Childhood absence seizures
Absence seizures are a common type of epilepsy in children, and consist of frequent brief staring spells, usually occurring daily, beginning at 4–8 years of age. It’s a generalised epilepsy and the EEG typically shows widespread bursts of spike and wave activity at 3 Hz. Although once called petit mal epilepsy, it’s less benign than it seems: affected children often have cognitive deficits and long-term psychosocial difficulties. A randomised trial in the NEJM compares three commonly used anti-epileptic drugs and finds that ethosuximide and valproate are substantially better at inducing remission than lamotrigine. Attentional deficit was less of a problem in those taking ethosuximide than in those taking valproate, clearly making it the best drug to try first.
Parent-administered steroids in childhood asthma
When treating an asthma attack, oral corticosteroids are most effective when given promptly, so it makes some sense to let parents administer them to their asthmatic children. On the other hand, steroids have adverse effects, and parents may tend to over treat. A trial in the BMJ randomises individual attacks to parent-initiated prednisolone or placebo in a double-blind fashion. Prednisolone treatment was associated with a modest benefit to symptom score (~15%) and reduced absence from school compared to placebo. However, the trial did not directly address the possibility of overtreatment, and the authors recommend monitoring parental use for frequency and appropriateness.
Aspirin for asymptomatic peripheral vascular disease
A low ankle brachial index (the ratio of systolic pressure at the ankle to systolic pressure in the arm) is a reliable indicator both of peripheral artery disease and of a high risk of vascular events generally. An RCT in JAMA looks at the value of aspirin in asymptomatic people discovered to have a low ankle brachial index when screened. Surprisingly, it finds no benefit over placebo in reducing stroke, TIAs, coronary events, intermittent claudication, angina or all-cause mortality. However, rates of haemorrhage severe enough to require admission to hospital were 70% higher in those allocated to aspirin.
Red flags for serious childhood infection
In the developed world, when a child presents to a GP with signs of infection, 99% of the time it’s nothing to worry about. But how to distinguish the other 1%? A systematic review in the Lancet examines published studies for indicators of serious infection. Few readers will be surprised to hear that a child who has turned blue and is gasping for breath is probably gravely ill. However, the main finding is that we know remarkably little about which signs and symptoms reliably distinguish the serious from the trivial. Diagnosis from presence or absence of single clinical features is untrustworthy, and the Yale Observation Scale is of little value. An accompanying Comment calls for better-designed diagnostic and prognostic studies in primary care soon.
Dopamine or noradrenalin for circulatory shock?
When intravenous fluids fail to stabilize a patient in circulatory shock, the next line of therapy is a vasopressor such as dopamine or noradrenalin. Both agents act on alpha-adrenergic and beta-adrenergic receptors, but to different degrees. Dopamine also stimulates dopaminergic receptors, resulting in an increase in splanchnic and renal perfusion. Which works best in practice? A large multicentre trial in the NEJM suggests that there is little to choose between them in terms of efficacy, but that dopamine is associated with a greater number of adverse events – especially cardiac arrhythmias.
Apixaban for preventing postsurgical deep-vein thrombosis
Prevention of venous thromboembolism after orthopaedic surgery inevitably trades off clots against bleeds. A double-blind trial in the Lancet compares apixaban, an oral anticoagulant targeting factor Xa, with enoxaparin, a low-molecular-weight heparin, in ~3000 patients. The outcome assessed was a composite of asymptomatic and symptomatic deep vein thrombosis, non-fatal pulmonary embolism, and death from any cause, and at 60 days, this was 15% in the apixaban group versus 24% in the enoxaparin group (p < 0•0001). Apixaban was also at least as safe, with fewer bleeding episodes.
Glycated haemoglobin for diagnosing diabetes
Despite a vigorous rearguard action, it‘s likely that glycated haemoglobin will soon replace fasting glucose or an oral glucose tolerance test as the diagnostic criterion for diabetes. Among the many advantages are that the patient doesn’t need to be fasting, and test-to-test repeatability is high. But the best indicator of a test’s value is prognostic accuracy: can it identify patients who will benefit from intervention? Results of a longitudinal community-based population study of non-diabetic adults in the NEJM show that while it may be a tie for predicting diabetes, glycated haemoglobin beats fasting glucose hands down in predicting cardiovascular disease and death from any cause.
Three diets for carotid atherosclerosis
A study in Circulation attempts to compare three diets (low carbohydrate, low fat, and Mediterranean) in their effects on carotid atherosclerosis over 2 years. The primary finding is that all three diets have a beneficial effect, with no significant difference between them, although with only 140 participants it is unclear what size of difference the study was powered to detect. The lack of a control group not following any prescribed diet is another fundamental weakness. So perhaps the conclusion should be that following any particular diet is less important than paying attention to what you eat, and exercising a degree of self-control.