Download Care of Patient With Coma

Care of Patient With Coma
Dr. Belal Hijji, RN, PhD
November 12, 2011
Learning Outcomes
At the end of this lecture, students will be able to:
• Describe what coma is, identify its causes, and discuss its
pathophysiology.
• Discuss assessment and clinical diagnosis of coma and
vegetative state.
• Describe the medical and nursing management of coma.
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Description of Coma and its Causes
• Normal consciousness requires awareness (cognition and
affect) and arousal. Deficits in awareness, arousal, or both may
result in altered consciousness.
• In coma, a patient is in the deepest state of unconsciousness;
awareness and arousal are lacking.
• Coma is a symptom not a disease; its causes are structural
(ischemic stroke, intracerebral hemorrhage, trauma, and brain
tumors) and metabolic (as in the case of drug overdose,
infectious disease, endocrine disorders, and poisoning).
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Pathophysiology of Coma
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• Ascending fibers of the reticular activating system (ARAS) in
the pons (contains respiratory centre; connects spinal cord with
brain & parts of brain with each other) , hypothalamus
(Reception of sensory impulses from viscera, control of body
temperature) and thalamus (relay station for nearly all sensory
impulses) are responsible for arousal.
• Neurons (see next slide) in the cerebral cortex (responsible for
thinking, learning, creativity, memory and emotion, and
decision-making) are responsible for awareness.
• Diffuse dysfunction of cerebral hemispheres and diffuse or
focal dysfunction of the RAS can cause coma.
• Structural causes produce dysfunction in ARAS; most
metabolic causes result in general dysfunction of cerebral
hemispheres.
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Diagnosis of Coma
• Patients in coma lie with their eyes closed and are unable to
interact meaningfully with the environment. Patients do not
communicate or perform intentional movements. Specific
diagnostic criteria for coma is presented on next slide.
• Coma is a time-limited condition; by 4 weeks after onset,
surviving individuals have either emerged into more
responsive states or have begun exhibiting signs of the
vegetative state (VS).
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Neurobehavioral Criteria for the Diagnosis of Coma
1. Eyes do not open spontaneously or to stimulation
2. Patient does not follow commands
3. Patient does not mouth or utter recognizable words
4. Patient does not demonstrate intentional movements
5. Patient cannot sustain visual pursuit movements when eyes
are manually held open
6. Criteria 1 through 5 are not secondary to use of paralytic
agents
American
Congress
of
Rehabilitation
Medicine.
Recommendations for use of uniform nomenclature pertinent to patients
with severe alterations in consciousness. Arch Phys Med Rehab
1995;76:205–209.
SOURCE:
Diagnosis of Vegetative State
• Patients in VS:
–
–
–
–
have the ability to open eyes and long periods of wakefulness
lack meaningful interaction with the environment
may open their eyes spontaneously or in response to stimuli
cannot communicate, follow commands, or demonstrate
intentional movements.
• For diagnosis to be considered, a number of conditions must
be met (see next slide).
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Neurobehavioral Criteria for the Diagnosis of the VS
• no evidence of awareness of self or environment, no volitional
[‫ ]إرادي‬response to visual, auditory, tactile or noxious stimuli and no
evidence of language comprehension or expression
• presence of cycles of eye closure and eye opening
• sufficient preservation of hypothalamic and brain-stem function to
ensure maintenance of respiration and circulation
• incontinence of bladder and bowel
• no visual fixation or tracking
• Inconsistent motor activity, without purpose and explainable as a
reflex response to external stimuli
SOURCE: Royal College of Physicians of London (1996) The permanent
vegetative state. Report by a working group convened by the Royal College
of Physicians and endorsed by the Conference of Medical Royal Colleges
and their faculties of the United Kingdom. Journal of the Royal College of
Physicians of London 30: 119–21.
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Medical Management of a Patient With Coma
• The main goal of medical management is to identify and treat
the underlying cause of coma.
• Initial emergency medical treatment aims to support vital
functions and prevent neurologic deterioration.
• Patients often need airway protection and ventilatory assistance.
• If the cause of coma is not immediately known, experts suggest
the administration of , at least, 100 mg of thiamine [vitamin B1],
followed by glucose and opoid antagonist [naloxone].
• Unresolved coma after emergency treatment requires supportive
measures to maintain physiologic body functions and prevent
complications.
• Intubation and nutritional support are essential. Anticonvulsant
therapy may be indicated to prevent further brain damage due to
ischemia.
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Nursing Management of a Patient With Coma
• Nursing diagnoses:
– Ineffective airway clearance related to excessive secretions.
– Ineffective breathing pattern related to decreased lung expansion.
– Imbalanced nutrition: Less than body requirements related to lack
of exogenous nutrients.
– Risk for aspiration.
– Risk for infection
• Nurses are responsible for monitoring and assessing changes in
neurologic status.
• Nurses support body functions by promoting pulmonary hygiene
[postural drainage, deep breathing, coughing], maintaining skin
integrity, initiating range-of-motion exercises, and ensuring
adequate nutritional support. Of particular importance is nurses’
attention to eye care which is presented next.
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• Eye care:
– The blink reflex is often diminished or absent in a comatose
patient. Blinking is an essential function of the eye that helps
spread tears across, protects the eye from, and remove, irritants.
Blinking moistens the eye by irrigation using tears and a lubricant
the eyes secrete. The eyelid provides suction across the eye from
the tear duct to the entire eyeball to keep it from drying out.
– Loss of the blink reflex results in drying and ulceration of the
cornea which may lead to permanent blindness.
– Therefore, nurses play a vital role in protecting the eyes of a
comatose patient by normal saline instillation every 2 hours and
tapping the eyelids in the shut position.
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