumatic tube system (PTS) is commonly used in hospital settings to transport blood samples to diagnostic laboratories. At our blood center, we receive blood requisitions via the PTS, but units are carried to the ward by human courier. Recently we considered using the PTS for transporting blood units. Since, there are reports of hemolysis in blood samples sent through the PTS, we evaluated this system for transporting red cell units.Aims:The aim was to assess the effect of PTS transport on the quality of packed red cell units.Materials and Methods:A total of 50 red blood cells units (RBC), (25 non-irradiated and 25 irradiated) were subjected to transportation through the PTS. The control arm in the study was age-matched RBC units not subjected to PTS transport. Each RBC unit was evaluated for hemoglobin (Hb), lactate dehydrogenase, potassium and plasma hemoglobin (Hb). The paired t-test was used to compare these parameters, and the P value was calculated.Results and Conclusion:The percentage of hemolysis after transportation through PTS was below the recommended guidelines. Delivery of the blood unit to the wrong station, bags lying unattended at the destination were few of the problems that had to be addressed. To conclude, though the PTS is a safe means of transporting blood products with reduction in the turn-around-time, it must be validated before use.

Interindividual variability of hemolysis in plasma samples during pneumatic tube system transport

Article Interindividual variability of hemolysis in plasma samples during pneumatic tube system transport was published on October 1, 2013 in the journal Clinical Chemistry and Laboratory Medicine (CCLM) (volume 51, issue 10).

Alterations in rotation thromboelastometry (ROTEM®) parameters: point-of-care testing vs analysis after pneumatic tube system transport

Thromboelastometry as point-of-care (POC) testing enables the analysis of the clotting process at the bedside, providing rapid results to guide haemostatic therapy. However, POC testing utilizes medical staff who are managing critically ill patients, as non-laboratory personnel may not be sufficiently trained to run the devices. To resolve these problems, thromboelastometry can be performed in the central laboratory and rapid transport of samples can be accomplished via a pneumatic tube system (PTS). This study compares thromboelastometry parameters of blood samples analysed immediately with those analysed after PTS transport. In patients with normal haemostasis, two arterial blood samples were collected from each patient (n=92) in citrated plastic tubes to investigate the assays INTEM (n=35), EXTEM (n=27), and FIBTEM (n=30). One blood sample was analysed immediately, the other sample after PTS transport. Thromboelastometry was performed using a single ROTEM(®) device. The mean clot firmness values were significantly lower for PTS samples in both the INTEM (-0.7 mm cf. -1.1 mm) and EXTEM (-1.4 cf. -1.7 mm) assays. INTEM coagulation time (CT) was significantly lower in PTS samples with a mean difference of -13 s. EXTEM CT was significantly higher in PTS samples with a mean difference of +3.9 s. Thromboelastometry parameters of blood samples analysed after PTS transport are significantly altered compared with those analysed immediately. However, in patients with normal haemostasis, the alterations were small and without clinical consequence, implying that analysis after PTS transport is an acceptable alternative to prompt analysis at the bedside. Further studies should focus on patients with impaired haemostasis.

Early recognition of reverse pseudohyperkalemia in heparin plasma samples during leukemic hyperleukocytosis can prevent iatrogenic hypokalemia

ObjectivesTo investigate the cause of apparent hyperkalemia in leukemic heparin plasma. Design and methodsLithium heparin plasma and serum samples from a patient with chronic lymphocytic leukemia (CLL) with hyperleukocytosis were transported by either a pneumatic tube system or manual transport and analyzed either immediately or after 4h. ResultsPneumatic tube transported samples resulted in higher plasma potassium levels than manually transported samples. Serum potassium was lower than plasma potassium, confirming the suspicion of “reverse” pseudohyperkalemia. Letting the pneumatic tube transported samples stand on the bench for 4h before centrifugation surprisingly resulted in decreased or unchanged plasma potassium. ConclusionsThe reverse pseudohyperkalemia in heparin plasma samples from a CLL patient was caused by pneumatic tube transport. Our results suggest extracellular leakage of potassium, followed by active transport of potassium into intact leukemic cells. This is the first Swedish case of reverse pseudohyperkalemia in a CLL patient, where clinical suspicion of false hyperkalemia and awareness of the phenomenon lead to a rapid laboratory diagnosis. The demonstration of reverse pseudohyperkalemia prevented potentially dangerous medical interventions, such as potassium lowering treatment.

The effects of pneumatic tube system transport on ROTEM analysis and contact activation assessed by thrombin generation test

Thromboelastometry (ROTEM) is a popular point-of-care test. It generates results quickly and may benefit individualised guided haemostatic therapy. However, processing of specimens by non-technicians might decrease the quality and reproducibility of results. Centralised laboratory equipment receiving specimens through a pneumatic tube system (PTS) could avoid this. This study aimed to evaluate the influence of PTS transport on ROTEM results and its contribution to contact activation assessed by thrombin generation (TG). MethodsSpecimens from 44 patients were drawn immediately after arterial puncture. Two were anticoagulated by citrate and two by citrate/corn trypsin inhibitor, a Factor XIIa pathway inhibitor. Both types of samples were transported by walking and PTS. Subsequently, analysis was performed: ROTEM on citrated blood, and TG on citrated and corn trypsin inhibitor (CTI) blood using either 0 or 1 pM tissue factor (TF). ResultsIn ROTEM analysis the NATEM assay showed significant differences. The EXTEM assay revealed small significant differences for clot formation time: 65seconds (SD±20) versus 67seconds (SD±17), and alpha angle 79° (SD±3) versus 77° (SD±3). The results remained within reference range. TG was not significantly affected by the type of tube transport, independent of the amount of TF. ConclusionPTS for ROTEM analysis is feasible except for NATEM assays. The amount of contact activation via Factor XIIa in terms of TG is independent of transport type. However, due to the different characteristics of pneumatic systems, hospitals should check its impact on the results before introducing this route of transport.

Effect of Pneumatic Tube Delivery System Rate and Distance on Hemolysis of Blood Specimens

We evaluated the effects of pneumatic tube system (PTS) transport rates and distances on routine hematology and coagulation analysis. PTS effects on centrifuged blood samples were also examined. The study was completed at Dicle University Hospital, which has the longest pneumatic tube system in Turkey. Blood samples were collected at three different locations within the hospital and an emergency department, and delivered to the central laboratory by the PTS or a human carrier. Samples were transported at different rates and over varying distances. Each specimen's potassium (K) and lactic dehydrogenase (LDH) levels, in both the serum and plasma, were tracked to monitor hemolysis. Measurements of LDH and K were obtained using heparin or citrate. A positive correlation was observed between distance and hemolysis in serum samples transported at 4.2 m/sec, and at 3.1 m/sec for more than 2200 m (r = 0.774 and r = 0.766, respectively). Distance and hemolysis were also correlated in non-centrifuged samples (r = 0.871). The alterations in plasma LDH and K levels at different rates and PTS lengths were not statistically significant. The rate of hemolysis in PTS transported samples, dependent on PTS length and rate, may seriously affect routine tests of non-centrifuged samples.