Evaluation of a new point-of-care testing for creatinine and urea measurement.

Point of care testing makes it possible to obtain results in an extremely short time. Recently, radiometer has expanded the panel of tests available on its ABL90 FLEX PLUS blood gas analyzer (ABL90) by adding urea and creatinine. The aim of this study was to verify the performance of these new parameters. This included assessment of imprecision, linearity, accuracy by comparison with central laboratory standard assays and interferences. In addition, clinical utility in a dialysis center was evaluated. Within-lab coefficients of variation were close to 2%. The mean and limits of agreement (mean ± 1.96 SD) of the difference between ABL90 and Roche enzymatic assays on cobas 8000 were 0.5 (from -1.4 to 2.3) mmol/L and -0.9 (from -19.5 to 17.8) µmol/L for urea and creatinine, respectively. The ABL90 enzymatic urea and creatinine assays met the acceptance criteria based on biological variation for imprecision and showed good agreement with central laboratory. The two assays were unaffected by hematocrit variation between 20 and 70%, hemolysis and icterus interferences. It should be noted that the relationship between lab methods and ABL90 was conserved even for high pre-dialysis values allowing easy access to dialysis adequacy parameters (Kt/V) and muscle mass evaluation (creatinine index). Rapid measurement of creatinine and urea using whole blood specimens on ABL90 appears as a fast and convenient method. Analytical performances were in accordance with our expectations without any significant interferences by hemolysis or icterus.

Development and evaluation of point-of-care testing recertification with e-learning.

One of the main requirements in point-of-care testing (POCT) is efficient operator training to avoid diagnostic errors. Considering a variety of users and time-independent learning, e-learning is preferred. However, in our experience, e-learning is not always accepted by employees. After using a commercial e-learning program with little success, we developed a specific e-learning offer to achieve a better acceptance of online-based training. Herein our goal was to identify the most relevant aspects for better acceptance. The new e-learning modules were implemented with the learning management system ILIAS and dealt with typical sources of error. The implementation was accompanied by an anonymous online questionnaire within the POCT operators examining differences between the acceptance of the commercial e-learning and the hospital-specific. The results show higher acceptance for clinic-specific e-learning whereby online training of the POCT operators could successfully established. Most relevant aspects are the relevance of contents for the personal work and the working processes within the clinic as well as processing time. Thereby, the recertification of the POCT operators based on the successful completion of the learning modules was fully integrated in the POCT process. In respect to the need for regular recertification of POCT operators, our study shows that the acceptance of e-learning could be improved by adapting e-learning modules to the specific workflows in the hospital.

Point-of-care blood gas analyzers have an impact on the acceptance of donor lungs for transplantation.

An organ donor PaO2 above 40 kPa is generally required for lung transplantation. Point-of-care (POC) blood gas analyzers are commonly used by organ procurement organizations (OPO) but may underestimate the PaO2 at high levels. We hypothesized that changing to a more accurate blood gas analyzer would result in additional lungs transplanted. All PaO2 measurements on organ donors managed at one OPO's recovery center were performed on an i-STAT POC analyzer prior to October 2015, and on a GEM 4000 subsequently. For 24 weeks, all blood gases were tested simultaneously on both analyzers. We compared lung outcomes of 147 donors in the year prior to this change (using the i-STAT) with 56 donors in the 24-week study period (using the GEM 4000 for lung allocation). When the PaO2 was above 40 kPa, the i-STAT PaO2 was 7.2 kPa lower on average than the GEM 4000. When the GEM PaO2 measured between 40 and 50 kPa, the corresponding i-STAT PaO2 value registered less than 40 kPa 25 out of 48 times (52%), with an average difference of 7.3 kPa (SD = 2.9). The rate of lungs transplanted using the GEM 4000 was 48% compared with 35% in the year prior using the i-STAT (p = .11), with equivalent recipient outcomes. The i-STAT analyzer underestimated the PaO2 above 40 kPa and changing to a more accurate PaO2 analyzer may increase lungs transplanted.

Comparison of electrolyte and glucose levels measured by a blood gas analyzer and an automated biochemistry analyzer among hospitalized patients.

