Common learning
issues
Test 2
MOSBYS
Anion gap (pages 66-67)
• Assists in the evaluation of patients with acid-base disorders
• Attempts to identify cause of the disorder and also to monitor therapy for acidbase abnormality
• Test explanation:
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Difference between anions and cations in extracellular space
(sodium + potassium) – (chloride + bicarbonate)
Test should be adjusted downwards if potassium is eliminated from test
Bicarb is actually venous CO2 not arterial bicarb
Determines cause of metabolic acidosis
• The build up of ketoacids and lactic acid will cause increased AG
• Albumin is one of the leading factors in increasing AG
• Nephrotic syndrome ( decrease in anions) or increased calcium or magnesium will cause
decreased AG
• Low anions causes increased bicarb
• Hypoproteinemia and increased immunoglobulins can lower AG
• Gives a complex metabolic picture along with ABG
• Interfering factors:
• Decreasing factors: hyperlipidemia, acetazolamide, lithium, polymyxin B,
spironolactone, and sulindac
• Increasing factors: carbenicillin, carbonic anhydrase inhibitors (acetaloamide),
diuretics, ethanol, methanol, penicillin, and salicylate
Blood glucose (267-268)
• Direct measure of blood glucose used mainly for diabetic patients
• Test explanation:
• Glucose levels are low in the fasting state which causes glucagon release by pancreatic alpha
islet cells
• Glucagon breaks glycogen down to glucose in the liver
• If fasting persists, proteins and fatty acids are broken down under glucagon stimulation
• Glucose levels are elevated after a meal causing a release of insulin from pancreatic beta cells
• Insulin causes up-regulation of insulin receptors and glucose uptake into mainly muscle, brain,
and adipose tissue
• ACTH, adrenocorticosteroids, epinephrine, growth, and thyroxine affect glucose
• Must be evaluated for the time of day
• True glucose elevation is usually DM
• Hypoglycemia is inadvertent insulin overdose in patients with brittle diabetes
• Must monitor frequently in diabetes patients
• Finger stick blood glucose are performed before meals and at bedtime
• Interfering factors:
• Increased levels: Stress (trauma), general anesthesia, infection, burns, MI, caffeine,
pregnancy, IV dextrose, antidepressants, beta blockers, corticosteroids, dextrothyroxine,
diazoxide, diuretics, epinephrine, estrogens, glucagon, isoniazid, lithium, phenothiazines,
phenytoin, salicylate, and triameterene
• Decreased levels: acetaminophen, alcohol, alpha glucosidase inhibitors, anabolic steroids,
biguanides, clofibrate, disopyramide, gemfibrozil, incretin mimetics, insulin, MAOi,
meglitinides, pentamidine, propanolol, sulfonylurea, and thiazolidinediones
Glucose, postprandial (270271)
• The 2 hour test is a measurement of the amount of glucose in the
patient’s blood 2 hours after a meal is ingested (postprandial)
• Test explanation:
• The meal acts as a glucose challenge to the body’s metabolism
• Insulin is normally secreted after a meal in response to the high blood
glucose
• In diabetes patients the glucose is usually still elevated 2 hours later
• If the levels are between 140-200 then a glucose tolerance test must be
obtained
• If the levels are greater than 200 then a diagnosis of DM is made
• 1 hour test detects gestational diabetes
• The detection of gestational diabetes prevents excessive fetal growth and birth
trauma, fetal death, neonatal morbidity
• O’ Sullivan test gives a 50 g oral glucose dose and tests 1 hour later 24-28 weeks
gestation; a 3 hour test is ordered for levels above 140
• Interfering factors
• Increasing factors: smoking during testing, stress, eating a snack or candy
• Falsely decreased if the person cannot eat the entire test meal or vomits
Glucose tolerance test (275278)
• Assists in the diagnosis of DM and the evaluation of patients with hyperglycemia
• Test explanation:
• Criteria to diagnose diabetes:
• Sufficient clinical symptoms ( polydipsia, polyuria, ketonuria, weight loss) plus random
blood glucose > 200
• Elevated FBG on more than one occasion
• 2 hour glucose > 200
• Used when diabetes in expected (retinopathy, neuropathy, renal disease) but
criteria for diagnosis can’t be met without GT
• May be used for the following
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Family history of diabetes
Patients who are massively obese
History of recurrent infections
Delayed healing of wounds
Women who have stillbirths or large babies
Transient glycosuria or hyperglycemia during pregnancy, or following MI, surgery or
stress
• The ability to tolerate glucose load is evaluated through serum and urine glucose
levels at 30 minutes, 1, 2, 3, and 4 hours
• Normally there is a rapid insulin response that peaks in 30- 60 minutes and
returns to normal in 3 hours, glucose shouldn’t spill into urine
Glucose tolerance test (275278) cont.
