CBT443: Altered Mental States 2010
© 2010 Seattle / King County EMS
Introduction
• Consciousness is being awake, alert, and
aware of your surroundings.
• A healthy person is aware of thoughts,
ideas and emotions when conscious.
• There are varying degrees of consciousness
ranging from conscious and alert to
lethargic to obtunded.
It is important for the EMS provider to
accurately assess and recognize changes
in a patient’s level of consciousness.
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Terms
brainstem — Area of the brain between the spinal cord
and cerebellum. The brain stem controls basic functions
that do not require conscious attention such as
breathing, digestion and heart activity.
central nervous system (CNS) — The main part of the
nervous system that includes the cerebrum,
cerebellum, brain stem and spinal cord.
cerebrum — Largest part of the brain. It controls
thought, movement, hearing, vision, speech, emotions
and personality.
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Terms, continued
cerebellum — A division of the brain also called the
“little brain.” It is located below the cerebrum and
coordinates involuntary and “primitive” functions such
as balance.
coma — A state of deep, often prolonged
unconsciousness, usually the result of injury, disease or
poison, in which a person cannot sense or respond to
external stimuli and internal needs.
neuron — A specialized type of cell whose main role is
to process and transmit information.
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Terms, continued
peripheral nervous system — This division of the
nervous system includes sensory and motor nerves
coming from the spinal cord and brain stem that run to
the body’s organs, skin and muscles.
postical state — The period following a seizure or
convulsion characterized by motor weakness, lethargy,
confusion and nausea.
tonic-clonic seizure — A type of seizure involving the
entire body, usually characterized by violent rhythmic
muscle contractions and loss of consciousness.
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Terms, continued
acidosis — Excessive acid in the blood.
lethargy — Pertaining to or resembling drowsiness.
miosis — Constriction of the pupil of the eye, resulting
from a normal response to an increase in light or
caused by certain drugs or pathological conditions.
obtunded — Dulled or deadened, responds to pain.
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Terms, continued
reticular activating system (RAS) — An area of nerves
in the brainstem, thalamus and hypothalamus that
controls consciousness.
toxidrome — A listing of specific signs and symptoms
caused by exposure to specific types of poisons or
toxins.
uremia — A condition resulting from advanced stages
of kidney failure in which urea and other “waste
products” are found in the blood in high concentration.
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Central Nervous System (CNS)
• Includes the brain and spinal cord
• Helps control all of the body systems
and organs
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Peripheral Nervous System
• Made of all the nerves that project out
of the brain and spinal cord
• Provides direct input to the central
nervous system from sensors in the
body
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Peripheral Nervous System
• Motor nerves extend from the spinal
cord and control the muscles of the
body
• Sensory nerves allow sensations of
feeling, hot or cold and travel back to
the spinal cord and up to the brain
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The Brain
cerebrum
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thought
personality
memory
motor skills
tactile (touch)
speech
vision
The Brain, continued
cerebellum
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coordination
balance
basic movement
muscle tone
The Brain, continued
brain stem
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• heart function
• respiration
• autonomic nervous
system
• digestion
• glandular secretions
4 Things You Need to Conscious
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Sugar
Oxygen
Intact neural pathways
Intact reticular activating system (RAS)
Anything that disturbs or disrupts these
can cause alterations in mental status.
© 2010 Seattle / King County EMS
Sugar
• Sugar (in the form of glucose) is the fuel on
which the brain runs.
• Oxygen is needed by brain cells to carry out
metabolism.
A sudden lack of blood flow to the brain
or lack of oxygen will shut the brain
down in 5 to 10 seconds.
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Neural Pathways
• Groups of nerves that run through the brain
• Carry signals from the brainstem to various
destinations in the brain
• These pathways can be disturbed by trauma,
tumors, chemicals (drugs) or electrical
interference (that which cause seizures).
• Stroke, epilepsy, and trauma are different
events that affect these pathways resulting
in altered mental states.
© 2010 Seattle / King County EMS
Intact RAS
• Consciousness center of the brain that
maintains wakefulness
• Small area of nerves in the brainstem that
controls consciousness
Altered LOC is a strong indication of
insult to the central nervous system.
© 2010 Seattle / King County EMS
AEIOU-TIPS
• A commonly used mnemonic to help
remember the causes of altered mental
states.
