Chap 19 Flashcards
RAS
Reticular Activating System- series of neurological circuits in the brain that control the functions of staying awake, paying attention and sleeping
The brain tissue of the RAS has simple requirements to function properly and thereby keep a person alert and oriented. oxygen is needed to perfuse brain tissue, glucose is needed to nourish brain tissue and water is needed to keep brain tissue hydrated. Other harm to the brain such as trauma, infection, and chemical toxins (as in overdose and substance abuse)
Altered mental status can result from a primary brain problem, such as a stroke or symptom of a problem within another system such as hypoxia due to asthma.
Most common cause of altered mental status
Hypoxia
Baseline level of consciousness
Ask parents, family member, or bystanders that would know if this is the patients normal acting behavior
Glucose
a form of sugar, the body’s basic source of energy
Comes from sugar we eat or carbohydrates that the digestive system will convert to glucose
The glucose molecule is large and will not pass into most cells without the assistance of insulin. The pancreas secretes insulin when the blood glucose rises above 90mg/dL. insulin binds to receptor sites on cells- especially those in the liver and muscles-and allows the large glucose molecule to pass into the cells
Patients who are diabetic
- Don’t produce insulin
- Don’t produce enough insulin
- Have a body that has become resistant to the insulin that is produced
Insulin-Glucose relationship has been described as the “lock and key” mechanism
insulin
A hormone produced by the pancreas or taken as a medication by many diabetics
Insulin and the pancreas
Within the pancreas, specialized clusters of cells called the islets of Langerhans secrete insulin. Brain cells do not require insulin to move glucose from the bloodstream.
Diabetes Mellitus
Also called “sugar diabetes” or just diabetes.
1 in 17 or 16 million Americans have diabetes
-Underproduction of insulin or inability of the bodies cells to use insulin properly
Type 1 diabetes
Formerly known as insulin-dependent diabetes
Occurs when pancreatic cells fail to function properly and insulin is not secreted normally.
Synthetic insulin is used to supplement
Type 2 diabetes
Formerly known as non-insulin-dependent diabetes
Occurs when the body’s cells fail to use insulin properly. The pancreas may be secreting enough insulin but the body is unable to use it to move glucose out of the blood and into the cells. Patients with type 2 diabetes can often control their condition with diet and/or oral antidiabetic medications
Hypoglycemia
Low blood sugar
Caused by
- Takes too much insulin thereby transferring glucose into the cells too quickly and causing rapid depletion of available sugar
- Reduces sugar intake by not eating
- Over exercises or overexerts himself, thus using sugars faster than normal
- Vomits a meal, emptying the stomach of sugar as well as other food
- Increases the metabolic rate in conditions such as fever or shivering
- Rapid onset
- Abnormal behavior that often mimics a drunken stupor
- Responds with a fight or flight response. The sympathetic nervous system signals the liver to release glycogen (a form of stored sugar) in an attempt to raise blood glucose levels. Signs of this sympathetic discharge, which are very common, including pale, sweaty skin; tachycardia; and rapid breathing. Seizures can occur as a result of altered brain function.
Treatment
-Oral glucose to patient with altered mental status, conscious (able to swallow), and has a history of diabetes
Hyperglycemia
High blood sugar
Hyperglycemia is usually caused by a decrease in insulin which leaves sugar in the bloodstream rather than helping it to enter the cells. The insulin deficiency may be due to the body’s inability to produce insulin or may exist because insulin injections were forgotten or not given in sufficient quantity. Infection, stress or increasing dietary intake can also be a factor
- typically develops over days and even weeks-in contrast to the typical rapid onset of hypoglycemia. Glucose levels in the blood creep up while the cells of the body begin to starve for sugar. As blood sugar levels increase, the patient may complain of chronic thirst and hunger. In an attempt to rid the blood of excess sugar, the body will increase urination. Nausea is also a frequent complaint
- Extremely high levels of sugar in the blood begin to draw water away from the body’s cells, potentially resulting in profound dehydration. Starving body cells begin to burn fats and proteins in a manner that results in excessive waste products being released into the system. These waste products build up and combine with dehydration to cause a condition called diabetic ketoacidosis (DKA). A person who has diabetic ketoacidosis will commonly have a profoundly altered mental status. He will also have the signs and symptoms of severe shock, caused by dehydration. A waste product of DKA is ketones. This complication will make breathing rapid and often a fruity, acetone odor on his breath.
