Guidelines for the investigation and management of a reduced level of consciousness in children: implications for clinical biochemistry laboratories

Abstract

Whenever a child presents to hospital with a reduced level of consciousness, admitting clinicians have to decide the underlying cause rapidly so that the correct emergency treatment can be initiated. Unfortunately, the clinical presentations of many of the possible diagnoses are very similar. The diagnosis often results from investigations within the clinical biochemistry laboratory. In the past, clinicians have had limited guidance on which tests to request when presented with a child with a reduced level of consciousness. Guidelines have recently been developed relating to all aspects of management of the child in a coma. Due to a lack of evidence in the literature regarding the most appropriate first line tests for children with a reduced level of consciousness, a formal consensus process ('Delphi consensus') was performed using a large multidisciplinary panel of experts. The recommendations reached by this process include the list of initial ('core') tests to request for all children with a reduced level of consciousness (excluding those immediately after suffering a convulsion and those involved in obvious trauma). Depending upon the results of these 'core' tests and the clinical condition of the child, further tests may be requested later. The key point is that all the samples have been taken at the time of presentation to provide the best chance of reaching a diagnosis and correctly treating the child. The article reviews the recommended core investigations and further tests and discusses how individual laboratories can help to implement the guidelines jointly with their Emergency and Paediatric Departments.

Etiologies and Yield of Diagnostic Testing in Children Presenting to the Emergency Department with Altered Mental Status

“…1,2,[4][5][6][7][8][9][10][11][12] Bowker et al highlighted the lack of evidence regarding recommendations for initial diagnostic testing in these patients, as well as the lack of specificity of presenting symptoms in children with altered mental status. 32 Case reports in the literature of children presenting to the ED with altered mental status have demonstrated widely varying etiologies such as acute disseminated encephalomyelitis, 6 central ,3,9,15 nervous system arteriovenous malformation, 7 ingestion, 3,9,15 hypoglycemia, 10 pericardial tamponade, 13 stroke, 18 and metabolic disorders such as ornithine transcarbamylase deficiency. 14 These case reports underscore the broad differential diagnosis facing clinicians caring for these patients as well as the often extensive initial diagnostic testing that may be performed including blood tests, urine studies, lumbar puncture, and imaging studies such as head CT, brain magnetic resonance imaging, and chest radiograph to elucidate the underlying etiology.…”

Prise en charge des détresses métaboliques aiguës

“…L'interrogatoire permet d'orienter facilement vers ce diagnostic chez un enfant habituellement né à terme et eutrophe avec un intervalle libre de plusieurs jours entre la naissance et les premiers symptômes (parfois dès H24), présentant un coma d'apparition progressive associant une hypotonie axiale et une hypertonie périphérique avec des mouvements anormaux des extrémités (trémulations, « pédalage », « boxe »…). Une odeur « de pieds en sueur » oriente vers une acidurie isovalérique [ou un déficit généralisé de l'OAG (acidurie glutarique de type II ou déficit multiple en déshydrogénases) dans le cadre des maladies énergétiques] pouvant bénéficier d'un traitement spécifique par la glycine, la carnitine et la riboflavine (B2) associé au traitement diététique [8][9][10].…”

“…Des examens biologiques simples (ionogramme sanguin avec calcul du trou anionique -voir chapitre « Interprétation du bilan biologique », glycémie, ammoniémie, lactatémie, corps cétoniques dans les urines et pH urinaire, bilan hépatique, facteur V, TP, calcémie, CPK) orientent vers un type de maladie d'intoxication [8] : un bilan biologique froid vers une leucinose, une déshydratation, une acidocétose, une hyperammoniémie et une hyperlactacidémie vers les aciduries organiques, et une hyperammoniémie isolée sans acidose (ou acidose modérée), ou une alcalose mixte, associée parfois à un bilan hépatique perturbé (cytolyse hépatique, voire insuffisance hépatique) vers les déficits du cycle de l'urée (voir aussi le chapitre « Interprétation du bilan biologique »). Un test à la DNPH conforte le diagnostic de leucinose.…”

Investigation of the child with an acute metabolic disorder

“…Reports of late-presentation are escalating as clinical awareness increases. An evidence-based guideline has been developed for the investigation and management of a reduced level of consciousness in children in the UK, which includes biochemical investigations 42 43…”

“…Distribution of emergency packs to the emergency department and acute paediatric admission wards, as used for acute hypoglycaemia (see above), would streamline investigation 42 43…”