This
document
is
a
collection
of
HY
notes
from
the
USMLE
World
Step
3
question
bank.
These
notes
are
not
‘bottom
line
statements’
nor
are
they
meant
to
be
unequivocally
comprehensive
in
all
subject
areas.
They
are
a
random
agglomeration
of
pearls
that
should
serve
as
review
and
to
fill
in
gaps
for
a
student
finishing
medical
school.
-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐
Iron
deficiency
in
an
infant
is
often
due
to
supplementing
with
cow/goat/soy
milk
under
the
age
of
1,
or
exclusively
breastfeeding
after
6
months.
Do
an
FBC
and
give
oral
iron
supplementation
if
anaemic.
Reticulocyte
count
increases
first,
followed
by
Hb
and
Hct
in
one
month.
‘Near-‐miss
events,’
or
medical
errors
caught
before
they
reach
the
patient,
must
be
reported
to
hospital
administration.
It
is
not
mandatory
to
report
near
misses
to
patients.
It
is
mandatory
to
report
to
patients
only
errors
that
have
occurred.
Caput
succedaneum
crosses
suture
lines;
cephalohaematoma
does
not.
Caput
can
be
ecchymotic;
it
presents
soon
after
birth
+
self-‐resolves
in
weeks.
Cephalohaematoma
is
associated
with
underlying
skull
fracture
in
10-‐25%,
there
is
no
discolouration
of
the
scalp,
and
it
is
not
visible
for
several
hours
because
of
slow
bleeding;
it
self-‐resolves
in
two
weeks
to
three
months.
Neither
requires
treatment.
Mammograms
should
be
done
every
two
years
age
50-‐75.
Ultrasound
alone
is
done
under
the
age
of
30.
Over
the
age
of
30,
mammogram
and
ultrasound
is
done.
Verapamil,
quinidine,
amiodarone
+
spironolactone
can
all
cause
digoxin
toxicity.
Bezold
abscess
=
neck
abscess
resulting
from
medial
spread
of
mastoiditis.
The
abscess
is
in
the
sternocleidomastoid.
A
patient
with
a
(+)
HepC
antibody
ELISA
screen
needs
confirmatory
testing
for
HCV
RNA
as
the
next
best
step.
A
(+)
ELISA
on
its
own
could
mean
persistent
infection,
cleared
infection,
or
false
(+).
A
child
has
a
3%
chance
of
acquiring
T1DM
if
only
his
or
her
mom
has
T1DM,
and
6%
chance
if
the
father
has
T1DM
(difference
not
fully
elucidated).
A
monozygotic
twin
has
a
50%
chance
of
developing
T1DM
if
his
or
her
twin
has
it.
Apnea
testing
confirms
brain
death
in
individuals
w/
absent
cortical
and
brainstem
reflexes.
,
Herbs
associated
with
increased
bleeding
risk:
Ginkgo
biloba,
ginsing,
saw
palmetto
(likely
platelet
dysfunction),
black
cohosh,
garlic,
horse
chestnut
Ginkgo
used
for
memory;
ginsing
used
for
increased
mental
function;
saw
palmetto
used
for
BPH
(also
causes
GI
disturbance);
black
cohosh
used
for
post-‐menopausal
Sx;
horse
chestnut
used
for
venous
stasis/insufficiency
Herbs
associated
with
hepatotoxicity:
black
cohosh,
kava
kava
(used
for
anxiety/depression
and
insomnia).
Drugs
that
can
cause
HTN:
ephedra
(used
for
colds/flus
and
to
increase
energy),
St
John
wort
when
with
other
serotonergic
drugs
(used
for
depression/anxiety
and
insomnia),
and
licorice
(also
causes
hypokalaemia).
Echinacea
causes
anaphylaxis,
especially
high
risk
in
asthmatics.
Black
cohosh
can
also
cause
hypotension.
Tx
of
malignant
otitis
externa
=
intravenous
anti-‐pseudomonals
(e.g.,
ciprofloxacin)
followed
by
oral
therapy
for
6-‐8
weeks
of
total
Abx
therapy.
An
individual
who
suffers
severe
traumatic
injury
should
be
given
narcotics
for
pain
relief
regardless
of
addiction/abuse
Hx.
MRI
is
best
to
Dx
suspected
osteonecrosis
(e.g.,
of
hip).
Plain
films
can
often
appear
normal,
especially
early
on.
