The management of children and young people with an acute decrease in conscious level (2015)

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A nationally developed evidence-based Guideline for practitioners, published in April 2015. It was updated with corrections in August 2016.


Decreased conscious level can be considered an acute neurological emergency characterised by significant brain impairment, necessitating a rapid and methodical approach to evaluation and treatment.

Regardless of the underlying cause, a decreased conscious level indicates a primary insult to the brain which, if left untreated, could rapidly progress to secondary damage leading to significant morbidity or even death.


The first guideline, 'The Management of Decreased Conscious Level', was published in 2005. Since, there had been significant changes in the demographics of the children and young people presenting to emergency settings with a decreased conscious level. This changing demographic was identified by a multi-centre audit carried out in 2010-11 with funding from the National Reye’s Syndrome Foundation UK.

The continuing support of The National Reye's Syndrome Foundation UK allowed the work required to update the Guideline.


The Guideline's aim is to give clinicians working acutely a framework to aid the timely and safe care of children and young people presenting with a decreased conscious level of unknown cause.

Consistent with the previous Guideline (2005), this version emphasises the importance of managing this condition in a standard manner from first presentation to health services, to ensure the best outcome for patients and their families.

Guideline and diagnosis algorithm poster

See guideline on screen, or download guideline, appendices and algorithm poster. These versions include corrections issued in August 2016.

Guideline - Management of children and young people with an acute decrease in conscious level (PDF, 938 KB)

Appendices (PDF, 13 MB)

Summary of recommendations (PDF, 465KB)

Diagnosis algorithm poster (PDF, 102 KB)

Erratum - August 2016

The following corrections are included in this clinical guideline and the algorithm poster.

  • The measurement unit for the ammonia levels for hyperammonaemia which is referred to in the metabolic section was incorrect. It has been changed to micromol/l instead of mmol/l.
  • The description on how best to take the plasma ammonia sample has been extended for clarity in the algorithm. 

For full details on where the changes have been inserted, please see the erratum document (PDF, 127 KB)

Training slides

A set of educational presentation slides has been developed to accompany the clinical guideline.

The slides aim to introduce and the clinical guideline, provide an overview of the methodology and development of the guideline, as well as reviewing some of the key recommendations made and providing a quick guide on how to use the clinical guideline.

Both the training slides (PowerPoint, 3.5MB) and a more detailed slide set (training slides with speaker notes (PDF, 530KB, 23 Pages)) are available for download for work related to the production of this clinical guideline.