An Evaluation of a Factor Xa-Based Clotting Time Test for Enoxaparin: A Proof-of-Concept Study

A well-accepted test for monitoring anticoagulation by enoxaparin is not currently available. As inadequate dosing may result in thrombosis or bleeding, a clinical need exists for a suitable test. Previous in silico and in vitro studies have identified factor Xa as an appropriate activating agent, and the phospholipid Actin FS as a cofactor for a Xa clotting time (TenaCT) test. A proof-of-concept study was designed to (1) explore the reproducibility of the TenaCT test and (2) explore factors that could affect the performance of the test. In vitro clotting time tests were carried out using plasma from 20 healthy volunteers. The effect of enoxaparin was determined at concentrations of 0.25, 0.50, and 1.0 IU/mL. Clotting times for the volunteers were significantly prolonged with increasing enoxaparin concentrations. Clotting times were significantly shortened for frozen plasma samples. No significant differences in prolongation of clotting times were observed between male and female volunteers or between the 2 evaluated age groups. The clotting times were consistent between 2 separate occasions. The TenaCT test was able to distinguish between the subtherapeutic and therapeutic concentrations of enoxaparin. Plasma should not be frozen prior to performing the test, without defining a frozen plasma reference range. This study provided proof-of-concept for a Xa-based test that can detect enoxaparin dose effects, but additional studies are needed to further develop the test

Red cell and platelet transfusions in neonates: a population based study

Objectives: Reports of neonatal transfusion practices have focused predominantly on premature neonates admitted to neonatal intensive care units (NICU), however little is known about transfusion among other neonates. This study aimed to describe the use of blood products among all neonates. Design: Linked population-based birth and hospital discharge data from New South Wales (NSW), Australia was used to determine rates of blood product transfusion in the first 28 days of life. The study included all livebirths ≥23 weeks’ gestation in NSW between 2001 and 2011. Results: Between 2001-2011, 5326 of 989,491 live born neonates received a blood product transfusion (5.4 per 1000 births). Transfusion rates were 4.8 per 1000 for red cells, 1.3 per 1000 for platelets and 0.3 per 1000 for exchange transfusion. High transfusion rates were seen in neonates with prior in-utero transfusion (631/1000), congenital anomaly requiring surgery (440/1000) or haemolytic disorder (106/1000). Among transfused infants, 7% received transfusions in a hospital without a NICU. Of those transfused, 64% were born ≤32 weeks gestation (n=3384, 255/1000 births), with 96% of these receiving red cells. 36% were born >32 weeks gestation (n= 1942, 1.98/1000 births), with 76% receiving red cells and 38% receiving platelets. Conclusions: In this population based study, high transfusion rates were seen in neonates with haemolytic disorders or requiring surgery, as well as in those born preterm. Thirty-six percent of neonates who received blood products were born >32 weeks gestation and 7% were transfused in hospitals without a NICU.NHMRC, AR

Age of blood and adverse outcomes in a maternity population

BACKGROUND In recent times there has been debate around whether longer storage time of blood is associated with increased rates of adverse outcomes following transfusion. It is unclear whether results focused on cardiac or critically ill patients apply to a maternity population. This study investigates whether older blood is associated with increased morbidity and readmission in women undergoing obstetric transfusion. STUDY DESIGN AND METHODS Women giving birth in hospitals in New South Wales, Australia between July 2006‐December 2010 were included in the study population if they had received between 1‐4 red cell units during the birth admission. Information on women’s characteristics, transfusions and outcomes were obtained from 5 routinely collected datasets including blood collection, birth and hospitalisation data. Generalised propensity score methods were used to determine the effect of age of blood on rates of severe morbidity and readmission, independent of confounding factors. RESULTS Transfusion data were available for 2990 women, with a median age of blood transfused of 20 days (interquartile range 14,27 days). There were no differences in the age of blood transfused between women with and without severe morbidity (21 (14,28) vs 22 (15,30) days), and in women readmitted or not (22 (14,28) vs 22 (16,30) days). After considering potential confounding factors, no relationship was found between the age of blood transfused and rates of severe morbidity and readmission. CONCLUSION Among women receiving low volume transfusions during a birth admission, there was no evidence of increased rates of adverse outcomes following transfusion with older blood.NHMRC, Australian Red Cross, NSW Clinical Excellence Commission, AR

WHAT FACTORS CONTRIBUTE TO HOSPITAL VARIATION IN OBSTETRIC TRANSFUSION RATES?

