© 2010 seattle / king county ems cbt443: altered mental states 2010

© 2010 Seattle / King County EMS

CBT443: Altered Mental States 2010


Introduction

It is important for the EMS provider to accurately assess and recognize changes

in a patient’s level of consciousness.

It is important for the EMS provider to accurately assess and recognize changes

in a patient’s level of consciousness.

• 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.


Termsbrainstem — 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.


Terms, continuedcerebellum — 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.


Terms, continuedperipheral 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.


Terms, continuedacidosis — 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.


Terms, continuedreticular 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.


Central Nervous System (CNS)• Includes the brain and spinal cord• Helps control all of the body

systems and organs


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


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


The Brain

• thought• personality• memory• motor skills• tactile (touch)• speech• vision

cerebrum cerebrum


The Brain, continued

• coordination• balance• basic movement• muscle tone

cerebellum cerebellum


The Brain, continued

• heart function• respiration• autonomic nervous

system• digestion• glandular secretions

brain stembrain stem


4 Things You Need to Conscious• Sugar• Oxygen• Intact neural pathways• Intact reticular activating system (RAS)

Anything that disturbs or disrupts these can cause alterations in mental status.

Anything that disturbs or disrupts these can cause alterations in mental status.


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.

A sudden lack of blood flow to the brain or lack of oxygen will shut the

brain down in 5 to 10 seconds.


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.


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. Altered LOC is a strong indication of

insult to the central nervous system.


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.


Acidosis

Acidosis is the increase in the acid level in the body. Its causes include:

• diabetes• shock• poisoning• overdose• kidney failure• impaired breathing


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.


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.


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.


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.


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.


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.


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.


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).


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.

Poisoning can occur through ingestion, inhalation, injection, absorption and ingestion.


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.


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.


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.


Noxious StimuliA 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


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.


Physical ExamA 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


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.


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.


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.


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.


Patient Position

• Position the patient according to the suspected illness or injury.


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


Summary, continued

The four things the brain needs to be conscious and alert:

• Sugar• Oxygen• Intact neural pathways• Intact reticular activating system

(RAS)


Summary, continued

Major causes of altered mentation are AEIOU-TIPS:

• Acidosis, Alcohol• Trauma, Tumors,

Temperature• Epilepsy/Seizures• Insulin

• 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.


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


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.


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).


Questions

Dr. Mickey EisenbergMedical DirectorAsk the Doc: http://www.emsonline.net/doc.asp

EMS OnlineGuidelines and Standing Ordershttp://www.emsonline.net/downloads.asp

Tracey WhiteTraining Division ManagerEmail support: [email protected]

© 2010 seattle / king county ems cbt443: altered mental states 2010

Documents

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