Levels of Consciousness

Assessment of LOC remains the earliest indicator of improvement or deterioration in neurologic status. LOC is determined by observations of the child’s responses to the environment. When it is being assessed in young children, it is often useful to have a parent present to help elicit a desired response. An infant or child may not respond in an unfamiliar environment or to unfamiliar voices. Children older than 3 years of age should be able to give their name, although they may not be cognizant of place or time. Other diagnostic tests such as motor activity, reflexes, and vital signs vary more and do not necessarily directly parallel the depth of the comatose state. The most consistently used terms are described in Box 45-2.

Coma Assessment

Several scales have been devised in an attempt to standardize the description and interpretation of the degree of depressed consciousness. The most popular of these is the Glasgow Coma Scale (GCS), which consists of a three-part assessment: eye opening, verbal response, and motor response (Fig. 45-2). Numeric values of 1 through 5 are assigned to the levels of response in each category. The sum of these numeric values provides an objective measure of the patient’s LOC. A person with an unaltered LOC would score the highest, 15; a score of 8 or below is generally accepted as a definition of coma; and the lowest score, 3, indicates deep coma. A decrease in the GCS score indicates a deterioration of the patient’s condition. In 1987 major medical and legal societies developed specific guidelines for the determination of brain death among children of all ages (Mathur, Peterson, Stadtier, et al., 2008).

Vital Signs

Pulse, respiration, and blood pressure provide information regarding the adequacy of circulation and the possible underlying cause of altered consciousness. Autonomic activity is most intensively disturbed in cases of deep coma or brainstem lesions.

Body temperature is often elevated, and sometimes the elevation may be extreme. High temperature is most frequently a sign of an acute infectious process or heat stroke but may also be caused by ingestion of some drugs (especially salicylates, alcohol, and barbiturates) or intracranial bleeding, especially subarachnoid hemorrhage. Hypothalamic involvement may cause elevated or decreased temperature. Coma of a toxic origin may produce hypothermia.

The pulse varies and may be rapid, slow and bounding, or feeble. Blood pressure may be normal, elevated, or very low. The Cushing reflex, or pressor response, causes a slowing of the pulse and an increase in blood pressure and is uncommon in children; when it occurs it is a very late sign of ICP. Medications may affect the vital signs. For assessment purposes actual changes in pulse and blood pressure are more important than the direction of the change.

Respirations are often slow, deep, and irregular. Slow, deep breathing is often seen in the heavy sleep caused by sedatives, after seizures, or in cerebral infections. Slow, shallow breathing may result from sedatives or opioids (narcotics). Hyperventilation (deep and rapid respirations) is usually a result of metabolic acidosis or abnormal stimulation of the respiratory center in the medulla caused by salicylate poisoning, hepatic coma, or Reye’s syndrome (RS).

Breathing patterns have been described with a number of terms (e.g., apneustic, cluster, ataxic, Cheyne-Stokes). However, it is better to describe what is being observed rather than placing a label on it because the traditional terms are often used and interpreted incorrectly. Periodic or irregular breathing is an ominous sign of brainstem (especially medullary) dysfunction that often precedes complete apnea. The odor of the breath may provide additional clues (e.g., the fruity, acetone odor of ketosis; the foul odor of uremia; the fetid odor of hepatic failure; or the odor of alcohol).

Skin

The skin may offer clues to the cause of unconsciousness. The head should be examined for trauma such as lacerations, ecchymosis, or hematoma; the body surface should be examined for signs of injury, needle marks, petechiae, bites, and ticks. Evidence of toxic substances may be found on the hands, face, mouth, and clothing, especially in small children.

Eyes

Pupil size and reactivity are assessed (Fig. 45-3; see also Fig. 45-2). Pinpoint pupils are commonly observed in poisoning such as opiate or barbiturate poisoning and in brainstem dysfunction. Widely dilated and reactive pupils are often seen after seizures and may involve only one side. Dilated pupils may also be caused by eye trauma. Widely dilated and fixed pupils suggest paralysis of cranial nerve III secondary to pressure from herniation of the brain through the tentorium. A unilateral fixed pupil usually suggests a lesion on the same side. If pupils are fixed bilaterally for more than 5 minutes, brainstem damage is usually implied. Dilated and nonreactive pupils are also seen in hypothermia, anoxia, ischemia, poisoning with atropine-like substances, or prior instillation of mydriatic drugs.

The description of eye movements should indicate whether one or both eyes are involved and how the reaction was elicited. The parents should be asked about preexisting strabismus, which causes the eyes to appear normal under compromise. Posttraumatic strabismus indicates cranial nerve VI damage.

Special tests, usually performed by qualified persons, include:

Motor Function

Observing spontaneous activity, gait, and response to painful stimuli provides clues to the location and extent of cerebral dysfunction. Even subtle movements (e.g., the outward rotation of a hip) should be noted, and the child observed for other signs. Asymmetric movements of the limbs or absence of movement suggests paralysis. In hemiplegia the affected limb lies in external rotation and falls uncontrollably when lifted and allowed to drop. In patients with cerebellum abnormalities heel-to-toe walking is difficult. Patients with cerebellar ataxia have an unsteady, broad-based gait. All motor functions should be described rather than labeled.

