Diagnosis and Monitoring of Neurological Changes in Intensive Care

Keywords

Intensive Care; Intensive Care Nursing; Medical History; Neurological Examination

Abstract

Since patients are usually incubated or sedated at intensive care units and they are given neuromuscular agents, neurological examination and early diagnosis of neurological complications is difficult and complex for both nurses and doctors. This review includes patient history, evaluation of physical, mental and motor functions and new methods on neurological diagnosis.

Introduction

At intensive care units, simultaneously evaluating and monitoring patients’ different systems and organs is vitally important in order to plan patient care and treatment. Neurological evaluation and diagnosis helps early detection of the neurological deterioration before irreversible brain damage occurs, planning the care according to the patient, evaluation of response to the treatment and preventing possible side effects. Furthermore, it is beneficial for the amelioration of the patients’ neurological prognosis and life quality after severe brain damage. Physical examination, monitoring methods and scoring methods are used for this evaluation process. Nurses are required to be acquainted with many steps like taking medical history, CVP measurement, cerebral oxymetry follow-up, Glasgow Coma scale, evaluation of pupil as, cranial nerves, deep tendon reflexes, sensory and motor function damages, changes in consciousness and delirium, distinguishing seizure types, knowing and monitoring the effects of drugs on neurological systems and apply them appropriately. For example, when nurses monitor the changes in pupillas, they should be able to recognize that if the pupil as are in size of pinpoint (<1mm) and not responsive to light, it usually indicates a lesion due to haemorrhage in Pons. Thus, nurses can have a primary role in the detection of changes in patients’ clinical condition and contribute to the early detection of irreversible situations. This review addresses the points that nurses should pay attention to in neurological diagnosis and evaluation methods.

Subjective Data

Medical history

Three points should be paid attention to when getting the history of patients with neurological problems. First one is to avoid offering the symptoms. For example, instead of asking questions like “Is your right side weak?” more open-ended questions like “Is there anything bothering you on your right side?” should be asked. Second point is how the problem started and medical history [1,2]. Nurses should reveal all the relevant data in the medical history of the current disease. Third point is that since some neurological diseases affect the patient’s mental health, it may be difficult the make a proper evaluation. In such a case, medical history should be taken from someone who knows patient’s problems and complaints directly [1-3]. Medical history can direct the clinician to the part where nervous system should be evaluated. If the patient’s complaint is primary dizziness, examination should be more focused on vision, balance and cerebellum functions instead of somatic, motor and sensorial functions [1,2]. Changes in behavior and consciousness, development problems, paroxysmal problems (like seizures) and traumas should warn the clinicians about the necessity of a detailed neurological examination. When taking the medical history from the patients, nurses should ask specific questions about situations that may affect nervous system like diabetes mellitus, pernicious anemia, cancer, infections, thyroid disease, drug abuse and hypertension [1-3].

Medical treatment

Use of sedatives, tranquilizers and mental drugs should be specifically questioned. If the patient is having dizziness as a side effect of a drug and the medication cannot be changed after detecting the side effect, new strategies will be required to prevent the patient from falling and to fight the dizziness [1-3]. Some patients with neurological problems may be using anti-confusion drugs like phenytoin (dilontin), carbamazepine (tegratol) and phenobarbital. Nurses should gather information about diplopia (double vision), hypokinesia, ataxia (imbalance) and mental retardation [1-3].

Surgical and other treatments

If the patient is going to go under a surgical operation, its date, reason, methods, healing state and present state should be investigated. Taking perinatal history may help reveal exposure to toxic agents affecting the development of nervous system like viruses, alcohol, tobacco, medications and radiation. A difficult childbirth causing brain damage as a result of Rh incompatibility, hypoxia and obstetrical forceps may be also revealed by taking the history. Growth and developmental history may be important in investigating whether there is problem in nervous system at early ages. Nurses should especially gather information on major developmental stages like talking and walking [1-3].

Objective Data

Physical examination functions are evaluated in six steps: Mental status, Cranial Nerve Functions, Motor Functions, Cerebellum Functions, Sensorial Functions and Reflex Functions. If the patient’s complaint is sensory loss in feet, the examination can be only focused on sense and motion of lower extremities. Similarly, if a patient came to emergency service after a head trauma and is unconscious, the examination will be limited since the patient cannot response to oral instructions. The main objection of the neurological examination done by nurses is to identify the neurological impairment and effects of the ability of patient and family to fight with the neurological deficit on daily life [1-3].

Mental status: Evaluation of mental status (brain functions) provides understanding in how the patient functions as a whole and how the patient adapts to the environment. Items of mental status examination are given below (Table 1).

Table 1: Mental status examination.

Evaluation of Mental Status

It is done by assessing the level of consciousness. Consciousness level has two components: wakefulness and awareness.

