Gerald Sendlhofer

Validation of home blood glucose meters with respect to clinical and analytical approaches

OBJECTIVE To evaluate the clinical and analytical accuracy of home blood glucose meters. RESEARCH DESIGN AND METHODS Six blood glucose meters—Reflolux S (Boehringer Mannheim, Mannheim, Germany), One Touch II (LifeScan, Milpitas, CA), Glucocard Memory (Menarini, Florence, Italy), Precision QID (Medisense, Cambridge, U.K.), HaemoCue (HaemoCue, Ängelholm, Sweden), and Accutrend a (Boehringer Mannheim, Mannheim, Germany)—were compared with a reference method (Beckman Glucose Analyzer II) under controlled conditions (glucose clamp technique). Validation of the blood glucose meters was accomplished by clinically oriented approaches (error grid analysis), statistical approaches (variance components analysis), and by the criteria of the American Diabetes Association (ADA), which recommend a target variability of <5%. RESULTS A total of 1,794 blood glucose monitor readings and 299 reference values ranging from 2.2 to 18.2 mmol/1 were analyzed (705 readings <3.89 mmol/1, 839 readings between 3.89 and 9.99 mmol/1, and 250 readings >9.99 mmol/1). According to error grid analysis, only Reflolux S and Glucocard M had 100% of estimations within the clinically acceptable zones A and B. Assessment of analytical accuracy revealed substantial differences between the glucose meters after separation of the data into defined glycemic ranges. None of the devices met the ADA criteria. CONCLUSIONS To evaluate accuracy of blood glucose meters, error grid analysis, as well as statistical models, are helpful means and should be performed together. Analytical performance of currently available home blood glucose meters differs substantially within defined glycemic ranges.

Post-prandial administration of the insulin analogue insulin aspart in patients with Type 1 diabetes mellitus.

Aims In intensified insulin therapy, the recent development of short‐acting insulin analogues with a very rapid onset of action forces a new discussion in terms of the optimal injection–meal interval. This study evaluated prandial glycaemia in patients with Type 1 diabetes following the subcutaneous injection of soluble human insulin (HI) and the insulin analogue insulin aspart (IAsp) at different injection–meal intervals and investigated whether administration of IAsp after the meal might provide satisfactory metabolic control.

Direct access to interstitial fluid in adipose tissue in humans by use of open-flow microperfusion.

To gain direct access to the interstitial fluid (ISF), a new technique called open-flow microperfusion has been evaluated. This method is based on a double-lumen catheter with macroscopic (0.3-0.5 mm diameter) perforations that is inserted into the subcutaneous adipose tissue and constantly perfused. Thus partial equilibration between the ISF and the perfusion fluid occurs. The glucose concentration of the ISF was determined by established (zero flow rate, no net flux, and recirculation procedures) and new (ionic reference and suction technique) calibration methods by use of open-flow microperfusion. The data show that 1) the glucose concentration in the ISF is significantly lower than the corresponding arterialized venous plasma values during basal steady-state conditions (adipose tissue 3.2 +/- 0.10 mM, plasma 5.27 +/- 0.12 mM) as well as during hyperglycemic clamp experiments (adipose tissue 7.3 +/- 0.13 mM, plasma 9.91 +/- 0.16 mM), and 2) it is possible to determine the recovery continuously by using the ion concentration of the ISF as an internal standard (ionic reference).To gain direct access to the interstitial fluid (ISF), a new technique called open-flow microperfusion has been evaluated. This method is based on a double-lumen catheter with macroscopic (0.3-0.5 mm diameter) perforations that is inserted into the subcutaneous adipose tissue and constantly perfused. Thus partial equilibration between the ISF and the perfusion fluid occurs. The glucose concentration of the ISF was determined by established (zero flow rate, no net flux, and recirculation procedures) and new (ionic reference and suction technique) calibration methods by use of open-flow microperfusion. The data show that 1) the glucose concentration in the ISF is significantly lower than the corresponding arterialized venous plasma values during basal steady-state conditions (adipose tissue 3.2 ± 0.10 mM, plasma 5.27 ± 0.12 mM) as well as during hyperglycemic clamp experiments (adipose tissue 7.3 ± 0.13 mM, plasma 9.91 ± 0.16 mM), and 2) it is possible to determine the recovery continuously by using the ion concentration of the ISF as an internal standard (ionic reference).

