1
Respiratory system includes: Nose and nasal cavity, Pharynx, larynx, trachea, Bronchi and their smaller
branches, Lungs and the air sacs called alveoli,
Hypoxemia - deficient oxygen in bloodstream / Hypoxia - a decrease in tissue oxygenation
Hypercapnia – excessive carbon dioxide levels in blood / Dyspnea – shortness of breath
Tachypnea – rapid respirations, >20 breaths per minute
1. Review the difference between primary and secondary brain injury
Primary brain injury - occurs as a direct result of the initial insult
Example – Stroke, concussion
Secondary injury - refers to progressive damage resulting from the body’s physiologic response
to the initial insult
Example – brain swelling secondary to stroke
Critical factor in determining the neuronal cell fate after injury - degree of adenosine
triphosphate (ATP) depletion
2. Review causes of intracranial pressure; how does it lead to impaired neurological function?
Increased Intracranial Pressure (ICP)
Volume of cranium composed of three elements:
o Brain tissue
o Cerebrospinal fluid (CSF)
o Blood
Normal ICP 0 to 15 mm Hg
Increased ICP can occur with space-occupying lesions, edema, or with obstruction or excessive
Increased Intracranial Pressure (ICP)
Leads to impaired neurological functions due to:
Compression of brain tissue
Inability of the cranium to expand in adults – bones of skull fused in adulthood
Reduced blood flow to the brain from increased pressure
production of CSF
3. What are signs of increased ICP?
Clinical manifestations
o Headache, vomiting, and altered level of consciousness (drowsiness)
o Blurry vision
o Pupil responsiveness to light becomes impaired
, 2
o Altered respiratory patterns and unresponsive to stimulation
o Patient may become unable to move, verbalize, or open the eyes
4. Review the Glasgow coma scale, what is it used to assess?
Standardized tool for assessing LOC in acutely brain-injured persons
Numeric scores given to arousal-directed responses of eye opening, verbal utterances, and motor
reactions
Mild (>12), moderate (9 to 12), to severe (<8)
Motor response is the most powerful predictor of patient outcome
Decorticate posturing, abnormal flexor
Decerebrate posturing, abnormal extension
Traumatic brain injury (TBI) leading cause of death and disability in United States
Most head injuries incurred in transportation-related accidents, falls, firearms, and sports
accidents
Severity of TBI is classified by the Glasgow coma scale (GCS) as:
Mild - GCS score 13 to 15
Moderate - GCS score 9 to 12
Severe - GCS score 8 or below
Primary injury
Usually caused by a sudden and violent blow or jolt to the head (closed injury) or a penetrating
(open injury) head wound that disrupts the normal brain function
The injury can bruise the brain, damage nerve fibers, and cause hemorrhaging
Secondary Injury
Body’s response to initial injury may cause more harm than the initial injury
, 3
Can cause ischemia, hypoxic events, vasogenic/neurogenic edema, and other processes that lead to
brain swelling and increased ICP
Ruptured vessels may rebleed or spasm, and CSF drainage can become clogged
5. Review the different types of stroke: ischemic versus hemorrhagic. How is a stroke diagnosed?
Ischemia and Hypoxia
Ischemia = decreased blood flow
o Ischemia results in immediate neurologic dysfunction because of inability of neurons to
generate ATP needed for energy-requiring processes
Hypoxia = decreased oxygen at cellular level
Usually ischemia and hypoxia occur together ****
o Stroke is a sudden onset of neurologic dysfunction caused by cardiovascular disease that results in an
area of brain infarction
o Transient ischemic attacks (TIA)
o Ischemic stroke
o Hemorrhagic stroke
Stroke is the fifth leading cause of death in the U.S.
