Test 3 revision Flashcards
What is a traumatic brain injury?
Traumatic brain injury (TBI) is an aquired injury that occurs when there is disruption in the normal function of the brain due to a bump, blow or jolt to the head or a penetrating head injury.
What are the two categories of a traumatic brain injury?
blunt/closed TBI: skull & dura mater remain intact and brain is NOT exposed to external environment
penetrating/open TBI: penetration or damage of skull & dura mater occurs and the brain is exposed to the external environment
What is a primary traumatic brain injury?
Primary injury:
tissue damage that occurs at the moment of trauma. This includes damage to tissue via penetration or compression and shearing forces associated with blunt trauma.
What is a secondary traumatic brain injury and what can it include?
Secondary injury:
Occurs in the hours to days after the primary injury and involves the inflammation, oedema and bleeding that occurs in response to the primary injury.
Secondary injury can include metabolic & electrolyte imbalances, neurotransmitter excitotoxicity, mitochondrial dysfunction, apoptosis and/or ischemia.
Secondary injury is going to have an impact on intracranial pressure (ICP) and can be even more detrimental than the primary injury in some cases.
How can you determine the severity of a TBI?
Brain imaging is used to distinguish between focal/ diffuse injuries
AND
to identify any intracranial hemorrhage/hematoma.
The Glasgow Coma Scale is often used to assess the neurological impact of a TBI and provides a rough guide to the severity of the TBI:
Mild TBI: score 13-15
Moderate TBI: score 9-12
Severe TBI: score 3-8
What is the management of a TBI?
A major component of TBI treatment is the monitoring and management of intracranial pressure (ICP) and cerebral perfusion pressure (CPP).
As well as monitoring and mainatining
- ventilation
- blood pressure
- electrolyte levels
- blood glucose levels
- temperature regulation.
Seizures are commonly associated with TBI, and thus seizure prophylaxis is important.
Affected/damaged tissue may need to be removed.
Penetrating injuries carry a risk of infection, so antibiotics are commonly used.
Whats a focal brain injury?
Focal brain injury refers to areas of localised damage
Either blunt (closed) or penetrating (open) TBI can result in focal injury.
What can a primary focal brain injury result in? Can result in either of both
Contusion: Injury to brain tissue (bruise from damage to the cells and blood vessels of a focal area. Pia mater is still intact in a contusion. Brain contusions result from coup and countercoup injuries.)
Intracranial hematoma: Accumulation of blood (clotted) within the cranium
What is the difference between a coop and contrecoup contusion
coup injury (1): injury occurring at the initial point of forceful impact. This includes compression damage occurring directly below the site(s) of impact (a & c) as well as any associated shearing injury (b).
contrecoup injury (2): injury occurring in areas of the brain opposite from the site of initial impact due to rebound effect (a) and associated shearing injury (b).
What are the different kinds of intracranial hemorrhage/hematoma? (4)
1) Epidural (extradural) hematoma
2) Subdural hematoma
3) Subarachnoid hemorrhage
4) Intracerebral hemorrhage
What are the layers of the brain? (Outermost to inner most)
Scalp, skull, dura mater, arachnoid mater, subarachnoid space, pia mater, and brain
Whats a epidural (extradural) hematoma
blood accumulation between the skull and outer layer of the dura mater. Blood loss may be arterial (most common) or venous
Whats a Subdural hematoma
blood accumulation between the dura mater and arachnoid mater. May be acute or chronic. Blood loss is typically venous and as pressure increases from the clot, blood vessels are compressed, reducing further bleeding.
What is a Subarachnoid hemorrhage
Bleeding within the subarachnoid space (between the arachnoid and pia mater). Blood mixes with the cerebrospinal fluid (CSF).
What is a Intracerebral hemorrhage?
Bleeding into the brain.
What is a diffuse brain injury? And what does it range from?
Widespread brain damage. Damage to neurons throughout the brain. Characterized by general disturbances in neuronal function
Diffuse brain injury ranges from concussion (mild form of TBI) to severe diffuse axonal injury (DAI) with coma.