BACKGROUND: Blood gas analyzers are capable of delivering results on electrolytes and metabolites within a few minutes and facilitate clinical decision-making. However, whether the results can be used interchangeably with values measured by chemistry analyzers remains controversial. Blood gas analyzers are capable of delivering results on electrolytes and metabolites within a few minutes and facilitate clinical decision-making. However, whether the results can be used interchangeably with values measured by chemistry analyzers remains controversial. METHODS: In total, arterial and matched venous blood samples were collected from 200 hospitalized patients. Arterial blood samples were evaluated using a RAPIDPOINT 500 to test electrolyte and glucose levels, then the samples were centrifuged and the same parameters were measured with an AU5800. Venous blood samples were processed and tested in accordance with standard operation procedures. Data were compared by using a paired t test, the agreement between the two analyzers was evaluated by using the Bland-Altman test, and sensitivity and specificity were calculated. RESULTS: Paired t tests showed that all parameters tested were significantly different between the two analyzers except chloride. The biases calculated indicated that blood gas analyzers tend to underestimate the parameters, and the linear regression showed a strong correlation between the two analyzers. The sensitivity, specificity and kappa values demonstrated that the diagnostic performance of blood gas analyzers is not satisfactory. CONCLUSION: The significant reduction in parameter estimation and diagnostic performance we observed suggested that clinicians should interpret results from blood gas analyzers more cautiously. The reference interval of blood gas analyzers should be adjusted accordingly, given that values are underestimated.

Comparison of cord blood lactate measurement by gas analyzer and portable electrochemical devices.

Objective To compare the accuracy of cord blood lactate measurement using gas analyzer and portable devices in order to assess possibility of implementation of these devices in clinical practice. Methods We performed a prospective observational study using 30 umbilical cord samples which were obtained immediately after birth. Portable electrochemical devices Lactate Scout (SensLab GmbH, Leipzig, Germany) and StatStrip Lactate (NOVA Biomedical, Waltham, MA, USA) were used to determine lactate level. A gas analyzer ABL800 FLEX (Radiometer Medical ApS, Brønshøj-Husum, Denmark) was used as a reference. Base excess (BE), pH, partial oxygen (pO2) and carbon dioxide (pCO2) pressure, hemoglobin (ctHb) and bilirubin (ctBl) levels were measured. Results The mean umbilical cord blood lactate level determined by the gas analyzer was 5.85 ± 2.66 mmol/L (ranging from 1.4 mmol/L to 13.4 mmol/L). Lactate level estimated by Lactate Scout was 5.66 ± 2.65 mmol/L and did not significantly differ from the reference method level (P = 0.2547). The mean lactate level determined by StatStrip Lactate was significantly lower than by the gas analyzer - 4.81 ± 2.38 mmol/L (P < 0.0001). Umbilical cord blood pH, BE, pO2 and pCO2, ctHb and ctBl levels did not affect the accuracy of the lactate measurement in absolute units (mmol/L). Conclusion Umbilical cord blood lactate level measured by StatStrip Lactate was lower than estimated by the ABL800 FLEX gas analyzer. This shows the necessity to develop decision-making reference points separately for each device. Umbilical cord blood pH, BE, pO2 and pCO2, ctHb and ctBl levels did not affect the accuracy of measurements by electrochemical portable devices.

Evaluation of a Novel Ear Pulse Oximeter: Towards Automated Oxygen Titration in Eyeglass Frames.