Wakefulness

Reticular Activation System (RAS) is functional, RAS is correlated with thalamus and cortex and it is the lowest level of consciousness. Patient’s response to oral and tactile impulses is evaluated.

Awareness

It constitutes cognitive mental functions. Cerebral cortex is functional. It is the high level of consciousness. Patient’s adaptation to people, places and time is evaluated.

Levels of Consciousness

Awake/full consciousness (Alert)

Patient is oriented to time, place and people. Patient can understand written and oral words and can communicate [4,5].

Lethargy/somnolence

Patient is oriented to time, place and people. Half-awakeness, obtuseness, deceleration in speaking, mental functions and motor activities and indolence is present. Patient responses properly to painful stimulants. Nurses should know that lethargic patients have a tendency to fall and get hurt. To protect the patient, bedsides should be removed; patient should be evaluated frequently and monitored closely.

Delirium

Attention disorder, disorganization in thoughts, disorientation, memory disorder, perception disorder (illusion, hallucination, and weird fantasies), deteriorations in sleep-wake cycle, convulsions, agitation and excessive excitement disorders are present. It emerges due to high fever caused by infection, toxic situations or alcohol. Patient is hyperactive and gives irrelevant answers to questions [4,5]. It emerges as delirium tremens due to the deterioration of the metabolism of nerves in brain.

Stupor

They move very little spontaneously and do not response if the stimulants are not given repeatedly. Incomprehensible voices and/or blinking may be seen. They respond to painful stimulants [4,5]. They cannot fulfill their responsibilities and there is a high risk of injury. Full attention and care is necessary. Physical and mental activities are at minimum level. Response to oral stimulants is inadequate. They respond to light, loud voices and painful stimulants [4,5].

Coma

Patient cannot respond to oral stimulants. Patient in minor or moderate coma wants to distract painful stimulant or give response by wincing. Patients do not respond to painful stimulant in severe coma. Extremities are relaxed and motionless. There is no response to painful stimulants. Incontinence is present. Pupillas might be dilated of constricted [4,5]. Asses for mental impairment using the Abbreviated Mental Test Score (AMTS). Each guest ion is valued at 1 point. A score of 6 or less suggests mental impairment that requires further testing (Table 2) [6].

Table 2: Abbreviated mental test score.

Nurses have a lot of responsibility requiring complex knowledge and skills for the evaluation of the neurological functions at intensive care units. Gathering subjective and objective data, patient preparation and monitorization are among these responsibilities. However, interpretation of the changes in classic sensor motor examination may vary from person to person [7]. For this reason, there are several scales to evaluate both the consciousness level and neurological state of the patients more objectively. Glasgow Coma Scale (GCS), FOUR (full outline of unresponsiveness score), Mains Emergency Evaluation Scale, Reaction Level Scale and Reviewed Trauma Scale are examples of these scales. GCS is the most precedence one among them [7].

In Which Situations Glasgow Coma Scale Is Used?

1. Spontaneous Subarachnoid Hemorrhage

2. Spontaneous Intracerebral Hemorrhage

3. Ischemic Stroke

4. Intracerebral infection and brain abscess

5. General Trauma

6. Non-traumatic coma

7. Intoxication.

Evaluation of Glasgow Coma Scale

When using GCS, it should be reminded that a clear assessment of sedation, drug use, alcohol intoxication, shock and low blood oxygen cannot be done (Table 3) [8-10].

Table 3: GCS assessment skor.

When and How often is GCS used when Evaluating GCS?

Until GCS is equal to 15= Observe and record in every half hour. For patients whose GCS is 15; start after the first assessment at emergency unit and the minimum observation frequency should be; For 2 hours= Once in every half hour, for 4 hours= Once in an hour, at final = once in every 2 hours [11].

How Much Change in GCS is Significant?

A constant (minimum 30 mins) one point decrease (One point decrease in GCS motor score is more significant). If the Oral Response scores decreases; Oral score should be checked before the change. The situation changed in the scale and the amount of the change should be checked: Motor Response usually requires a faster intervention than eye opening and oral response [11].

Sensory Examination

Various features are tested during somatic nerve examination. Every feature is carried through spinal cord before reaching sensorial cortex. Patients must keep their eyes closed all the time during sensory examination in order to avoid visual clues. Sensory tests of four extremities are adequate for the routine neurological examination. First, patient’s subjective complaints are recorded and patient’s cooperation should be fine. After that objective sensory examination is conducted. It should be identified if the sensory deficits are suitable to the anatomic localizations [12]. Light touch, pain and heat, sense of vibration and position and cortical sensorial functions are controlled when evaluating sensorial system.

Cortical sensory examination

Sterognatic, two point discrimination, grafesthesia and tactile localization is used (Table 4) [12].