• Test explanation:
• Patients with diabetes won’t tolerate this load so their serum levels remain high;
glucose spills into urine
• Some patients cannot tolerate oral dose (gastrectomy, short bowel syndrome,
malabsorption) so they’re given an IV dose
• Cushing’s , pheocromocytoma, acromegaly, aldosteronism, or hyperthyroidism
may all cause glucose intolerance
• Chronic renal failure, acute pancreatitis, myxedema, type IV lipoproteinemia,
infection or cirrhosis cause abnormal GT test
• Contraindications
• Serious concurrent infections or endocrine disorders (glucose intolerance)
• Patients who vomit all or part of the meal
• Potential complications
• Dizziness, tremors, anxiety, sweating, euphoria, or fainting
• Interfering factors
• Increasing factors: smoking, eating, stress, exercise
• Fasting or reduced caloric intake before test can cause intolerance
• Drugs that cause intolerance: antihypertensives, antiinflammatories, aspirin, beta
blockers, furosemide, nicotine, oral contraceptives, phenothiazines, psychiatric
drugs, steroids, and thiazides
Glycosylated hemoglobin (280282)
• Used to monitor diabetes treatment because it provides
accurate long-term index of patient’s average glucose index
• Test explanation:
• Glycosylation of hemoglobin A
• A1c combines the most with glucose
• The amount of GHb (glycohemoglobin) depends on the most of
glucose available in the bloodstream
• This shows an average glucose concentration over 100-120 days
• Usually the degree of glucose elevation results not from a
transient high level but from persistent elevation
• Does not need to be drawn at a specific time
• Serum glycalated proteins (a different test) shows a more recent
evaluation of elevated blood glucose because the are degraded
faster than RBC
Glycosylated hemoglobin (280282) cont.
• Test explanation
• Good for determining:
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Evaluation of the success of diabetic treatment and patient compliance
Comparing and contrasting the success of past and new forms of diabetic therapy
Determining duration of hyperglycemia
Providing sensitive estimate of glucose imbalance in patients with mild diabetes
Individualizing diabetic control
Providing a sense of reward for many patients
Evaluating the diabetic patient whose glucose levels change significantly from day
to day (brittle diabetes)
• Mean plasma glucose = (35.6 x GHb) – 77.3
• Interfering factors
• Hemoglobinopathies affect results because quantity of hemoglobin A varies
• False elevation: when RBC life span is lengthened because the HBA1 has
longer period for glycosylation
• Abnormal low levels of proteins may falsely indicate normal glycalated
fructosamine levels despite reality of high glucose
• Ascorbic acid may cause false lows
Vitamin B12 (540-541)
• Identify the cause of megoblastic anemia and evaluate malnourished patients
• Test explanation:
• B12 is needed for the conversion of folate to the active form
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Necessary for synthesis of nucleic acids and amino acids
Most notable in the formation of RBC
RBC are megoblastic in B12 deficiency so they cannot conform to the size of small capillaries
RBC fracture and hemolyze causing shortened life span
Giant, segmented neutrophils and large nucleated platelets are also seen
May take 6-8 months (of absence of B12) to be seen
Meat, eggs, and dairy are main source of B12
Intrinsic factor is needed for B12 absorption (pernicious anemia)
Gastric acid separates B12 from its binding protein
Malabsorption also causes decrease
More prolonged deficiency is best measured by MMA (urinary methylmalonic acid)
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Elevated serum MMA and urinary excretion of MMA measure B12 activity
The active form of B12 converts L-methylmalonyl CoA to succinyl CoA so without active B 12
larger quantities of MMA is seen in urine
Urine MMA test is more accurate
Mass spect measures MMA in urine
• Interfering factors
• Chloral hydrate increases B12
• Drugs that decrease: alcohol, aminoglycosidesm aminosalicylic acid, anticonvulsants,
colchicine, oral contraceptives
Electroneurography (581-582)
• Normal findings show no peripheral nerve injury or disease
• Identifies peripheral nerve injury in patients with localized or diffuse
weakness, to differentiate primary peripheral nerve disease from
muscular injury, and to document the severity of injury in legal cases
• Monitors nerve injury and response to treatment
• Criteria for brain death
• Absence of hypothermia (meaning only determined if core temp has been
restored)
• Absence of neuromuscular blockade administration
• Absence of possibility of drug or metabolic induced coma
• Absence of response to painful stimuli or other noxious stimuli
• Cerebral flow studies show no blood flow to brain
• Isoelectric EEG
• No attempt at respiration with PCO2 > 500 mmHg
• Fixed pupils
• No corneal reflexes
Electroneurography (581-582)
Cont.