Novel system for real-time ex vivo lactate monitoring in human whole blood

The objective of the study was to evaluate the performance of an amperometric enzyme based lactate sensor and to investigate the possibility of replacing a double lumen catheter based blood withdrawal system with a heparin coated single lumen system. The inner lumen of a double lumen catheter which was placed in a peripheral vein was perfused with heparin solution. The outer lumen was used to collect heparinized blood samples at a defined flow rate. The single lumen system was attached to a heparinized catheter which was also placed in a peripheral vein. The undiluted blood samples were collected at a specified flow rate. A sensor flow chamber incorporating an amperometric thin-film lactate microbiosensor was placed in the sampling line for real-time lactate monitoring. Plasma lactate concentrations were measured during frequently performed hyperlactatemia bicycle ergometer experiments in six healthy volunteers (age 25.8 +/- 2.8 years, BMI 22.7 +/- 1 kg/m2). Additionally, plasma lactate was measured in real-time using the lactate sensors. The first three experiments were performed with a double lumen based catheter system whereas the following three experiments were performed with a heparin coated catheter system. The correlation coefficients of sensor readings and laboratory analyzer results in all six experiments were between 0.93 and 0.99, respectively (P < 0.001). The miniaturized lactate sensors showed a linear range up to 25 mmol/l lactate concentration and 95% response times < 30 s in undiluted serum. During the experiments maximum lactate concentrations of 14 mmol/l were achieved. Improvements of system performance using heparin coated catheter systems could be shown. The overall SD of the sensor readings compared to laboratory results using three double lumen catheter based systems was 0.91 mmol/l whereas the SD using three heparin coated systems was 0.65 mmol/l. In summary, real-time monitoring of lactate in human whole blood is feasible with such a device and can be improved by using heparin coated catheter systems.

Implementation of a Surgical Safety Checklist: Interventions to Optimize the Process and Hints to Increase Compliance

Background A surgical safety checklist (SSC) was implemented and routinely evaluated within our hospital. The purpose of this study was to analyze compliance, knowledge of and satisfaction with the SSC to determine further improvements. Methods The implementation of the SSC was observed in a pilot unit. After roll-out into each operating theater, compliance with the SSC was routinely measured. To assess subjective and objective knowledge, as well as satisfaction with the SSC implementation, an online survey (N = 891) was performed. Results During two test runs in a piloting unit, 305 operations were observed, 175 in test run 1 and 130 in test run 2. The SSC was used in 77.1% of all operations in test run 1 and in 99.2% in test run 2. Within used SSCs, completion rates were 36.3% in test run 1 and 1.6% in test run 2. After roll-out, three unannounced audits took place and showed that the SSC was used in 95.3%, 91.9% and 89.9%. Within used SSCs, completion rates decreased from 81.7% to 60.6% and 53.2%. In 2014, 164 (18.4%) operating team members responded to the online survey, 160 of which were included in the analysis. 146 (91.3%) consultants and nursing staff reported to use the SSC regularly in daily routine. Conclusion These data show that the implementation of new tools such as the adapted WHO SSC needs constant supervision and instruction until it becomes self-evident and accepted. Further efforts, consisting mainly of hands-on leadership and training are necessary.

Dissociation of leptin and body weight in hyperthyroid patients after radioiodine treatment.

