In-Training Exam Zebras 2013

Dan Girzadas Jr. MD

Financial Disclaimer

I am not a paid speaker.

I am not promoting any product.

Zebras are not commonly used in medical practice and hence there is no company willing to pay doctors to promote their sale.

What’s a Zebra?

When you hear hoof beats, it’s usually horses not zebras.

Think of the in-training as a safari

Zebras are relatively rare clinical entities

Distraction

Foils

Sew doubt

What’s a Zebra? Objectives

The Attendee should be able to recognize uncommon emergencies known to be used on board exam questions (Zebras).

The Attendee will have familiarity with these uncommon emergencies and rule them in/out of a board question more quickly and confidently

Zebra Subcategories

Cardiovascular

Toxicology

Infectious Disease

Neuro/Neurosurgery

OB-Gyne

Heme-Onc

GI

Orthopedics

Miscellaneous

Environmental

Cardiovascular

Torsades

QTc>500 is high risk

Romano-Ward (Autosom Dom)

Jervell and Lang-Nielson (Auto Rec, Deafness)

Long QT Syndrome

Treat with Mag, Pacing, Isoproteronol, 1b’s

Murmur increased with standing/valslava

Murmur decreased with squatting or leg elevation

Fluids and beta blockers decrease obstruction

Decreased preload and increased inotropy worsen obstruction

Assymetric LV wall thickening

HOCM

Betablockers/AICD

Syncope

Sudden death

Southeast Asian Men

Brugada Syndrome

AICD

1. Hypothermia

2. Osborne wave

1. Vasculitis

2. Associated with colic, gi bleed, intussusception, abdominal pain (65%)

3. Glomerulonephritis (25-50%)

4. Arthritis, scrotal swelling

5. Palpable purpura on buttocks and lower extremities

6. TX: Supportive care

7. Henoch-Schonlein Purpura

Pericarditis

Most Common Cause of Cyanotic Heart Disease over the age of 4

RV outflow obstruction/VSD

Left sternal border murmur

Squatting Boot heart with

decreased lung markings

Tetrology

Terrible T’s: Cyanotic Heart Lesions Right to Left Shunt

Transposition

Tetrology

TAVR

Truncus

Tricuspid/Pulmonary Atresia Hypoplasts

Ebstein’s, Some Coarcts

1. Hypertension/flushing

2. severe headache

3. Dx test:urine catecholamines

4. Alpha and beta block prior to surgery

5. Pheochromocytoma

Sudden painless vision loss

Associated with HTN, vasculitis, hypercoaguable,and glaucoma

Diffuse retinal hemorrhages; “Blood and thunder”

