>In Case You Missed It – Fall 2012

Bad news for shift workers

Many of you will be interested in a paper published in the BMJ 2012;345:e4800). A systematic review and meta-analysis investigated some of the potential risks associated with shift work and discovered a rather worrying answer. Shift work is associated with myocardial infarction, coronary events and ischaemic stroke and although the relative risks are modest, the population attributable risks are not insignificant. It is possible that disruption of circadian rhythms may be responsible for predisposing shift workers to vascular events.

Out of hospital cardiac arrest

In 2005, the American Heart Association published their ‘chain of survival’ concept for resuscitation of patients with out of hospital cardiac arrest. The chain will be familiar to many practitioners, comprising four links: early access to emergency medical care, early cardiopulmonary resuscitation, early defibrillation and early advanced cardiac life support. A recent paper in Circulation (2012;126:589–97) recommends the implementation of a fifth link: transfer to a tertiary hospital where patients may receive intensive post-resuscitation care, appropriate circulatory and respiratory support, therapeutic hypothermia and percutaneous coronary intervention. Data suggests that implementation of the fifth link is associated with a significant improvement in neurological outcome after out of hospital cardiac arrest.

Injuries from bouncers

Lausanne is famous for its nightlife, with 30 000 night clubbers enjoying it on a typical weekend. However, there may be another side to the story. A study published in the Journal of Forensic and Legal Medicine (2012;19:341–4) describes injuries allegedly inflicted by nightclub security guards on 70 of their ‘clients’ in the city over a 3 year period. 18 of these clients sustained one or more fractures (all involving the face or head). Based upon their results, the authors raise concerns about the violent way that nightclub security guards interact.

Suicide

Evidence that the current economic downturn may be responsible for increased rates of suicide is presented in the BMJ (2012;345:e5142). The data suggest that a significant proportion of the increase in the number of suicides may be attributed to rising unemployment. In what might be considered to be an equally depressing article in the same journal (BMJ 2012;345:e4972), a randomized controlled trial failed to show any significant effect for assertive outreach intervention after a failed suicide attempt.

Diagnosing appendicitis in children

Diagnosing appendicitis in the pediatric population is often challenging due to the lack of clear historical and physical examination findings. The use of CT scanning in suspected appendicitis has increased, but the importance of minimizing radiation exposure has resulted in the development of clinical practice guidelines. The evaluation of one set of clinical guidelines was undertaken in a US Emergency Department. Researchers found that implementation of guidelines based on risk-stratification, staged imaging and early surgical intervention in high-risk cases resulted in lower rates of negative appendectomy and missed appendicitis. 58% of patients were managed without a CT scan (Academic Emergency Medicine 2012;19:886–93).

Poisoning in young children

In the 1950s most cases of childhood poisoning were due to ingestion of household products. However, today, an overwhelming majority of overdoses in children are due to ingestion of medication and pharmaceutical agents. Recent data reveals a 20% rise in ED visits of children aged less than 5 years presenting with medication overdose between 2005 and 2009. This may be due to the increasing availability of medicines in the home. An expert from the UK National Poisons Information Service argues that blister packs (which are excluded from standards set for child-resistant packaging) should also be adapted to protect children, along with further education of parents regarding storage of medicines. While child-resistant packaging has undoubtedly been a great advancement in the protection of children against accidental poisoning, it is clear that further action still needs to be taken (Arch Dis Child 2012;97:831–2).

Administration of medication in children

The potential for over-dosage and administration of sub-therapeutic dosage is much greater in children than in adults. This may partly reflect inconsistencies in the various devices used to measure oral medication, including metal spoons, calibrated spoons and oral syringes. A study from Cambridge found that although oral syringes produce the smallest variance in volume, parents are most accurate at administering medication with a calibrated spoon. The researchers conclude that in order to further improve dosing accuracy, parents should be educated on the correct use of oral syringes (Arch Dis Child 2012;97:838–41).

Treatment of bronchiolitis in children

The mainstay of treatment for bronchiolitis in children is supportive care with an emphasis on fluid replacement, gentle suctioning of nasal secretions, prone positioning, and respiratory support if needed. For a long time, pharmacological agents were not thought to be of any benefit in the treatment of this self-limiting viral respiratory tract infection. However, a review of recent literature published in Archives of Diseases in Childhood (2012; 97: 827–30) suggests that the combination of nebulized adrenaline with either oral dexamethasone or mixed with 3% nebulized hypertonic saline can be beneficial in treating the acute symptoms of bronchiolitis, as well as decreasing the length of hospital stay. Although both strategies appear to be safe and well tolerated, further research is needed to clarify their roles in clinical use.