Table 4: Sensory examination

Evaluation of Motor Functions

Muscular strength, muscular tonus, muscular atrophy and involuntary movements are taken into consideration when evaluating motor functions. Initially, muscles should be inspected for size and shape. The presence of atrophy is noted. The patients are instructed to relax the extremity while the nurse performs passive range-of-motion movement and evaluates the degree of resistance. Muscle tone is appraised for sings of flaccidity (no resistance), hypotonia (little resistance), hypertonia (increased resistance), spasticity, or rigidity [4]. Second, muscle strength in the upper and lower extremities is assessed by having the patient perform a number of movements and movement’s against resistance. Muscle Strength Grading Scale graded on the six point scale (Table 5) [4].

Table 5: Muscle strength grading scale.

Reflexes

Nervous system, which serves as a regulator of all the incidents in an organism, performs these functions is reflexes. A reflex is a response given by the organism to a stimulant. It is performed with the help of central nervous system and without conscious [1-3]. A simple reflex is usually executed by swiftly hitting the tendon of the muscle with a reflex hammer. When the tendon is stretched, a reflex stretch in the skeletal muscle occurs. Normal reflexes are the reflexes found in neurologically healthy individuals and classified in 3 groups [1-3].

Superficial reflexes: Corneal reflex, pharyngeal reflex, palatine reflex, abdominal reflex, plantar reflex and anal reflex.

Deep tendon reflexes: When the relevant muscle is hit by the reflex hammer, muscle stretches. Biceps reflex, ciliospinal reflex, oculocardiac reflex (deceleration in cardiac rhythm when eyeballs are pressed), carotids reflex (decrease in cardiac rhythm and blood pressure when carotid sinus in neck is pressed) are among these reflexes. Pathological reflexes are reflexes which normal people do not have [1-3].

Visceral reflexes: Light reflex, ciliospinal reflex (dilatation of the pupillas when neck is scratched), oculo-cardiac reflex (deceleration in cardiac rhythm when eyeballs are pressed), karotis sinus reflex (decrease in cardiac rhythm and blood pressure when carotic sinus in neck is pressed) [1-3].

Pathological reflexes: Pathological reflexes are reflexes which normal people do not have. These reflexes are Babinski reflex, clonuses and Hoffman sign [1-3].

How to Assess the Cranial Nerves

Visual fields are tested by having the patient look straight ahead with one eye covered. The examiner moves a finger from the periphery of each quadrant of vision toward the patient’s center of vision (Table 6). The patient should indicate when the examiner’s finger is seen. This is done for both eyes, and the results are compared with the examiner’s visual fields, which are assumed to be normal (Table 7) [12].

Table 6: Cranial nerves function and examine.

Table 7: Visual field defects associated with defects on the visual system.

Pupillary Function and Assessment

Asessment of pupillary function focuses on three areas: 1. Estimation of pupil size and shape, 2. Evaluation of pupillary reaction to light and 3. Assessment of eye movement.

Estimation of pupil size and shape

Pupil diameter should be documented millimeters (mm) with the use of a pupil gauge to reduce the subjectivity of description. Most people have pupils have equal size between 2 and 5 mm. [4]. The other pupil description and condition have table 8.

Table 8: Recognizing Pupillary Changes.

The technique for evaluation of the pupillary right response involves use of a narrow-beamed bright light shined into the pupil from the outer canthus of the eye [4]. If the light is shined directly onto the pupil, glare or reflection of the light may prevent assessor’s proper visualization. Pupillary reaction to light is identified as brisk, sluggish, or nonreactive or fixed. Each pupil should be evaluated fordirect light response and for consensual response [4].

Assessment of eye movement

Extraocular eye movements are controlled by muscles innervated by cranial nerves III, IV, and VI. To test extraocular movements, the patient is asked to follow an object through six positions. A normal response consists of the eyes moving in the same direction, at the same speed, and in constant alignment. Abnormal eye movements include nystagmus or an extraocular palsy. Mild nystagmus with extreme lateral gaze may be normal. Dysconjugate gaze, in which the eyes are not aligned, is an abnormal finding (Table 8) [13]. Bilaterally dilated pupillas, bigger than 5 mm, indicates me encephalon damage.

Coma, atropine (for fundus oculi examination). Eye assessment; Pupil, Equal, Round, Reactive, Light, (PERRLA) method is used. The popular acronym PERRLA-pupils equal, round, and reactive to light and accommodation-is a convenient but incomplete description of pupillomotor function. It specifically omits important clinical data such as the actual size and shape of each pupil, the speed and extent of pupillary constriction, and the results of determining an afferent pupillary defect [15]. Consequently, since nurses monitor the patients closely for 24 hours, having advanced skills and knowledge in the assessment of neurological functions will be beneficial for the early detection of complications, survival, patient prognosis and increase in the life quality.

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Citation

TOPBA? E. Diagnosis and Monitoring of Neurological Changes in Intensive Care. SM Emerg Med Crit Care. 2018; 2(1): 1019.