Medical Emergencies reading assignments Flashcards
Chapters assigned in class
The eye is composed of three layers which are
The fibrous tunic, the vascular tunic, and the nervous tunic.
NOTE
Eye movement is controlled by cranial nerves 3, 4, 6 (Oculomotor, Trochlear, Abducens). Remember that visual disturbances of the eyes may be an early indication of stroke, tumor, or other CNS disease. Always consider when dealing with a patient with an eye movement disorder!
Conjunctivitis
Inflammation or infection of the conjunctiva (the membrane lining the eyes). condition is also commonly called pink eye.
Two causes. Bacterial and Viral.
If the cause of pink eye is viral, the discharge will be…
A watery mucus
If the cause of pink eye is bacterial, the discharge will be…
Thick and yellow/green
What is a corneal abrasion?
A painful scrape or scratch on the cornea of the eye. Most often caused by trauma or foreign objects in the eye. Symptoms include pain, feeling as if something is in the eye, tearing/redness, headache, blurred vision, and photophobia (sensitivity to light).
Photophobia
Sensitivity to light
Conjunctiva
The membrane lining of the eye
Inflammation of the eyelid usually results from blockage of the gland or from bacterial infection. The two main conditions that cause this are…
Chalazion and hordeolum
Chalazion
A small bump in the eyelid caused by a blockage of a tiny oil gland in the upper/lower eyelid. Lump appears hard and may grow in size over weeks. Symptoms include painful swelling, tearing, tenderness, and photophobia.
NOTE-oil glands
There are about 40 oil glands in the upper and lower eyelids. They secrete oil into tears.
Hordeolum
Commonly referred to as a sty. Acute inflammation of the oil gland. More painful that a chalazion and may look infected. Can cause redness around the eye, the eyelid and cheek tissue. Advise to apply warm compresses and gently clean with warm water/soap. Do not squeeze or pop. Can cause severe infection.
Glaucoma
Group of diseases that affect the optic nerve. Too much fluid accumulates in the anterior chamber of the eye between the cornea and the iris. Fluid channel gets blocked (trabecular channel) causing increase in intraocular pressure that damages the optic nerve and can lead to loss of vision.
Glaucoma usually affects people who are ( ) and older…
40
Iritis
Inflammation of the iris of the eye. Serious disease can cause blindness if not treated. Causes are trauma, inflammatory/autoimmune disorders, infection and cancer. Classified as acute or chronic. Chronic usually has a higher risk of vision impairment. management is primarily supportive.
Papilledema
Swelling of the head of the optic disk caused by a rise in ICP. Swelling is usually bilateral and may be more severe in one eye. Patient complains of headache (worse on awakening, by coughing, holding their breath or straining. Vision disturbances include double vision or temp. flickers or gray spots.
NOTE on papilledema
Infants who are victims of shaken baby syndrome may be unconcious with papilledema. With this presentation, shaken baby syndrome should be suspected.
Retina
Light-sensitive tissue that lines the inside of the eye and sends visual messages through the optic nerves to the brain
Retinal detachment
True emergency can lead to perm. vision loss. More common in people who have had retinal detachment, have had cataract surgery, eye injury, etc. Sudden or gradual increase in number of floaters, cobwebs, or specks in field of vision. Curtain light and can be light flashes as well.
Retinal vascular occlusion
Blockage of a vessel in the retina of the eye. Common cause of blindness.
Central retinal vein occlusion
Blockage of blood supply to the main vein of the retina. Obstruction causes leakage of blood and excess fluid into the retina. When fluid collects in macula, vision becomes blurry and may produce floaters. Patient experiences painful pressure in the eye and loss of vision in one part or all of the eye.
CRAO Central retinal artery occlusion.
Blockage of blood supply to the arteries of the retina. Essentially a stroke of the eye. Sudden, painless loss of vision in one eye. True ocular emergency and needs urgent treatment. Irreversible vision loss after 4 hours.
The nervous system is divided into two parts…
CNS (Central nervous system) and PNS (peripheral nervous system)
Total of 43 pairs of nerves originate from the CNS to form the PNS this includes…
12 pairs of cranial nerves originating from the brain and 31 pairs of spinal nerves originating from the spinal cord
Each neuron has three main parts…
the cell body, the dendrites, and an axon
What are the three types of neurons?
