Neural crest (clinical aspect)

Hello Awesomites! :D

Let us go back to the contribution of neural crest cells to many different systems (neural, skin, teeth, head, face, heart, adrenal glands, and gastrointestinal tract).

Neural crest forms neural and non-neural population.

-Cranial neural crest

-cardiac neural crest

-trunk neural crest

-Vagal neural crest

So,

Malformations of NC origin

-Facial clefts, ear malformations, and other Facial defects 

-Branchial fistulae and anomalies of pharyngeal arch derivatives

-Cardiovascular malformations 

-Pigmentary disorders

-Abnormal enteric innervation 

-Tumors 

-Hemangiomas and vascular malformations

1. Facial clefts, ear malformations, and other facial defects-

 The shaping of the face is therefore patterned under the influence of the NC.

The more common malformations of the region

-preauricular tags

-microtia

-cleft lip, and cleft palate

-CHARGE association

-Treacher Collins, or Goldenhar syndrome.

2. Branchial fistulae and anomalies of pharyngeal arch derivatives 

-Malformations of the endocrine glands that are derived from the pharyngeal arches and pouches have the same origin. That is:-

The paired thymus which originate from the third pharyngeal pouch on each side,

The parathyroids, derived from the third (lower glands) and fourth pharyngeal pouches (upper glands) ,

C-cells of the thyroid (derived from the ultimobranchial body in the fifth pouch)

-Branchial cyst

3. (IMPORTANT) Cardiovascular malformations

TA, DORV, Tetralogy of Fallot (TOF), narrow outflow pulmonary tract (NOPT), transposition of the great vessels, perimembranous ventricular septal defect (VSD), and other heart defects are the result of defective NC influence on the region.

4. Pigmentary disorders 

-Albinism

-Neurocutaneous melanoses 

-neurofibromatosis of Von Recklinghausen 

-Tuberous sclerosis and all the gastrointestinal polyposes in which there are mucosal or cutaneous pigmentary spots (Peutz Jeghers, Cowden, Cronkhite- Canada etc.)

-neurofibromatosis albinism

5. Abnormal enteric innervation

-Hirschsprung disease

- Neuronal intestinal dysplasia

6. Tumors

Due to abnormal proliferation of NC cells

-Peripheral neuroectodermal tumor

7. Hemangiomas and vascular malformations 

The concept that hemangiomas and vascular malformations are derived from the NC is relatively new, but accepted. The flat vascular malformations that are located in the areas corresponding to the cutaneous innervation of the cranial nerves may have intracranial extension (Sturge-Weber syndrome) and are of this origin.

In next post, I will discuss NEUROCUTANEOUS SYNDROME as an extension of this post.

Feel connected: D

-Upasana Y. :)

Hepatic encephalopathy

Hello Awesomites! :D

Long time.

Today we will be discussing the Treatment of Hepatic Encephalopathy.

I like this topic because of its integration with biochemistry.

-After stable: Identify and treat trigger of Encephalopathy.

-Nasogastric aspiration (in case of bleeding) and protection of airway with a endotracheal tube. Always prefer to give prophylaxis for SBP with Amoxiclav / Cephalosporin if GI bleed is the trigger.

-Avoid constipation and favour bowel emptying by bowel wash, enema or by lactulose (15-30ml 3 to 4 times daily) or lactitol.  

-Bowel sterilisation by neomycin 1 gm qid or ampicillin. Neomycin helps in decreasing ammonia production or its absorption from the bowel. 

-Avoid drugs, especially sedatives and diuretics. 

-Protein is restricted and vegetable based protein may be given. 

-IV mannitol as a fast drip for reducing cerebral oedema.

-Newer/ Experimental modalities:

Bromocriptine

Flumezanil (BDZ antagonist)

*LACTULOSE OR LACTILOL

-It creates an acidic intestinal environment to prevent NH3 absorption.

-Promote growth of glycolytic bacteria rather than proteolytic bacteria.

-Increase GI motility.

* L-ornithine-L-aspartate (LOLA)

-Provide a urea cycle alternative substrate.

* Rifaximin

-The recommended dose is one 550 mg tablet taken orally two times a day. Poorly absorbed Antibiotic to alter GI microbes.

*Correct Hyponatremia,Hypoglycemia and Hypovolemia.

*Branched chain Amino acids in diet. (Leucine and isoleucine)

-When no response to standard treatment, portosystemic shunting is considered.

Liver transplant allocation can be determined by using the MELD and sodium level (MELD-NA) score.

MELD score consist of:-

-Bilirubin (Means how well my liver take up byproduct from blood)

-INR (Means synthesis function of liver)

-Creatinine (Hepatorenal syndrome)

I hope it helped.