• Test explanation:
• Allows the detection and location of peripheral nerve injury or disease
• Initiate an electrical impulse at one site (proximal) of a nerve and record the
time required for that impulse to travel to a second site (distal) of the same
nerve
• The conduction velocity can be determined
• Done in conjunction with EMG (Electromyography = skeletal muscle eval)
• Normal values vary from nerve to nerve and among individuals
• Compare conduction velocity of the suspected side with the contralateral nerve
conduction velocity
• Normal conduction velocity is 50-60 m/sec
• Traumatic transection or contusion of a nerve will usually cause maximal slowing
of conduction
• Neuropathies, both local and general, cause slowing
• Greater than normal values are not pathologic
• Primary muscle disorders can cause a slow conduction because conduction may
require muscle contraction
• Muscular factor can be evaluated by measuring latency (time required for
stimulation of distal end to cause muscular contraction)
• Conduction velocity = (distance (m))/ (total latency – distal latency)
• Interfering factors
• Patients in severe pain
Urine glucose (969-970)
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Part of a routine urinalysis
If present, reflects degree of glucose elevation in blood
Monitors the effectiveness of therapy for DM
Test explanation
• May indicate DM or other glucose intolerance disorders
• Normally blood glucose is filtered from blood by glomeruli and all the glucose is reabsorbed in
proximal tubules
• Blood glucose exceeds capability of renal threshold to reabsorb and it spills into the urine
• Glucosuria may occur immediately after a high carb meal or in patients on IV dextrose or due
to stress or injury
• Glucosuria can indicate diseases that affect renal tubule or genetic defects in metabolism and
excretion of glucose
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•
In these disorders renal threshold for glucose is low so normal blood glucose cannot be
reabsorbed
GT test in these patients are usually normal
• Interfering factors
• Sugars can cause false positive
• Drugs that cause false positive: ASA, aminosalicylic acid, ascorbic acid, cephalothin, chloral
hydrate, nitrofurantoin, streptomycin, and sulfonamides
• False negative: ascorbic acid (clinistix test), levodopa, and phenazopyridine
• Drugs that increase urine glucose: ASA, cephalosporins, chloral hydrate, chloramphenicol,
dextrothyroxine, diazoxide, diuretics, estrogen, glucose infusions, isoniazid, levedopa, lithium,
nafcillin, nalidixic acid, and nicotinic acid
DRUGS TO KNOW
Drug
Uses
Side effects
Contraindications
Therapeutic
considerations
Alendronate
Class: Bisphosphonate
Mech: Decreases bone
reabsorption by osteoclasts;
blocks a step in the
mevalonate pathway
Indications:
•
Osteoporosis
prevention and
treatment
•
Paget’s disease
•
Jaw osteonecrosis in
cancer patients
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•
•
Extended skeletal
effects,
•
Cessation of bone
remodeling
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•
unclear how to
define overdose
•
Gastroesophageal pain
•
IV dose corrects
hypercalcemia in
days
all secreted by kidney
Calcitonin
(Salmon)
Mech: binds to and activates
a G-protein coupled receptor
on osteoclasts to decrease
resorptive activity
Indications:
•
Hypercalcemia
•
Paget’s disease
•
Postmenopausal
osteoporosis
•
•
•
•
Raloxifene
Class: Selective estrogen
receptor modulator (SERMs)
Mech: Estrogen receptor
agonist in bone, estrogen
receptor antagonist against
endometrium and breast
Indication:
• Osteoporosis prevention
• Retinal vascular
occlusion
• Venous
thromboembolism
• Pulmonary embolism
• Hot flashes
• Leg cramps
Delayed gastric emptying
Inability to sit up for 30
minutes after taking drug
hypocalcemia
•
Flushing
Nausea
Diarrhea
Tachyphylaxis
• Hypersensitivity
• Nasal spray or
subcutaneous
• Subcutaneous lowers
blood calcium over
hours
• Pregnancy
