Wednesday, May 30, 2012

CK done!

I've had to pinch myself a few times in the last 2 days because it has hardly sunk in that USMLE step 2ck is over!

Day 0, I was 45mins flight away from home, totally psyched up, ready as I could be and knowing that my loved ones were back home praying for me. I got up early, prayed, exercised, got dressed, made sandwiches for my breaks,  read  1 or 2 pages of MTB to wake my brain cells and had a good proteinous breakfast. On my way out of the hotel, I sat down for about 10mins at the computer station and just scrolled through week 2 of this mental map (the week with the highest number of posts), nodding along. Those highlights bounced back and forth in my brain as I did the 10mins walk to the exam centre.

Generally, the exam went very well save for the intermittent drilling noise coming from outside the window at the prometric centre. It was distracting at first but when I talked to the proctor after block 1 and learnt that there was nothing they could do about it, (not even to change my seat to one farther from the window!), I told myself :" You can do this, the noise is now part of the exam and you just have to surmount it!" After that I wasn't as bothered by the noise. Nine hours went by quickly and before you knew it I was on my way back to my hotel room saying "thank you God" and telling Hubby (on the phone) how it went.

Well, the 4weeks wait is on...

I prepared for this USMLE step using U world, MTB, Kaplan Qbank, a few Kaplan videos and many online resources. One tool which was however extremely useful to me was this blog which I started about a month to the exam, when I was feeling like I needed some form of 'decongestion' or was it 'info organisation'? Whatever it was, trying to put down the most important facts about each condition or concept was really helpful in consolidating what I knew well and identifying what I didn't know  enough about. Also, the product of my mental mapping (this blog) was good for quick revision anywhere internet was available. I hope someone else will also find it useful.

To all those at the stage that I was when I started this blog, good luck!

Saturday, May 26, 2012

PPD Interpretation

Classification of the Tuberculin Skin Test Reaction

An induration of 5 or more millimeters is considered positive in
-HIV-infected persons
-A recent contact of a person with TB disease
-Persons with fibrotic changes on chest radiograph consistent with prior TB
-Patients with organ transplants
-Persons who are immunosuppressed for other reasons (e.g., taking the equivalent of >15 mg/day of prednisone for 1 month or longer, taking TNF-a antagonists)
An induration of 10 or more millimeters is considered positive in
-Recent immigrants (< 5 years) from high-prevalence countries
-Injection drug users
-Residents and employees of high-risk congregate settings
-Mycobacteriology laboratory personnel
-Persons with clinical conditions that place them at high risk
-Children < 4 years of age
- Infants, children, and adolescents exposed to adults in high-risk categories
An induration of 15 or more millimeters is considered positive in any person, including persons with no known risk factors for TB. However, targeted skin testing programs should only be conducted among high-risk groups.
CDC (Center for Disease Control and Prevention)

Friday, May 25, 2012


Normal values

75-gram 2 Hour oral glucose tolerance test
  • Fasting    60 -100 mg/dL
  • 1 hr:        less than 200 mg/dL
  • 2 hrs:      less than 140 mg/dL. 
140 - 200 mg/dL = Impaired glucose tolerance
> 200 mg/dL = Diabetes

50-gram 1 hour oral glucose tolerance test
  • 1 hour: < or =140 mg/dL
if >140, do
100-gram 3 hour oral glucose tolerance test
  • Fasting: less than 95 mg/dL
  • 1 hour: less than 180 mg/dL
  • 2 hour: less than 155 mg/dL
  • 3 hour: less than 140 mg/dL
2 or more abnormal values = GDM

Random facts (statistics)

Differential loss to follow up: Attrition. A type of selection bias found in cohort studies

Reliability: repeatability of a measure

Validity: absence of bias

Bias: systematic error

Selection bias: deferential access to study population (from selection process, respodents no longer available at the end, attrition etc)

Confounding: unfair comparison

Volunteer bias: type of selection bias, the tendency for one's health to influence decision to participate in a study

Information bias: occurs when the means of obtaining information from cases and controls differ

Hazards ratio, Relative risk

HR = Probability of event in treatment grp/Probability of event in control group

RR = Probability of event in treatment grp/Probability of event in control group

Exactly! same formular!

Hazard ratio is actually a type of Relative risk (a.k.a Risk ratio)

The difference?
HR is instantaneous while RR is culmulative.
RR can only be calculated at the end of the study while HR can be calculated at different points in time. Hazard ratios are calculated using the survival analysis technique. This keeps track of the number of subjects who haven't had the event (e.g death) at a particular time.