What is a diffuse axonal injury (DAI)?
Is associated with the majority of neurons firing action potentials simultaneously following concussion.
This leads to release of glutamate resulting in excitotoxicity, which alters normal neuronal ion transport. Abnormal ion transport can disrupt mitochondrial function and ATP prodution, therefore reducing the neurons ability to generate and propagate action potentials.
DAI occurs due to shearing forces generated within the brain at impact. It can be visualized by multiple, small lesions within the white matter tracts of the brain. The majority of individuals with severe DAI will not wake up from their coma.
What are the percentages of intracranial volume?
10% cerebral blood volume
10% cerebrospinal fluid (CSF)
80% brain tissue
What is the normal intracranial pressure?
5-15mmHg.
How does the brain accommodate for changes in intracranial pressure?
Small increases in the volume of one component can typically be compensated for by small decreases in another component, but only up to a certain point.
If compensation is not adequate, intracranial pressure (ICP) continues to rise, leading to life-threatening conditions.
What are reasons ICP may rise?
- brain tumours
- cerebral oedema (increased intra- or extracellular fluid in brain tissue) from infection
- intracranial hemorrhage/hematoma
- hydrocephalus (accumulation of CSF)
- cerebral vasodilation (e.g. in response to hypercapnia, hypoxia)
What are symptoms of a high ICP?
◦ Decreased Glasgow Coma score – difficulty staying awake
◦ Central neurogenic hyperventilation
◦ Widening pulse pressure
◦ Bradycardia (but bounding)
◦ Firstly the pupils will constrict, and be sluggish. Then once the pressure continues to rise: Ipsilateral dilation and fixation (the pupil on the side of the bleed/herniation) is large
and unresponsive. The other pupil is still constricted. As pressure increases, the brain herniates through the foramen magnum, down into the neck. Bilateral dilated and fixed pupils.
- Reduced consciousness and impairment of sensory and motor functions (e.g. reduced response to pain, weakness) leading to coma
- Decreased ventilation leading to alterations in breathing patterns. Ultimately reducing respiration
What happens when ICP is too high?
When the pressure in the brain raises enough that it is equal to the blood pressure in the cranial arteries, then there is no pressure gradient to push blood out of the arteries into the brain.
Hypoxia and hypercapnia occur. This then causes acidosis in the brain
What’s the difference between a concussion and an axonal diffusion injury?
Technically, the difference between a concussion and a diffuse axonal
injury is that a person is diagnosed with a concussion if they are unconscious for 6 hours or less
What are special needs of the brain?
The brain does not store large amounts of glycogen or ATP.
The brain cannot do anaerobic respiration. The brain must have a constant supply of blood to bringm oxygen and glucose or it will start to die very quickly.
15-20% of the blood from the left ventricle goes directly to the brain.
What is the nursing Assessment for TBI
Glasgow Coma Score
Mild TBI: 13-15
Moderate TBI: 9-12
Severe TBI: 3-8
Reflexes
◦ Pupils: PERRLA
Equalization
◦ Equality of strength in left versus right arms and legs
◦ Drift: Can the arms stay up for a count of 10, legs for a count of 5?
◦ Ataxia: Finger to nose rapidly
What are nursing interventions for ICP?
◦ Head of the bed at least 30 degrees
◦ Corticosteroids to decrease oedema
◦ Administer mannitol (osmotic diuretic) or possibly hypertonic saline (3%)
◦ Cooling to lower brain and body metabolic requirements
◦ Induce hyperventilation to reduce CO2 level and induce vasoconstriction
◦ Keep blood pressure high enough for perfusion
◦ Seizure prophylaxis
◦ Monitor ICP and prepare for surgery or medically induced coma
What is the function of the skin?
Protection
Sensation
Metabolic
Temperature regulation
Absorption
Excretion
Blood reservoir
What is Cellulitis?
Cellulitis is a bacterial infection of the dermis and subcutaneous tissue that can easily, and rapidly spread.
