Approach to the Child with Coma - MedIND

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Sep 10, 2010 - of non-traumatic coma include central nervous system infections, metabolic encephalopathy (hepatic, uremic, diabetic ketoacidosis etc.) ...
Indian J Pediatr (2010) 77:1279–1287 DOI 10.1007/s12098-010-0191-1

SYMPOSIUM ON PICU PROTOCOLS OF AIIMS

Approach to the Child with Coma Suvasini Sharma & Gurpreet Singh Kochar & Naveen Sankhyan & Sheffali Gulati

Received: 3 August 2010 / Accepted: 18 August 2010 / Published online: 10 September 2010 # Dr. K C Chaudhuri Foundation 2010

Abstract Coma and other states of impaired consciousness represent a medical emergency. The potential causes are numerous, and the critical window for diagnosis and effective intervention is often short. The common causes of non-traumatic coma include central nervous system infections, metabolic encephalopathy (hepatic, uremic, diabetic ketoacidosis etc.), intracranial bleed, stroke and status epilepticus. The basic principles of management include 1) Rapid assessment and stabilization, 2) Focussed clinical evaluation to assess depth of coma, localization of lesion in the central nervous system and possible clues to etiology, and 3) Treatment including general and specific measures. Commonly associated problems such as raised intracranial pressure and seizures must be recognized and managed to prevent secondary neurologic injury. Keywords Altered sensorium . Encephalopathy . Impaired consciousness . Intracranial pressure

Introduction Coma is a medical emergency which presents diagnostic as well as therapeutic challenges. The potential causes of coma are numerous, and the critical window for diagnosis and effective intervention (not only to ensure survival but also to prevent long-term sequelae) is short. Pediatricians in the emergency services and intensive care units (ICU) have to frequently manage comatose patients. The incidence of S. Sharma : G. S. Kochar : N. Sankhyan : S. Gulati (*) Department of Pediatrics, Child Neurology Division, All India Institute of Medical Sciences, New Delhi 110029, India e-mail: [email protected]

non-traumatic coma is 30/100,000 children per yr, and that of traumatic brain injury is 670/100,000 [1, 2]. Central nervous system (CNS) infections are the most common cause of non-traumatic coma in children in our scenario. This article provides a practical approach to evaluate a child with non-traumatic coma.

Definitions: Coma and Other States of Impaired Consciousness Impaired consciousness implies a significant alteration in the awareness of self and of the environment, with varying degrees of wakefulness [3]. Descriptive terms such as somnolence, stupor, obtundation, and lethargy used to denote different levels of wakefulness are best avoided, given the lack of uniformity in the way these states are defined in the literature. Coma is characterized by the total absence of arousal and of awareness. Comatose patients have no eye opening. As opposed to states of transient unconsciousness such as syncope or concussion, coma must last for at least 1 h [3]. Vegetative state describes a condition of complete unawareness of the self and the environment accompanied by sleep wake cycles with variable preservation of brainstem functions. The vegetative state is deemed to be permanent 12 months after traumatic brain injury and 3 months after non-traumatic injury [4]. Minimally conscious state is defined as a condition of severely altered consciousness in which the patient demonstrates minimal but definite behavioural evidence of self- or environmental awareness [5]. Brain death is defined as the permanent absence of all brain functions including those of the brainstem [6]. Brain-dead patients are irreversibly comatose and apneic with absent brainstem reflexes.