Again, HR is an estimate of RR

HR of 1 means the rate of occurrence of the event in treatment/intervention grp is same as in control/placebo grp

HR >1  means event occurs more in the intervention grp

HR <1  means event occurs less in the intervention grp

To convert a HR to probability,

Probability of event occurring = HR/1+ HR

So, HR of 1 is a probability of 50%. A 50:50 chance, i.e treatment and placebo grps are the same in terms of outcome

Wednesday, May 23, 2012

Regarding asthma treatment

Practice recommendations
  • Every patient with persistent asthma, regardless of disease severity, should use a daily controller medication.

  • Consider an inhaled corticosteroid (ICS) first when choosing controller medications for long-term treatment of mild, moderate, and severe persistent asthma in adults and children. Leukotriene modifiers, cromolyn, and nedocromil may be considered as alternative, not preferred, controller medications for patients with persistent asthma.

  • Long-acting β2-adrenergic agonists should not be used as monotherapy.

  • Long-term use of ICSs within labeled doses is safe for children in terms of growth, bone mineral density, and adrenal function; nonetheless, asthma should be monitored and ICS therapy stepped down to the lowest effective dose.

  • Low-to medium-dose ICSs are not associated with the development of cataracts or glaucoma in children, but high cumulative lifetime doses may slightly increase the prevalence of cataracts in adults and elderly patients.

  • ICSs are recommended for use in pregnant women with asthma; budesonide is the only ICS rated Pregnancy Category B.
 From:The Journal of Family Practice

Oral corticosteroids are used in acute exercerbations not for long term management.

Neonatal conjuctivitis

"Silver eyed on day 1
Gon home within 7 days
only to return after a week
with trachs on his chlam
and again in a month
when the herpes showed up!"

Day 1:Chemical conjuctivitis
Day 3-7: Gonococcal
After wk 1: Chlamydia
After 3wks: Herpes 

Monday, May 21, 2012


7 days to go!

Wao! excited actually...

Kaplan q bank scores were initially lower than I expected but have improved now, I have a simulated exam to take when today dawns but first, I've got to catch some sleep!

Friday, May 18, 2012


In constrictive pericarditis and tamponade, catheterisation shows the same diastolic pressure in all 4 chambers!

Reye syndrome

Encephalopathy following an acute viral illness  in a child due to aspirin use

high level of ammonia

liver biopsy shows fatty changes

No treatment. supportive care: correct hypoglycemia, anti emetics, electrolytes etc

Rash involving hands and feet

Most rashes don't involve hands and feet. If an acute illness with rash involves hands and feet, think of
  • Syphilis (secondary)
  • Rocky mountain spotted fever (centrifugal rash)
  • Coxsackie virus (hand, foot and mouth disease)


Pronator drift is a sign of upper motor neurone lesion

Patient is asked to hold out both arms at shoulder level, fully extended with forearms supine, and hold the position.

If the patient is unable to hold the position and the forearm pronates, then pronator drift is positive and the patient most likely has a contralateral pyramidal tract (UMN) lesion.

Closing the eyes accentuates it.

School phobia

School phobia is a seperation anxiety disorder.

It must be present for at least 4 weeks

Order of changes at Puberty

At puberty, it's time to TAG along!
Thelarche - breast development (usually the first sign of Gonardache -onset of true central puberty)
Adrenarche: axillary hair and Pubarche- pubic hair (Adrenarche:can preceed true puberty)
Growth acceleration
Then Menarche

Testicular growth (due to gonardache)
Adrenarche : axillary and pubic hair
Growth acceleration
Then Spermache


If u see migratory thrombophlebitis, look for visceral malignancies.


FeNa> 2% = intrinsic renal disease i.e acute tubular necrosis or acute interstititial nephritis

In prerenal azotemia e.g due to dehydration, FeNa is <1%, urine sodium is <20mEq/L, urine osmolality> 500mEq/L
Kidney reabsorbs Na and water to compensate for the hypovolaemia or hypotension.

Pneumococcal vaccine indications for adults

age >65yrs

Chronic diseases (hrt disease, lung disease, DM, cochlear implants, CSF leak, SCD, alcoholism)

Immunosuppressive diseases (HIV/AIDS, MM, Lymphomas,Leukemias, Chronic renal failure, organ transplant, nephrotic syndrome etc)

Immunosuppressive therapy (long term steroids, chemotherapy, radiotherapy)



Nursing home residents

Splenectomized individuals


Tetralogy of Fallot
Pulmonary stenosis+ VSD+overriding aorta+RVH

Cyanotic congenital heart disease (The 5 Ts. others are TGA, Truncus arteriosus, Total anomalous pulm venous return, Tricuspid atresia)

Right to left shunt leads to mixing

May not be cyanotic at birth

Difficulty feeding, polycythaemia, finger clubbing, dyspnoea, FTT, murmur

Tet spells
sudden, marked increase in cyanosis followed by syncope ,often precipitated by crying, feeding or exercise , may also occur on waking up.
It is due to an increase in rt to left shunting of unoxygenated blood following a decrease in systemic vascular resistance or increased pulmonary vascular resistance, favouring the "right to left to aorta shunt"
It can be relieved by squatting or placing child in knee chest position (This increases afterload thus allowing more blood to go thru pulmonary circulation rather than systemic)

Chest x ray shows boot shaped heart and decreased pulmonary vascular markings.

