[The effect of tailored training courses in preanalytical procedures on the quality of laboratory results]. / Einfluss einer maßgeschneiderten Präanalytik-Fortbildung auf die Qualität der Laboruntersuchungen.

INTRODUCTION: In 31 to 75 percent of cases, errors in laboratory medicine have preanalytical causes such as erroneous blood sampling. Erroneous blood sampling may lead to false test results and additional laboratory cost; it may increase analyzing time and endanger the health of patients and employees. In particular, under- and overfilling of blood sampling tubes can considerably distort laboratory values. So far there has been a lack of studies investigating the effect of a tailored training for ward staff to improve preanalytical procedures on blood sampling. ISSUE: Can a tailored preanalytical training significantly reduce the number of commented under- and overfilled coagulation samples, reduce the number of hemolytic serum and lithium heparin samples and increase the number of standards-compliant blood sampling? METHODS: In an intervention study we compared the number of commented under- and overfilled coagulation tubes and the number of hemolytic serum and lithium heparin samples on the basis of laboratory data and, using participant observation, compared the blood sampling quality on a surgical ward before and after participation in a training course. Based on prior results of participant observation, a 20-minute training was conceptualized and conducted. Target criteria were a) the number of commented under- and overfilled coagulation tubes and b) the number of hemolytic serum and lithium heparin samples in a before/after comparison (Oct-Dec 2017 and Jan-Mar 2018 compared with Jun-Aug 2018) and an annual comparison (Jun-Aug 2017 compared to Jun-Aug 2018), and c) a standards-compliant performance of blood sampling in a before/after comparison (Apr 2018 and Jun 2018). The number of commented under- and overfilled coagulation tubes in the annual comparison was compared using the Chi-square test. RESULTS: After the training (Jun-Aug 2018) the number of commented under- and overfilled coagulation tubes decreased significantly in annual comparison to Jun-Aug 2017 (-68.07%, p < 0.001). The number of commented under- and overfilled coagulation tubes and of hemolytic serum and lithium heparin samples decreased in the before/after and in the annual comparison, and the number of standards-compliant blood samplings increased in the before/after comparison. CONCLUSION: The training contributed significantly to reducing the number of commented coagulation samples and hemolytic serum and lithium heparin samples and to increasing standards-compliant blood sampling. There is a need to investigate to what extent this concept can be transferred to other wards, and in which intervals further trainings should be conducted in order to maintain these positive effects.

Results of concomitant groin-free percutaneous temporary RVAD support using a centrifugal pump with a double-lumen jugular venous cannula in LVAD patients.

BACKGROUND: Modern left ventricular assist devices (LVAD) have evolved to become standard of care in severe heart failure (HF) patients. Right HF (RHF) is a major complication responsible for early mortality. Several techniques for temporary right ventricular assist device (t-RVAD) have been described before, baring relevant disadvantages such as limited mobilization or the need for re-thoracotomy. We describe the results of an alternative technique for t-RVAD using the Tandem Heart™ with ProtekDuo™ cannula. METHODS: An institutional retrospective single centre outcome analysis was performed including all permanent LVAD recipients with concomitant groin-free t-RVAD support. RESULTS: Between October 2015 and September 2017, 11 patients (10 male, 90.9%) were included. Preoperative NYHA class was 3.8±0.75 and INTERMACS class 3.5±1.5. Four (36.4%) patients were already on mechanical circulatory support (MCS) at time of implantation with 4 (36.4%) patients already on inotropic support. All LVAD implantations were performed on-pump and 3 cases (27.3%) were re-do cases. Mean t-RVAD duration was 16.8±9.5 days. Ten patients (90.9%) could be weaned from temporary RVAD support, 1 patient deceased on support. Mean ICU stay was 23.8±16.5 days, while 30-day survival was 72.7%. Follow-up was complete with 214.7±283 days. Three patients (27.3%) died following multi-organ failure (MOF), 1 patient (9.1%) following intracranial bleed 12 days after t-RVAD explantation. No severe t-RVAD associated complications were observed. CONCLUSIONS: Our technique allows for safe groin-free t-RVAD providing all advantages of percutaneous implantation including complete mobilization and bedside explantation without any need for operation.

Antithrombotic therapy in pediatric ventricular assist devices: Multicenter survey of the European EXCOR Pediatric Investigator Group.