Current oxygen delivery modes lack monitoring and can be cumbersome for patients with chronic respiratory diseases. Integrating a pulse oximeter and nasal oxygen cannulas into eyeglasses would reduce the burden of current solutions. An ear pulse oximeter (OxyFrame) was evaluated on 16 healthy volunteers and 20 hypoxemic patients with chronic respiratory diseases undergoing a prespecified protocol simulating daily activities. Correlation, error, and accuracy root mean square error (ARMS) were calculated to compare SpO2 measured by OxyFrame, a standard pulse oximeter (MASIMO), and arterial blood gas analysis (aBGA). SpO2 measured by OxyFrame and MASIMO correlated strongly in volunteers, with low error and high accuracy (r = 0.85, error = 0.2 ± 2.9%, ARMS = 2.88%). Performances were similar in patients (r = 0.87, error 0 ± 2.5%, ARMS = 2.49% compared with MASIMO; and r = 0.93, error = 0.4 ± 1.9%, ARMS = 1.94% compared with aBGA). However, the percentage of rejected measurements was high (volunteers 77.2%, patients 46.9%). The OxyFrame cavum conchae pulse oximeter was successfully evaluated, and demonstrated accurate SpO2 measurements, compliant with ISO 80601-2-61:2017. Several reasons for the high rejection rate were identified, and potential solutions were proposed, which might be valuable for optimization of the sensor hardware.

Discrepancy in Chloride Measurement with Decreasing Bicarbonate Concentrations.

BACKGROUND: Accurate chloride measurement is important in critically ill patients. METHODS: Chloride concentration measured simultaneously between the central laboratory (indirect ion-selective electrode) and blood gas analysis (direct ion-selective electrode) were compared. RESULTS: We report a discrepancy with chloride measurement between the central laboratory and blood gas analysis at low bicarbonate levels. CONCLUSIONS: Caution should be applied while interpreting the chloride concentration when indirect ion-selective electrode methodology is used, especially in the setting of low serum bicarbonate levels.

Assessment of haemoglobin measurement by several methods - blood gas analyser, capillary and venous HemoCue® , non-invasive spectrophotometry and laboratory assay - in term and preterm infants.

A laboratory haematology analyser is the gold standard for measuring haemoglobin concentration but has disadvantages, especially in neonates. This study compared alternative blood-sparing and non-invasive methods of haemoglobin concentration measurement with the gold standard. Haemoglobin concentrations were measured using a laboratory haematology analyser (reference method), blood gas analyser, HemoCue® using venous and capillary blood samples and a newly developed non-invasive sensor for neonates < 3 kg. A total of 63 measurements were performed. Body weight (2190 (1820-2520 [967-4450]) g) and haemoglobin concentration (12.3 (10.6-15.2 [8.2-20.5]) g.dl-1 ) varied widely. Bias/limits of agreement between the alternative methods and reference method were -0.1/-1.2 to 1.0 g.dl-1 (blood gas analyser), -0.4/-1.8 to 1.1 g.dl-1 (HemoCue, venous blood), 0.7/-1.9 to 3.2 g.dl-1 (HemoCue, capillary blood) and -1.2/-4.3 to 2 g.dl-1 (non-invasive haemoglobin measurement). Perfusion index, body weight and fetal haemoglobin concentration did not affect the accuracy of the alternative measurement methods, and these were successfully applied in term and preterm infants. However, the accuracies of non-invasive haemoglobin measurement and HemoCue of capillary blood especially lacked sufficient agreement with that of the reference method to recommend these methods for clinical decision making.

Correlation between sodium, potassium, hemoglobin, hematocrit, and glucose values as measured by a laboratory autoanalyzer and a blood gas analyzer.

INTRODUCTION: Blood gas analyzers can be alternatives to laboratory autoanalyzers for obtaining test results in just a few minutes. We aimed to find out whether the results from blood gas analyzers are reliable when compared to results of core laboratory autoanalyzers. MATERIALS AND METHODS: This retrospective, single-centered study examined the electronic records of patients admitted to the emergency department of a tertiary care teaching hospital between May 2014 and December 2017. Excluded from the study were patients under 18 years old, those lacking data, those who had any treatment before the laboratory tests, those whose venous gas results were reported more than 30 minutes after the blood sample was taken and for whom any of the laboratory tests were performed at a different time, and recurrent laboratory results from a single patient. RESULTS: Laboratory results were analyzed from a total of 31,060 patients. The correlation coefficients for sodium, potassium, hemoglobin, hematocrit, and glucose levels measured by a blood gas analyzer and a laboratory autoanalyzer were 0.725, 0.593, 0.982, 0.958, and 0.984, respectively; however, there were no good, acceptable agreement limits for any of the parameters. In addition, these results did not change according to the different pH stages (acidosis, normal pH and alkalosis). CONCLUSION: The two types of measurements showed a moderate correlation for sodium and potassium levels and a strong correlation for glucose, hemoglobin, and hematocrit levels, but none of the levels had acceptable agreement limits. Clinicians should be aware of the limitations of blood gas analyzer results.

