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Apparent life-threatening events in babies


While 3 month old Hamish’s parents were enjoying their favourite Scottish drink, they suddenly looked over and noticed that Hamish had gone blue in the face. They were terrified, but fortunately it resolved quickly and Hamish is back to his normal, bonny self. They’ve rushed him to see you in hospital. Could the answer have been right in front of them?

This month saw the publication of a new guideline from the American Academy of Pediatrics for babies who have unexplained episodes that you might know as ALTEs. Check out this week’s FOAMCast to hear more about it.

An ALTE, or acute life-threatening event was first described in 1986. The definition is:

an episode that is frightening to the observer and that is characterised by some combination of apnoea (central or occasionally obstructive), colour change…marked change in muscle tone (usually marked limpness), choking, or gagging. In some cases, the observer fears that the infant has died.

This broad definition causes some difficulties for those of us assessing babies in hospitals. Although an ALTE can indicate a serious underlying problem – NAI, infection, seizure – commonly the infant is completely well. ALTEs by definition are subjective and this makes the management of them tricky. Often these babies will have overnight admissions to hospital for observation.

A systematic review in 2013, looked at 1400 ALTEs (Tieder et al). However, the authors found that there was such a wide variation in the interpretation of the definition that no conclusions could be drawn.

In short, the term ALTE doesn’t really help anyone.

This guideline suggests a new term, BRUE – a brief, resolved, unexplained event.

A BRUE has occurred if the observer reports a sudden, brief, and now resolved, unexplained episode of ≥1 of the following:

  • cyanosis or pallor
  • absent, decreased, or irregular breathing
  • marked change in tone (hyper- or hypotonia)
  • altered level of responsiveness

If your patient has had a BRUE, then the guideline suggests assessing them to see if they would qualify as being ‘low risk’

Low risk BRUE patients fulfil all of the following:

  • age >60 days
  • gestational age ≥32 weeks and postconceptional age ≥45 weeks
  • occurrence of only 1 BRUE (no prior BRUE ever and not occurring in clusters)
  • duration of BRUE <1 minute
  • no cardiopulmonary resuscitation by trained medical provider required
  • no concerning historical features
  • no concerning physical examination findings

What should I do with a low risk BRUE patient?

You can see the full flowchart and all the evidence base here. But essentially, you don’t need to be doing bloods, LPs, echos, x-rays, or EEGs. You should educate the parents about BRUEs and implement a discharge/follow-up plan so they are happy, and make sure to point them in the direction of CPR training resources.

You should take a history that includes assessment of social risk factors for NAI.  It’s reasonable, but not mandatory, to get an ECG and observe on a pulse ox monitor for 1-4hrs.  You may also consider doing a PCR for pertussis if the history suggests exposure is likely, particularly if mum did not get her antenatal booster immunisation.

The authors make a weak recommendation that low risk infants need not be admitted overnight solely for the purposes of cardiorespiratory monitoring, they make a moderate recommendation that clinicians should engage in shared decision making.  You don’t have to admit but you do have to make sure the parents are comfortable with your plan.

It is also worth noting that when the authors said “discharge” what they meant was follow up by a paediatrician for repeat history and exam within 24hrs.

CAUTION: This guideline does not tell us to ignore babies with ALTEs (or BRUEs). It does tell us to take a very careful history and examination and reassures us that in low risk babies we can rely on those assessments. (We should ensure that the person conducting the history/examination has sufficient clinical experience to make a decision that there is no underlying cause.) Investigations are useful only when specifically indicated from the clinical assessment and prolonged observation may be offered for either clinician or parental reassurance.



Tieder JS, Altman RL, Bonkowsky JL, et al Management of apparent life-threatening events in infants: a systematic review. J Pediatr. 2013;163(1):94–99, e91–e96

About the authors

  • Tessa Davis is a Consultant in Paediatric Emergency Medicine at the Royal London Hospital and a Senior Lecturer at Queen Mary University of London.


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1 thought on “Apparent life-threatening events in babies”

  1. Hi Tessa,

    What’s your opinion on admission for monitoring with 1/1 nursing care? I have seen conflicting advice on this in clinical guidelines. Bit of a back story, my daughter presented to ED twice with a BRUE/ALTE we were admitted for ward monitoring 1/7 care and discharged. A week later my daughter stopped breathing and I had to give CPR from my timing she didn’t wake up for 5 minutes, I feel as if 1/1 nursing care would have avoided this and they would have picked up she had periodic breathing and chronic reflux that the PICU observed overnight. I am now completing my nursing degree in hopes to go ahead and become a nurse practitioner with high hopes to complete research in this area. I also found conflicting evidence whether children that present with an ALTE/BRUE in the neonate period go on to pass from sids or not. I really hope to conduct a study on this.



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