It more commonly occurs in older adults, though a particular type- periorbital cellulitis- occurs in children.
What bacteria is the most common with a Cellulitis infection?
Most commonly “streptococcus pyogenes”
or
“staphylococcus aureus (staph infection)
How is cellulitis typically acquired and where is it usually located?
Occurs when the skin barrier is broken and bacteria have access to the lower dermis and fatty tissue layers.
Can be via cut, insect bite, burn, scrape, puncture wound, or patches of dry skin.
Most commonly found on the legs
What are risk factors for cellulitis?
People with..
- Diabetes
- Venous diseases
- Lymphoedema
- Leg ulcers
- Oedema
- IV drug use
- Over weight
- Have a weakened immune system
- Other skin diseases (eczema or athletes foot)
- Already have a swollen arm or leg
- Have had cellulitis before
What are symptoms of cellulitis?
Red, swollen, painful, blisters, warmth. Sometimes there are blisters filled with yellow fluid.
May develop fever if infection becomes symptomatic.
Can cause sepsis if enters the blood stream, low blood pressure, high fever.
What is the treatment for cellulitis?
Treatment: Antibiotics (oral or IV), elevate legs, wound care and antibiotic creams, possibly compression stocking to reduce fluid
How to prevent cellulitis?
Bandage, keep skin wounds clean, antibiotic cream, heal exciting breaks in the skin.
Diabetes or poor circulation: Examine feet every day, moisturize, avoid injury
What are pressure Injuries?
“localized damage to skin and/or underlying tissue as a result of pressure or pressure in combination with shear”
What causes pressure in pressure injuries?
Bones – skin, subcutaneous tissue, and muscle caught between bone and a hard surface are under great pressure
Mechanical devices – oxygen tubing, canes, bed rails, catheters, nasogastric tubes
Pressure occludes blood vessels, which causes ischemia
Muscle may actually be affected first as it is less resistant than skin
What causes shearing?
Skin and subcutaneous tissue may stay in place due to friction against a surface
When moved, or when sliding down in a chair, muscle and bone may move
This shears the skin and subcutaneous tissue from the muscle
How many stages of pressure injuries are there?
6
What are the stage pressure injuries are there?
Stage 1, stage 2, stage 3, stage 4, unstageable and deep tissue injury
What is pressure injury stage 1?
Skin remains intact with localized area of erythema or discolouration that is non-blanchable (Does NOT change color/lighten when pressure (e.g. finger-press) is applied)
(Just red no skin breakage)
What is pressure injury stage 2?
Partial-thickness skin loss. Dermis intact but exposed. No granulation tissue, slough, or necrosis
Partial thickness injury that exposes the dermis; may appear blister-like.
(Skin that appears when a blister pops)
What is pressure injury stage 3?
- Full thickness loss of skin that exposes the hypodermis (Adipose tissue, granulation tissue visible).
- Ulcer typically has rolled edges.
- Eschar and slough may be visible at the edges but do not cover the wound
- No exposure of muscle, fascia, bone, tendon, ligament, or cartilage
What is pressure injury stage 4?
Full thickness loss of skin that exposes further underlying tissues such as fascia, tendon/muscle, ligament, bone, etc.
Slough or eschar may be present but do not cover the wound
What is an unstageable pressure injury?
Full thickness loss of skin (stage 3 or 4) but slough, eschar and/or necrosis cover the wound so damage is unable to be confirmed
What is a deep tissue pressure injury?
Injury in tissues deep to the skin which appears as a persistent, non-blanchable, deep red, maroon or purple discolouration or blood-filled blister (skin may or may not be intact).
How can you prevent pressure injuries?
Repositioning, using supportive surfaces that distribute or relieve pressure (e.g. certain types of mattresses), reducing exposure to sustained moisture (e.g. due to incontinence), reducing shear and friction forces, etc.
Further management may include wound dressing/treatment, debridement, infection prevention/management, pain management and nutritional/hydration management.
What’s gastroenteritis?
Gastroenteritis is inflammation of the lining of the stomach and the intestines.
