Performance evaluation the new automated Atellica Hema 580 hematology analyzer

INTRODUCTION

The Atellica Hema (Siemens Healthineers, Tarrytown, NY, USA) is a new generation multi-parameter analyzer for full blood count, 6-part differential and reticulocyte testing by impedance variation and fluorescence flow cytometry. In this study, we verified the whole blood and limited body fluid modes of the Atellica Hema 580.

METHODS

We evaluated precision, linearity, carry-over, throughput and performed a method comparison to assess the performance of the Atellica Hema 580. For comparison of the Atellica Hema 580 with the Sysmex XN-1000 (Sysmex, Kobe, Japan), 140 samples from adult and pediatric patients including both normal and abnormal hematology profiles were analyzed in parallel.

RESULTS

The Atellica Hema 580 demonstrated acceptable imprecision within the manufacturer's specifications for whole blood and body fluid modes, good linearity for high and low ranges and no significant carryover. The full blood count, differential and reticulocyte correlated well with the Sysmex XN-1000, except for mean cell hemoglobin concentration, basophil and large immature cells. The optical platelet count, reflexed in 34 samples with a platelet count <150 × 109 /l, showed a strong correlation with the fluorescent platelet count on the Sysmex XN-1000. The morphology flagging efficiency was 92% for white blood cells, 95% for red blood cells and 87% for platelets.

CONCLUSION

The Atellica Hema 580 showed good analytical performance and workflow efficiency for a wide range of patient samples.

The profile of orthopaedic sports medicine publishing in South Africa

Background

The South African Journal of Sports Medicine (SAJSM) and the South African Orthopaedic Journal (SAOJ) are two open access, peer-reviewed journals which provide ongoing education to the sports medicine community.

Objectives

The purpose of this review was to appraise articles with a sports orthopaedic focus published in SAJSM and SAOJ. A secondary aim was to evaluate trends regarding the focus of the articles, levels of evidence, authors' affiliations, and country of origin.

Methods

An electronic search of the SAJSM from 1982 to 2021 and SAOJ from 2008 to 2021 was conducted to identify relevant articles. The eligibility of the articles was determined according to the following inclusion criteria: SAJSM articles with reference to musculoskeletal anatomy and/or an injury in any sport, and SAOJ articles focusing specifically on sports, sports teams and low-velocity traumatic injuries in sports people.

Results

This study included specific sports orthopaedic articles in SAJSM (n=161) and SAOJ (n=41). The articles originated from 67 institutions in 19 countries. In SAJSM, the majority of articles were published by local authors (n=44, 61%). There was a non-significant difference in the proportion of articles from local and international institutions in SAOJ. In SAJSM, the sports covered most frequently included rugby, cricket, running and soccer, whereas in SAOJ most articles referred to low-velocity injuries. With regard to trend analysis, a significant decline in articles with Level V evidence published by SAJSM was observed (p<0.001). Similarly, articles with Level V evidence published by SAOJ showed a decline, although it was non-significant.

Conclusion

The focus of SAJSM in particular is relevant to sports played, injury patterns and the healthcare resources for sports people in South Africa. The level of evidence published by SAJSM has improved significantly over time.

A Longitudinal Study of Thrombosis and Bleeding Outcomes With Thromboprophylaxis in Pregnant Women at Intermediate and High Risk of VTE

BACKGROUND

The efficacy and safety of thromboprophylaxis in pregnancy at intermediate to high risk of venous thrombo-embolism (VTE) is an area of ongoing research.

AIM

This study aimed to assess thrombosis and bleeding outcomes associated with thromboprophylaxis in women at risk of VTE.

METHODS

A cohort of 129 pregnancies, who received thromboprophylaxis for the prevention of VTE, were identified from a specialist obstetric clinic in Johannesburg, South Africa. Intermediate-risk pregnancies, with medical comorbidities or multiple low risks, were managed with fixed low-dose enoxaparin antepartum and for a median (interquartile range) of 4 (4) weeks postpartum. High-risk pregnancies, with a history of previous VTE, were managed with anti-Xa adjusted enoxaparin antepartum and for a median of 6 (0) weeks postpartum. Pregnancy-related VTE was objectively confirmed. Major bleeding, clinically relevant nonmajor bleeding (CRNMB) and minor bleeding were defined according to the International Society on Thrombosis and Hemostasis Scientific Subcommittee.