• History or presence of
venous thromboembolism
• Decreases breast
cancer incidence
Drug
Uses
Side effects
Contraindications
Therapeutic considerations
Metformin
Class: Insulin sensitizing biguanides
Mech: Activates AMP
dependent protein kinase to
block synthesis of fatty acids and
to inhibit hepatic
gluconeogenesis and
glycogenolysis; increases insulin
receptor activity and metabolic
responsiveness of liver and
skeletal muscle
Indications:
• Type 2 diabetes
• Polycystic ovarian syndrome
• Lactic acidosis
• GI distress: diarrhea,
dyspepsia, flatulence,
nausea, vomiting,
cobalamin deficiency
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Heart failure*
Septicemia
Alcohol abuse*
Hepatic disease*
Respiratory disease*
Renal impairment*
Iodinated contrast
material if acute
alteration of renal
function is suspected
which may further lactic
acidosis
• Metabolic acidosis
• GI distress associated with
metformin is usually transient
and can be minimized by slow
titration of dose
• Incidence of lactic acidosis is
low and predictable; lactic
acidosis typically occurs with
metformin use in patients who
have other conditions that
predispose to metabolic
acidosis
• Does not induce hypoglycemia
• Lowers serum lipids and
decreases weight
Insulin
Class: exogenous insulin
Mech: Promotes carb
metabolism and facilitates
glucose, amino acid, and Tg
uptake and storage in liver,
cardiac and skeletal muscle, and
adipose tissue
Indication:
• Diabetes mellitus
• Hypglycemia
• Injection site reaction
• Lipodystrophy
• Hypoglycemia
• Not orally available,
subcutaneous route
• Rapid acting analogues lispro,
aspart, and glulisine offer
flexibility and convenience
• Regular insulin is short acting
must be give 30 minutes
before meal
• NPH is intermediate acting
contains protamine which
prolongs time required for
absorption
• Insulin glargine and detemir
are long acting steady release
without peak
• Hypoglycemia is a major
danger especially without carb
intake
(Prandial
bolus or Basal
“long acting”
insulins)
Drug
Uses
Side effects
Contraindications
Therapeutic considerations
Enalapril
Class: ACE Inhibitors
Mech: Decreases
conversion of angiotensin
(AT) I to AT II, which
decreases vasoconstriction
of arterioles, aldosterone
synthesis, renal proximal
tubule NaCl reabsorption,
and ADH release; also
inhibit degradation of
bradykinin, which
increases vasodilation
Indications:
• Hypertension
• heart failure
• diabetic nephropathy
• MI
• Angioedema (more
frequent in black
patients)
• Agranulocytosis
• Neutropenia
• Cough,
• Edema
• Hypotension
• Rash
• Gynecomastia
• Hyperkalemia
• Proteinuria
• History of
angioedema
• Bilateral renal artery
stenosis
• Renal failure
• Pregnancy
• Ester prodrug activated
in plasma
• Bradykinin causes cough
and edema; angioedema
can be potentially lifethreatening
• Delays progression of
cardiac contractile
dysfunction in HF and
after MI; delay diabetic
neuropathy
• Co-admin with
allopurinol may
predispose to
hypersensitivity rxn
including Steven Johnson
syndrome
Lisinopril
Same as above
Same as above
Same as above
Same as above
Amlodipine
(Dihydropyridine)
Class: Calcium channel
blocker
Mech: Another calcium
channel blocker
Indication:
• Exertional angina
• Unstable angina
• Coronary spasm
• Hypertension
• Hypertrophic
cardiomyopathy
• Pre-eclampsia
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• Preexisting
hypotension
• Arteriolar dilation
greater than venous
• High vascular to cardiac
selectivity
• Less depression of
myocardial contractility,
minimal effects on nodal
conduction
• Higher bioavailability,
longer time to peak
plasma concentration,
and slower hepatic
Increased angina,
Rare MI
Palpitations
Peripheral edema
Flushing
Constipation
Heartburn
Dizziness
Drug
Uses
Side effects
Contraindicatio
ns
Therapeutic
considerations
Cisplatin
Class: Directly modify DNA structure
Mech: Platinum compound that
cross-links intrastrand guanine bases
Indications:
• Genitourinary and lung cancer