It is usually caused by an infectious agent but can also be a reaction to medication or poisons.
The pathophysiology of gastroenteritis is different for different kinds of infections.
Why is gastroenteritis critical in children?
Children have a greater percentage of water which increases their risk of dehydration.
In addition children have immature kidneys (so cannot reabsorb water as well) and they have a great surface area to weight so can lose water easier
What are examples of viral gastroenteritis?
Rotavirus
Norovirus
How is viral gastroenteritis transmitted?
Transmitted faecal-orally
Occurs when microorganisms from an infected stool of one person enter the mouth of another.
Germs are transferred from hand to mouth because the hands have touched contaminated items and have not been well washed afterwards.
How does viral gastroenteritis affect the body?
Viruses invade and take over the cells that line the stomach and the gut
These are the cells that first absorb nutrients and water from the stomach and intestines
Additionally, the viruses release toxins that cause the death of surrounding cells.
Ultimately, the intestines cannot absorb nutrients and water well,
and even lose some of the fluid that they do have in their tissue
What are symptoms of viral gastroenteritis?
Symptoms start with vomiting followed by watery diarrhoea
Low fever is present, but high fever is typically not from a gastroenteritis virus.
What are some examples of bacterial gastroenteritis?
Clostridium difficile (Cdiff)
Campylobacter
Shigella
Salmonella
How does bacterial gastroenteritis spread?
The spread of gastroenteric bacteria is usually through undercooked food (especially chicken or eggs) or unpasteurized milk.
C. diff used to be thought of as a nosocomial infection (one obtained through the hospital) but it is now prevalent in the community
What is the two mechanisms of bacterial gastroenteritis?
Release of a toxin –
in some cases, the bacteria itself doesn’t even have to get into the body, but if the toxin made by the bacteria is taken in and is not killed by sufficient heat in cooking. The toxin causes the cells that line the gut to stop taking in water and nutrients and instead to
dump fluid and electrolytes into the gut, causing diarrhoea.
Invasion by the bacteria itself –
Bacteria get into the mucosa. The immune system responds by causing inflammation, which can cause ulceration of the tissue of the intestines and bleeding.
What are the symptoms of bacterial gastroenteritis?
Cramping and vomiting followed by diarrhoea
Bacterial gastroenteritis is more likely (not always) to present with a high fever and bloody or mucous-filled diarrhoea.
What are complications of GASTROENTERITIS IN CHILDREN?
Diarrhoea requires three or more loose stools in a day. Unless stools are loose and unless there are at least three
stools in a day, diarrhoea is not generally diagnosed or treated.
Dehydration/Hypovolemia (liquid portion of the blood (plasma) is too low):
- Sunken fontanels in a baby; dry mucosal membranes, sunken eyes, decreased tears.
- Weight loss – especially for a baby
- Rapid thready pulse; decreased blood pressure; dizziness
Hyponatremia
- Less sodium = less nervous activity
- Apathy, weakness
- Depressed reflexes, twitches
Hypokalaemia
- Less potassium = less muscle
- Muscle weakness that can lead to paralysis
- Pulse may be bradycardic from lack of potassium or can be tachycardic from dehydration
Metabolic acidosis
- Rapid breathing to blow out the acid
- As acidosis gets worse, especially with low potassium, may greatly increase bradycardia
How to care for children with severe GASTROENTERITIS?
Monitor diarrhoea, dehydration and electrolyte & acid-base imbalances.
Treatment
* Handwashing with soap, not just gel
At home:
* Oral rehydration therapy (ORT)
* Usually prepackaged.
* Rough guide: A litre of water, 6
teaspoons of sugar, and ½
teaspoon of salt.
* If child will not drink, may need
ondansetron to reduce nausea and to
give ORT with a syringe.
In hospital:
* NG fluids, possibly with electrolytes
* Possibly medication for diarrhoea;
however, if diarrhoea is from an
infectious cause, medication may not
be given so that the body can wash
the pathogen out of the body.
* Feeding as soon as child will take in
food.