Sensory, motor, and interneurons
NOTE for interneurons
The are more than 100 billion interneurons in the human body, which makes them the most abundant of the three major types of neurons.
Efferent neurons
Exits the brain to the muscle
Afferent neurons
Arrives to the brain from the body
Myelinated axons conduct action potentials faster than
unmyelinated
Most common neurotransmitters (4)
Acetylcholine, norepinephrine, epinephrine, and dopamine
What is the circle of Willis?
Important safeguard. Helps ensure the supply of blood to all parts of the brain in the event of a blockage.
Monroe Kellie Doctrine
Intracranial vault is made up of 80% brain, 10% blood and 10% cerebral spinal fluid
Normal ICP is…
10-15mmhg
Normal CPP is…
60-80mmhg
Normal MAP
65-90
To calculate CPP
CPP=MAP-ICP
To calculate MAP
DBP (Diastolic blood pressure) + 1/3PP (pulse pressure)
ICP cant be measure in prehospital setting so its best to keep SBP above 90 or better; MAP above 70 with head injury
What is cushings triad?
Indicates increased ICP. Bradycardia, widened pulse pressure with hypertension, abnormal slow respiratory pattern
AEIOU TIPS
Alcohol, Epilepsy, endocrine, electrolytes, Insulin, Opiates and other drugs, Uremia, Trauma, temperature, Infection, Poisoning, psychogenic causes, Shock, stroke, seizure, syncope, space-occupying lesion, subarachnoid hemorrhage
Orbital Cellulitis
Acute infections of the tissues surrounding the eye. Such an eyelid, eyebrow, and cheek. Can quickly lead to blindness in children. S&S include fever, painful swelling, appearance shiny/red or purple eyelid, bulging eyes, painful eye movements.
Foreign body in the ear
Do not try to extract by pushing in further. Advise patient to seek care in a clinic/hospital. Oil/alcohol can be used if patient has a live bug in ear.
How many cranial nerves are there?
12 cranial nerves
What is the 1st cranial nerve called? What is it’s function? How can it be tested?
Olfactory nerve. It’s function is smell. Have patient smell something familiar.
What is the 2nd cranial nerve? Function? How can it be tested?
Optic nerve. Visual acuity and field. Have patient identify number of fingers you’re holding up and their peripheral vision
What is the 3rd cranial nerve? Function? How can it be tested?
Oculomotor. Pupillary reaction. Shine a light in the patients eyes for PERRL.
What is the 4th cranial nerve? Function? How can it be tested?
Trochlear nerve. Eye movement. Have patient follow your finger without moving their head.
What is the 5th cranial nerve? Function? How can it be tested?
Trigeminal. Facial sensation and motor function. Touch patients face and see if they report sensation. Have them smile or open their mouth.
What is the 6th cranial nerve? Function? How can it be tested?
Abducens. Motor function. Check lateral eye movements.
What is the 8th cranial nerve? Function? How can it be tested?
Acoustic nerve. Hearing and balance. Snap fingers by patients ear and perform Romberg test
What is the 9th cranial nerve? Function? How can it be tested?
Glossopharyngeal. Swallowing and voice. Have patient swallow and say “Ah”.
What is the 10th cranial nerve? Function? How can it be tested?
Vagus nerve. Gag reflex. Use a tongue depressor.
What is the 11th cranial nerve? Function? How can in be tested?
Spinal accessory nerve. Neck motion. Have patient shrug their shoulders.
What is the 12th cranial nerve? Function? How can it be tested?
Hypoglossal. Tongue movement and strength. Have patient stick out their tongue and use a tongue depressor to test strength.
what is the 6th cranial nerve? Function? How can it be tested?
Facial. Motor function and sensory. Have patient smile, wrinkle their face, and puff their cheeks. Test different tastes.
What is decorticate posturing?
Abnormal flexion of the elbows with extension of the legs.
What is decerebrate posturing?
Abnormal extension at the elbow with internal rotation of the shoulders and leg extension.
What abnormal reflex can present with decerbrate/decorticate posturing?
Babinski reflex.
NOTE on strokes
About 85% of strokes are the ischemic type
Whats the difference between a thrombosis and an embolism?
Thrombosis stays where it forms and an embolism moves from one area to another (PE)
NOTE on TIA
More than 5% of TIA patients have a completed stroke within 7 days.
