Helping, not harming: with a little help from the Cochrane Library

The Ancient Greeks knew a thing or two, not least about medicine. We are hearing a lot about shared decision-making in these days of ‘no decision about me without me’, but the notion that the patient must combat the disease along with the physician appears in Hippocratic writings from the early fourth century BC and so does the requirement that the doctor’s job is to do good or to do no harm.

intensive care

HES: risks may outweigh benefits

Fast forward a couple of millennia and we come to the Cochrane Library! Looking through the newest evidence there put me in mind of these basic principles of medicine, particularly how vital it is to know about the possible harms resulting from treatments, and that researchers must ask useful questions and measure the right things if that research is going to help patients. These things are clearly demonstrated in an updated review on hydroxyethyl starch (HES) versus other fluid therapies for critically ill patients. HES is commonly used but has been associated with kidney damage and this potential harm was the subject of the review. A large body of good evidence was added this time round and the review’s conclusions changed. HES was shown to substantially increase the risk of renal replacement therapy and acute kidney injury and the authors conclude that “in most clinical situations where HES products have been used, it is likely that these risks outweigh any benefits and other volume replacement therapies should be used instead of HES.” They also offer the sobering observation that “Despite concerns regarding adverse kidney outcomes with HES products since the mid 1990’s, hundreds of RCTs identified by this review did not evaluate kidney outcomes. This data, had it been collected, could have contributed significantly to answering this important clinical question many years ago.”

baby and motherPossible harms were also the focus of a new review on misoprostol to prevent or treat postpartum haemorrhage (PPH), severe bleeding from the womb after childbirth. This medicine, given by mouth or vaginally, has the advantage over injectable medicines of being easily distributed and it’s currently being introduced on a large scale in low-income countries, as well as being commonly used in well-resourced settings. However, there are concerns about possible side effects, including hyperpyrexia (very high body temperature), and this review set out to look specifically at serious ill effects of misoprostol, including deaths, when used to prevent or treat PPH. Seventy-eight studies with almost 60,000 women were included. Whilst misoprostol did not seem to increase or reduce maternal deaths or severe side effects overall, it was associated with increased risk of pyrexia and hyperpyrexia, especially at the higher doses of 600µg or more, and all 11 deaths amongst those taking misprostol were in women taking the higher doses. An earlier review found that there was no difference between 400µg and 600µg in terms of blood loss and this new review supports the use of the lowest effective dose.

Did somebody mention childbirth? What a palaver over the arrival of young George! With the media frenzy surrounding his birth, someone was bound to get it wrong. First in line for being exiled must be the folk at OK! magazine who caused an outcry by publishing a feature on how Kate could lose her Lindo wings and other bits of unwanted flab, practically as she was leaving the hospital. Jo Swinson, the minister for woman and equalities, spoke out against this kind of pressure on new mums, two-thirds of whom say it’s a concern, blaming the media for churning out “impossible standards on losing baby weight within ridiculous timeframes”. At the other extreme, a friend recently expressed concern at advice given by the community midwife to his recently-delivered wife to have plenty of energy drinks and cake. You won’t find that on NHS Choices.

mum doing yoga with baby

Diet and exercise: a good combination for post-baby weight loss

Long-term, we know it’s not great for health to be carrying extra weight. So, if you are looking to lose weight after having a baby, what does Cochrane evidence say? Diet and exercise are recommended elements of weight loss programmes in the general population, but is this so for new mums? A review looking at this has just been updated, with results available from 910 women in twelve trials. It suggests that both diet and exercise combined and diet alone, but not exercise only, help women lose weight after childbirth. Whilst these two approaches were comparable in terms of weight loss, it’s suggested that combining diet and exercise is best because of the known benefits of exercise, for circulation and heart fitness for example. More research is needed to find out whether there is any effect on breastfeeding.

Knowing that something works is great but only if you remember to use it. There are safe and effective ways to prevent venous thromboembolism (VTE), blood clots in the leg veins and lungs, which are complications for many hospital patients, but we know they are underused. A new review looking at interventions to increase the use of preventive measures in adult hospitalized patients at risk of VTE drew on 54 studies (including eight randomized trials) with over 73,000 patients. Alerts, such as computer reminders and stickers on patients’ charts, increased the number of patients who got preventive measures by 13%. Education and alerts increased the amount of appropriate prevention and multifaceted interventions were associated with any preventive measures and appropriate ones. The reviewers conclude that multifaceted interventions plus alerts may be the most effective. It’s a shame that many studies did not report on the appropriateness of the preventive measures prescribed and most didn’t report clinical outcomes such as VTE and bleeding!

boy showing teethFinally, the producers of various evidence-based guidelines recommending fluoride varnishes for preventing tooth decay in children and teens can relax, as the newly-updated review on this topic has not changed its conclusion that fluoride varnishes are good at preventing tooth decay in both baby teeth and permanent teeth. New studies were added and the moderate quality evidence showed the varnishes reduced tooth decay by over 40%. The reviewers felt there was more work to be done though, on aspects such as the acceptability of the varnish. You can read more on this in a blog by the Dental Elf. All too late for my great-gran, who missed out on a school open day because she’d just had all her teeth removed and my Nan was too embarrassed to invite her. Instead she enjoyed mooching round school with a friend who’d also kept her mum at bay, not wanting her to come because she had grey hair. The state of the nations teeth has moved on but teenagers haven’t changed a bit.


Mutter TC, Ruth CA, Dart AB. Hydroxyethyl starch (HES) versus other fluid therapies: effects on kidney function. Cochrane Database of Systematic Reviews 2013, Issue 7. Art. No.: CD007594. DOI: 10.1002/14651858.CD007594.pub3.

Hofmeyr GJ, Gülmezoglu AM, Novikova N, Lawrie TA. Postpartum misoprostol for preventing maternal mortality and morbidity. Cochrane Database of Systematic Reviews 2013, Issue 7. Art. No.: CD008982. DOI: 10.1002/14651858.CD008982.pub2.

Cochrane summary

Duchess of Cambridge baby weight coverage disgraceful, says minister. The Guardian, Sunday 28th July 2013.

Amorim Adegboye AR, Linne YM. Diet or exercise, or both, for weight reduction in women after childbirth. Cochrane Database of Systematic Reviews 2013, Issue 7. Art. No.: CD005627. DOI: 10.1002/14651858.CD005627.pub3.

Cochrane summary

Kahn SR, Morrison DR, Cohen JM, Emed J, Tagalakis V, Roussin A, Geerts W. Interventions for implementation of thromboprophylaxis in hospitalized medical and surgical patients at risk for venous thromboembolism. Cochrane Database of Systematic Reviews 2013, Issue 7. Art. No.: CD008201. DOI: 10.1002/14651858.CD008201.pub2.

Cochrane summary

Marinho VCC, Worthington HV, Walsh T, Clarkson JE. Fluoride varnishes for preventing dental caries in children and adolescents. Cochrane Database of Systematic Reviews 2013, Issue 7. Art. No.: CD002279. DOI: 10.1002/14651858.CD002279.pub2.

Cochrane summary

The Dental Elf blog. Updated review confirms substantial reductions in caries from fluoride varnish applications. July 12th 2013.

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