Comparison of point-of-care and central laboratory analyzers for blood gas and lactate measurements.

BACKGROUND: Blood gas analysis and blood lactate measurement have important roles in patient management. Point-of-care (POC) testing simplifies and provides rapid blood gas and lactate measurements. This study aimed to compare pH, pCO2 , pO2 , and lactate measurements between a POC device and a benchtop blood gas analyzer typically used in a hospital central laboratory, and to evaluate the inter-device variability of the POC device. METHODS: A cross-sectional study was conducted with a sample size of 100. Each sample was measured for pH, pCO2 , pO2 , and lactate using a Nova pHOx plus L® benchtop blood gas analyzer in the central laboratory and an i-STAT® handheld POC device. The results of both devices were compared using Pearson or Spearman correlation coefficients and Bland-Altman tests. Testing of the inter-device variability was done by using three different i-STAT® devices, and the results were compared statistically. RESULTS: Strong correlations were observed for all test results. In Bland-Altman analysis, ≥95% of the results were within the limits of agreement, with the exception of lactate, which had only 93%. The results that were beyond the limits were primarily lactate levels >8 mmol/L. Biases between the benchtop analyzer and the i-STAT® were not clinically significant, except pH. No significant inter-device variability was observed between the i-STAT® analyzers. CONCLUSION: This comparison study of pH, pCO2 , pO2 , and lactate measurements between Nova pHOx plus L® and i-STAT® analyzers showed good agreement. However, lactate measurement results >8 mmol/L on the i-STAT® analyzer should be interpreted with caution.

Pulse oximeter to detect peripheral oxygen saturation in underwater rebreather ECCR diver: a preliminary study.

Hypoxia is one of the main problems an underwater diver may have to face. The probability of experiencing hypoxia is related to the type of dive and the equipment used. Hypoxia in diving is a potentially fatal event for the diver, as it can lead to the loss of brain functions and consequently to the loss of breathing control, all in the absence of specific premonitory symptoms. It is a risk that may be encountered more frequently by divers who use a closed-circuit rebreather (CCR). For those who use this type of equipment, hypoxia is usually the most frequent cause of death [1]. Our study was aimed at the detection of peripheral oxygen saturation in order to identify, in the future, a preclinical hypoxic condition. We combined the use of pulse oximetry with two forehead sensors on an underwater diver subject who was using an electronic closed-circuit rebreather (ECCR). Despite the known limits of this method and the preliminary status of these findings [2], the recorded data show a clear validity in the use of pulse oximetry in immersion for the detection of peripheral oxygen saturation. In the future, the pulse oximeter could become part of the instrumentation of the diver who uses CCR gear. The device could easily be implemented in these rebreathers. The possibility of being able to perform a basic instrumental analysis means that the diver can become more quickly aware of imminent hypoxia, characterized by the absence of clearly identifiable warning symptoms, and can put in place all the correct procedures for an emergency ascent, avoiding serious consequences.

Portable Blood (Gas) Analyzer in a Helicopter Emergency Medical Service.