In the deeper comatose states there is little or no spontaneous movement, and the musculature tends to be flaccid. There is considerable variability in the motor behavior in lesser degrees of coma. For example, the child may be relatively immobile or restless and hyperkinetic; muscle tone may be increased or decreased. Tremors, twitching, and spasms of muscles are common observations. The patient may display purposeless movements. Combative or negativistic behavior is common. Hyperactivity is more common in toxic states than in cases of increased ICP. Seizures are common in children and may be present from any cause. Any repetitive or seizure movements should be described precisely.

Posturing

Primitive postural reflexes emerge as cortical control over motor function is lost in brain dysfunction. These reflexes are evident in posturing and motor movements directly related to the area of the brain involved. Posturing reflects a balance between the lower exciting and the higher inhibiting influences and strong muscles overcoming weaker ones. Decorticate or flexion posturing (Fig. 45-4, A) is seen with severe dysfunction of the cerebral cortex or lesions to corticospinal tracts above the brainstem. Typical posturing includes rigid flexion with the arms held tightly to the body; flexed elbows, wrists, and fingers; plantar flexed feet; legs extended and internally rotated; and possibly the presence of fine tremors or intense stiffness. Decerebrate posture or extension posturing (see Fig. 45-4, B) is a sign of dysfunction at the level of the midbrain or lesions to the brainstem. It is characterized by rigid extension and pronation of the arms and legs, flexed wrists and fingers, a clenched jaw, an extended neck, and possibly an arched back. Unilateral decerebrate posture is often caused by tentorial herniation.

Posturing may not be evident when the child is quiet but can usually be elicited by applying painful stimuli such as a blunt object pressed on the base of the nail. Nurses should avoid applying thumb pressure to the supraorbital region of the frontal bone (risk of orbital damage). Noxious stimuli (e.g., suctioning) elicits a response, as may turning or touching. When the nurse is describing posturing, the stimulus needed to provoke the response is as important as the reaction.

Reflexes

Testing of some reflexes may be of limited value. In general the corneal, pupillary, muscle-stretch, superficial, and plantar reflexes tend to be absent in deep coma. The state of reflexes varies in lighter grades of unconsciousness and depends on the underlying pathologic process and the location of the lesion. Absence of corneal reflexes and presence of a tonic neck reflex are associated with severe brain damage. The Babinski reflex (see Extremities, Chapter 29) may be of value if it is found to be present consistently in children older than 18 months. A positive Babinski reflex is significant in assessment of pyramidal tract lesions when it is unilateral and associated with other pyramidal signs.

Nursing Activities

In cases of high levels of increased ICP, procedures tend to trigger reactive pressure waves in many patients. For example, increased intrathoracic or abdominal pressure is transmitted to the cranium. Particular care should be taken in positioning these patients to avoid neck vein compression, which may further increase ICP by interfering with venous return.

The child can be propped to one side or the other, and the use of an alternating-pressure mattress reduces the chance of prolonged pressure to vulnerable areas. Frequent clinical assessment of the child cannot be replaced by an ICP monitoring device.

It is important to avoid activities that may increase ICP by causing pain or emotional stress. Gentle range-of-motion exercises can be carried out but should not be performed vigorously. Nontherapeutic touch can cause an increase in ICP. Any disturbing procedures to be performed should be scheduled to take advantage of therapies such as osmotherapy and sedation that reduce ICP. Efforts are taken to minimize or eliminate environmental noise. Assessment and intervention to relieve pain are important nursing functions to decrease ICP. Individualizing nursing activities and minimizing environmental stimuli by decreasing elective procedures help control ICP (Sankhyan, Raju, Sharma, et al., 2010).

Suctioning

Suctioning and percussion are poorly tolerated and therefore are contraindicated unless concurrent respiratory problems exist. Hypoxia and the Valsalva maneuver associated with cough both acutely elevate ICP. Vibration, which does not increase ICP, accomplishes excellent results and should be tried first if treatment is needed. If suctioning is necessary, it should be brief and proceeded by hyperventilation with 100% oxygen, which can be monitored during suctioning with a pulse oxygen sensor reading to determine oxygen saturation.

Altered Pituitary Secretion

An altered ability to handle fluid loads is attributed in part to the syndrome of inappropriate antidiuretic hormone secretion (SIADH) and diabetes insipidus (DI) resulting from hypothalamic dysfunction (see Chapter 46). SIADH frequently accompanies CNS diseases such as head injury, meningitis, encephalitis, brain abscess, brain tumor, and subarachnoid hemorrhage. In patients with SIADH, scant quantities of urine are excreted, electrolyte analysis reveals hyponatremia and hyposmolality, and manifestations of overhydration are evident. It is important to evaluate all parameters because the reduced urinary output might be erroneously interpreted as a sign of dehydration. The treatment of SIADH consists of restriction of fluids until serum electrolytes and osmolality return to normal levels.

DI may occur after intracranial trauma. In DI there are large amounts of diluted urine and the accompanying danger of dehydration. Adequate replacement of fluids is essential, and observation of electrolyte balance is necessary to detect signs of hypernatremia and hyperosmolality. Exogenous vasopressin may be administered.