RESULTS

Venous thrombo-embolism occurred antepartum in 1.4% (95% CI: 0.04-7.7) of intermediate and 3.4% (95% CI: 0.4-11.7) of high-risk pregnancies. Bleeding events occurred in 7.1% (95% CI: 2.4-15.9) of intermediate and 8.5% (95% CI: 2.8-18.7) of high-risk pregnancies. Of these bleeding events, 3.1% (95% CI: 1.0-8.0) were classified as major bleeding. On univariate analysis, no independent predictors of bleeding were identified.

CONCLUSION

The rates of thrombosis and bleeding in this predominantly African population were consistent with similar studies and can be used to inform pregnant women of the benefits of anticoagulation and the risks of potential bleeding.

Gaucher disease: A cause of massive splenomegaly in a 15-year-old black African male

Patients with Gaucher disease (GD), a rare autosomal recessive lysosomal storage disease, commonly present to paediatricians with massive splenomegaly. While the diagnosis and management of patients with this chronic multisystem disorder has evolved significantly in recent years, the initial diagnosis represents a challenge. We describe the case of a 15-year-old black African male who presented with abdominal distension, delayed growth and fatigue. Initial laboratory studies revealed severe anaemia (haemoglobin concentration 8 g/dL) and moderate thrombocytopenia (platelet count 80 × 109/L). A computed tomography scan of the abdomen showed an enlarged liver of 173 mm and massive splenomegaly of 27 mm. The diagnosis of GD was confirmed by reduced beta-glucocerebrosidase activity and heterozygous mutations in the GBA1 gene. The patient was managed at a dedicated paediatric haematology unit with enzyme replacement therapy and regular clinical, biochemical and radiological monitoring.

Recommendations for the diagnosis and management of vaccine-induced immune thrombotic thrombocytopenia

There have recently been safety concerns regarding an increased risk of vaccine-induced immune thrombotic thrombocytopenia (VITT) following administration of SARS-CoV-2 adenoviral vector vaccines. The Southern African Society of Thrombosis and Haemostasis reviewed the emerging literature on this idiosyncratic complication. A draft document was produced and revised by consensus agreement by a panel of professionals from various specialties. The recommendations were adjudicated by independent international experts to avoid local bias. We present concise, practical guidelines for the clinical management of VITT.

Verification of the qLabs international normalized ratio point-of-care device for monitoring of patients attending an anticoagulation clinic

INTRODUCTION

In the developing world, point-of-care (POC) testing for international normalized ratio (INR) plays an important role in the monitoring of patients on long-term warfarin therapy with limited access to healthcare ensuring safe and effective anticoagulation. A newly developed POC device for INR measurement by healthcare workers is the handheld qLabs POC device^® (Micropoint Biotechnologies Incorporated, Guangdong, China).

METHODS

The qLabs POC device^® was evaluated in 262 patients attending an anticoagulation clinic with regards to accuracy and precision of the INR results. The results were compared to the results obtained on the Stago STA R Max^® coagulation analyzer (Stago Diagnostica, Paris, France) on a wide range of normal and abnormal results of clinical relevance.

RESULTS

The mean laboratory INR (2.50 ± 1.08) was significantly higher than the qLabs POC device^® INR (2.38 ± 1.07) (P < .0001). The correlation coefficient (r) was .88, the slope coefficient was 1.0 (CI, 0.8-1.2), and the intercept was -0.10 (CI, -0.50 to 0.30). The mean of the differences was -0.13% (CI, -0.19 to -0.06). Dosage concordance was 85.46% and clinical agreement was 92.37%. However, clinical agreement was 42.42% in the subgroup above the target range (>3.5). The imprecision was within acceptable limits (<5%) and the error message rate was 4.38%.

CONCLUSION

In conclusion, the qLabs POC device^® is accurate and precise with high levels of dosage concordance and clinical agreement for INR values within and below the target range.

Critical limits for urgent clinician notification at South African intensive care units

BACKGROUND

Critical value policies are used by clinical laboratories to decide when to notify caregivers of life-threatening results. There, however, remains much debate regarding which tests should be included in critical value lists and clinically relevant limits.

