Oxygen in heart failure Heart 2010; 96: 533-8
In the very sick patient, it can almost be a reflex action to reach for the oxygen cylinder. However, if the patient has heart failure this may not be such a good idea.
It has recently been suggested that the use of oxygen in uncomplicated MI may actually lead to increased infarct size and worse mortality.
This was a small double blind, placebo controlled crossover study looking at the effect of 40 per cent oxygen on patients with stable heart failure and left ventricular systolic dysfunction.
They found that cardiac output fell, heart rate decreased (this was the case whether the patient was on a beta-blocker or not) and systemic vascular resistance increased when the patients had high flow oxygen.
These patients were stable, not decompensated, but similar effects might be expected in decompensated patients and the authors suggest caution in using oxygen in these patients unless they are hypoxic.
Trends in the epidemiology of smoking recorded in general practice Br J Gen Pract 2010; 60 (572): e121-7
Smoking is the principal cause of premature death in the UK, with the most vulnerable in society suffering from the most adverse effects.
This study included data from 525 practices on the QRESEARCH database covering 2.7 million patients from 2001 to 2007.
Looking at two time periods 2001/2 and 2006/7, higher smoking rates in younger, male and more socially deprived patients were apparent in both time periods. Male, older, deprived patients received most advice in 2001/2, whereas more women and older age groups with equal socio-economic distribution received more advice in 2006/7. Although the study indicates a significant decline in the rate of smoking and an increase in advice over the time period, high smoking rates in both younger and more socially deprived groups persisted. This study had limitations mainly due to the improvements in recording over the time period. The changes observed might not be directly attributable to government initiatives
Pandemic flu incidence Lancet 2010; 375: 1100-8
While pandemic flu was more of an issue in 2009, a lot of lessons can be learned from its spread to help model responses to future pandemics. The Health Protection Agency has an annual collection of serum samples to assess levels of flu immunity and contact.
They compared levels of H1N1 in samples taken in 2008, before the pandemic, with samples taken in August and September 2009, after the first wave of infection. In the baseline 2008 samples the antibody levels against H1N1 varied dramatically with age, with only 1.8 per cent of children under 5 years showing antibodies, compared with 31.3 per cent in the over 80-year-olds.
From comparing the 2008 and 2009 levels, they found one child in three was infected in the 2009 pandemic, 10 times higher than estimations from clinical surveillance, with little change in the older groups in antibody levels. These children have an important role in influenza transmission and would be the target group for vaccination, possibly even adding them to the annual flu vaccination campaign.
Gut flora and diabetes Diabetologia 2010; 53: 606-13
This is a review of the role of gut microbiota (bacteria) in the development of obesity and type-2 diabetes.
These are between 500 and 1,000 different species of gut bacteria. The composition varies from person to person.
The interesting part of this paper was the effect the bacteria have on our metabolism. They can influence the way we absorb carbohydrates, can increase pro-inflammatory cytokines, and influence glucagon like peptide-1. The bacterial colonisation is altered by obesity itself.
The article points the way to potential use of this new knowledge, for example selective antibiotic use.
Musculoskeletal episodes and mortality Br J Gen Pract 2010; 60 (572): e112
This study looked at patients who were 50 years old or older with a diagnosis of regional musculoskeletal pain in 1996. The researchers looked at whether the patients had died in the next year or in the next 10 years. They were compared with controls that had no musculoskeletal diagnosis. It was a large study with about 40,000 subjects in each group.
The results showed that patients with a diagnosis of musculoskeletal pain were 1.59 times more likely to die in the next year. The excess mortality came predominantly from back and hip pain with increased risks of 2.07 and 2.36 respectively.
After 10 years the risk had dropped down to an overall increased risk of 1.11.
The initial increase in risk was partly explained by an increase in pre-diagnosed cancers in the pain group. Although the absolute numbers of additional deaths were not great, these results should be considered when there is a new diagnosis of regional pain in the elderly.
Treating myocarditis with clarithromycin Heart 2010; 96: 523-7
Myocarditis is an inflammatory condition and one of the main causes of dilated cardio-myopathy.
Inflammatory cells such as lymphocytes produce matrix metalloproteinases (MMPs) that proteolytically degrade the extracellular matrix, remodelling the inflamed myocardium in myocarditis.
Clarithromycin is known to have a suppressive effect on MMPs. This was a study on rats with myocarditis, which were treated with clarithromycin.
It was found that treatment with clarithromycin reduced BP decline and impairment of cardiac function, as well as the pathological findings of myocardial cell infiltration and fibrosis. They found that the earlier the treatment the better.
Although this was a study of rats, it raises questions about prescribing clarithromycin.
- Dr Hunter is a GP in Bishops Waltham, Hampshire, and a member of our team who regularly review the journals
|The Quick Study|