• BLS providers are not expected to know
and recognize all these causes, but it is
helpful to be familiar with them in order
to know what types of questions to ask
when assessing a patient.
© 2010 Seattle / King County EMS
Acidosis
Acidosis is the increase in the acid level in
the body. Its causes include:
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diabetes
shock
poisoning
overdose
kidney failure
impaired breathing
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Alcohol
• A depressant that inhibits the brain
• As the blood alcohol level rises, reason
and judgment are impaired.
• Intoxicated patients may progress from
stupor to coma to death primarily from
respiratory depression and arrest.
• These people cannot maintain their airway
and are in danger of aspirating their saliva
or vomitus.
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Epilepsy/Seizures
• occurs when the neural pathways become
disturbed by excessive discharge of electricity
in the brain
• can affect either part of the brain or the
whole brain itself
• Alcohol withdrawal in addicts may cause
seizures due to disruptions in the neural
pathways.
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Infection
• Usually causes high temperatures and
inflammation that affect the brain’s
neural pathways, the brainstem and
supplies of sugar and oxygen
• Infection of the central nervous system,
such as meningitis or encephalitis, may
cause an altered LOC.
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Overdose
• Barbiturates and narcotics (for example,
heroin) are drugs that can suppress
brainstem function.
• Narcotics can slow the respiratory centers
of the brain resulting in a lack of oxygen.
• Cocaine can produce extreme CNS
stimulation resulting in seizures and
strokes.
© 2010 Seattle / King County EMS
Underdose/Uremia
• Some medical conditions may cause
altered LOC when the patient does not
take adequate amounts of his or her
prescribed medication.
• Diabetic coma may occur in diabetics
who do not take adequate amounts of
insulin.
• COPD patients can develop an altered
LOC from retaining too much carbon
dioxide when they do not use medicines
delivered by their metered-dose inhaler.
© 2010 Seattle / King County EMS
Trauma/Tumors/Temp
• Trauma to the head can cause damage to
vessels and brain tissue.
• Tumors can affect neural pathways and the
brainstem, neural pathways, oxygen and
sugar.
• Temperature extremes have a dramatic
impact on all four elements of consciousness.
© 2010 Seattle / King County EMS
Insulin
• The insulin-dependent diabetic produces an
insufficient amount of insulin and must
inject insulin into the body.
• If the diabetic forgets to eat, overexerts, or
takes too much insulin, there is a serious
shortage of glucose (hypoglycemia).
• The brain, which is very sensitive to sugar
supplies, begins to shut itself down.
• Another condition called hyperglycemia
may occur when there is not enough insulin
in the blood.
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Psychosis
• A mental illness that commonly affects
personality, for example, schizophrenia and
manic depression.
• Delirium and acute brain syndrome are
specific types of psychoses where the patient
displays disorientation, memory-loss, and
lapses in consciousness.
• Common medications for these patients
include lithium (Lithobid, Eskolith),
risperidone (Rusoerdak) and olanzapine
(Zyprexa).
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Poisoning
• Mechanism that causes unconsciousness
varies greatly depending on the substance.
• Carbon monoxide prevents oxygen from
reaching the brain.
• An overdose of tricyclic antidepressants can
cause hypotension, cardiac dysrhythmias and
a lack of oxygen and sugar.
Poisoning can occur through ingestion,
inhalation, injection, absorption and ingestion.
© 2010 Seattle / King County EMS
Stroke
• A stroke occurs when a portion of the brain is
damaged due to interruption of blood flow
(lack of sugar and oxygen).
• Strokes affecting one side of the brain may
cause altered LOC.
• Massive strokes involving the brainstem will
cause coma.
• Transient ischemic attacks (TIAs) can be
thought of as "mini-strokes"—symptoms of
these events subside completely within 24
hours.
© 2010 Seattle / King County EMS
Scene Size-up
• Observe the surroundings, the patient’s
body position, bystanders and other clues
that may indicate danger to you, your
crew or the patient.
• Decide if it safe to enter the scene and if
you need additional resources.
© 2010 Seattle / King County EMS
Baseline LOC
• LOC is the single most important element in
the assessment of a patient with altered LOC.
• Establish a baseline LOC using AVPU early.
• Document the baseline LOC and subsequent
changes.