METHOD

An electronic survey was designed to determine the critical value policies of specialists for haematology tests in South African intensive care units. Data collected included a demographic component, critical value policies and critical value reporting.

RESULTS

There were 68 respondents who represented a range of specialists from different disciplines. Four key critical values were identified, namely white cell count (WCC), haemoglobin, platelet count and international normalised ratio (INR). Median low and high adult and paediatric critical limits for the most frequently listed tests were as follows: haemoglobin <7 and >20 g/dL, platelet count <50 and >1000 × 10(9) /L, WCC < 2 and >20 × 10(9) /L and INR > 4. Specific critical limits for neonates were reported by 20 of the respondents. Of the respondents, 95.92% indicated that it was important to be contacted with first-time critical results and approximately half for repeat critical values. The majority preferred that the person notified of the critical value be the caregiver directly involved with the patient's care.

CONCLUSION

It is important for critical value policies to be reviewed by each discipline to ensure cut-offs are clinically relevant.

Venous thromboembolism--prophylactic and therapeutic practice guideline

BACKGROUND

Pharmacological prophylactic anticoagulation in many countries, including South Africa, is under-prescribed, which unfortunately results in unacceptable morbidity and mortality in a substantial number of patients.

METHOD

The Southern African Society of Thrombosis and Haemostasis reviewed the available literature as well as guidelines from other societies. Specialties represented on the committees included anaesthetics, cardiology, clinical haematology, critical care, gynaecology, haematopathology, internal medicine, neurology, orthopaedic surgery, pulmonology and vascular surgery. A draft document was produced, which was revised by consensus agreement. To avoid local bias, the guidelines were adjudicated by recognised independent international external experts. RESULTS AND CONCLUSION. A concise, practical guideline for thrombo-prophylaxis and treatment in medical and surgical patients has been produced for South African conditions. These guidelines will hopefully lead to improved anticoagulation practice in this country, which we believe will directly benefit patient outcomes.

Thrombo-embolic and bleeding complications in patients with mechanical valve replacements--a prospective observational study

BACKGROUND AND OBJECTIVES

Long-term anticoagulation therapy is essential to prevent thrombo-embolic events in patients with mechanical valve replacements. In order to offer indigent patients mechanical heart valve replacement surgery, dedicated anticoagulation clinics are necessary for follow-up. This study assessed the safety and efficacy of lifelong oral anticoagulation therapy in Johannesburg General Hospital mechanical heart valve replacement recipients. The incidence of bleeding and thrombo-embolic complications was documented in three groups of patients with mechanical valve replacements. The groups included patients with aortic valve replacements (AVRs), mitral valve replacements (MVRs) and double (aortic and mitral) valve replacements (DVRs).

MATERIALS AND METHODS

A prospective observational study was conducted over a 4-month period. Data on 306 patients attending the Johannesburg General Hospital anticoagulation clinic between 2000 and 2005 were analysed. Of the total patients selected, 205 were assigned to the mechanical valve replacement group (which included 63 patients with AVRs, 93 with MVRs and 49 with DVRs); a control group of 101 nonmechanical valve replacement patients were also included. At each visit the level of anticoagulation was assessed from the international normalised ratio (INR) values, and the presence of bleeding and/or thrombo-embolic complications was documented.

RESULTS

There were a total of 51 bleeding and thrombo-embolic complications in the study population. Patients with DVRs had a higher proportion of combined complications (30.61%) than patients with single valve replacements (14.29% in the AVR group and 18.05% in the MVR group) and patients in the control group (12.87%). There were 38 bleeding complications, 30 minor and 8 major. Twelve thrombo-embolic events were documented. Individually, there was no significant difference in thrombo-embolic and bleeding complications between the subgroups. Eighty-two per cent of patients in the mechanical valve replacement group were within the therapeutic range for anticoagulant control (INR 2.5-3.5) v. 54% in the control group (INR 2.0-3.0). Anticoagulant control was of a high quality and was not a contributing factor to the incidence of bleeding and/ or thrombo-embolic complications.

CONCLUSION

The finding of a low incidence of bleeding and thrombo-embolic complications in patients with mechanical valve replacements supports the continued placement of mechanical valves in our setting and use of oral anticoagulation therapy at an INR of 2.5-3.5. However the increased risk of both bleeding and thrombo-embolic complications in the DVR group is cause for great concern and warrants further investigation.