Glucose readings
Value less than 60mg/dL- in a symptomatic diabetic patient with a mild alteration in mental status or who is diaphoretic is typically of hypoglycemia. Patients values less than 50mg/dl will typically have significant alterations in mental status that may include complete unresponsiveness. Often will be unable to receive glucose safely.
A value of greater than 140 indicates hyperglycemia. Patients in the mid and high 100s are often without acute symptoms, although over time this level of hyperglycemia can cause damage to various organs. Levels greater than 300, especially for a prolonged time, may experience dehydration and other more serious symptoms
If reading is inconsistent with patients symptoms, potential of inaccurate results
Sometimes a reading of High/ HI means excess of 500mg/dL and LOW less than 15mg/dL
Hypoglycemia and Hyperglycemia compare
Onset- Hyperglycemia usually has a slower onset, whereas hypo tends to come on suddenly. this is because some sugar still reaches the brain in hyper. With hypo, it is possible that no sugar reaching the brain. Seizures may occur
Skin- Hyper patients often have warm, red, dry skin. Hypo patients have cold, pale, moist, or clammy skin
Breath- Hyper often have acetone breath. Hyper also breathe very deeply and rapidly as though they have just run a race. Dry mouth, intense thirst, abdominal pain and vomiting are all common signs and symptoms
Rule of thumb for diabetics
“Sugar for everyone”
Sepsis
Infection, especially a severe, systemwide response to infection
One of the most dangerous causes of altered mental status. Normally when an infection occurs, the body takes steps to fight the invaders locally at the site of infection. Blood vessels dilate to allow white blood cells to respond and capillaries become more permeable to allow fluid to dilute toxins released by the invaders. Severe sepsis occurs when these steps move from the local site of infection and become a systemic problem (systemic inflammatory response). The vasodilation that once helped move white blood cells now causes a severe drop in pressure within the cardiovascular system. Distributive shock results. The capillary permeability that helped dilute toxins now results in a massive fluid shift out of the cardiovascular system, causing hypovolemic shock. These two combined factors can lead to massive hypo perfusion of the body tissues. Finally if the infection becomes severe enough, the offending microbes, such as bacteria, can release toxins that harm cardiac out-put, furthering the shock state.
Three types of infections most commonly associated with severe sepsis are respiratory infections and pneumonia, urinary tract infections (UTI’s), and skin/wound infections.
Evidence of severe sepsis
- Altered mental status
- Increased heart rate
- Increased respiratory rate
- Low blood pressure
- High blood glucose levels
- Decreased capillary refill time
Always suspect sepsis in patients with altered mental status and recent infections
Seizure disorders
If a normal function of the brain are upset by injury, infection, or disease, the brains electrical activity can become irregular. A seizure (fit, spell or attack) is a sudden change in sensation, behavior or movement. The most severe form of seizure produces violent muscle contractions called convulsions. A seizure is not a disease in itself but rather a sign of some underlying defect, injury, or disease.
Two types of seizures
- Partial Seizure- Affect only one part, or one side of the brain
- Generalized Seizure- Affect the entire brain and as a result affect the consciousness of the patient
Tonic-clonic- generalized seizure in which the patient loses consciousness and has jerking movements of paired muscle groups. The patient will thrash about wildly, using his entire boy. The convulsions usually lasts only a few minutes and has three distinct phases
- tonic phase- The body becomes rigid, stiffening for no more than 30 secs. Breathing may stop, the patient may bite his tongue (rare) and bowel and bladder control could be lost
- clonic phase- The body jerks about violently, usually for no more than 1 or 2 minutes (some can last 5 minutes). The patient may foam at the mouth an drool. His face and lips often become cyanotic
- Postictal phase- Begins when convulsions stop. the patient may regain consciousness immediately and enter a state of drowsiness and confusion, or he may remain unconscious for several hours. Headache is common
Some seizures are preceded by an Aura ( a sensation experienced by a seizure patient right before the seizure, which might be a smell, sound, or general feeling. Its important to document this findings when it exists.