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• Severe bone marrow
depression
• Renal or hearing
impairment
• Can be injected
intraperitoneally for
treatment of ovarian
cancer
• Co-administration of
amifostine can limit
nephrotoxicity
Ezetimibe
Class: Inhibitors of cholesterol
absorption
Mech: Decreases cholesterol
transport from micelles into
enterocyte inhibiting NPC1L1
Indications:
• Primary hypercholesterolemia
• Familial hypercholesterolemia
• Sitosterolemia
• Elevated liver function
tests
• Myopathy
• Dyspepsia
Arthralgia
• Myalgia
• Headache
• Active liver disease
• Persistently elevated
liver function tests
when co-administered
with statin
• Modest LDL
reduction, small effect
on HDL and Tgs
• Inhibition of hepatic
cholesterol absorption
causes compensatory
increases in synthesis
partially off setting;
prevented by giving
statin
• Rapidly absorbed
• Levels are increased
by cyclosporines and
fibrates
Vincristine
Class: Inhibit microtubule
polymerization
Mech: Binds tubulin subunits and
prevents microtubule polymerization
Indications:
• Leukemia
• Hodgkin’s disease
• Non-hodgkins lymphoma
• Rhadomyosarcoma
• Nephroblastoma
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• Charcot-Marie Tooth
syndrome
• Intrathecal use
• Peripheral neuropathy
is dose limiting
Nephrotoxicity
Myelosuppression
Peripheral neuropathy
Ototoxicity
Electrolyte imbalance
Peripheral neuropathy
Myopathy
Myelosuppression
Alopecia
GI disturbances
Diplopia
Drug
Uses
Side effects
Contraindications
Therapeutic considerations
Dexamethasone
Class: Glucocorticoid
receptor agonist
Mech: Mimic cortisol
function by acting as
agonists at glucocorticoid
receptor
Indications:
•
Inflammatory
conditions in many
different organs
•
Autoimmune diseases
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Immunosupression
Cataracts
Hyperglycemia
Hypercortisolism
Depression
Euphoria
Osteoporosis
Growth retardation in
kids
Muscle atrophy
Impaired wound healing
Hypertension
Fluid retention
Inhaled may cause
oropharyngeal
candidiasis and
dysphonia
Topical causes skin
atrophy
Systemic fungal
infection
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•
Doesn’t correct
underlying etiology just
limits inflammation
Should be tapered when
given chronically to
avoid withdrawal and
acute adrenal
insufficiency
Intranasal and inhaled
greatly reduce systemic
adverse effects
Hydrocortisone
Indications:
• Same as above
•
Replacement therapy
for primary and
secondary adrenal
insufficiency
Same as above
Same as above
Same as above
Verapamil
(Phenylalkylamine)
Class: Calcium channel blocker
Mech: block voltage-gated Ltype calcium channels &
prevent influx of calcium that
promotes actin-myosin crossbridge formation
Indications:
• Prinzmetal or variant
angina or chronic stable
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•
• IV is contraindicated
in patients with
ventricular
tachycardia and
patients receiving IV
beta blockers
• Sick sinus syndrome
or 2nd or 3rd AV block
• SVT associated with
• Low ratio of vascular to
cardiac selectivity
• Depresses both SA and AV
node conduction velocity
• Raises serum carbamazepine
levels which may cause
toxicity
• Avoid using with beta
blockers
Rare cardiac arrhythmia
AV block
Bradyarrhythmia
Exacerbation of heart failure
Peripheral edema
Syncope
Gingival hyperplasia
Dizziness
Drug
Uses
Side effects
Contraindications
Therapeutic considerations
Glyburide
Class: Insulin secretagogues;
sulfonylureas and meglitinides
Mech: Inhibit the beta K+/ATP
channel at SUR1 subunit
stimulating insulin release from
beta cells
Indication:
• Type 2 diabetes mellitus
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•
•
•
•
Hypoglycemia
Rash
Diarrhea
Nausea
Dizziness
• Diabetic ketoacidosis
• Major adverse effect is
hypoglycemia from too much
insulin
• Can cause weight gain
secondary to increased insulin
activity in adipose tissue –
better for non obese people
• Mainstay treatment for type II