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Etiology (Table 1) It is clinically useful to categorize the causes of coma into [7]: 1) Coma with focal signs 2) Coma without focal signs and without meningeal irritation 3) Coma without focal signs and with meningeal irritation There maybe overlap within these categories. For example, a child with meningitis may also have focal neurological deficits. In a study from our center comprising 70 children aged 5–15 yrs with non-traumatic impairment of consciousness, CNS infections accounted for 33 (50%) of cases (Kochar GS et al. unpublished data). Out of these, 13 children were diagnosed to have viral meningo-encephalitis, five had tuberculous meningitis, five had brain abscess, two children

Table 1 Causes of coma in children Coma with focal signs • Intracranial hemorrhage • Stroke: arterial ischemic or sinovenous thrombosis • Tumors • Focal infections-brain abscess • Post seizure state: Todd’s paralysis • Acute disseminated encephalomyelitis Coma without focal signs and without meningeal irritation • Hypoxia-Ischemia: Cardiac or pulmonary failure, Cardiac arrest, Shock, Near drowning • Metabolic disorders: Hypoglycemia Acidosis (e.g. Organic acidemias, diabetic keto-acidosis) Hyperammonemia (e.g. hepatic encephalopathy, urea cycle disorders, valproic acid encephalopathy, disorders of fatty acid metabolism, Reye syndrome) Uremia, Fluid and Electrolyte disturbances (dehydration, hyponatremia, hypernatremia) • Systemic Infections: Bacterial: gram-negative sepsis, meningitis, toxic shock syndrome, cat-scratch disease, Shigella encephalopathy, Enteric encephalopathy • Post infectious disorders: Acute necrotizing encephalopathy, ADEM, Hemorrhagic shock and encephalopathy syndrome • Post immunization encephalopathy: Whole cell pertussis vaccine, Semple Rabies vaccine • Drugs and toxins • Cerebral malaria • Rickettsial: Lyme disease, Rocky mountain spotted fever • Hypertensive encephalopathy • Post seizure states • Non-convulsive status epilepticus • Post migraine Coma without focal signs and with meningeal irritation • Meningitis • Encephalitis • Subarachnoid hemorrhage

Indian J Pediatr (2010) 77:1279–1287

each had pyogenic meningitis, enteric encephalopathy, and multiple neurocysticercosis, and one child each had cerebral malaria rabies encephalitis, meningococcemia and dengue encephalopathy. Among the other 35 children, seven each had fulminant hepatic failure, or intracranial bleed. Other causes included hypoxic ischemic encephalopathy following cardiac arrest (n=4), metabolic encephalopathy (n=4, uremia-3, DKA-1), hypertensive encephalopathy (n=2), ADEM (n= 3), refractory status epilepticus (n=3), tumor (n=1). No cause could be ascertained in 3 cases.

Evaluation of the Comatose Child Coma is a medical and neurological emergency, requiring immediate consideration of key issues including immediate life support, identification of cause, and institution of specific therapy. The evaluation (clinical as well as investigations) and treatment have to proceed simultaneously (Fig. 1). Stabilization As in any emergency, initial steps should be directed to ensuring adequacy of airway, breathing and circulatory function [8]. Airway management is of paramount importance in children with altered states of consciousness, as their protective reflexes are obtunded and they are more prone to aspiration. Children with Glasgow Coma Score less than 8 should preferably be intubated; mechanical ventilation should be provided in case the breathing efforts are not adequate. Appropriate oxygenation should be ensured. The next most important step is establishment of vascular access. If there is evidence of circulatory failure, fluid bolus (20 mL/kg- Normal saline) should be adminsitered. Samples should be drawn for various investigations. If hypoglycemia is present, intravenous glucose should be administered. If the child is having seizures, or there is history of a seizure preceding the encephalopathy, anticonvulsant (inj Lorazepam, 0.1 mg/kg followed by phenytoin loading 20 mg/kg) should be administered. If there are features of raised intracranial pressure (asymmetric pupils, tonic posturing, papilledema, evidence of herniation), measures to decrease intracranial pressure should be rapidly instituted (hyperventilation, mannitol etc.). Acid base and electrolyte abnormalities should be corrected. Normothermia should be maintained (see algorithm).

History A careful history should be taken with special emphasis on the events prior to the onset of coma. Presence of fever,

Indian J Pediatr (2010) 77:1279–1287

1281 Rapid assessment and stabilization

Evaluate



Establish and maintain Airway: Intubate if GCS≤8, impaired airway reflexes, abnormal respiratory pattern, signs of raised ICP, oxygen saturation