INTRODUCTION: In prehospital helicopter emergency medical services (HEMS), the medical team frequently manages critical patients with only limited, noninvasive monitoring options on-site and during HEMS transport. To gain deeper insight into the patient's pathology and to track prehospital treatment effects, a point-of-care blood (gas) analyzer appears desirable also in HEMS. Thus, we hypothesized that prehospital blood (gas) analysis is feasible in the HEMS setting. METHODS: A prehospital evaluation of a portable blood (gas) analyzer (i-Stat 1; Abbott, Chicago, IL) with appropriate laboratory cartridges was performed within the Dutch HEMS Lifeliner 1, serving a region of ∼4.5 million inhabitants. Venous blood (gas) measurements were performed in our HEMS collective in both trauma and nontrauma cases. RESULTS: The HEMS team identified benefits (eg, portability and speed) and limitations (eg, a narrow operational temperature range) regarding the tested blood (gas) analyzer. Regarding the actual blood (gas) results, the team collected results without major abnormalities but also cases identifying major pathologies, including several cases of marked acidosis, refractory hypoglycemia, or severe anemia. CONCLUSION: In conclusion, portable blood (gas) analysis proved feasible in an HEMS operation but with relevant limitations. Future studies will have to show how these limitations can be overcome and how the implementation of portable blood (gas) analyzers may support improved patient outcome.

[Development of Blood Flow and Oxygen Monitoring System for Mice Based on Laser Speckle and Spectrum].

In vivo simultaneous monitoring of blood flow and changes of concentration of oxyhemoglobin (ΔHbO2) in brain is a key important method for the research of cerebrovascular disease. In this study, a new monitoring system, combining laser speckle contrast imaging method and spectral analysis method, was proposed, which could be utilized to measure the cerebral blood flow and ΔHbO2 on mice during traumatic brain injury. The principle of the present system was studied and the hardware platform of the detection system was built. Then, user interface software and algorithms were implemented based on Labview and Matlab software. Finally, the performance of the present system was verified by the in vivo experiments.

Emergency medical technician-performed point-of-care blood analysis using the capillary blood obtained from skin puncture.

OBJECTIVE: Comparing a point-of-care (POC) test using the capillary blood obtained from skin puncture with conventional laboratory tests. METHODS: In this study, which was conducted at the emergency department of a tertiary care hospital in April-July 2017, 232 patients were enrolled, and three types of blood samples (capillary blood from skin puncture, arterial and venous blood from blood vessel puncture) were simultaneously collected. Each blood sample was analyzed using a POC analyzer (epoc® system, USA), an arterial blood gas analyzer (pHOx®Ultra, Nova biomedical, USA) and venous blood analyzers (AU5800, DxH2401, Beckman Coulter, USA). Twelve parameters were compared between the epoc and reference analyzers, with an equivalence test, Bland-Altman plot analysis and linear regression employed to show the agreement or correlation between the two methods. RESULTS: The pH, HCO3, Ca2+, Na+, K+, Cl-, glucose, Hb and Hct measured by the epoc were equivalent to the reference values (95% confidence interval of mean difference within the range of the agreement target) with clinically inconsequential mean differences and narrow limits of agreement. All of them, except pH, had clinically acceptable agreements between the two methods (results within target value ≥80%). Of the remaining three parameters (pCO2, pO2 and lactate), the epoc pCO2 and lactate values were highly correlated with the reference device values, whereas pO2 was not. (pCO2: R2=0.824, y=-1.411+0.877·x; lactate: R2=0.902, y=-0.544+0.966·x; pO2: R2=0.037, y=61.6+0.431·x). CONCLUSION: Most parameters, except only pO2, measured by the epoc were equivalent to or correlated with those from the reference method.

Technical note: Evaluation of a wireless pulse oximeter for measuring arterial oxygen saturation and pulse rate in newborn Holstein Friesian calves.