If
hypoglycaemia
is
present
and
serum
insulin
+
C-‐peptide
both
elevated,
do
oral
hypoglycaemic
serum
screen
(e.g.,
for
sulfonylurea
levels)
as
next
best
step
in
management.
C-‐peptide
can
be
increased
in
this
case
and
insulinoma
isn’t
necessarily
the
answer.
Restless
leg
syndrome
can
be
caused
by
iron
deficiency.
Ferritin
should
be
ordered
as
iron
deficiency
can
be
seen
in
the
absence
of
anaemia.
Chronic
renal
failure/uraemia,
diabetes,
pregnancy,
multiple
sclerosis,
Parkinson
disease,
and
drugs
(e.g.,
metoclopramide,
antidepressants)
can
also
cause
it.
Treat
with
iron
supplements
when
ferritin
<75
ug/dL,
and
w/
dopamine
agonists
or
alpha2-‐delta2
Ca
channel
ligands
(gabapentin).
,Risk
of
future
peripartum
cardiomyopathy
is
ascertained
with
transthoracic
echocardiogram.
Decreased
EF
suggests
worse
prognosis
if
subsequent
pregnancy
occurs.
If
suspected
breast
abscess
(e.g.,
secondary
to
mastitis),
first
do
ultrasound
to
Dx
then
needle
aspiration.
Only
do
incision
+
drainage
if
that
fails.
HIV
(+)
patients
who
are
not
on
HAART
should
have
CD4
count
measured
every
3-‐4
months
to
determine
optimal
time
to
commence
therapy.
HIV
post-‐exposure
prophylaxis
in
high-‐risk
situations
within
72
hours
(e.g.,
post-‐
needle
stick;
exposure
to
any
secretion
with
blood,
breast
milk,
semen,
rectovaginal,
eye,
mucous
membrane,
non-‐intact
skin)
=
two
NRTIs
+
either
an
NNRTI,
integrase
inhibitor
or
protease
inhibitor
=
three
drugs
total
for
FOUR
weeks.
If
presents
>72
hours
post-‐exposure
of
source
of
HIV
was
low-‐risk
(urine,
nasal
secretions,
saliva,
sweat,
tears
[no
visible
blood
in
any
as
well]),
post-‐exposure
prophylaxis
is
not
recommended.
Examples
of
NRTIs:
tenofovir,
lamivudine,
emtricitabine,
zidovudine
Integrase
inhibitor:
raltegravir
Protease
inhibitors:
atazanavir,
ritonavir
Hypercalcaemia
can
cause
anxiety/depression,
mild
weakness,
constipation,
peptic
ulcer
disease
and
diastolic
hypertension.
Hypocalcaemia
can
cause
hyperpigmentation,
seizures,
weakness
and
hypotension.
Mendelson
syndrome
=
pneumonitis
from
aspiration
of
gastric
contents
Fluid
status
(i.e.,
IV
fluids)
should
be
closely
monitored
in
patients
with
kidney
injury
(e.g.,
ATN)
to
prevent
pulmonary
edema
and
hyperchloraemic
metabolic
acidosis.
Gonorrhea
Tx
=
single
intramuscular
dose
of
250mg
ceftriaxone
plus
oral
doxy
100mg
bid
or
1g
oral
azithro
stat
Oral
erythromycin
(14
days)
is
Tx
for
both
neonatal
conjunctivitis
and
pneumonia.
Topical
is
not
effective.
Although
erythromycin
increases
risk
of
pyloric
stenosis,
it
is
, the
only
macrolide
well-‐studied
to
be
effective.
Prophylactic
eye
drops
are
not
effective.
Most
important
management
step
in
septic
shock
is
fluid
resus
to
CVP
of
8-‐12
mm
Hg.
If
poorly
responsive
à
vasopressors.
In
patients
taking
corticosteroids,
stress-‐dose
steroids
should
also
be
given
in
septic
shock
due
to
adrenal
suppression.
Target-‐specific
oral
anticoagulants
(TSOAC),
such
as
dabigatran,
rivaroxaban,
apixaban,
edoxaban,
are
not
recommened
in
AF
if
three
is
valvulopathy
(especially
mitral)
or
renal
disease.
TSOACs
are
best
for
non-‐valvular
AF
or
mild
AS.
RDA
for
calcium
is
1200
mg/day;
RDA
for
vitamin
D
is
600-‐800
IU/day.