Tx:asa

Central Retinal Vein Occlusion

1. Sudden painless vision loss

2. Ophth artery first branch of IC/embolic event

3. Pale retina and cherry red macula

4. Tx with ocular massage, topical beta blocker,paper bag,diamox,ant chamber paracentesis

5. Central Retinal Artery Occlusion

3-5 Days following AMI

Associated with small to medium inferior MI’s

Acute CHF with holosystolic murmur

Treatment is surgical

Papillary Muscle Rupture

Stabilize with afterload reduction/nitroprusside

Toxicology

Welders/solderers/

smelters

Fever/chills/myalgias

Inhaled zinc oxide fumes

Cough and hemoptysis

Can have abnormal CXR

Gets better when away from the job

Metal fume fever

1. Agents that cause SLUDGE + weakness and seizures

2. All potent organophosphates

3. Sarin/VX

4. Nerve agents/Chemical warfare agents

5. Treat with atropine (muscarinic symptoms) and 2-PAM (nicotinic symptoms)

Cause of 95% of deaths from Mushroom Poisoning

Intense Nausea/vomiting that begins greater than 6 hours post-exposure

Hepatic toxicity

AC/Pen g/silibinin/NAC

Beware hypoglycemia

Amanita phalloides

Gyromitra similar

presentation but can also cause seizures

Antivenin indications

Local progression

Coagulopathy

Systemic effects

SPREAD/BLED/ALMOST DEAD

All coral snake bites

10 vials for crotalids/3 vials for coral snakes

1. Toxin in paint stripper that may cause delayed endogenous production of carbon monoxide

2. Methylene chloride

3. Methylene Chloride=Carbon Monoxide

1. Multi-use antidote

2. Gyromitra poisoning

3. One ancillary treatment for ethylene glycol poisoning

4. Treat seizures related to isoniazid poisoning

5. Pyridoxine

1. Blocks cytochrome A3,

2. Doesn’t bind hemoglobin

3. Acidosis/coma/shock/dyspnea

4. Industrial exposure (plastics/photography/ electroplating), smoke inhalation

5. Scent of bitter almonds

6. Tx: hydroxocobalamine or sodium nitrite/sodium thiosulfate

7. Cyanide poisoning

1. Toxin blocks inhibitory glycine at post-synapse brainstem and spinal cord

2. Muscle spasms/ conscious “convulsions”

3. Tx:benzos/ neuro-muscular blockade

4. Pt’s remain conscious

5. Can cause rhabdomyolysis

6. Strychnine poisoning

Sour gas leak kills worker: Employee never returned from changing flow meter at remote gas facility (The Edmonton Journal, March 8, 2008, Jennifer Fong).[8]

Blocks cytochromes

Acts similar to cyanide plus it is a lung and eye irritant

Shorter acting so victims may recover from brief exposure

Tx:Sodium nitrite/hydroxocobalomine?

Hydrogen sulfide poisoning

3rd Cytochrome poison=CO

1. Toxin causing crampy abdominal pain

2. Vomit and diarrhea followed by hypotension

3. Garlic odor to breath

4. Weakness, paresthesias, and rash (Chronic)

5. Arsenic poisoning

Binds sulfhydryl groups/vasodilation/edema/tx with chelation BAL

Pregnant Mom ingests Amanita Mushrooms. Should you induce delivery? Should you advise the mom that the baby has a high risk of hepatic damage?

Neither. Amatoxins don’t cross the placenta.

Infectious Disease

EOM weakness/diplopia

Absence of papillary light reflex/blurred vision

Generalized muscle weakness, poor suck in infants/ constipation

Causes: improperly canned foods, honey (infants), wounds (rare)

TX: pen in infants?/antitoxin for adults and immune globulin for infants<1yr

Botulism Nerve conduction studies, Blood for botulinum toxin or

positive stool Cx are Dx

Botulism

Infection following laceration in fresh water lake

Most common organism: aeromonas hydrophilia

FQ/Bactrim/Doxy

Infection following laceration in sea water

Most common organism: vibrio species

3rd Gen Ceph and Doxy

Parasitic infection Taenia saginata, Taenia solium

Seizures (#1 cause adult-onset SZ world-wide)

Calcifications or cystic lesions in brain

Mexican immigrants

Undercooked pork

Cystercircosis

1. Posterior cervical adenopathy

2. Macular rash starting at face and moving to trunk and arms

3. Rubella

4. German measles

Palatal Weakness

Pseudomembrane

Myocarditis

Tx: pcn or erythro and antitoxin

Diphtheria

1. Dermacentor tick is vector

2. Rickettsial infection

3. Fever before rash (ankles and wrists)/ bad headache

4. Tx:doxy or chloramphenicol

5. Rocky Mountain Spotted Fever

BIL R DR

Borellia

Ixodes

Lyme

Ricketsia

Dermacentor

RMSF

1. Viral illness 2. Vectors: bats/foxes/

raccoons/skunks/livestock 3. Squirrels, hamsters and rats don’t carry the

disease 4. TX: Irrigate wound with povidone-iodine

solution 5. HRIG 20IU/kg as much as possible around

wound, plus 5 doses of vaccine (in the deltoid) on days 0,3,7,14,28.

