A Clinical Approach to Altered Level of Consciousness in the Pediatric Patient

Review Article

Austin Pediatr. 2016; 3(5): 1046.

A Clinical Approach to Altered Level of Consciousness in the Pediatric Patient

Krmpotic K*

Pediatric Critical Care Medicine, Janeway Children’s Health and Rehabilitation Centre, and Faculty of Medicine, Memorial University of Newfoundland, Canada

*Corresponding author: Krmpotic K, Division of Pediatric Critical Care Medicine, Janeway Children’s Health and Rehabilitation Centre, Memorial University of Newfoundland, Canada

Received: November 21, 2016; Accepted: December 19, 2016; Published: December 21, 2016

Abstract

Altered level of consciousness in infants, children, and adolescents represents a spectrum of disease ranging from mild agitation to coma, and fluctuations in between. Early recognition and immediate management of airway, breathing and circulation are often required before a specific etiology has been identified. Common causes include toxic ingestions, systemic or central nervous system infection, metabolic derangements, and structural lesions. Consultation with pediatric subspecialists and referral to tertiary care facilities for intensive care is often required. Outcomes are typically good, with most patients experiencing full recovery, depending on severity of underlying disease. This review provides a clinical approach to the pediatric patient with altered level of consciousness, reviewing the initial management strategies required for stabilization, preliminary investigations that will aid in delineating cause for symptoms, and resources for specific situations.

Keywords: Coma; Consciousness disorders; Critical illness; Encephalopathy; Pediatrics

Abbreviations

ALC - Altered Level of Consciousness; CXR - Chest Radiograph; DKA: Diabetic Ketoacidosis; ECG - Electrocardiogram; EEG - Electroencephalogram; IV - Intravenous

Introduction

Altered level of consciousness (ALC) is a spectrum of disease that presents a diagnostic and therapeutic challenge to the practitioner caring for infants, children and adolescents. Clinical presentation can range from confusion, disorientation or agitation, to lethargy, obtundation and coma. History may be incomplete and patients may require stabilization of airway, breathing, and circulation prior to performing a more thorough physical examination and investigations to aid in diagnosis. Oftentimes, determination of the likely cause(s) and initiation of appropriate treatment(s) are required to stabilize the patient, and will need to occur in the community hospital setting prior to transfer to a regional referral centre offering pediatric intensive care. This article provides a brief synopsis of this disease, reviews the emergency management of the pediatric patient presenting with ALC, and outlines an approach to diagnosis and treatment of common underlying etiologies.

Epidemiology

Although no large population-based studies regarding the incidence of pediatric ALC are available in the published literature, the annual rate of hospital admission for significantly depressed level of consciousness secondary to non-traumatic causes has been documented at 30 per 100,000 children [1]. Estimated rates of severe traumatic brain injury from accidental and non-accidental causes are similar [2], with accidental injury remaining the leading cause of pediatric mortality in developed countries [3].

The outcome for infants, children and adolescents presenting with ALC varies depending on the etiology, with mortality rates ranging from 3 to 84% [1]. Whereas patients presenting with seizures or symptoms of delirium and agitation from intoxications tend to fully recover, those with more significant alterations in mental status, such as coma secondary to infection or severe traumatic brain injury, are less likely to survive or do so with permanent neurological sequelae [1].

Clinical Presentation

Infants, children and adolescents presenting with ALC may have a broad range of signs and symptoms. Fluctuating level of consciousness is not uncommon, and progression from confusion, disorientation, and agitation to lethargy and coma may occur quickly. Any change in level of responsiveness should prompt reassessment and consideration of the need for acute interventions that may be required to stabilize the patient.

Confusion and disorientation may be easily recognizable in older children and adolescents, but in the infant or young child, these symptoms may only manifest as inconsolability by parents or another familiar caregiver. By definition, the encephalopathic patient may have a non-specific presentation, whereas agitation secondary to ingestion may be accompanied by classic signs and symptoms suggesting intoxication with a particular substance.

The lethargic child presents with extreme drowsiness, drifting in and out of sleep states only when aroused by moderate stimuli. In severe cases, these patients will become unresponsive when left undisturbed and require vigorous and repeated simulation to arouse them again. Finally, in the worst case of altered level of consciousness, patients are completely unresponsive to stimulation, a state referred to as “coma”.

Impaired consciousness is almost always a feature of generalized seizure activity and is a distinguishing feature in the classification of focal seizures [4]. Status epilepticus may present as continuous clinical and / or electrographic seizure activity that lasts duration of 5 minutes or more, or as recurrent seizure activity without return to baseline between seizures [5]. Non-convulsive status epilepticus may be clinically indistinguishable from the post-ictal state in pediatric patients with decreased level of consciousness following the cessation of obvious seizure activity and the clinician should maintain a high index of suspicion.

Standard and pediatric versions of the Glasgow Coma Scale are available to describe level of responsiveness in infants, children and adolescents. However, the AVPU mnemonic (A: alert, V: responsive to verbal stimulation, P: responsive to painful stimulation, U: unresponsive) allows for rapid assessment using four simple categories that are easy for the clinician to remember and apply [6].

Differential Diagnosis

The pediatric patient with ALC presents a challenge to the clinician, as initial stabilization and ongoing management often must occur in the absence of a clear etiology. The mnemonic “DIMS” can be used to remember the common causes of ALC in the pediatric patient (Table 1). This can help guide the focused history and physical examination, as well as the laboratory and radiographic investigations that will aid in correctly identifying the underlying etiology. Accidental ingestions and intentional overdoses of potentially toxic substances can exert significant pharmacodynamic effects on the central nervous system and result in metabolic derangements that further contribute to alterations in mental status. Similarly, the omission of prescription medications, or altered pharmacokinetics due to impaired absorption or transiently abnormal metabolism of medication, can lead to similar effects. Both severe systemic infection and localized infections of the central nervous system (e.g., meningitis, encephalitis, and abscess) can lead to ALC, secondary to decreased cerebral perfusion or direct irritation of cerebral tissues, respectively. Metabolic abnormalities range from electrolyte disturbances that can be easily corrected, to more complex conditions such as uremic or hyperammonemic encephalopathy. Finally, structural causes of ALC include spaceoccupying lesions (e.g., tumor, blood) and obstructions to cerebral blood flow (e.g., thrombus, vasculitis). Determination of the cause for clinical presentation will guide many of the therapeutic decisions beyond initial stabilization, and the clinician must simultaneously initiate treatment and consider a broad differential diagnosis.

Citation: Krmpotic K. A Clinical Approach to Altered Level of Consciousness in the Pediatric Patient. Austin Pediatr. 2016; 3(5): 1046. ISSN:2381-8999