Pulse oximetry is a well-established technique in human and veterinary medicine. In farm animals, it could also be a useful tool for the detection of critical conditions relating to oxygen supply and the cardiovascular system. Among other uses, an innovative application could be the monitoring of fetuses during birth. This could help in the early identification of critical situations and support farmers and veterinarians in their decision to start obstetric or life-support interventions. Until now, however, its use in ruminant medicine was still limited to experimental applications. The objective of this study was to evaluate the accuracy of the Radius-7 Wearable Pulse CO-Oximeter (Masimo Corporation, Irvine, CA) for monitoring vital parameters in newborn calves. All measurements were conducted on animals in the lying down position. The sensor of the pulse oximeter was placed in the interdigital space of the calves' front legs and fixed with a homemade latex hoof cover. The pulsoximetric measurements of arterial oxygen saturation (SpO2) in 40 newborn calves were compared with the corresponding results (SaO2) from a portable blood gas analyzer (VetScan iStat1, Abaxis Inc., Union City, CA), which served as the reference. For this, an arterial blood sample was taken from the medial intermediate branch of the caudal auricular artery. In addition, the pulse rate was measured in 10 calves aged between 0 and 7 d with the pulse oximeter and simultaneously with a heart rate belt (Polar Equine Belt, Polar Electro Oy, Kempele, Finland) to determine their level of agreement. Spearman correlation coefficient for oxygen saturation was 93.8% for the pulse oximeter and the blood gas analyzer, and 97.7% for the pulse rate measured with the pulse oximeter and the heart rate belt. Bland-Altman plots revealed an overestimation of SaO2 by 2.95 ± 6.39% and an underestimation of the pulse rate by -0.41 ± 3.18 beats per minute compared with the corresponding reference methods. In summary, the pulse oximeter is suitable for continuous monitoring of arterial oxygen saturation and pulse in newborn Holstein Friesian calves. For practical use, purpose-built technical equipment is required to attach the sensor to the calves' legs.

Point-of-care measurement of fetal blood lactate - Time to trust a new device.

BACKGROUND: Point-of-care lactate devices are used worldwide for intrapartum decision making. Current practice is often based on Lactate Pro (Arkray) but its imminent product discontinuation necessitates determination of an optimal replacement device. AIMS: To evaluate the performance of Lactate Pro and two other point-of-care devices, Lactate Pro 2 (Arkray) and StatStrip (Nova Biomedical), and to derive scalp lactate cut-offs equivalent to the current intervention trigger of >4.8 mmol/L. MATERIALS AND METHODS: Paired umbilical cord arterial and venous blood samples from 109 births were tested on the three point-of-care products (two devices each), cross-compared with the reference method blood gas analyser. RESULTS: All brands deviate from the blood gas analyser, with Lactate Pro and StatStrip results consistently lower and Lactate Pro 2 consistently higher. Standard deviation from the blood gas analyser was smallest for StatStrip (0.78 mmol/L, cord artery), and largest for Lactate Pro 2 (1.03 mmol/L, cord artery). Within-brand variation exists and is similar for all brands (mean absolute difference on cord artery 0.23-0.30 mmol/L). Equivalent values to the 4.8 mmol/L intervention threshold based on Lactate Pro are 4.9-5.0 mmol/L for StatStrip and 5.3-5.9 mmol/L for Lactate Pro 2, calculated by receiver-operating characteristic analysis. CONCLUSIONS: StatStrip appears superior to Lactate Pro 2 to replace the original Lactate Pro. Using StatStrip, the 4.8 mmol/L intervention threshold equivalent was 4.9-5.0 mmol/L. The variation in accuracy of point-of-care lactate devices may exceed the small increments (eg <4.2 mmol/L vs >4.8 mmol/L) that guide obstetric decisions.

High altitude arterialised capillary earlobe blood gas measurement using the Abbott i-STAT.

INTRODUCTION: Measurement of physiological parameters in extreme environments is essential to advancing knowledge, prophylaxis and treatment of altitude sickness. Point-of-care testing facilitates investigation in non-specialist and remote settings, as well as becoming increasingly popular at the bedside for real-time results in the clinical environment. Arterialised capillary earlobe blood gases are recommended as a valid alternative to arterial sampling in research. This study aimed to test the feasibility of obtaining and analysing daily earlobe samples at high altitude. METHODS: From 17 to 24 January 2016, 24 participants on a research expedition to Ecuador underwent daily earlobe blood gas measurements including pH, partial pressure of oxygen and partial pressure of carbon dioxide to 5043 m. Samples were analysed using an Abbott i-STAT blood gas analyser and G3+ cartridges. RESULTS: Daily measurements were successfully obtained and analysed at the point of care in 23/24 participants and were well tolerated with no adverse events. 12% (27/220) cartridges failed and required repeat sampling. CONCLUSIONS: Daily earlobe blood gas analysis using the Abbott i-STAT is feasible in a protected environment at high altitude. Participants and equipment should be kept warm before and during testing. Spare cartridges should be available. This methodology may be useful for both research and therapeutic measurements in remote, rural and wilderness medicine.