6. Only one survivor in US without pre/post exposure prophylaxis

7. Rabies

Wound Preparation: Buy or Sell

Povidone-Iodine or Chlorhexidine in wound

Shaving surrounding hair

Irrigation pressure of 8 psi

Scrub wound with sponge

Wound soaking

Best irrigation fluid

Category A Bioterrorism Agents

USA Beats Extremist Plotters

1. Small Pox

2. Anthrax

3. Plague (Y. Pestis)

4. Botulism

5. Tularemia

6. Ebola et al.

supportive

AG/Cipro/Doxy

AG/Cipro/Doxy

Antitoxin

AG/Cipro/Doxy

Supportive

1. Tick borne illness

2. Like RMSF, but rash less common

3. Liver dysfunction

4. Leukopenia/

5. encephalitis/renal failure

6. Tx:doxy

7. Bacteria is Ehrlichia

8. Erlichiosis

1. Protozoan infection

2. Heart failure (#1cause in Latin America)

3. Megaesophogus/

4. megacolon

5. Kissing bug

6. Periorbital swelling

7. Tx: nifurtimox or benznidazole

8. Chaga’s Disease/trypanosomiasis

Worm, most common parasitic disease in the world

Eosinophilia

Pneumonitis/hemoptysis

Intestinal or biliary obstruction

Treat with mebendazole

Ascaris lumbricoides

Protozoan parasite

Malaria like, febrile illness

Hemolysis/rings in rbc’s

20% also have lyme disease/ same tick vector

Treatment is quinine and clindamycin

Babesiosis

1. Parasitic infection

2. Eating pork

3. Affects striated muscle

4. GI symptoms/periorbital edema/ muscle spasms

5. Myocarditis/gi/pulmonary edema

6. Eosinophilia

7. Trichinosis

1. Cough, coryza and conjunctivitis

2. Macular erythematous rash starts at hairline and moves down to feet

3. Koplick’s spots

4. Supportive care

5. Rubeola

6. Measles

1. Major Jones criteria for Rheumatic Fever

2. Polyarthrits (Joints)

3. Carditis (echO)

4. Subcutaneous nodules (Nodules)

5. Erythema marginatum (Erythema)

6. Chorea (Sydenham’s)

Aschoff Body: Damaged collagen

1. Enter through skin or be ingested

2. Hematuria/

3. hemetemesis/

4. cirrhosis/CNS symptoms

5. DX confirmed with eggs in feces and rectal biopsy/

6. Tx:prazaquantel

7. Schistosomiasis

1. Worm that sucks blood from intestinal villi

2. Anemia/ hi output chf

3. Hand and foot rash and pruritus

4. Mebendazole for treatment

5. Hookworm

Toxic appearing/fever

Headache

Coma

Periorbital edema

Proptosis

Cavernous sinus Thrombosis

1. Tender red nodules on lower extremities

2. Causes: drugs/UC/strep

3. Tx:bedrest/intralesional steroids/potassium iodide

4. Erythema nodosum

A form of malaria

The most lethal form

Tx:Malarone or quinine and doxy or mefloquine and doxy

Falciparum

Neurology/Neurosurgery

1. Eye physical exam finding

2. Interruption of sympathetics

3. Causes include:

4. Internal carotid dissection/pancoast tumor /CVA/herpes zoster

5. Ptosis/miosis/anhidrosis

6. Horner’s syndrome

Lower extremity weakness

Back pain

Band sensation around thorax

Sphincter dysfunction

MRI shows no tumor, abscess hematoma, or disc problem

LP shows pleocytosis

Some association with MS

Multiple other etiologies

Transverse Myelitis

TX: Steroids or immunoglobulin but both are controversial