Tangier disease

Tangerines in the throat!

Aut recessive, rare

Deficiency of ABCA1 transporter needed to transport cholesterol out of cells

Low serum cholesterol, No cholesterol to pick up leading to low HDL

cholesterol accumulation in cells and tissues

Enlarged, yellow or orange tonsils, premature artherosclerosis, hepatosplenomegaly, corneal clouding

Thursday, May 17, 2012


Both are microangiopathic hemolytic anemias
Both present with
  1. Thrombocytopenia
  2. hemolytic anemia (low hct, schistocytes, unconjugated hyperbilirubinemia, high LDH etc)
  3. Acute renal insufficiency (high BUN)
  4. Fever
  5. Altered mental status
To differentiate however,

Altered mental status is more prominent in TTP
Acute anuric renal failure is more prominent in HUS

less specific is that HUS more in children while TTP more in adults

Wednesday, May 16, 2012

Colles fracture

Fall on outstretched hand,

Fracture of distal radius and ulna, dorsal angulation= dinnerfork deformity

Tmt: closed reduction and long arm cast involving wrist and elbow works well

de Quervain tenosynovitis

Tendons involved can be remembered by ALEB (ALL Exclusively Breastfeeding mothers!)

Abductor pollicis Longus and Extensor policis Brevis

Remember, it occurs commonly in new mothers due to the awkward way they support the baby's head with their hand e.g during breastfeeding. It can also be occupational (washer woman, carpenters, musicians, office workers)

The Finkelstein test is positive

© Cork Emergency Medicine 2013.

Bell's palsy

a post infectious demyelinating facial neuritis.

Associated infections include:

Herpes simplex
Varicella zoster
Lyme dx (Borrelia)

Selective Estrogen Receptor Modulators

Clomifene: @ hypothalamus: antagonist

Raloxifene:                              @breast :antagonist   @bone: agonist   @uterus: antagonist

Tamoxifene:                            @breast :antagonist   @bone: agonist   @uterus: agonist

Others include: femarelle, toremifene etc.

All reduce risk of breast cancer
All reduce risk of postmenopausal osteoporosis
Tamoxifene increases risk of endometrial cancer
SERMs increase risk of DVT

Clomifene used for treatment of infertility(anovulation)
Raloxifene used for treatment of Osteoporosis and breast cancer
Tamoxifene used for treatment of breast cancer

Tuesday, May 15, 2012

Dieulafoy lesion

Upper GI bleeding with no risk factors and normal endoscopy findings: suspect Dieulafoy lesion- a submucosal vessel that fails to divide into capillaries but bleeds intermittently and retracts under the mucosa during non bleeding periods.

Fanconi anemia

Autosomal recessive

Aplastic anemia



Short stature



upper limb anomalies
File:Fanconi's anemia 101.jpg
Cure is BM transplant

Glaucoma screening

 > 40yrs with risk factors: every year

>40 but <60yrs, no risk factors: every 3-5 yrs

 >60yrs , no risk factors: every 1-2 yrs

Risk factors for glaucoma include:
Black race
High IOP
Family history
Severe eye injury
Chronic corticosteroids

Treatment of Primary pulmonary hypertension

IV vasodilator  challenge (prostacyclin, NO, adenosine) in order to decide definitive treatment

Definitive treatment:
If responsive to vasodilator challenge, start Calcium channel blockers. Try for at least 3-6months, if no response use prostacyclin

If no response to vasodilator challenge, other modalities including Transplant depending on the NYHA classification

Anticoagulation for all patients (Warfarin)

Monday, May 14, 2012


Neonate turns blue when feeding, turns pink when crying = choanal atresia

may be part of the CHARGE Syndrome

Heart defects
Atresia of the choanae
Retardation (mental)
Genitourinary anomalies
Ear anomalies

suspect if you can't pass an intranasal catheter, confirm with  contrast CT.


Psychogenic non epileptic seizure
Triggered by emotional stress
Normal EEG
Normal prolactin level following episode unlike in neurogenic seizure in which prolactin is elevated within 20 minutes of seizure.
There may be side to side head movement, pelvic thrusting, eyes may be closed, no post ictal confusion or incontinence
Very easy to be taken as malingearing.
Tmt is psychotherapy +/- antidepressants. Do not use anticonvulsants.