Altered Level of Consciousness

The differential diagnosis for a child who has a clearly altered level of consciousness is broad; careful consideration of the leading etiologies by age group can limit the scope of the initial evaluation. One popular mnemonic for the causes of altered consciousness is "TIPS from the Vowels" (T-I-P-S-A-E-I-O-U), which represents Trauma/Tumor, Insulin/hypoglycemia/Intussusception, Poisons, Shock, Alcohol/Abuse, Epilepsy/Encephalopathy, Infection/Inborn errors, Opiates, and Uremia.

For the toddler who presents with no known acute trauma, the leading causes of changes in consciousness include ingestion, infection, intussusception, seizure, and nonaccidental trauma (child abuse). Among the questions in a careful history that can help to guide further management are: Has the child been ill? Have any medications been administered recently? Does the child have access to other sources of medications, including alcohol-containing items such as mouthwash? Is there a history of seizures?

Narcotics, sedatives, hypnotics, tricyclic antidepressants, organophosphates, and alcohols all can produce the symptoms described for the child in the vignette (see below) in a relatively short period of time, and the symptoms would be expected to continue for hours or days. Accordingly, a toxicology screen would be very helpful in making the diagnosis.

Because acute cardiac or pulmonary pathology leading to coma in otherwise healthy children is exceedingly rare, neither chest radiography nor electrocardiography is likely to aid in this child’s diagnosis. Uremia can cause encephalopathy or coma in patients who are in the late stages of renal failure, but nothing in this child’s history suggests the presence of such a chronic disease. The prolonged depressed level of consciousness, elevated respiratory rate, lack of prior seizure history, and absence of witnessed seizures either at home or in the emergency department make seizure less likely.
References:
Isaacman DJ. Coma and altered mental status. In: Barkin RM, ed. Pediatric Emergency Medicine: Concepts and Clinical Practice. 2nd ed. St Louis, Mo: Mosby, Inc; 1997:974-981
Rubenstein JS. Initial management of coma and altered consciousness in the pediatric patient. Pediatr Rev. 1994;15:204-207
Shannon M. Index of suspicion. Case 2. Acute ethanol intoxication. Pediatr Rev. 1994;15:117-119

Vignette
A previously healthy 2-year-old child is brought to the emergency department because her mother has been unable to awaken her for 45 minutes. She has not been ill. Physical examination reveals an afebrile, hypotonic child who withdraws her hand from painful stimuli but does not spontaneously open her eyes. Her respiratory rate is 36 breaths/min, and her blood pressure is 92/64 mm Hg.