Microbial
Dx
of
diabetic
foot
ulcers
is
best
achieved
via
deep
curettage.
Before
Dx
fibromyalgia,
must
do
FBC,
ESR/CRP
and
TSH/T3/T4.
Antenatal
steroids
are
given
intramuscularly.
Tx
for
uraemic
platelet
dysfunction
is
IV
desmopressin,
not
platelet
transfusion.
Tx
for
hyperglycaemic
hyperosmolar
non-‐ketotic
state
(HHS)
is
fluids:
0.9%
NaCl
initially
then
switch
to
5%
dextrose
once
glucose
<200
mg/dL;
insulin:
IV
infusion
initially
then
switch
to
SQ
long-‐acting
basal
insulin
(e.g.,
glargine,
detemir)
with
a
1-‐
2-‐hr
overlap
once
1)
the
patient
can
tolerate
oral
feeds,
2)
glucose
is
<200,
bicarb
is
>15,
and
there’s
no
anion
gap
acidosis;
potassium:
must
give
K+
once
under
5.2
mEq/L;
withhold
insulin
if
K+
under
3.3
mEq/L;
patients
are
always
potassium-‐
depleted
even
if
hyperkalaemic;
bicarb:
consider
if
pH
<6.9;
phosphate:
consider
if
<1
mEq/L
or
cardio/respiratory
compromise;
monitor
calcium
frequently.
Diabetic
ketoacidosis
is
defined
as
pH
<7.3,
bicarb
<15,
and
glucose
>200
mg/dL.
Treatment
is
10
mL/kg
normal
saline
over
one
hour,
followed
by
an
insulin
drip.
K+
is
added
to
the
insulin
if
<5.2.
Severe
DKA
is
pH
<7.1,
bicarb
<5,
or
altered
mental
status;
admit
to
ICU.
Three
Dx
criteria
for
ankylosing
spondylitis:
1)
low
back
pain/stiffness
>3
months
that
improves
with
exercise/activity,
2)
decreased
range
of
motion
of
lumbar
spine,
3)
decreased
chest
expansion;
initial
Dx
made
via
X-‐ray
of
sacroiliac
joints.
document
is
a
collection
of
HY
notes
from
the
USMLE
World
Step
3
question
bank.
These
notes
are
not
‘bottom
line
statements’
nor
are
they
meant
to
be
unequivocally
comprehensive
in
all
subject
areas.
They
are
a
random
agglomeration
of
pearls
that
should
serve
as
review
and
to
fill
in
gaps
for
a
student
finishing
medical
school.
-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐
Iron
deficiency
in
an
infant
is
often
due
to
supplementing
with
cow/goat/soy
milk
under
the
age
of
1,
or
exclusively
breastfeeding
after
6
months.
Do
an
FBC
and
give
oral
iron
supplementation
if
anaemic.
Reticulocyte
count
increases
first,
followed
by
Hb
and
Hct
in
one
month.
‘Near-‐miss
events,’
or
medical
errors
caught
before
they
reach
the
patient,
must
be
reported
to
hospital
administration.
It
is
not
mandatory
to
report
near
misses
to
patients.
It
is
mandatory
to
report
to
patients
only
errors
that
have
occurred.
Caput
succedaneum
crosses
suture
lines;
cephalohaematoma
does
not.
Caput
can
be
ecchymotic;
it
presents
soon
after
birth
+
self-‐resolves
in
weeks.
Cephalohaematoma
is
associated
with
underlying
skull
fracture
in
10-‐25%,
there
is
no
discolouration
of
the
scalp,
and
it
is
not
visible
for
several
hours
because
of
slow
bleeding;
it
self-‐resolves
in
two
weeks
to
three
months.
Neither
requires
treatment.
Mammograms
should
be
done
every
two
years
age
50-‐75.
Ultrasound
alone
is
done
under
the
age
of
30.
Over
the
age
of
30,
mammogram
and
ultrasound
is
done.
Verapamil,
quinidine,
amiodarone
+
spironolactone
can
all
cause
digoxin
toxicity.
Bezold
abscess
=
neck
abscess
resulting
from
medial
spread
of
mastoiditis.
The
abscess
is
in
the
sternocleidomastoid.
A
patient
with
a
(+)
HepC
antibody
ELISA
screen
needs
confirmatory
testing
for
HCV
RNA
as
the
next
best
step.