diabetes
• Orally available and
metabolized by the liver
Ocreotide
Class: Somatostatin analogue
Mech: Inhibits GH release
Indications:
• Acromegaly
• Flushing and diarrhea from
carcinoid tumors
• Carcinoid crisis
• Diarrhea from vasoactive
intestinal peptide secreting
tumors
• TSH producing adenomas
• Esophageal varicies
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Arrthymias
Bradycardia
Hypoglycermia
Gallstone formation
Abdominal pain
Constipation
Diarrhea
Nausea
Vomiting
• Hypersensitivity
• Used to control GI bleeding
and reduces secretory diarrhea
• Available in monthly depot
formulation
• longer half life than
somatostatin
Lomustine
Lomustine is used to treat certain
types of brain tumors. Lomustine
is also used with other
medications to treat Hodgkin's
lymphoma (Hodgkin's disease)
that has not improved or that has
worsened after treatment with
other medications. Lomustine is in
a class of medications called
alkylating agents. It works by
slowing or stopping the growth of
cancer cells in your body.
Nausea, vomiting, loss of
appetite, sores in the mouth
and throat tiredness or
weakness, pale skin
Fainting, hair loss, unsteady
walk, slurred speech, difficulty
breathing, shortness of breath,
dry cough, wheezing,
decreased urination; swelling of
the face, arms, hands, feet,
ankles, or lower legs.
yellowing or eyes and skin
Confusion sudden change or
loss of vision
Hypersensitivity,
pregnancy breast
feeding
Taken orally
Wear gloves so skin doesn’t
contact drug
BATES
Abnormalities in rate and rhythm of breathing (134)
Pupils and extraocular muscles
(215-218)
• Miosis is pupillary constriction, mydriosis is dilation
• Inspect size, shape and symmetry of pupils (3-5 mm)
• Anisocoria is pupillary inequality of less than 0.5 mm, benign if reactivity is normal (20% of
normal people, these values are slightly different from the cranial nerve section)
• Test reaction to light: direct (constriction in the same eye) consensual (constriction in
opposite eye)
• If reaction is impaired test near reaction in normal room light testing one eye at a time
• Hold pencil 10 cm and alternate having the patient look at it then at a distant object, monitor
constriction with near effort
• From 2 feet away test reflection of light in the cornea to test for deviation. Should be visible
slightly nasal to the center of the pupil
• cover- uncover test may reveal slight or latent muscle imbalance
• Nystagmus is a fine rhythmic oscillation of the eyes; seen with neurologic conditions, if
seen bring finger into binocular field of vision and look again
• Lid lag as eyes move up to down
• Move finger in the ‘H’ pattern to test EOM Lr6So4Ao3 (Pause during lateral gaze to test for
nystagmus)
• Test for convergence as well by asking patient to follow finger, light, object as you bring it
toward them
• Hyperthyroidism shows poor convergences and proptosis with lid lag
Pupillary abnormalities (259)
Dysconjugate gaze (260)
The cranial nerves (672-678)
• CN I olfactory: test smell by presenting patient with smells
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Smoking, parkinson’s, head trauma, aging, cocaine can eliminate sense
Compress each nasal passage to test separately
Have patient close eyes
Avoid using noxious triggers as sample smells because this will stimulate CN V
• CN II optic
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Papilledema, disc pallor in atrophy by inspecting optic fundi
Bitemporal hemianopsia from defects in optic chiasm
Hemonymous hemianopsia means loss of peripheral vision seen with parietal lobe; findings of a
stroke
• CN III oculomotor:
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Inspect size and shape of pupil - Anisocoria is a difference between pupils > 0.4mm, seen in 38%
of normal individuals.
Test reaction to light
Check near response (Tests pupillary constriction, convergence and accommodation of the lens)
Horners may lead to miosis = small pupil.