1. Most common cause of optic nerve related vision loss in 20-40yo’s

2. Painful , especially with eye movement

3. Afferent pupillary defect

4. Associated with MS

5. IV steroids or nothing, prednisone has worse outcome

6. Optic neuritis

Tumor

Deafness/ataxia

Ipsilateral facial weakness

Decreased corneal reflex

Cerebellar signs

ACOUSTIC NEUROMA/CPA tumor

Loss of motor function and pinprick sensation

Retains position and vibratory sense

10-20% recover some motor function

Give steroids

Anterior Cord Syndrome

Penetrating trauma to spinal cord

Ipsilateral weakness/loss of proprioception and vibration

Contralateral loss of pain-temp

Brown- Sequard Syndrome

1. Treatment of Cyclic Antidepressant Seizures?

2. NaHCO3

3. Phenytoin

4. Phenobarbital

5. Lorazepam

6. Lorazepam=yes

Hyperextension cervical spine trauma in old guy

Upper extremities weaker than lower extremities

MUD

Central cord syndrome

Due to Lung tumor or liver metastasis

Serotonin and other vasoactive substances

Right side valvular heart disease

Diarrhea

Facial Flushing

Carcinoid Syndrome

1. Big ventricles on brain CT

2. Dementia/ataxia/ incontinence

3. Normal pressure hydrocephalus

1. Autoimmune disease

2. Post synaptic antibodies causing weakness

3. Affects young women and old guys

4. Avoid steroids/aminoglycosides/narcotics

5. Myasthenia gravis

Acute weakness

Classic patient is a male waking the next day after a large meal

Ate carbohydrate rich meals

Low k/high K/abnormal thyroid function on lab testing

TX: cautiously manage hypo/hyperkalemia, manage hyperthyroidism with propranolol

Familial periodic paralysis/Thyrotoxic periodic paralysis

SIADH vs. DI

Hyponatremia vs. hypernatremia

concentrated urine dilute urine

Water restrict NS or vasopressin

Tumor central or renal

Lung Cancer

Proximal weakness

Presynaptic pathophysiology; Antibodies to calcium channels

Grip gets stronger over seconds

Muscarinic insufficency

Eaton-Lambert syndrome

OB-Gyne

Test for greater than 30ml of fetal-maternal hemorrhage in trauma

Indicates need for more than usual 300micrograms of rhogam in rh- females greater than 12 weeks pregnant.

Kleihauer-Betke test

Other tests like K-B are flow cytometry and rosette test

Upper Abdominal Pain

Pre-ecclampsia complication?

Multiparous/ maternal age >35

BP may be normal

Hemolysis,elevated liver enzymes, low platelets/

HELLP syndrome

1. Right sided thoraco-abdominal pain

2. Adhesions around liver

3. Perihepatitis

4. Secondary to a pelvic infection

5. Chlamydia or gonorrhea

6. Fitz-Hugh Curtis syndrome

1. Which of the following vaccines and immunoglobins are safe in pregnancy?

2. Rabies=yes

3. Tetanus=yes

4. Hepatitis B=yes

5. Influenza=yes

6. Varicella=no

7. (Shot’s gonna HIRT)

Heme-Onc

1. Most common inherited bleeding disorder

2. Prolonged bleeding time

3. NL PT/PTT

4. Treat with desmopressin, factor 8,cryopercipitate

5. Von Willebrand’s disease

Coombs test direct is positive :

Immune mediated hemolytic anemias/ antibodies on the rbc

Coombs test indirect is used for:

Antibodies in the serum

Autoimmune hemolytic anemia

Hd of newborn, drugs, scd, thalasemia, mult myeloma, hodgkin/hiv

Hemolytic anemia

Thrombocytopenia

Renal vascular endothelial injury/platelet thrombi

Kids

Ecoli 0157:H7

HUS

Supportive Care, Dialysis, watch for hyperkalemia

1. Thrombocytopenia

2. Hemolysis/renal failure/fever/multiple organ ischemic damage

3. Similar to HUS but more neuro signs

4. Tx: plasma exchange, steroids, supportive care

5. TTP or TTP-HUS

1. Hemophilia with head injury :Treatment?

2. 100%, 50u per kg of Factor 8 BEFORE CT BRAIN

3. Joint pain

4. 50%, 25u per kg of Factor 8

1. Hemolytic anemia

2. Sulfa drugs, pyridium, nitrofurantoin and fava beans

3. Heinz bodies (precipitated hgb within RBC)

4. African-Americans higher risk

5. G6PD deficiency

1. Abdominal pain/weakness/psychiatric symptoms

2. Diminished reflexes

3. DX test:Urine aminolevulonic acid and porphobilinogen

4. Tx: Supportive care, iv glucose, hemin, B6, stop offending drug

5. Acute Intermittent Porphyria

Disease due to platelet autoantibodies

Pupura and bleeding with low platelets

Tx:steroids and sometimes splenectomy

Acute in kids/chronic in adults

ITP

GI

Marathon Runners

Youngish adults

Mobile Cecum

Surgical Tx

Cecal volvulus

Most common Neonatal GI Emergency

Vomiting/poor feeding/abdominal distension

Increased incidence with prematurity

Pneumatosis intestinalis/hepatic portal air

NEC Vanc/Gent/Clinda ICU and Surgery Consults

Orthopedics

1. 4-9yo child with a limp/no fever

2. Avascular necrosis of the femoral head

3. Legg-Calve-Perthes

4. 12-15 yo with groin/hip/thigh/

5. knee pain

6. SCFE

1. Salter Harris

2. 1-M-E- (metaphysis)-epiphysis)-4

3. This is a SH3

1. Autoimmune disease in kids 2. Usually involves a single joint (knee) and not

destructive 3. Associated with iridocyclitis, inflammatory bowel

disease, Reiter’s syndrome 4. Polyarticular version with positive ana titers and

more destructive 5. Systemic version has high

fevers,rash,pericarditis,negative ana,joint destruction

6. Treat with asa or steroids 7. Juvenile rheumatoid arthritis

Environmental

1. How do you remove jelly fish Nematocysts?

2. Acetic acid (vinegar)

3. Supportive care afterward, pain relief, wound care, and for Chironex envenomnations antivenin

1. How do you treat pain from sea urchins?

2. Immerse in hot water as high as 113F

1. Prolonged exposure can cause chemical burn

2. Classic patient is brick layer or mason

3. TX: treat with copious water irrigation

4. Portland Cement

A Few Radiation ?’s

1. Blocked by paper, blocked by clothing, blocked by concrete

2. Alpha, beta, Gamma

3. The best marker for outcome:

4. 24 hour lymphocyte count

5. Blood 200 rads/gi 600 rads/cns 2000 rads

6. New patient: remove clothing, wash, place sheet

Miscellaneous

More Common left side

Dilatation of pampiniform plexus

Venous drainage in to left renal vein (caught between SMA and AO)

Valsalva makes veins more prominent

Men may have decreased fertility

Boys may retroperitoneal mass

Varicocele

1. Autosomal-dominant disease

2. Mucosal telangiectasias

3. Epistaxis

4. Osler-Weber-Rondu syndrome

1. Complication of hi potency neuroleptics

2. Idiosyncratic reaction

3. Hyperthermia/rigidity/autonomic instability/altered mental status

4. Tx:rapid cooling/ fluids/ benzos/ dantrolene/bromocriptine/ECT?

5. Neuroleptic malignant syndrome

1. Elevated liver enzymes/prolonged pt/increased ammonia level/

2. Nl bilirubin

3. Increased ICP

4. Chicken pox and ASA

5. Reye’s syndrome

Oral-eye-genital lesions

Erythema nodosum

Autoimmune

Cholchicine, prednisone, cyclosporine

Behcet’s disease

Hocm

Papillary muscle rupture

ludwigs

Reiter’s

Transverse Myelitis

Glaucoma E=M2C