A
(+)
ELISA
on
its
own
could
mean
persistent
infection,
cleared
infection,
or
false
(+).
A
child
has
a
3%
chance
of
acquiring
T1DM
if
only
his
or
her
mom
has
T1DM,
and
6%
chance
if
the
father
has
T1DM
(difference
not
fully
elucidated).
A
monozygotic
twin
has
a
50%
chance
of
developing
T1DM
if
his
or
her
twin
has
it.
Apnea
testing
confirms
brain
death
in
individuals
w/
absent
cortical
and
brainstem
reflexes.
,
Herbs
associated
with
increased
bleeding
risk:
Ginkgo
biloba,
ginsing,
saw
palmetto
(likely
platelet
dysfunction),
black
cohosh,
garlic,
horse
chestnut
Ginkgo
used
for
memory;
ginsing
used
for
increased
mental
function;
saw
palmetto
used
for
BPH
(also
causes
GI
disturbance);
black
cohosh
used
for
post-‐menopausal
Sx;
horse
chestnut
used
for
venous
stasis/insufficiency
Herbs
associated
with
hepatotoxicity:
black
cohosh,
kava
kava
(used
for
anxiety/depression
and
insomnia).
Drugs
that
can
cause
HTN:
ephedra
(used
for
colds/flus
and
to
increase
energy),
St
John
wort
when
with
other
serotonergic
drugs
(used
for
depression/anxiety
and
insomnia),
and
licorice
(also
causes
hypokalaemia).
Echinacea
causes
anaphylaxis,
especially
high
risk
in
asthmatics.
Black
cohosh
can
also
cause
hypotension.
Tx
of
malignant
otitis
externa
=
intravenous
anti-‐pseudomonals
(e.g.,
ciprofloxacin)
followed
by
oral
therapy
for
6-‐8
weeks
of
total
Abx
therapy.
An
individual
who
suffers
severe
traumatic
injury
should
be
given
narcotics
for
pain
relief
regardless
of
addiction/abuse
Hx.
MRI
is
best
to
Dx
suspected
osteonecrosis
(e.g.,
of
hip).
Plain
films
can
often
appear
normal,
especially
early
on.
If
hypoglycaemia
is
present
and
serum
insulin
+
C-‐peptide
both
elevated,
do
oral
hypoglycaemic
serum
screen
(e.g.,
for
sulfonylurea
levels)
as
next
best
step
in
management.
C-‐peptide
can
be
increased
in
this
case
and
insulinoma
isn’t
necessarily
the
answer.
Restless
leg
syndrome
can
be
caused
by
iron
deficiency.
Ferritin
should
be
ordered
as
iron
deficiency
can
be
seen
in
the
absence
of
anaemia.
Chronic
renal
failure/uraemia,
diabetes,
pregnancy,
multiple
sclerosis,
Parkinson
disease,
and
drugs
(e.g.,
metoclopramide,
antidepressants)
can
also
cause
it.
Treat
with
iron
supplements
when
ferritin
<75
ug/dL,
and
w/
dopamine
agonists
or
alpha2-‐delta2
Ca
channel
ligands
(gabapentin).
,Risk
of
future
peripartum
cardiomyopathy
is
ascertained
with
transthoracic
echocardiogram.
Decreased
EF
suggests
worse
prognosis
if
subsequent
pregnancy
occurs.
If
suspected
breast
abscess
(e.g.,
secondary
to
mastitis),
first
do
ultrasound
to
Dx
then
needle
aspiration.
Only
do
incision
+
drainage
if
that
fails.
HIV
(+)
patients
who
are
not
on
HAART
should
have
CD4
count
measured
every
3-‐4
months
to
determine
optimal
time
to
commence
therapy.
HIV
post-‐exposure
prophylaxis
in
high-‐risk
situations
within
72
hours
(e.g.,
post-‐
needle
stick;
exposure
to
any
secretion
with
blood,
breast
milk,
semen,
rectovaginal,
eye,
mucous
membrane,
non-‐intact
skin)
=
two
NRTIs
+
either
an
NNRTI,
integrase
inhibitor
or
protease
inhibitor
=
three
drugs
total
for
FOUR
weeks.
If
presents
>72
hours
post-‐exposure
of
source
of
HIV
was
low-‐risk
(urine,
nasal
secretions,
saliva,
sweat,
tears
[no
visible
blood
in
any
as
well]),
post-‐exposure
prophylaxis
is
not
recommended.