OBJECTIVES: Mechanical circulatory support for pediatric heart failure patients with the Berlin Heart EXCOR ventricular assist system is the only approved and established bridging strategy for recovery or heart transplantation. In recent years, the burden of thromboembolic events has led to modifications of the recommended antithrombotic therapy. Therefore, we aimed to assess modifications of antithrombotic practice among the European EXCOR Pediatric Investigator Group members. METHODS: We sent a questionnaire assessing seven aspects of antithrombotic therapy to 18 European hospitals using the EXCOR device for children. Returned questionnaires were analyzed and identified antithrombotic strategies were descriptively compared to "Edmonton protocol" recommendations developed for the US EXCOR pediatric approval study. RESULTS: Analysis of 18 received surveys revealed substantial deviations from the Edmonton protocol, including earlier start of heparin therapy at 6-12 h postoperatively and in 50% of surveyed centers, monitoring of heparin effectiveness with aPTT assay, administering vitamin K antagonists before 12 months of age. About 39% of centers use higher international normalized ratio targets, and platelet inhibition is changed in 56% including the use of clopidogrel instead of dipyridamole. Significant inter-center variability with multiple deviations from the Edmonton protocol was discovered with only one center following the Edmonton protocol completely. CONCLUSION: Current antithrombotic practice among European EXCOR users representing the treatment of more than 600 pediatric patients has changed over time with a trend toward a more aggressive therapy. There is a need for systematic evidence-based evaluation and harmonization of developmentally adjusted antithrombotic management practices in prospective studies toward revised recommendations.

Closing the gap in paediatric ventricular assist device therapy with the Berlin Heart EXCOR® 15-ml pump.

OBJECTIVES: The Berlin Heart EXCOR ® (EXCOR) paediatric ventricular assist device is used worldwide for mechanical support of infants and small children with end-stage heart failure. A clinically important gap between the smallest EXCOR blood pump (10 ml) and the next larger size (25 ml) limited the choice of pump size in patients with a body surface area (BSA) between 0.33 and 0.5 m 2 . We present the first clinical experience from the early product surveillance (EPS) of the new EXCOR 15-ml blood pump. METHODS: After CE and U.S. Food and Drug Administration approval in January 2013, 20 patients with a mean age of 1.6 years (range 0.5-3.5 years) and a mean BSA of 0.45 m 2 (range 0.33-0.59 m 2 ) were enrolled in the EPS. The main diagnosis was idiopathic cardiomyopathy in 13 patients; the majority ( n = 16) of children were in INTERMACS level 1 or 2. Data from high-volume paediatric transplant centres were collected prospectively for a defined follow-up period of 60 days after device implantation. RESULTS: Mean time on the EXCOR 15-ml blood pump was 43 days; the survival rate was 100% at the end of the EPS period. Seven patients underwent a heart transplant from the device; 2 children were weaned; and 11 patients remained on support. Infection of cannula exit sites occurred in 3 patients. Two patients had minor thromboembolic strokes but made a complete neurological recovery. CONCLUSIONS: The new EXCOR 15-ml blood pump demonstrated optimal ventricular assist device support of children with a BSA of 0.33-0.5 m 2 .

Direct quantification of mitral regurgitant flow volume by real-time three-dimensional echocardiography using dealiasing of color Doppler flow at the vena contracta.

BACKGROUND: Real-time 3-dimensional color Doppler echocardiographic (RT3DE) imaging has recently been demonstrated to provide accurate direct measurement of vena contracta area (VCA). The quantification of mitral regurgitant (MR) flow directly at the lesion using color Doppler echocardiography, however, has been prevented because of multiple aliasing from high flow velocities. Recent studies, however, have demonstrated that flow at the vena contracta is laminar, with a narrow velocity spectrum that should allow the dealiasing of color Doppler flow velocities for the accurate measurement of MR flow. This hypothesis was tested in an in vitro flow model and initial patient application, with magnetic resonance imaging (MRI) used as a reference. METHODS: In an in vitro flow model, MR jets of flow rates from 5 to 60 mL/s were produced through asymmetric orifices of 0.2 to 0.6 cm(2). From RT3DE data sets, MR flow was calculated by the automated integration of the nonaliased color Doppler velocities over the VCA, with aliasing avoided by maximum baseline shift. Aliased flow was calculated as VCA times the Nyquist velocity times the number of aliasing transitions derived from the maximum continuous-wave Doppler velocity. Total MR flow was calculated as the sum of nonaliased and aliased flow. This approach was also clinically evaluated in 23 patients for the measurement of MR stroke volume against MRI and the hemispheric and hemielliptic proximal isovelocity surface area methods. RESULTS: In vitro RT3DE imaging of VCA was feasible in all flow stages without color Doppler aliasing. Flow rates calculated from RT3DE data sets showed excellent correlation with actual flow rates (r = 0.99), with a mean difference of -0.05 +/- 0.5 mL/s (not significant by t test). In vivo, good correlation and agreement were found between MR stroke volume by dealiasing and MRI (r = 0.91, -1.8 +/- 7.1 mL; not significant by t test), with better correlation and agreement compared with hemispheric proximal isovelocity surface area (r = 0.81, -17.4 +/- 9.4 mL, P < .05) and hemielliptic proximal isovelocity surface area (r = 0.89, -11.7 +/- 7.4 mL, P < .05). CONCLUSIONS: Dealiasing of color Doppler flow at the vena contracta is feasible and appears promising for measuring MR severity quantitatively. This novel approach can be readily implemented in current systems to provide rapid semiautomated MR flow volume and MR fraction.