Rethinking our approach to postpartum haemorrhage and uterotonics

Analysis Rethinking our approach to postpartum haemorrhage and uterotonics BMJ 2015; 351 doi: https://doi.org/10.1136/bmj.h3251 (Published 08 July 2015) Cite this as: BMJ 2015;351:h3251 Article Related content Metrics Responses Peer review Andrew D Weeks, professor of international maternal health1, James P Neilson, professor of obstetrics and gynaecology1 Author affiliations Correspondence to: AD Weeks [email protected] Accepted 30 March 2015 Andrew Weeks and James Neilson suggest that we have inappropriately generalised evidence on the use of uterotonics from uncomplicated births to all births. They call for stronger focus on women with complex births to reduce deaths from postpartum haemorrhage Postpartum haemorrhage (defined as a bleed >500 mL) is estimated to affect 1-15% of vaginal births, depending on the definition used, the method of assessing blood loss, the setting, and the population studied. Risk factors include Asian ethnicity, obesity, previous postpartum haemorrhage, multiple pregnancy, anaemia, large baby, age over 40, induction of labour, prolonged labour, placental abruption, and caesarean delivery.1 Although global mortality from postpartum haemorrhage is falling, its incidence is increasing in high resource settings, the reasons for which are unclear.2 3 4 Many of those who survive have severe anaemia, renal failure, or psychological trauma, and the offspring may have difficulties in breast feeding and bonding. Current best practice globally is for all pregnant women to receive a uterotonic drug at the time of childbirth to prevent postpartum haemorrhage. This recommendation has been in place since the 1980s when randomised trials showed that routine prophylaxis with oxytocin based uterotonic drugs reduced the rate of postpartum haemorrhage.5 The assumption that this would translate into fewer maternal deaths—based on the understanding that atony was the most common cause of haemorrhage related deaths—led to the promotion of active management of the third stage of labour, which comprises a prophylactic uterotonic drug, early cord clamping, and controlled cord traction. Here we discuss the problems with generalising data from spontaneous vaginal (“normal”) births to complex births, and call for a change in global strategy on postpartum haemorrhage

Attachment of bacteria to glass surfaces in pure culture and in mixed suspensions and the effect of growth conditions on that attachment

The attachment of selected freshwater bacteria, Aeromonas Chromobacterium, a coryneform and Staphylococcus In pure culture and in mixed suspensions with one other bacterium to glass surfaces was investigated in the laboratory. Changes in the nutrient conditions of the growth medium during growth and attachment and the temperature, pH and electrolyte type and concentration present in the attachment solution during attachment experiments all influenced bacterial attachment. The pure culture attachment results obtained depended on the bacterial species being investigated. When bacterial species were attached in the presence of one other species the growth conditions still had a profound effect on attachment. The results obtained depended on the bacterial species present in the mixed suspension, with some bacterial species having a more profound effect on the attachment of other species than others. The bacterial species used to study bacterial attachment in the laboratory were used along with Acinetobacter and Pseudomonas to investigate bacterial attachment in vivo using a model system. The attachment of these bacteria were investigated in two- to six-membered suspensions. The biofilms obtained in the model system consisted of smaller bacterial cells in a more densely packed biofilm. These biofilms could still be influenced by growth conditions as temperature was seen to influence the bacterial biofilm obtained. During these attachment experiments the Acinetobacter which did not attach itself had a profound effect on the attachment of other bacterial species when present in the liquid phase. The mechanism by which Acinetobacter inhibited the attachment of other bacteria was investigated and it appeared Acinetobacter did not excreate a chemical to influence the attachment of other species, but the Acinetobacter cells themselves had to be present in the liquid phase to influence the attachment of other species. The effects of different molecular weight fractions of Tocil Lake water were investigated for their effect on bacterial attachment. The fraction containing the > 30,000 MV component was found to influence bacterial attachment. The results obtained, depended on the bacterial species being investigated

The annual course of precipitation over much of the United States: observed versus GCM simulation

General Circulation Models (GCMs) may be useful in estimating the ecological impacts of global climatic change. We analyzed seasonal weather patterns over the conterminous United States and determined that regional patterns of rainfall seasonality appear to control the distributions of the Nation's major biomes. These regional patterns were compared to the output from three GCMs for validation. The models appear to simulate the appropriate seasonal climates in the northern tier of states. However, the spatial extent of these regions is distorted. None of the models accurately portrayed rainfall seasonalities in the southern tier of states, where biomes are primarily influenced by the Bermuda High