Most common form of stroke is ischemic
Risk factors include:
Hypertension
DM
Hyperlipidemia
Smoking
Advancing age
Family history
Results from sudden blockage (occlusion) of cerebral artery secondary to thrombus formation
or emboli
Thrombotic strokes associated with atherosclerosis and clotting disorders (coagulopathies)
Embolic strokes associated with cardiac dysfunction or dysrhythmias (atrial fibrillation)
Clinical manifestations Ischemic stroke
Contralateral paralysis on one side of the body (hemiplegia)
Facial dropping, ptosis
Hemisensory loss
Contralateral visual field blindness
Difficulty with speech (aphasia)
Hemorrhagic Stroke
o Result of a bleed within the brain
o Less common compared to ischemic stroke
, 4
o Usually occurs secondary to severe, chronic hypertension
o Can also be the result of severe head trauma, an aneurysm, or an arteriovenous malformation (AVM)
o Anticoagulant use puts an individual more at risk for hemorrhagic stroke
HOW IS STROKE DIAGNOSED?
Brain CT determines type and location
o Cardiovascular stabilization
o ICP monitoring and management
o Ischemic stroke - treatment aimed at minimizing infarct size and preserving neurologic function
o Thrombolytics, anticoagulant, antiplatelet, endarterectomy, angioplasty, stents
o Hemorrhagic stroke - blood pressure management (keep patient mildly hypertensive at first)
6. Review the difference between meningitis versus encephalitis
Meningitis - Inflammation of the meninges of the brain
Can be due to bacterial, viral or fungal infections
Most common causes: Streptococcus pneumoniae (pneumoncoccus), Neisseria meningitidis
(meningococcus), Haemophilus influenzae
Bacteria usually reach the CNS via the bloodstream from sinuses or ears
Most cases of viral meningitis due to Enteroviruses
Other viruses include herpes virus, West Nile virus, mumps, HIV
Classic presentations - headache, fever, stiff neck (nuchal rigidity), photophobia, “splotchy” purple rash,
confusion, delirium
Diagnosis - lumbar puncture
Treatment - intravenous antibiotic therapy for bacterial, supportive measures for viral, corticosteroids
Prevention - vaccinations for Hib and N. meningitidis
Respiratory system includes: Nose and nasal cavity, Pharynx, larynx, trachea, Bronchi and their smaller
branches, Lungs and the air sacs called alveoli,
Hypoxemia - deficient oxygen in bloodstream / Hypoxia - a decrease in tissue oxygenation
Hypercapnia – excessive carbon dioxide levels in blood / Dyspnea – shortness of breath
Tachypnea – rapid respirations, >20 breaths per minute
1. Review the difference between primary and secondary brain injury
Primary brain injury - occurs as a direct result of the initial insult
Example – Stroke, concussion
Secondary injury - refers to progressive damage resulting from the body’s physiologic response
to the initial insult
Example – brain swelling secondary to stroke
Critical factor in determining the neuronal cell fate after injury - degree of adenosine
triphosphate (ATP) depletion
2. Review causes of intracranial pressure; how does it lead to impaired neurological function?
Increased Intracranial Pressure (ICP)
Volume of cranium composed of three elements:
o Brain tissue
o Cerebrospinal fluid (CSF)
o Blood
Normal ICP 0 to 15 mm Hg
Increased ICP can occur with space-occupying lesions, edema, or with obstruction or excessive
Increased Intracranial Pressure (ICP)
Leads to impaired neurological functions due to:
Compression of brain tissue
Inability of the cranium to expand in adults – bones of skull fused in adulthood
Reduced blood flow to the brain from increased pressure
production of CSF
3. What are signs of increased ICP?
Clinical manifestations
o Headache, vomiting, and altered level of consciousness (drowsiness)