Causes of seizures
The most common cause of seizure in adults is failure to take prescribed antiseizure medication. The most common cause of seizures in infants and children six months to 3 years of age is high fever (febrile seizures)
- Hypoxia
- Stroke
- Toxins
- Hypoglycemia
- Brain tumor
- Congenital brain defects- Defects one is born with, often in infants and children
- Infection
- Metabolic- Irregularities in the patients body chemistry
- Idiopathic- Occurring spontaneously with an unknown cause
Seen with
- Epilepsy- umbrella term for a person that has multiple seizures for unknown causes
- Measles, mumps and other childhood diseases
- Eclampsia- a severe complication of pregnancy
- Heat stroke
Seizure disorders assessment
What was the person doing before the seizure started? Was there an aura?
Exactly what did the person do during the seizure- movement by movement-especially at the beginning? Was there loss of bladder and/or bowel control?
How long did it last?
What did the person do after the seizure? was he asleep and for how long? Was he awake? Was he able to answer questions?
Seizure care
Present during convulsive seizure
- Place the patient on the floor or ground. If there is no possibility of spine injury, position the patient on his side for drainage from the mouth
- Loosen restrictive clothing
- Remove objects that may harm the patient
- Protect the patients from injury but do not try to hold the patient still during convulsions
After convulsions have ended
- Protect the airway
- If the patient is cyanotic, ensure an open airway and provide artificial ventilations wit supplemental oxygen
- Treat any injuries the patient may have sustained during convulsions
- Transport
Status epilepticus
Seizures usually last no longer more than 3 minutes. When the patient has two or more convulsive seizure in a row without regaining full consciousness or a single seizure lasting more than 10 minutes, it is known as status epilepticus
Partial seizure
also called focal motor, focal sensory or jacksonian
Tingling, stiffening, or jerking in just one part of the body. There may also be an aura, which sensation such as a smell, bright lights, a burst of colors, or a rising sensation in the stomach. There is no loss of consciousness. In some cases the jerking may spread and develop into tonic-clonic seizures.
A complex partial seizure (psychomotor or temporal lobe) is often preceded by an aura. It may involve confusion, a glassy stare, aimless moving about, lip smacking or chewing, or fidgeting with clothing. The person may appear to be drunk or on drugs. He is not violent but may struggle or fight if restrained. Very rarely such extreme behavior as screaming, running, disrobing, or showing great fear may occur. No loss of consciousness but may be confused and no memory. In some cases the seizure may develop into tonic-clonic seizures.
Generalized seizures
Tonic-clonic seizures
Absence seizure (petit mal) is brief usually less than 10 secs. There is no dramatic motor activity and the person usually does not slump or fall. Instead there is a temporary loss of concentration or awareness. An absence seizure may go unnoticed by everyone except the person and knowledgeable members of his family. A child may suffer several hundred a day, severely interfering with his ability to pay attention and do well in school. Often stops before adulthood but sometimes worsens and become tonic-clonic seizures.
Stroke
Formerly called cerebral vascular accident (CVA)
Death or injury of brain tissue that is deprived of oxygen. This can be caused by blockage of an artery that supplies blood to part of the brain or bleeding from ruptured blood vessels in the brain.
Two types of strokes
- Ischemic
- Hemorrhagic
Common signs
- one sided weakness (hemiparesis)
- Headache caused by bleeding
If the patient cried out in pain, clutched his head and collapsed, this is very important information too relay to the hospital staff. The patient may have had a particular kind of bleeding from an artery under the arachnoid layer of the meninges. This is called a subarachnoid hemorrhage. Most stroke patients are not hemorrhaging and do not experience headaches.
The left side of the brain controls the right side and vice versa, so stroke on one side of brain affects opposite side. Face muscles don’t cross over, so you’ll see sagging or drooping on same side.