• CN III, IV, VI Occulomotor, Trochlear, Abducens
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Lr6So4Ao3
Test extraocular muscles in the six cardinal directions of gaze
Diplopia means double vision binocular (M. gravis, trauma, thyroid opthalmopathy, internuclear
opthalmoplegia) monocular ( glasses or contact problems, cataracts, astigmatism, ptosis)
Check for convergence
Nystagmus [ an involuntary jerking movement of the eyes with quick and slow components] seen in
cerebellar disease with gait ataxia and dysarthria, vestibular disorders, internuclear othalmoplegia
Ptosis is 3rd nerve palsy in horners and m. gravis
The cranial nerves (672-678)
• CN V Trigeminal
• Motor: difficulty clenching the jaw or moving it to the opposite side in masseter and lateral
pterygoid weakness
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Palpate temporal and masseter muscles and ask patient to clench teeth, move jaw side to side
Bilateral weakness is cerebral hemisphere disease
In stroke it’s ipsilateral face and contralateral body
• Sensory
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Test forehead, jaw and cheeks for pain sensation with patient’s eyes closed
If you find an abnormality test it for temperature sensation
Light touch sense with a wisp of cotton
• Corneal reflex
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•
Ask patient to look up and away from you approach other side lightly touch with a fine wisp of
cotton ( Make sure you are touching the cornea not the conjuctiva)
Absent blinking is CN V lesion
• CN VII Facial
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Look at face at rest and during conversation notice any asymmetry
Drooping of eyelid and flattening of nasolabial fold
Bell’s palsy affects both sides of lower face
Patient should raise eyebrows, frown, close both eyes tightly, show upper and lower teeth,
smile, puff out both cheeks
• CN VIII
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Assess hearing with whispered voice
Conductive (air through ear) or sensorineural from cochlear CN VIII damage
Rinne test for air and bone conduction
Lateralization using weber test
The cranial nerves (672-678)
• IX and X Glossopharyngeal and Vagus
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Hoarseness in voice, vocal cord paralysis
Nasal voice in palate paralysis
Pharyngeal or palate weakness
Difficulty swallowing
Have patient say “Ah” and watch the movement of soft palate and pharynx
Deviation of uvula points to X damage
Palate fails to rise in vagus injury, uvula pulled away from lesion
Stick out tongue and test gag reflex ( elevation of tongue and soft palate and constriction of
pharyngeal muscles)
• XI spinal accessory
• Trapezius weakness with fasciculations shoulder droops and scapula is displaced downward
and laterally
• Fasciculations are fine flickering irregular movements of small groups of muscle fibers
• Patient shrugs both shoulders against resistance
• Turn head to each side against your hand, testing opposite side SCM
• XII hypoglossal
• Poor word articulation or dysarthria may mean tongue atrophy and fasciculations in
amyotrophic lateral sclerosis, polio
• Have patient protrude tongue looking for asymmetry, atrophy or deviation
• Have patient move tongue from side to side
• Have patient push tongue against cheek, and dr pushes on it externally to palpate for
strength
• Lick your wounds in unilateral cortical lesion
Exam of tympanic membrane
(813-814)
• In kids pull auricle upward, outward and backward
• Tips: use best angle of otoscope, use largest possible speculum, don’t
apply too much pressure, insert speculum ¼-1/2 inch into canal, note
whether tympanic membrane is abnormal, remove cerumen if blocking
view using plastic curettes, moistened microtipped cotton swab,
flushing of ears
• Hold the lateral aspect of your hand that has the otoscope against the
child’s head to buffer against sudden movements
• Or, hold handle facing downward at feet and hold head with other hand
• Otitis media shows red, bulging tympanic membrane with dull or absent
light reflex, purulent matter may be seen
• Pneumatic otoscope improves accuracy assess mobility of tympanic
membrane (mobility is absent in effusion, can have temporal hearing
loss) When air is removed the Tympanic Membrane moves towards
you. When air is added its light reflex moves inwards.
• Otitis externa: movement of pinna causes pain
• Mastoiditis: auricle protrudes forward area over mastoid is swollen
Babinski and Brudzinski signs
(701-703)
• Dorsiflexion of the big toe is a positive babinski response
from a CNS lesion in corticospinal tract (upper motor neuron)
• May also been seen in unconscious states from drug or alcohol
intoxication or postictal period following a seizure
• Can be accompanied by reflex flexion of hip and knee
• Preformed by stroking from the lateral aspect of the sole from
the heat to the ball of the foot, curving medially across the ball.