Post-intubation hypotension

A retrospective study of 336 consecutive patients intubated in the ED examined the relationship between post-intubation hypotension and mortality rates. Post-intubation hypotension was relatively common, occurring in 23% of all cases. It was associated with increased mortality and increased length of hospital stay. The study was conducted in a single, large ED in the USA where etomidate and suxamethonium were the standard RSI drugs. Patients with post-intubation hypotension were more likely to have left ventricular dysfunction, to be taking β-blockers and to have required intubation for respiratory failure. Although post-intubation hypotension was an independent risk factor for death, the design of the study does not allow any comment regarding causality. Further work looking at aggressive correction of hypotension after intubation with vaso-active drugs would be useful (J Crit Care 2012;27:417.e9–13).

Improving arrest outcomes

A very large study of community cardiac arrests in the USA has revealed a major reduction in hospital mortality rates (from 70% to 58%) between 2001 and 2009, despite an increase in the number of relevant co-morbidities. The authors postulate that interventions such as therapeutic hypothermia, promoting uninterrupted chest compressions and increased public access to automatic external defibrillators may be responsible (Circulation 2012;126:546–50).

Bedside Focused Echocardiography as Predictor of Survival in Cardiac Arrest Patients

This systematic review in Acad Emerg Med 2012:19 confirmed that bedside echocardiography is able to help predict which patients will and will not survive cardiac arrest, when combined with clinical findings. It also demonstrated though that patients should not be pronounced deceased on the basis of a single ultrasound scan alone. It called for a larger trial to be done, which we are currently participating in (REASON).

 

 

Statins and sepsis

It has been suggested that statins may modulate the immune cascade in severe infection. A small, retrospective cohort study of 91 patients examined outcomes in patients admitted to the intensive care unit with severe sepsis, focusing particularly upon whether they were already on statin treatment prior to presentation. Severity of illness appeared to be similar in both groups. Patients taking statins required mechanical ventilation for significantly fewer days and there was a strong trend to improved mortality compared to those patients not taking statins. Future researchers might consider investigating the effect of commencing statins on presentation in patients with severe sepsis (Eur J Em Med 2012;19:226–30).

Stroke thrombolysis at 6hours?

The Lancet reports on the largest trial to date of stroke thrombolysis (2012;379:2352–62). The third international stroke trial (IST-3) recruited patients of all ages and treated with thrombolysis up to 6 h after the onset of symptoms. The majority of patients were over 80 years of age and the mean time to thrombolysis was 4.2 h. Mortality rates and the number of patients living independently at 6 months follow up were similar. The study was slow to recruit and despite involving 3000 patients underpowered.

Curb-65 could be sweeter

A German study published in the BMJ (2012;344:e3397) interrogated a database of community acquired pneumonia patients (‘CAPNETZ’) and reports the association of hyperglycemia on admission and death. Mortality rates were not only higher in diabetic patients, but also in patients who had high glucose levels without being known to be diabetic. An admission glucose of 11 mmol/l or more significantly increased the risk of death. Future research is needed to examine benefit on glycemic control.

Pain in the elderly

A retrospective study of a large American database of patients attending the ED with painful conditions revealed that elderly patients (aged 74 or over) were much less likely to receive opioid analgesia or indeed, any analgesia. The authors suggest that doctors may be over-concerned about possible adverse effects of analgesia or pre-occupied by diagnosis in the elderly (Ann Emerg Med 2012;60:199–206).

Don’t give magnesium

In some centres, an intravenous infusion of magnesium sulphate solution is given as standard therapy following aneurysmal subarachnoid hemorrhage. Magnesium is believed by some to have a neuro-protective role in cerebral ischemia. The Magnesium for Aneurysmal Subarachnoid Hemorrhage (MASH-2) trial involved 1204 patients treated in specialist neurosurgical centres with either daily intravenous magnesium sulphate (64 mmol per day) or placebo. There was no difference in dependence or mortality rates at 3 months after hemorrhage (Lancet 2012;380:44–9).

D-Dimer cut off for DVT

A Dutch study of primary care patients suspected of having a deep venous thrombosis (DVT) found that increasing the cut off value for D-Dimer (from 500 to 750 μg/l) in patients aged 60 years and over reduced the number of false positives by 5% without missing any more DVTs. The authors argue that changing the cut off value would reduce the cost and inconvenience of subsequent Doppler ultrasound testing (BMJ 2012;344:e2985).