• Be specific about what you observe.
• Repeat LOC checks every few minutes to
detect changes and trends.
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Noxious Stimuli
A noxious stimulus is a test of central
nervous system function.
Document the reaction to the stimulus:
• Appropriate response (e.g. attempts
to push away the stimulus)
• Inappropriate response (e.g.
decerebrate posturing)
• No response
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Focused History
• The key to a good assessment of an altered
level of consciousness is taking a thorough
history and examining the surroundings for
clues about what happened.
• Remember to look for medic-alert
information on necklaces or bracelets.
• You may need to check refrigerators,
medicine cabinets and bedside tables.
© 2010 Seattle / King County EMS
Physical Exam
A complete physical exam for a patient with
an altered level of consciousness should
include:
• Assess LOC
• Check vital signs
• Check pupils for size, symmetry and
reactivity to light
• Auscultate breath sounds
• Glucometry
• Pulse oximetry
© 2010 Seattle / King County EMS
AVPU
• Alert means the patient is awake and aware
of his surroundings. The oriented patient
remembers person, place, time, and event.
• Verbal means that the patient awakens or
responds to verbal stimulus. Use a simple
command such as "stick out your tongue."
• Pain means the patient awakens or responds
to painful stimulus.
• Unresponsive means the patient does not
respond to verbal or painful stimuli.
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Pupil Response
• Pupils should respond briskly and equally
to a penlight.
• Abnormal pupil response may indicate
depressed brain function or central
nervous system depression or injury.
• Record the results of this check—even if
it is negative.
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ABCs
• Airway, breathing and circulation (ABCs)
must be monitored closely.
• An altered mental status especially requires
that you attend to the airway and breathing.
• You may need to manually hold the airway
open, remove obstructions, or breathe for a
patient using a BVM and high-flow oxygen.
• Consider the use of an airway adjunct if the
airway cannot be maintained.
© 2010 Seattle / King County EMS
Oxygen
• Oxygen is vital to sustaining the brain and
maintaining consciousness.
• Remember that unresponsive patients can
lose their gag and cough reflexes.
• Keep the airway clear and open and monitor
the airway closely.
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Patient Position
• Position the patient according to the
suspected illness or injury.
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Summary
• The central nervous system includes the
brain and spinal cord.
• The peripheral nervous system is made of all
the nerves that project out of the brain and
spinal cord
© 2010 Seattle / King County EMS
Summary, continued
The four things the brain needs to be
conscious and alert:
•
•
•
•
Sugar
Oxygen
Intact neural pathways
Intact reticular activating system (RAS)
© 2010 Seattle / King County EMS
Summary, continued
Major causes of altered mentation are
AEIOU-TIPS:
• Acidosis, Alcohol
• Trauma, Tumors,
Temperature
• Epilepsy/Seizures
• Insulin
© 2010 Seattle / King County EMS
•
•
•
•
•
Infection
Psychosis, Poisoning
Overdose
Stroke
Underdose, Uremia
Summary, continued
• The major safety concern associated with
overdose patients is protecting you and your
crew.
• The first step in the assessment of a patient
with altered mentation is determining
baseline LOC.
© 2010 Seattle / King County EMS
Summary, continued
The essential components of a physical
exam for a patient with an altered LOC:
• Assess LOC
• Check vital signs
• Check pupils for size, symmetry and
reactivity to light
• Auscultate breath sounds
• Glucometry
• Pulse oximetry
© 2010 Seattle / King County EMS
Summary, continued
• Abnormal pupillary response may indicate
depressed brain function or brain injury.
• Proper emergency care for a patient with an
altered mental status includes the ABCs,
oxygen therapy to meet patient needs and
proper positioning.
© 2010 Seattle / King County EMS
Resources
The recertification exam for this module is
based on a variety of resources. We
recommend that you review the following:
• Chapter 13: Neurologic Emergencies in
Emergency Care and Transportation of the
Sick and Injured, 9th edition (AAOS).
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Questions
EMS Online
Guidelines and Standing Orders
http://www.emsonline.net/downloads.asp
Tracey White
Training Division Manager
Email support: help@emsonline.net
Dr. Mickey Eisenberg
Medical Director
Ask the Doc: http://www.emsonline.net/doc.asp
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