• Normal (NEGATIVE babinski) big toe will plantar flex
• Brudzinski
• As you flex the neck, watch the hips and knees in reaction to your
maneuver. Normally they should remain relaxed and motionless
• Flexion of the knees and the hips is a positive Brudzinski sign and
suggests meningeal inflammation
RADIOLOGY 101
Radiography, CT, and MRI (211)
• Radiography
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Common views are posterioranterior, anteriorposterior, oblique, and lateral
PA means beams travel back to front
Lateral means side to side
AP is sitting, upright or supine
Density determines how much beam will be absorbed
Air and fat black, water gray, bone or metal white
Muscles, organs, or soft tissue appear different shades of gray depending on
water density
• Radiographic screens are on bold sides of the film and they emit light flashes
and fluoresce which becomes the exposure
• Digital or computed radiography
• Producing a digital image by scanning the phosphor plate with a laser beam
that causes light to be released from phosphor plate
• The intensity of emitted light depends on local radiation exposure
• A photomultiplier tube amplifies the light and converts it into an electron
stream, the electron stream is digitized and then converted into an image
Radiography, CT, and MRI (211) cont.
• Contrast media
• Using pharmaceuticals to differentiate between normal and abnormal tissues, to
define vascular anatomy, and to improve visualization of some organs
• Iodine molecules bound to chemicals that absorb varying degrees of x-ray
absorption
• More uptake of contrast = enhancement
• With the high osmolar contrast there were reactions of vomiting, pain at injection
site, respiratory symptoms, urticaria, and generalized burning
• Low osmolar contrast agents have replaced high ones and improve comfort but
there is still a risk of nephropathy
• Arthography: inject contrast media or air into a joint
• Myelography: places it in spinal subarachnoid space usually with lumbar puncture
diagnosing diseases around cord
• Orally ingested tablets are metabolized by liver and concentrated in gall bladder
providing information about function, calculi, and tumors
• Barium used for GI usually with air to provide double contrast, but if perf or
serious damage suspected use water based
• MRI uses gadolinium or other metals with unpaired electrons it changes T1
useful in imaging tumors, infections and acute cerebral vascular accidents, can
cause NSF (nephrogenic sclerosing fibrosis) if patient on dialysis or has creatinine
clearance less that 30 mg/dL
CT
• Sagittal, coronal, and axial
• Originally created exclusively for brain
• Looking at slices of a loaf of bread 1-10 mm slices.
• Usually 10mm cuts for lung because of large tissue
• X ray beams pass through and eventually meet detectors
• Intracerebral hemorrhage or fracture: contrast not needed
• Contrast increases density of blood vessels, vascular soft tissue,
organs and tumors
• High resolution uses thinner slices 1-2 mm
• Useful in parenchymal lung disease
• Helical or spiral patient continuously moves while beams encircle
the patient improving images in thorax and abdomen
• Multislice/dynamic: multiple detectors that yield multiple
tomographic slices
MRI
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Coronal and sagittal
Small changes within contrast and MRI soft tissue
Exposure to magnetic fields and radio frequency waves
Not recommended during first trimester
Bad for those with claustrophobia and loud
Imaging of protons (hydrogen) which have a spin frequency
Compares spin frequency
Short bursts of radio-frequency waves are broadcast and protons absorb wave energy and become energized or
resonate
The intensity of radio wave signal detected by coil determines number and locations of resonating hydrogen
Many in fat so it will be bright, less in bone
If radio receivers listen early in the decay following discontinuance of radio wave broadcast it is T1 weighted where
fat is white and gray soft tissue detail is excellent, good for anatomy
Late listening is water in soft tissue a lighter gray and fat is gray is T2; better for pathology
Angiography: image vessels without catheters, iodine blood appears bright
fMRI: identifying activity by oxygenated and deoxygenated blood
• Can be used for heart too
• Infarcted areas appear white
Diffusion weighted
• Ischemic stroke
• Abnormal motion is detected
Spectroscopy
• Assessing protons in acetyl aspartate, choline, creatinine, and lactate
• Evaluate cancerous lesions since they have increased choline and reduced NAA
• Stroke has increased lactate
• Disorders of metabolism