I want to thank Antariksh for edits in this post. :))

-Upasana Y. :)

Step 3 CCS tips & Frequently Asked Questions

Hey!
This post is all about how to study for CCS.

How to study for CCS?
Use the UW software. It is more than enough.

Should I do Archer videos?
They are just 5 videos and are not mandatory to do. It's just that most students do not know how to fast forward the clock, change location, etc. and Archer does a pretty good job at explaining it. (I might do a video later!)

Should I opt for softwares other than UW?
It is not necessary because UW has just enough. Other softwares might train you to do "extra" unnecessary orders which maybe sub-optimal in the real exam because there is not enough time to do everything.

MUST DO before the real exam: Practice the CCS cases on the usmle.org website. You have to be comfortable with the software and the different orders available.

Interesting physical exam finding in Henoch-Schonlein purpura

Hello everyone!

Here's a cool fact that someone I absolutely adore shared with me: The Pediatricians call Henoch-Schonlein purpura as, “Butt-itis” because the rash frequently coalesces on the pressure points and is gravity dependent, in other words, on the buttock!

Henoch Schonlein purpura

HSP is also known as Anaphylactoid purpura.

• Most common vasculitis in children.
• Most common Leucocytoplastic vasculitis.
  It predominantly affects small vessels (venules, capillaries, arterioles).
  It is usually self limited but may progress to end stage renal disease.
 
Clinical features:
1) Skin: rash, palpable purpura (non-thrombocytopenic purpura).
2) Joints: arthritis, arthalgia.
3) Kidneys: glomerulonephritis (proteinuria, hematuria).
  ° Severe renal failure occurs in about 1-2%, characterized by crescenteric glomerulonephritis which is treated with intravenous methyl prednisolone.
4) GIT : colicky abdominal pain.

   On investigation: total Ig A increases.
Renal biopsy: mesangial Ig A deposits.

Treatment: conservative treatment
    Oral prednisolone may be given.

Thanks for reading.

Madhuri Reddy.

Differentiating restrictive lung disease

Hello!

Let's talk about restrictive lung diseases today.

We know that an increased FEV1 / FVC ratio is suggestive of a restrictive lung disease.

However, you want to get lung volumes and confirm it by looking at the reduced TLC.

There are two types of restrictive lung diseases that you want to differentiate - pulmonary and extrapulmonary.

In pulmonary restrictive lung disease, all lung volumes are reduced due to fibrosis.

In extrapulmonary restrictive lung disease, the residual volume will be normal or even increased.

Why? Because in neuromuscular diseases, the muscles don't have the strength to blow air out.

DLCO is another way you can differentiate the two.

In pulmonary restrictive lung disease, the surface of alveolar membrane that participates in gas exchange is reduced and the DLCO is low.

In extrapulmonary restrictive lung disease, the DLCO is normal.

That's all!

-IkaN

My USMLE journey by IkaN

Hey!

A couple of you wanted me to write about my USMLE journey - I am almost at the end so lemme start telling you about my story.

Ocular Therapeutics (DYES)

Hello Awesomites! :D

Today I will discuss here

DYES:-

USES OF FLUORESCEIN DYE
-This dye stain damaged corneal epithelium bright green best seen under cobalt blue and ultraviolet light.
1. To detect breach in continuity of corneal epithelium.
2. Contact lens fitting.
3. Applanation tonometer.
4. Test for leaking wound (Seidel test)
5. Patency of nasolacrimal duct.
6. Fluorescein angiography.
7. Diagnosis of lacrimal fistula.
8. Treatment of pediculosis (Fluorescein dye strips, which are used in the diagnosis of corneal abrasions, may be used in combination with white petrolatum. The strips are applied to the eyelashes for 3 nights)
9. Differential stain along with Rose bengal.

Pattern of stain:-
- interpalpebral staining of cornea & conjuctiva is common in aqueous tear deficiency
-superior Conjuctival Staining in superior limbic keratoconjuctivitis
-Inferior corneal &conjuctival staining in blepheritis & exposure keratitis.


USES OF ROSE BENGAL:-
-Stain the devitalized corneal and conjuctival epithelium. The drawback with rose bengal is it stings.
-Seen under white light /red free light. (Red-free light is absorbed by the RPE, creating increased contrast)

1. CORNEA -Staining corneal ulcer,erosion and abrasion.
2. LID- Meibomian gland dysfunction.
3. CONJUCTIVA- Conjuctival staining and evaluation of ocular surface disorder.

I hope it helped.
More is coming up in this section.

-Upasana Y. :)

Nasotracheal intubation

Hello!

This post is about the indications and contraindications of nasotracheal intubation.