Examples
of
NRTIs:
tenofovir,
lamivudine,
emtricitabine,
zidovudine
Integrase
inhibitor:
raltegravir
Protease
inhibitors:
atazanavir,
ritonavir
Hypercalcaemia
can
cause
anxiety/depression,
mild
weakness,
constipation,
peptic
ulcer
disease
and
diastolic
hypertension.
Hypocalcaemia
can
cause
hyperpigmentation,
seizures,
weakness
and
hypotension.
Mendelson
syndrome
=
pneumonitis
from
aspiration
of
gastric
contents
Fluid
status
(i.e.,
IV
fluids)
should
be
closely
monitored
in
patients
with
kidney
injury
(e.g.,
ATN)
to
prevent
pulmonary
edema
and
hyperchloraemic
metabolic
acidosis.
Gonorrhea
Tx
=
single
intramuscular
dose
of
250mg
ceftriaxone
plus
oral
doxy
100mg
bid
or
1g
oral
azithro
stat
Oral
erythromycin
(14
days)
is
Tx
for
both
neonatal
conjunctivitis
and
pneumonia.
Topical
is
not
effective.
Although
erythromycin
increases
risk
of
pyloric
stenosis,
it
is
, the
only
macrolide
well-‐studied
to
be
effective.
Prophylactic
eye
drops
are
not
effective.
Most
important
management
step
in
septic
shock
is
fluid
resus
to
CVP
of
8-‐12
mm
Hg.
If
poorly
responsive
à
vasopressors.
In
patients
taking
corticosteroids,
stress-‐dose
steroids
should
also
be
given
in
septic
shock
due
to
adrenal
suppression.
Target-‐specific
oral
anticoagulants
(TSOAC),
such
as
dabigatran,
rivaroxaban,
apixaban,
edoxaban,
are
not
recommened
in
AF
if
three
is
valvulopathy
(especially
mitral)
or
renal
disease.
TSOACs
are
best
for
non-‐valvular
AF
or
mild
AS.
RDA
for
calcium
is
1200
mg/day;
RDA
for
vitamin
D
is
600-‐800
IU/day.
Microbial
Dx
of
diabetic
foot
ulcers
is
best
achieved
via
deep
curettage.
Before
Dx
fibromyalgia,
must
do
FBC,
ESR/CRP
and
TSH/T3/T4.
Antenatal
steroids
are
given
intramuscularly.
Tx
for
uraemic
platelet
dysfunction
is
IV
desmopressin,
not
platelet
transfusion.
Tx
for
hyperglycaemic
hyperosmolar
non-‐ketotic
state
(HHS)
is
fluids:
0.9%
NaCl
initially
then
switch
to
5%
dextrose
once
glucose
<200
mg/dL;
insulin:
IV
infusion
initially
then
switch
to
SQ
long-‐acting
basal
insulin
(e.g.,
glargine,
detemir)
with
a
1-‐
2-‐hr
overlap
once
1)
the
patient
can
tolerate
oral
feeds,
2)
glucose
is
<200,
bicarb
is
>15,
and
there’s
no
anion
gap
acidosis;
potassium:
must
give
K+
once
under
5.2
mEq/L;
withhold
insulin
if
K+
under
3.3
mEq/L;
patients
are
always
potassium-‐
depleted
even
if
hyperkalaemic;
bicarb:
consider
if
pH
<6.9;
phosphate:
consider
if
<1
mEq/L
or
cardio/respiratory
compromise;
monitor
calcium
frequently.
Diabetic
ketoacidosis
is
defined
as
pH
<7.3,
bicarb
<15,
and
glucose
>200
mg/dL.
Treatment
is
10
mL/kg
normal
saline
over
one
hour,
followed
by
an
insulin
drip.
K+
is
added
to
the
insulin
if
<5.2.
Severe
DKA
is
pH
<7.1,
bicarb
<5,
or
altered
mental
status;
admit
to
ICU.
Three
Dx
criteria
for
ankylosing
spondylitis:
1)
low
back
pain/stiffness
>3
months
that
improves
with
exercise/activity,
2)
decreased
range
of
motion
of
lumbar
spine,
3)
decreased
chest
expansion;
initial
Dx
made
via
X-‐ray
of
sacroiliac
joints.