o Blurry vision
o Pupil responsiveness to light becomes impaired
, 2
o Altered respiratory patterns and unresponsive to stimulation
o Patient may become unable to move, verbalize, or open the eyes
4. Review the Glasgow coma scale, what is it used to assess?
Standardized tool for assessing LOC in acutely brain-injured persons
Numeric scores given to arousal-directed responses of eye opening, verbal utterances, and motor
reactions
Mild (>12), moderate (9 to 12), to severe (<8)
Motor response is the most powerful predictor of patient outcome
Decorticate posturing, abnormal flexor
Decerebrate posturing, abnormal extension
Traumatic brain injury (TBI) leading cause of death and disability in United States
Most head injuries incurred in transportation-related accidents, falls, firearms, and sports
accidents
Severity of TBI is classified by the Glasgow coma scale (GCS) as:
Mild - GCS score 13 to 15
Moderate - GCS score 9 to 12
Severe - GCS score 8 or below
Primary injury
Usually caused by a sudden and violent blow or jolt to the head (closed injury) or a penetrating
(open injury) head wound that disrupts the normal brain function
The injury can bruise the brain, damage nerve fibers, and cause hemorrhaging
Secondary Injury
Body’s response to initial injury may cause more harm than the initial injury
, 3
Can cause ischemia, hypoxic events, vasogenic/neurogenic edema, and other processes that lead to
brain swelling and increased ICP
Ruptured vessels may rebleed or spasm, and CSF drainage can become clogged
5. Review the different types of stroke: ischemic versus hemorrhagic. How is a stroke diagnosed?
Ischemia and Hypoxia
Ischemia = decreased blood flow
o Ischemia results in immediate neurologic dysfunction because of inability of neurons to
generate ATP needed for energy-requiring processes
Hypoxia = decreased oxygen at cellular level
Usually ischemia and hypoxia occur together ****
o Stroke is a sudden onset of neurologic dysfunction caused by cardiovascular disease that results in an
area of brain infarction
o Transient ischemic attacks (TIA)
o Ischemic stroke
o Hemorrhagic stroke
Stroke is the fifth leading cause of death in the U.S.
Most common form of stroke is ischemic
Risk factors include:
Hypertension
DM
Hyperlipidemia
Smoking
Advancing age
Family history
Results from sudden blockage (occlusion) of cerebral artery secondary to thrombus formation
or emboli
Thrombotic strokes associated with atherosclerosis and clotting disorders (coagulopathies)
Embolic strokes associated with cardiac dysfunction or dysrhythmias (atrial fibrillation)
Clinical manifestations Ischemic stroke
Contralateral paralysis on one side of the body (hemiplegia)
Facial dropping, ptosis
Hemisensory loss
Contralateral visual field blindness
Difficulty with speech (aphasia)
Hemorrhagic Stroke
o Result of a bleed within the brain
o Less common compared to ischemic stroke
, 4
o Usually occurs secondary to severe, chronic hypertension
o Can also be the result of severe head trauma, an aneurysm, or an arteriovenous malformation (AVM)
o Anticoagulant use puts an individual more at risk for hemorrhagic stroke
HOW IS STROKE DIAGNOSED?
Brain CT determines type and location
o Cardiovascular stabilization
o ICP monitoring and management
o Ischemic stroke - treatment aimed at minimizing infarct size and preserving neurologic function
o Thrombolytics, anticoagulant, antiplatelet, endarterectomy, angioplasty, stents
o Hemorrhagic stroke - blood pressure management (keep patient mildly hypertensive at first)
6. Review the difference between meningitis versus encephalitis
Meningitis - Inflammation of the meninges of the brain
Can be due to bacterial, viral or fungal infections
Most common causes: Streptococcus pneumoniae (pneumoncoccus), Neisseria meningitidis
(meningococcus), Haemophilus influenzae
Bacteria usually reach the CNS via the bloodstream from sinuses or ears
Most cases of viral meningitis due to Enteroviruses
Other viruses include herpes virus, West Nile virus, mumps, HIV
Classic presentations - headache, fever, stiff neck (nuchal rigidity), photophobia, “splotchy” purple rash,
confusion, delirium
Diagnosis - lumbar puncture
Treatment - intravenous antibiotic therapy for bacterial, supportive measures for viral, corticosteroids
Prevention - vaccinations for Hib and N. meningitidis