OBJECTIVE: Leptin regulates energy production rates and body weight, which are frequently altered in hyperthyroidism. Data on a possible interaction between leptin and thyroid hormones are controversial. We assessed leptin serum concentrations, BMI, proportional fat tissue mass and thyroid hormones in hyperthyroid patients in a long-term follow-up after radioiodine therapy.DESIGN: The study included 28 hyperthyroid patients (mean age 66 y) before and up to one y after radioiodine therapy. Leptin and thyroid hormones, general parameters, BMI, proportional fat tissue (PFT) measurements by DEXA and thyroid morphology were recorded. Twenty-four age-matched euthyroid individuals (mean age 63 y) served as controls.RESULTS: At baseline, leptin concentrations were significantly decreased in all hyperthyroid patients as compared to controls. One year after radioiodine therapy, 71% of the patients were euthyroid (group A) and 29% remained hyperthyroid (group B). BMI and PFT increased in both groups. While leptin concentrations remained low in group B, they normalised in group A after 6 to 12 months. Changes in leptin and thyroid hormone concentrations were positively correlated in group A patients (r=0.49, P=0.03) but not in patients remaining hyperthyroid.CONCLUSION: Our data indicate a dissociation in the regulation of plasma leptin and BMI as well as proportional fat tissue in hyperthyroid patients which may be attributable to differences in lean and adipose mass weight gain after radioiodine therapy or direct influences of thyroid hormones on leptin regulation.

The Gap between Individual Perception and Compliance: A Qualitative Follow-Up Study of the Surgical Safety Checklist Application

Background “The Surgical Safety Checklist (SSC) is important, but we don’t use it adequately” is a well-suited statement that reflects the SSCs application in hospitals. Our aim was to follow up on our initial study on compliance (2014) by analysing differences between individual perception and compliance with the SSC. Methods We conducted a follow-up online survey to assess healthcare professionals’ individual perception of, as well as satisfaction and compliance with the SSC three years following its thorough implementation. Results 171 (19.5%) of 875 operating team members completed the online survey. 99.4% confirmed using the SSC. Self-estimated subjective knowledge about the intention of the checklist was high, whereas objective knowledge was moderate, but improved as compared to 2014. According to an independent audit the SSC was used in 93.1% of all operations and among the SSCs used the completion rate was 57.2%. The use of the SSC was rated as rather easy [median (IQR): 7 (6–7)], familiar [7 (6–7)], generally important [7 (7–7)], and good for patients [7 (6–7)] as well as for employees [7 (7–7)]. Only comfort of use was rated lower [6 (5–7)]. Conclusion There is a gap between individual perception and actual application of the SSC. Despite healthcare professionals confirming the importance of the SSC, compliance was moderate. The introduction of SSCs in the health care sector remains a constant challenge and requires continuous re-evaluation as well as a sensible integration into existing workflows in hospitals.