Indications:
1) Oral surgery
2) Fracture mandible
3) Inadequate mouth opening
4) Tube to be kept for longer time
5) Awake fibre-optic intubation

Contraindications:
1) Fracture of base of skull (may directly enter inside skull)
2) CSF rhinorrhea (increases infection - meningitis)
3) Nasal mass (do not allow tube to pass)
4) Adenoids
5) Coagulopathy
6) Decreased movement of endotracheal tube
7) Nasal mucosal damage.

Thanks for reading.

Madhuri Reddy

Malignant hyperthermia

Malignant hyperthermia is a syndrome of rapidly rising temperature.

It occurs due to abnormality of Ryanodine receptors which cause release of large amount of calcium from sarcoplasm reticulum leading to sustained muscular contraction.

It is triggered by:
1) Succinylcholine (50%) - most common
2) ether
3) methoxyflurane
4) halothane
5) enflurane
6) isoflurane
7) Desflurane
8) sevoflurane

Clinical features:
1) Masseter muscle spasm - most initial sign
2) Rise in end tidal CO2
3) Tachycardia
4) Respiratory/ metabolic acidosis
5) Hyperkalemia
6) Pulmonary edema
7) Cerebral edema
8) Myoglobinuria
9) Renal failure
10) Rise in temperature - late sign

Treatment:
1) Stop all anesthetic agents (because one of it is a triggering factor).
2) Hyperventilate with 100% O2.
3) Inj.Dantrolene - 2 mg/kg  intravenously every 5 minutes to a maximum dose of 10 mg/kg.
Dantrolene can be continued for next 48 hours.
4) Sodabicarb to correct metabolic acidosis.
5) Cooling of body.
6) Other symptomatic treatment.

To detect malignant hyperthermia:
BEST DIAGNOSTIC TEST -> Halothane Caffeine muscle contraction test.
BEST SCREENING TEST -> Creatinine kinase test.

Thanks for reading.

Madhuri Reddy

Transient Tachypnea of Newborn notes

Hello!

What is Transient Tachypnea of Newborn (TTN)?

Step 3 NBME Form 4 Answer key

Hey, here is the answer key.

Lemme know if I accidentally typed some wrong!

Foreign body aspiration - Flexible or rigid bronchoscopy?

Foreign body aspiration (FBA) - Which bronchoscopy should you do? Flexible or rigid?

#TLDR:
Life threatening - Rigid bronchoscopy
Diagnosis not clear - Flexible bronchoscopy

Children - Rigid bronchoscopy
Adults - Flexible bronchoscopy

Mnemonic: childRen thReatening - Rigid bronchoscopy

So first ask - is this a life threatening FBA? Yes - Rigid bronchoscopy (after airway stabilization of course)

Then ask - Is the diagnosis clear? No - Flexible bronchoscopy

If the diagnosis is clear and the FBA is not life threatening - See the age.

If it is a child - Rigid bronchoscopy
If it is an adult - Flexible bronchoscopy

Here's a looooong copy paste explanation from UpToDate:

Varenicline mnemonic

Hello!

A short post on Varenicline :)

Mirtazapine mnemonic

Hello!

Here's a short post on the atypical antidepressant, Mirtazapine! It's an alpha 2 antagonist that increases release of NE (norepinephrine) and 5-HT (serotonin)

Mirtazapine causes sedation (desirable in depressed patients with insomnia)

Mnemonic: MirtaZZZZapine
Zzz for 😴 sleep

Mirtazapine increases appetite, causes weight gain (desirable in elderly or anorexic patients)

Mnemonic:
M - Mirtazapine makes you motu
(Motu in Hindi / Urdu is fat)

-IkaN

USMLE Step 3 CCS: Fracture of the hip / femur

Hello!
Here are orders for the hypothetical case - let me know if I missed out on something! :)

Tuberculosis: Eponymous pathologies picmonic

Hey guys!!

So TB, huh? As if the complicated diagnostic and treatment modalities aren't enough, we also have to remember some characteristic pathological entities, especially the eponymous ones like Ghon, Rancke, Assmann, Rich, Simond, Simon, Weigert, Puhl, Rasmussen and I am sure there are more. Lucky for us, we have a pimonic for this.

Thank you Subasini for this wonderful illustration! Inspired! :*

Pulmonary Embolism Picmonic

Hey guys!!

Pulmonary embolism is a diagnosis of exclusion. I am sure this illustration will help you to make a diagnosis of PE after you have ruled out the other differentials.

Thank you Subasini for this wonderful illustration! Inspired! :*

Algrove Syndrome Picmonic

Hey guys!

This picture will help you get a visual recollection of Algrove syndrome.

