Evaluating the sensitivity and specificity of dried blood spots for serological testing of HIV, syphilis, hepatitis B and C Elecsys assays on the Roche Cobas system.

This study was performed to validate a dried blood spot (DBS) method for the serological screening of HIV, syphilis, hepatitis B and C. It included 250 paired DBS and serum samples and 116 unpaired DBS samples from 366 unique patients from two laboratories between 8 October and 2 November 2021. As determined by original test request, these were tested using a DBS method for HIV Ag/Ab (n=216), anti-treponemal Ab (n=166), hepatitis B sAg (n=100), and hepatitis C Ab (n=100) Elecsys assays on the Roche Cobas automated platform. Using the manufacturer's (serum) cut-off for reactivity ('positivity'), the sensitivity and specificity of DBS testing compared with serum were: for HIV Ag/Ab 100% and 100%, for anti-treponemal Ab 68.3% and 100%, for hepatitis B sAg 95.9% and 100%, and for hepatitis C Ab 84.0% and 100%, respectively. Adjusting the assay cut-off using receiver operator curve analysis increased sensitivity of DBS testing for anti-treponemal Ab to 90.0%, hepatitis B sAg to 97.9% and hepatitis C Ab to 94.0% whilst maintaining specificity of 98.8%, 100% and 100%, respectively. With optimisation of assay cut-off, DBS can perform comparably with serum for serological testing for HIV, syphilis, hepatitis B and C and may be a valuable tool in increasing access to testing in New Zealand.

A mixed method, phase 2 clinical evaluation of a novel device to treat postpartum haemorrhage.

BACKGROUND: We evaluated the safety, efficacy, and acceptability of a new device designed to facilitate uterine compression in women with postpartum haemorrhage (PPH). METHODS: A prospective, phase two clinical device trial with concurrent qualitative study, conducted in a UK consultant obstetric unit. The device was used in addition to standard care in women unresponsive to initial oxytocin therapy. The primary effectiveness outcome was additional blood loss of over 1000mls, whilst safety was assessed through adverse events. Interviews assessed device feasibility and acceptability, and were analysed using framework analysis. RESULTS: We recruited 57 women with clinical PPH after vaginal birth; 67% were primiparous and 47% had undergone operative birth. All but two (96%) had atony as a cause of the haemorrhage; in addition, 30% also had bleeding from lacerations and 11% had retained tissue. After device use, only one woman had additional blood loss over 1000mls, although 3 women (7%) needed a Bakri balloon and 14% received a blood transfusion. All but one clinician felt that the device was easy to use. Clinicians stated that the device assisted management in 85% of cases. All 56 women who responded stated that if they bled in a future birth they would want the device to be used again. There were no serious adverse events related to the device. However, 3 events were judged as 'possibly' being caused by the device - 2 minor vaginal grazes and one postnatal episiotomy infection and breakdown. Lax vaginal tissue complicated the use of the device in three women. In 47 interviews, participants, birth partners, clinician users and attending midwives viewed the device positively. Clinicians found it useful as a way of stopping blood loss and as an aid to diagnose the source of bleeding. CONCLUSIONS: The PPH Butterfly may provide a rapid, acceptable and effective treatment for postpartum haemorrhage. Clinical Trial Registration prospective with ISRCTN15452399 11/09/2017 (www.isrctn.com/ISRCTN15452399).

PPH Butterfly: a novel device to treat postpartum haemorrhage through uterine compression.

OBJECTIVE: Postpartum haemorrhage (PPH) is a significant cause of maternal morbidity and mortality. The most common cause is an inability of the uterus to contract adequately after childbirth. In bimanual compression (BMC), one hand is placed within the vagina and the other hand is on the abdominal wall to compress the uterus. It is effective, but very uncomfortable for the woman. We designed a device that could replicate BMC without inserting a hand vaginally, therefore being less invasive. It could also help in diagnosing the source of the bleeding. DESIGN: Mixed methods, combining an iterative design process with input from clinicians in simulations, and focus groups of clinicians and consumers. SETTING: Department of Women's and Children's Health and Department of Medical Physics and Clinical Engineering, University of Liverpool, UK. METHODS: A multidisciplinary team developed the design, using an obstetric manikin. Clinician and consumer groups also gave input on the concept and design. A healthcare product company and prototype manufacturer provided input into strategy, design and manufacture. RESULTS: The PPH Butterfly is a single piece, plastic medical device that replicates BMC. It is designed to be easy to use and low-cost and allows for smooth insertion and removal. It is acceptable to clinicians and consumers and performs well in tests. CONCLUSIONS: This is the first device designed to replicate BMC while being less invasive. It could potentially be an effective form of PPH management, while also diagnosing the source of the bleeding. The device will now be tested in humans.

Intraoperative red cell salvage.

In this article, Tony Fisher explores the background to autotransfusion and how recent advances in equipment and techniques have facilitated intraoperative cell salvage, thus reducing the need for homologous transfusion.