Measurement of total CO2 in microliter samples of urine and other biological fluids using infrared detection of CO2.

The purpose of this study is to describe a low-cost and simply made instrument capable of measuring the total CO2 content of microliter volumes of biological fluids utilizing a commercially available CO2 sensor based on a NDIR detector. The described instrument is based on transformation of dissolved HCO3- to CO2 by acidification and subsequent measurement of the produced CO2. The instrument has a linear response in the range 0.025-10 µmol HCO3-, which enables measurements in fresh urine and plasma samples down to 5 µl. The values from plasma were compared to measurements made on 65 µl whole blood in an automatic blood gas analyzer and found not to differ significantly. Compared to currently commercially available instruments applying the same principles to measure total CO2, this study provides a simple and robust alternative which even can be used on smaller sample volumes.

Comparison of pneumatic tube system with manual transport for routine chemistry, hematology, coagulation and blood gas tests.

BACKGROUND: The pneumatic tube system (PTS) is commonly used in modern clinical laboratories to provide quick specimen delivery. However, its impact on sample integrity and laboratory testing results are still debatable. In addition, each PTS installation and configuration is unique to its institution. We sought to validate our Swisslog PTS by comparing routine chemistry, hematology, coagulation and blood gas test results and sample integrity indices between duplicate samples transported either manually or by PTS. METHODS: Duplicate samples were delivered to the core laboratory manually by human courier or via the Swisslog PTS. Head-to-head comparisons of 48 routine chemistry, hematology, coagulation and blood gas laboratory tests, and three sample integrity indices were conducted on 41 healthy volunteers and 61 adult patients. RESULTS: The PTS showed no impact on sample hemolysis, lipemia, or icterus indices (all p<0.05). Although alkaline phosphatase, total bilirubin and hemoglobin reached statistical significance (p=0.009, 0.027 and 0.012, respectively), all had very low average bias which ranged from 0.01% to 2%. Potassium, total hemoglobin and percent deoxyhemoglobin were statistically significant for the neonatal capillary tube study (p=0.011, 0.033 and 0.041, respectively) but no biases greater than ±4% were identified for these parameters. All observed differences of these 48 laboratory tests were not clinically significant. CONCLUSIONS: The modern PTS investigated in this study is acceptable for reliable sample delivery for routine chemistry, hematology, coagulation and blood gas (in syringe and capillary tube) laboratory tests.

Comparison of tranexamic acid plasma concentrations when administered via intraosseous and intravenous routes.

INTRODUCTION: There is a lack of information regarding intraosseous (IO) administration of tranexamic acid (TXA). Our hypothesis was that a single bolus IO injection of TXA will have a similar pharmacokinetic profile to TXA administered at the same dose IV. METHODS: Sixteen male Landrace cross swine (mean body weight 27.6±2.6kg) were divided into an IV group (n=8) and an IO group (n=8). Each animal received 30mg/kg TXA via an IV or IO catheter, respectively. Jugular blood samples were collected for pharmacokinetic analysis over a 3h period. The maximum TXA plasma concentration (Cmax) and corresponding time as well as distribution half-life, elimination half-life, area under the curve, plasma clearance and volume of distribution were calculated. One- and two-way analysis of variance for repeated measures (time, group) with Tukey's and Bonferonni post hoc tests were used to compare TXA plasma concentrations within and between groups, respectively. RESULTS: Plasma concentrations of TXA were significantly higher (p<0.0001) in the IV group during the TXA infusion. Cmax occurred at 4min after initiation of the bolus in the IV group (9.36±3.20ng/µl) and at 5min after initiation of the bolus in the IO group (4.46±0.49ng/µl). Plasma concentrations were very similar from the completion of injection onwards. There were no significant differences between the two administration routes for any other pharmacokinetic variables measured. CONCLUSION: The results of this study support pharmacokinetic bioequivalence of IO and IV administration of TXA.