Thank you Subasini for this wonderful illustration! Inspired! :*

Bacterial Protein Synthesis Inhibitors

Hey guys

Here are two pics to help you all to better understand the mechanism of action of bacterial protein sysnthesis inhibitors: antibacterials.

Thank you Jailene for contributing to the blog! :)

USMLE Step 3 CCS: Rape

Hello!

These are my CCS steps for a case of rape. Lemme know if I missed out on anything!

Consent
Rape evidence kit

Complete physical examination

CBC
BMP
Vaginal fluid analysis
Vaginal, cervical, rectal cultures
BHCG
UA
Urine culture
HIV test, P24 antigen
VDRL
HbSAg
Gonococcal tests
Chlamydial tests

Emergency contraception (ulipristal / levonogestrol)
Ceftriaxone
Azithromycin
Metronidazole
Tenofovoir + emtricitabine + raltegravir
HBIG (if unvaccinated)

Psych consult
Drug screen
Colposcopy (for injuries)

That's all!
-IkaN

USMLE Step 3 CCS: Kawasaki disease

Hello, these are my hypothetical orders for KD.
Let me know if I missed something out!

Physical examination (PE)

CBC
BMP
ESR
CRP
Blood culture (to rule out infection)
Urinanlysis (to rule out infection)
Urine culture (to rule out infection)
CXR (to rule out infection)

LFT
ASO
Strep pharyngitis culture
EKG
Echocardiogram

IVIG
Aspirin

That's all!
-IkaN

Save, near miss and preventable adverse effect mnemonic

Hey!

These are for USMLE ethics.

Poor prognostic factors for schizophrenia mnemonic

Hello!

This is a mnemonic for some (not all) prognostic factors for schizophrenia.

Likelihood ratio mnemonic

Hello! :)

The likelihood ratio of a positive test result (LR+) is sensitivity divided by 1- specificity.

The likelihood ratio of a negative test result (LR-) is 1- sensitivity divided by specificity.

How I remember the formulae for LR+ and LR-

Mnemonic on viral structures

Hey guys!! Long time!

As the title suggests this post will help you remember the different viral structures in a way that is fun and easier.

Puerperal sepsis

PUERPERAL SEPSIS

Puerperal sepsis is any bacterial infection of the genital tract which occurs after the birth of a baby. It is usually more than 24 hours after delivery before the symptoms and signs appear.

Some of the most common bacteria are:
Streptococci
Staphylococci
Escherichia coli (E.coli)
Clostridium tetani
Clostridium welchii
Chlamydia
Gonococci

SYMPTOMS AND SIGNS 
Fever (temperature of 38°C or more)  Chills and general malaise
Lower abdominal pain
Tender uterus
Subinvolution of the uterus
Purulent, foul-smelling lochia.
Slight vaginal bleeding
Shock.

RISK FACTORS
Some women are more vulnerable to puerperal sepsis, including anaemia and/or malnourished, protracted labour, prolonged rupture of the membranes, frequent vaginal examinations, a traumatic delivery, caesarean section and retained placental fragments, PPH, diabetes all predispose to puerperal infection.

SITES
The most common site of infection in puerperal sepsis is the placental site.
Other sites of infection are abdominal and perineal wounds following surgery and lacerations of the genital tract, e.g. cervix, vagina and perineum.

Following delivery, puerperal sepsis may be localized in the perineum, vagina, cervix or uterus.
Infection of the uterus can spread rapidly if due to virulent organisms, or if the mother’s resistance is impaired.
It can extend beyond the uterus to involve the fallopian tubes and ovaries, to the pelvic cellular tissue causing parametritis , to the pelvic peritoneum, causing peritonitis , and into the blood stream causing septicaemia

DIFFERENTIAL DIAGNOSIS
Fever  in the puerperium can also be caused by:  urinary tract infection (acute pyelonephritis)  wound infection (e.g. scar of caesarean section)  mastitis or breast abscess  thrombo-embolic disorders, e.g. thrombophlebitis or deep vein thrombosis  respiratory tract infections.

-Md Mobarak Hussain (Maahii)

Adrenaline : Dosage

Dose of Adrenaline :

Anaphylaxis :- 0.5mg 1:1000 IM

Anaphylactic Shock :-  1mg 1:10000 IV

Cardiac Arrest :-  1:10000 IV

CPR :-  1:10000 IV/IO, if not accessible 1:1000 ET

With LA :- 1:200000 SC

-Md Mobarak Hussain (Maahii)

Flap Valve Mechanism of Inguinal Canal

Hello Everyone!

     Today lets understand the Flap Valve mechanism of Inguinal Canal:

That's all,

Thank you!

Chaitanya Inge

Cryoprecipitate constituents mnemonic

Hello!

This is a post on the constituents of Cryoprecipitate :)