Scaphoid fractures

News from a systematic review and meta-analysis of the management of acute scaphoid fractures published in Surgeon (2012;10:218–29). Having reviewed the available evidence, the authors conclude that undisplaced fractures of the scaphoid can be satisfactorily managed by a period of immobilization in a Colles type cast. They argue that operative treatment for displaced fractures (using an open rather than percutaneous approach) may help to provide a higher union rate.

Sudden unexpected death in young childhood

A paper in the Arch Dis Child (2012;97:692–7) reports the analysis of all Sudden Unexplained Deaths in Children (SUDC) in 1–4-year-olds in Ireland for a 15 year period and makes comparisons to Sudden Infant Death Syndrome (SIDS). Although rare, SUDC rates are increasing. Unlike SIDS, SUDC cases often have a history of preceding illness or febrile seizures, slept alone and are found prone. The evidence presented suggests that the two events are not degrees of the same spectrum, but have different causal factors.

Survival after cardiac arrest in hospital improves in the US

Survival after cardiac arrest in hospital improved significantly between 2000 and 2009 in a study from the US (N Engl J Med2012;367:1912-20). A large group of well motivated hospitals saw overall survival rise from 13.7% to 22.3% (P<0.001 for trend), while the prevalence of neurological disability in survivors fell from 32.9% to 28.1% (P=0.02). The authors report significant improvements in survival for adults with asystole or ventricular fibrillation, for men and women, and for adults under and over 65 years.

The positive trends remained significant through extensive adjustments for changes in patient and hospital characteristics, including a shift in initial rhythm (proportion with asystole or pulseless electrical activity 68.7% in 2000 and 82.4% in 2009).

By 2009, more people were surviving their initial arrest, and more of those survivors were making it home. The authors suspect that improvements in care before, during, and after an arrest are responsible and call for further work to find out. They analyzed data from a register of cardiac arrests that did not record response times, quality of resuscitation techniques, or specific treatments such as hypothermia.

In all, 374 hospitals across the US contributed data to the register, which was set up as part of a quality improvement initiative. These findings may not extend to hospitals outside the network or to patients who arrest in emergency departments, procedure suites, and operating theatres, say the authors. All 84 625 adults in this study had their cardiac arrest on wards and intensive care units.

Administer tranexamic acid early to injured patients at risk of substantial bleeding

In a systematic review of antifibrinolytic drugs in trauma the only trial to assess hemorrhage was the randomised placebo controlled CRASH-2 trial (Cochrane Database Syst Rev 2011;1:CD004896.), which evaluated the effects of tranexamic acid in 20 211 adult trauma patients with or at risk of bleeding in 274 hospitals in 40 countries. Tranexamic acid given within eight hours of injury reduced all cause mortality from 16.0% to 14.5% (relative risk 0.91, 95% confidence 0.85 to 0.97), and the risk of death resulting from bleeding from 5.7% to 4.9% (0.85, 0.76 to 0.96). There did not seem to be more vascular occlusive events, nor did the effect of tranexamic acid seem to vary by baseline risk of death. Subsequent re-examination of the 1063/3076 (35%) deaths that resulted from bleeding found that the benefit of tranexamic acid was greatest when given early (<1h: 0.68, 0.57 to 0.82; 1-3 h: 0.79, 0.64 to 0.97) and that, when given more than three hours after injury, an unexpected increase in deaths from bleeding was observed (1.44, 1.12 to 1.84). Extrapolation of the CRASH-2 data led to estimates that more than 100 000 in-hospital deaths globally could be averted annually and 315 to 755 life years saved per 1000 trauma patients, at a cost of $45-$64 (£28-£40; €35-€49) per life year saved.

How should we change our practice?

Administer tranexamic acid 1g intravenously in 100 mL normal saline over 10 minutes then 1 g over eight hours, starting as early as possible and no later than three hours after injury, to trauma patients who have or are at risk of major hemorrhage. Prehospital services with capacity for drug administration should consider incorporating its administration into protocols for trauma care.

 

Best regards,

 

Paul Atkinson

Site Director Research

 

Sources:

  1. Sophia Series. Emergency Medicine Journal 2012
  2. Clinical Topics: Emergency Medicine. BMJ 2012

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