Get in touch with safety in health

Keywords: Patient Safety, Quality and ProcessManagement, Simulation and Training, Health economicaspectsEditorialHealthcare systems have always striven to avoid errorsand to have safe procedures in place. The EuropeanCommission estimated that in member states, between8% and 12% of patients admitted to hospital suffer fromadverse events while receiving care [1]. In 1999, the pub-lication of ‘to err is human’ suggested a comprehensiveapproach in improving patient safety [2] and exploredthe need to enhance knowledge and tools to improvesafety. In the meantime, patient safety activities havestarted around the world [3]. Subsequently, patientsafety has received considerable attention and is fast be-coming an important research area [4].Patient safety is linked to human errors and the riskassessment approach of the aviation industry has pro-vided healthcare with some best practice examples ondealing with this systematically. For example, checklists,team training, and incident reporting have been widelyimplemented in healthcare systems worldwide. Follow-ing the introduction of the WHO-Surgical Safety Check-list by Gawande in 2009 several comprehensive studieshave evaluated its use [5]. The findings of these studiesindicate that even where there is an evidence-base dem-onstrating a benefit from the use of such tools, this doesnot guarantee acceptance and appropriate use by health-care professionals [6,7]. The reasons for this can lie in alack of positive role models, hierarchical barriers, limitedmethodological knowledge and inappropriate implemen-tation procedures [8].It is obvious that patient safety is linked to a broadspectrum of challenges and needs to include a varietyof interventions in order to succeed. The WHO and theEuropean Commission as well as other official bodieshave suggested implementing national strategies toaddress the key issues relating to the improvement ofpatient safety (Table 1) [9]. This includes fields of inter-vention such as organizational, policy and personneldevelopments, monitoring measures and measures toraise public awareness. Furthermore, within the health-care system we have to consider environmental, cul-tural, professional and healthcare financing differences.To enable these national strategies the establishment ofI. clinical risk management strategies,II. the implementation of health promotion schemesandIII. the development of safe and user-friendly systems,processes and toolsfor patient safety accompanied by information and com-munication technologies are needed [10]. All of thesemeasures will help to support comprehensive changes thatdevelop safe procedures in healthcare systems.Patient safety is an international imperative and is fun-damental to healthcare policy, planning, organization,delivery, evaluation and quality improvement. However,investment in patient safety research and outstanding re-search goals by healthcare organizations and by govern-ments are lacking. As described by Shojania [11], threedistinct achievements have to occur in order to showprogress in patient safety:I. Identification of interventions that reduce commontypes of adverse events,II. Dissemination of these effective interventions intoroutine practice, andIII. Development of tools to measure improvements inpatient safety issues.For this reason, the journal Safety in Health pays par-ticular attention to global trends in healthcare that affectpatient safety. The journal has four dedicated sections.Research in the section Patient Safety mainly focuses onstudies of patient safety showing evidence in implemen-tation and effectiveness in primary care, ambulatorycare, hospitals, care transitions at hospital discharge and

Estimation of human leptin concentration in the subcutaneous adipose and skeletal muscle tissues

Interstitial leptin concentrations in subcutaneous adipose and skeletal muscle tissues were determined by open‐flow microperfusion.

Neue Wege zur Evaluierung von patientensicherheitsrelevanten Aspekten: Feedback-Patientensicherheit

Zusammenfassung Hintergrund Patientensicherheit ist in aller Munde, und es werden zahlreiche Initiativen gesetzt, um patientenrelevante Prozesse sicherer zu gestalten. Doch wie wurden bislang die eingefuhrten Sicherheitsmasnahmen hinsichtlich Effektivitat und Nachhaltigkeit bewertet? Ziel dieser Arbeit war daher die Beschreibung der Entwicklung eines Instrumentes zur Beurteilung patientensicherheitsrelevanter Aspekte, die bei vor-Ort-Begehungen auf Stationen, Intensivstationen und im Operationssaal herangezogen werden kann. Methodik Es wurden alle patientensicherheitsrelevanten Richtlinien und Checklisten des LKH-Univ. Klinikum Graz erhoben. In weiterer Folge wurden mogliche Fragen daraus extrahiert, die man bei Beobachtungen in „real-time“ durch Experten vor Ort bewerten kann. Ergebnisse Auf Basis der Recherchen wurden zwei Kriterienkataloge, je einer fur Operationssale und einer fur Stationen sowie Intensivstationen erstellt. In weiterer Folge wurden daraus mit Hilfe eines Befragungstools zwei Checklisten generiert, die bei den sogenannten „Feedbacks-Patientensicherheit“ vor Ort von den Beobachtern verwendet werden. Schlussfolgerung Ob Richtlinien oder Checklisten, die die Patientensicherheit theoretisch verbessern sollen, vor Ort von den Gesundheitsexperten auch tatsachlich richtig integriert und angewendet werden, kann nur durch direkte Interaktion, also Beobachtung der Prozesse vor Ort, beurteilt werden. Die Checklisten zur Durchfuhrung der Patientensicherheit-Feedbacks sind ein probates Mittel zur Beurteilung der patientensicherheitsrelevanten Prozesse im „real-time“-Modus.