A study looking at survival following out of hospital cardiac arrest in a selected group of more than a thousand people (Heart 2005;91:1537‐40) discovered that 80% of non‐medically witnessed events happen in the home. Such events are less likely to be witnessed, less likely to receive bystander cardiopulmonary resuscitation and (perhaps as a result) only have a 2% thirty‐day survival rate. Having a cardiac arrest witnessed by a doctor or paramedic increases chance of thirty‐day survival to 35%. A large proportion of patients experience more than 15 minutes of premonitory symptoms before having cardiac arrest—an early call for help could massively improve the chance of survival.

If you are worried about the outcome after having a cardiac arrest at home, perhaps it is time to consider a radical solution. An alternative to relying upon an early call to the emergency services could be to install a defibrillator in your home. In a study of 172 cases, nearly 30% of patients treated with an automated external defibrillator by a lay person survived to hospital (Heart 2005;91:1299‐1302). An editorial in the same journal (Heart 2005;91:1505‐6) contains a reminder that the falling cost of automated external defibrillators brings them in the same price bracket as home entertainment systems!

Sport‐related head injuries are relatively common, with many patients attending hospital for assessment and treatment. It can be difficult in the field soon after injury to decide if hospital transfer is required. A position statement by the National Athletic Trainers' Association (Br J Sports Med 2006;40:6‐10) is designed to help those providing medical support at sporting events to make these decisions. It also suggests advice to be given to those competitors with minor head injuries who do not need to attend an Emergency Department immediately.

Justification for the regionalisation of trauma care in the US in the form of trauma centres is the central feature of a paper in the New England Journal of Medicine (N Engl J Med 2006;354:366‐78). Using data from 69 hospitals and having made difficult adjustments for differences in case mix, the in‐hospital mortality of patients treated in trauma centres was significantly lower than those treated in non‐trauma centres. Differences in mortality were principally confined to patients with more severe injuries.

Non‐invasive ventilation (either continuous or bilevel positive airway pressure) for pulmonary oedema is still regarded with suspicion by some sceptics. This systematic review and meta‐analysis (JAMA 2005;294:3124‐30) sets out to raise the profile of this still under‐utilised approach. The meta‐analysis reveals significant reductions in both mortality and need for intubation associated with the use of non‐invasive ventilation, with no significant difference between continuous or bilevel positive airway pressure. The authors promote non‐invasive ventilation as a first‐line treatment.

This study (J Emerg Med 2006;30:1‐5) examined the role of activated charcoal after paracetamol overdose. Based upon changes in biochemical markers of liver damage, the authors show that activated charcoal appears to be beneficial even when given much later than the currently recommended time frame (of up to one hour after ingestion). The evidence suggests that oral activated charcoal can reduce liver damage after paracetamol overdose even when given more than four hours after overdose. Charcoal may do more than simply decrease absorption.

Three studies published in different journals report three different pulmonary embolus ‘rule‐out' strategies for use in Emergency Departments. These comprise: clinical probability scoring, d‐dimer blood test and one or both of ventilation: perfusion scan and CT pulmonary angiogram (Emerg Med J 2006;23:123‐7); clinical probability scoring, d‐dimer blood test and CT pulmonary angiography +/‐ bilateral leg vein compression ultrasound (J Emerg Med 2005;29:399‐404); and a simplified clinical decision rule, d‐dimer testing and CTPA alone (JAMA 2006;295:172‐9). The last approach seems slightly less sensitive – probably reflecting the absence of any imaging in addition to CT pulmonary angiography. Given a choice of comparable ‘rule‐out' algorithms, a local strategy can be chosen to suit availability of imaging.

Ultrasound continues to develop its role in the Emergency department (J Emerg Med 2006;30:69‐74). Emergency physicians in Texas appeared to be able to identify gallstones using ultrasound with an acceptable level of sensitivity, even with relatively limited training. Consistent identification of associated important findings and complications (such as dilated common bile duct) required additional training.

Clinicians are often rightly concerned about the possibility of underlying acute coronary syndrome in patients presenting with chest pain. A review of the available evidence suggests that identifying certain characteristics of chest pain can help to stratify patients into various levels of risk for acute coronary syndromes. However, no particular chest pain characteristics allow patients to be discharged safely without further investigation (JAMA 2005;294:2623‐9).

The risks from taking amphetamine and its derivatives are understandably difficult to quantify. Researchers from Belgium provide a worrying report on 34 deaths, in which amphetamine and its derivatives (including ecstacy and ‘MDA') were implicated (Med Sci Law 2006;46:37‐65). Unintentional overdose was responsible for most of the deaths, which involved a variety of mechanisms including cardiopulmonary failure and (in a minority) hyperthermia.

Sophia wonders if readers are aware that European Union Directives on blood transfusion have been transposed into UK law. The Blood Safety and Quality Regulations (2005) affect the administration of blood products, particularly in relation to traceability, documentation and the reporting of reactions (www.transfusionguidelines.org.uk).