The difficulty in using words is known as expressive aphasia. Aphasia is a general term that refers to difficulty in communication. Another form of it is receptive aphasia. In this case the patient can speak clearly but cannot understand what you are saying, so he will clearly say things that do not make much sense or are inappropriate for the situation
Ischemic Stroke
A stroke caused by a blockage
Hemorrhagic stroke
A stroke caused by bleeding into the brain. Frequently is the result of long-standing high blood pressure. It also can occur when a weak area of an artery (an Aneurysm) bulges out and eventually ruptures, forcing the brain into a smaller than usual space within the skull.
expressive aphasia
The difficulty in using words
receptive aphasia
In this case the patient can speak clearly but cannot understand what you are saying, so he will clearly say things that do not make much sense or are inappropriate for the situation
TIA
transient ischemic attack (mini stroke)
When this condition occurs, a patient looks as though he is having a stroke but a TIA patient has complete resolution of his symptoms without treatment within 24 hours.
With TIA, small clots may be temporarily blocking circulation to part of the brain. When the clot breaks up the patients symptoms resolve because the affected brain tissue had only a short period of hypoxia and didn’t sustain permanent damage.
Impossible to distinguish between a stroke and a TIA in the field
Three parts of the Cincinnati Prehospital Stroke Scale
- Ask the patient to grimace or smile
- Ask the patient to close his eyes and extend his arms straight out in front of him with his palms facing upward. Have him hold this position for 10 secs
- Ask the patient to say, “You can’t teach an old dog new tricks”
A patient who demonstrates any one of the three findings of the Cincinnati Prehospital Stroke Scale has a 70% chance of having an acute stroke
Other signs
- Confusion
- Dizziness
- Numbness, weakness, or paralysis
- Loss of bowel and/or bladder control
- Impaired vision
- High blood pressure
- Difficult respiration or snoring
- Nausea or vomiting
- Seizures
- Unequal pupils
- Headache
- Loss of vision in one eye
- Unconsciousness
Thrombolytic
Clot buster drug in cases of ischemic stroke
Criteria for receiving Thrombolytic
- Definite onset of stroke symptoms less than 3 hours prior to administration of the thrombolytic drug
- An emergency CT scan of the brain confirming that there is no evidence of a hemorrhagic stroke
- Blood pressure that is not excessively hypertensive at the time the drug is administered
Dizziness and syncope
Separated problems that are sometimes related.
Syncope (presyncope or near syncope)- Fainting, could be a few seconds to a few minutes
Vertigo- is the sensation of your surroundings spinning around you
Patients will often have some warning that a syncopal episode or fainting spell is about to occur. Symptoms as light-headedness, dizziness, nausea, weakness, vision changes, sudden pallor (loss of normal skin color) or sweating. Other fluttering in the chest (palpitations), a sensation of a racing heart (tachycardia), a slow heart rate (bradycardia) or headache.
Causes of dizziness and syncope
problems such as hypoxia, hypoglycemia, and hypovolemic all interfere with normal brain function. These events may happen rapidly, such as blood flow to the brain being reduced by a cardiac dysrhythmia; or they may happen slowly, such as slow gastrointestinal bleeding that finally reaches a point where the patient is unable to stand without losing consciousness.
Four main causes
Cardiovascular causes
- Tachycardia
- Bradycardia
- Carotid sinus- Under the mandible and when stimulated, it slows the heart rate down
- Vasovagal syncope (simple fainting)- stimulation of the vagus nerve which signals the heart to slow down. Frightening or emotional stress can also stimulate the nerver.
Hypovolemic Causes
- Loss of blood flow to brain from laying down to standing up
- Common causes include dehydration, internal bleeding and trauma.
Metabolic and structural causes
- Something wrong with the brain or structures near it
- Properly functioning brain is necessary to maintain consciousness, alterations in the brain chemistry or structure can lead to a diminished level of consciousness. Similarly, because the inner and middle ears must be properly functioning for a person to maintain a sense of balance, a problem in this region can lead to dizziness.
- Hypoglycemia leads to problems with the brain
- If patient syncope’s for more than a few minutes, then more serious problems causes faint
Environmental/ toxicological causes
- Alcohol is the most commonly used drug, and when a patient drinks to much, it can lead to an altered level of consciousness. Syncope and near-syncope also occur with carbon monoxide poisoning
- Panic attacks and anxiety attacks
