29th August 2014, Volume 127 Number 1401

Health and fracking: should the medical profession be concerned?

This interesting paper notes that South Africa is about to embark on exploratory high-volume hydraulic fracturing (fracking) to extract the huge reserves of natural gas contained in shale rock.

Some countries, such as France and Bulgaria, have banned fracking, while others such as the UK believe that it can be performed safely if regulations are strictly enforced. Although fracking has taken place for a decade in the US, there is surprisingly little scientific evidence on the health impacts.

The drilling and fracking processes use hundreds of chemicals as well as silica sand. Additional elements are either released from or formed in the shale during drilling. These substances can enter the environment in various ways: through failures in the well casing; via alternative underground pathways; as wastewater, spills and leaks in the wellpad; through transportation accidents; and as air pollution. Although many of these chemicals and elements have known adverse health effects, there is little evidence available on the health impacts of fracking. These health concerns have not yet been fully addressed in policy making, and the authors recommend that the voice of health professionals should be part of the public debate on fracking and that a full health impact assessment be required before companies are given the go-ahead to drill.

S Afr Med J 2014;104(5):332–335.

 

Delayed umbilical cord clamping. Does gravity matter?

The World Health Organization (WHO) recommends delayed cord clamping for 1–3 minutes after birth with the infant held at or below the level of the placenta. This technique allows significant transfusion of blood to the infant and will help prevent infantile iron deficiency. This procedure is cumbersome and may contribute to non-compliance.

This non-inferiority trial in Argentina questions the merit of gravity in this matter. Approximately 400 vaginally born babies were randomised to be held for 2 minutes before cord clamping at the level of the vagina or on the mother’s abdomen or chest. The babies were weighed immediately after birth and after cord clamping. Weight was used as a proxy of placental transfusion volume. The researchers report that gravity did not have an effect on the volume of placental transfusion.

This change in practice might increase compliance with delayed cord clamping, enhance maternal–infant bonding and decrease iron deficiency in infants.

Lancet 2014;384:235–40.

 

Long term drug treatment strategies to prevent asthma exacerbations

This meta-analysis addresses the question of which drug maintenance treatment is most effective at preventing asthma exacerbations in adults.

The authors compared 16 different therapeutic trials of at least 24 weeks duration. The primary outcomes were severe exacerbations as well as withdrawals as a result of adverse events. The conclusions reached were that compared with low-dose inhaled corticosteroids, combined inhaled corticosteroids and long acting β agonists, either as maintenance and reliever treatment or in fixed daily dose, significantly reduced exacerbations of asthma.

An editorial commentator is a little cynical noting that treatment rankings from network analysis can be unreliable when dominated by indirect evidence. Nevertheless he agrees with the superiority of the combination of long acting β agonists and inhaled corticosteroids over other treatment options for adults with asthma who remain symptomatic despite regular use of inhaled corticosteroids.

BMJ 2014;348:g3009 & g3148.