Background & Objectives: To explore variation in red blood cell transfusion rates between hospitals, and the extent to which this can be explained. A secondary objective was to assess whether hospital transfusion rates are associated with maternal morbidity. Materials & Methods: Linked hospital discharge and birth data were used to identify births (N=279,145) in hospitals with at least 10 deliveries per annum between 2008-2010 in New South Wales, Australia. To investigate transfusion rates, a series of random effects multilevel logistic regression models were fitted, progressively adjusting for maternal, obstetric and hospital factors. Correlations between hospital transfusion and maternal, neonatal morbidity and readmission rates were assessed. Results: Overall, the transfusion rate was 1.4% (hospital range 0.6 to 2.9) across 89 hospitals. Adjusting for maternal casemix, reduced the variation between hospitals by 26%. Adjustment for obstetric interventions further reduced variation by 8% and a further 39% after adjustment for hospital type. At a hospital level, high transfusion rates were moderately correlated with maternal morbidity (0.56, p=0.01) and low Apgar scores (0.54, p=0.002), but not with readmission rates (0.18, p=0.28). Conclusion: Both casemix and practice differences contributed to the variation in transfusion rates between hospitals. The relationship between outcomes and transfusion rates was variable, however low transfusion rates were not associated with worse outcomes.Partnership Grant from the Australian National Health and Medical Research Council NHMRC (#1027262), the Australian Red Cross and the NSW Clinical Excellence Commission, NHMRC Senior Research Fellowship (#1021025). ARC Future Fellowship (#120100069)

WHAT FACTORS CONTRIBUTE TO HOSPITAL VARIATION IN OBSTETRIC TRANSFUSION RATES?

Background & Objectives: To explore variation in red blood cell transfusion rates between hospitals, and the extent to which this can be explained. A secondary objective was to assess whether hospital transfusion rates are associated with maternal morbidity. Materials & Methods: Linked hospital discharge and birth data were used to identify births (N=279,145) in hospitals with at least 10 deliveries per annum between 2008-2010 in New South Wales, Australia. To investigate transfusion rates, a series of random effects multilevel logistic regression models were fitted, progressively adjusting for maternal, obstetric and hospital factors. Correlations between hospital transfusion and maternal, neonatal morbidity and readmission rates were assessed. Results: Overall, the transfusion rate was 1.4% (hospital range 0.6 to 2.9) across 89 hospitals. Adjusting for maternal casemix, reduced the variation between hospitals by 26%. Adjustment for obstetric interventions further reduced variation by 8% and a further 39% after adjustment for hospital type. At a hospital level, high transfusion rates were moderately correlated with maternal morbidity (0.56, p=0.01) and low Apgar scores (0.54, p=0.002), but not with readmission rates (0.18, p=0.28). Conclusion: Both casemix and practice differences contributed to the variation in transfusion rates between hospitals. The relationship between outcomes and transfusion rates was variable, however low transfusion rates were not associated with worse outcomes.Partnership Grant from the Australian National Health and Medical Research Council NHMRC (#1027262), the Australian Red Cross and the NSW Clinical Excellence Commission, NHMRC Senior Research Fellowship (#1021025). ARC Future Fellowship (#120100069)

Hematologi Klinik Pendekatan Berorientasi Masalah

x.273 hal;24 c

Coagulopathy from tiger snake envenoming and its treatment

[Extract] Sir, We would like to make some comments on two articles recently published on tiger snake bite and the resultant coagulopathy that occurs with envenoming. Both articles discuss important issues relating to the coagulopathy associated with Australasian elapid envenoming. They correctly make the distinction between snake venominduced activation of the coagulation cascade (VIACC) and disseminated intravascular coagulation (DIC). VIACC is often loosely referred to as defibrination, but is more accurately termed fibrinogen depletion. The article on eastern tiger snake envenoming provides important new information by reporting serial measurements of prothrombin cleavage fragments which has not been previously investigated. It demonstrates that the presence of F1 + 2 levels are possibly highly sensitive tests for envenoming

Physician autonomy and patient rights: lessons from an enforced blood transfusion and the role of Patient Blood Management

This article provides an ethical and medico-legal analysis of ruling no. 465 of 30 May 2018 issued by the Court of Termini Imerese (Palermo) and confirmed on appeal on 11 November 2020, which, in the absence of similar historical precedents in Eur ope, convicted a medical doctor of a crime of violent assault for having ordered the administration of a blood transfusion to a patient specifically declining blood trans fusion on religious grounds. We analyse the Court’s decision regarding the identifi cation of assault in performing the blood transfusion and its decision not to accept exculpatory urgent ‘necessity’ as a defence. In addition, we present an updated revi sion of the current standard of care in transfusion medicine as well as the ethical principles governing the patient’s declining of transfusion. In doing so, we highlight that respect for the patient’s self-determination in declining transfusions and respect for the professional autonomy of the doctor protecting the safety and life of the patient could be equally satisfied by applying the current peer-reviewed evidenc