Study group discussion: Single Breath Count test in Guillain Barre syndrome

I was reading about Guillain Barre syndrome and came across single breath count test.

Does any one know what is it / how to perform it?

GBS can cause respiratory paralysis. So you do the breath count test to know the level of respiratory compromise. The exact mechanism.. I am not sure..But you ask the patient to take a breath and count as many numbers he can starting from one.

Is it done to measure inspiration or expiration? They say that inspiration is affected in GBS but I think counting is expiration.. So I am confused.

I haven't read much into it..Can't answer that with confidence.

I tried Googling. No satisfactory answers. Maybe someone else in the group knows!

SBC is measured by asking patients to take a deep breath and count as far as possible in their normal speaking voice without taking another breath. It's measure your fvc (forced volume capacity).
Normal values are 40 to 44.

If the patient can count to 10 on one breath they likely have a forced vital capacity of about 1000 ml, if they can count to 25 then the vital capacity can be estimated at about 2000 ml.

Normal fvc values are 3000 ml to 4000 ml.

FVC is sum of inspiratory reserve volume, tidal volume, and expiratory reserve volume.

Meaning SBC value is not just for your inspiration or expiration. But the whole capacity of lung to perform either of the function.

Thank you so much!

Study group discussion: Lepra type 1 and type 2 reaction

Can somebody explain lepra reaction in leprosy?

When the bacteria is killed, it's toxins are released & these toxins exaggerate the lesions.. More painful more red etc..

Lepra reaction 1 and 2?

I know that Lepra reaction 1 is type 4 HR and Lepra reaction 2 is type 3 HR.

Yes, 1 is 4, 2 is 3. The sum should be 5, that was my mnemonic

Oh okay ! Thanks for clearing this!!

This is a good way of remembering! 4+1=5 & 2+3=5!

Mnemonic you have to sum up so that total comes out to be 5
So in Lepra 1 + 4 HR = 5
And Lepra 2 + 3 HR =5

It's similar to the Jarisch Herxheimer reaction in syphilis right?!

Yes, the antigens cause the reaction.

Sometimes it happens when the patient begins treatment and loses faith in the doctor because of the reaction!

Woah! Loses faith in doctor!

Yes, so you have to explain the patient well. Maybe inform about the possibility before hand.

Is ENL the same? Or the severe form of lepra reaction?
Type 2 is ENL.
What's the difference between type 2 and 1?

The 2 is a type 3 hypersensitivity. Meaning deposition of antigen-antibody complexes.

Type 4 reaction is a delayed hypersensitivity due to t- lymphocytes. Which is seen lepra reaction type 1.

Type 1 is mediated by Th1 cells and type 2 is mediated by Th2 cells

In lepra reaction type 1 - there is widespread new lesions all over the body, cause those  Ag-ab reactions get deposited everywhere.

In type 2, the existing lesions become more pronounced, more red.

There are other differences based on extent of nerve damage and blah blah..Which I don't remember!

Treatment?

Aspirin!

Treatment is aspirin, steroids and even an anti leprosy drug, I guess.

Chloroquine.

Thalidomide used to be ...Not used now, right? Thalidomide is completely discarded due to  phocomelia.

Oh no.. It is still used. But strictly avoided in pregnancy.

In which case?

Used in behcet disease, Multiple myeloma.

Thalidomide is used only for type 2 reaction, not type 1.

And which anti leprosy drug was it? Clofamizine?

Yes.

*the discussion went on types of hypersensitivity reactions, which will be continued in the next post!*

Study group discussion: G6PD deficiency and Myoglobinuria

If a person has presents with hemolysis after ingestion of flava beans and dapsone, when will you ask to get G6PD levels?

Study group discussion: Short course chemotherapy

What's short course chemotherapy?

Earlier Tb treatment was given for 1.5 to 2 years, Tb drugs have lots of side effects and patient adherence to such long treatment is not good either. So after various research WHO introduced short course chemotherapy treatment for Tb under the name of Dots which gives treatment for 6-8 months. Good patient adherence and compliance.

Study group discussion: Studying physiology

Could you share with me tips to study pre med subject? Like physiology perhaps?

Physiology is my major, I draw diagrams basically. Understanding the stimulus and response first, then learn the steps in the middle.

Yup, flow charts for physiology!

Physiology is easier when you start at the big picture then elaborate on each pathway.

And make lots of notes. Here's a link on that http://medicowesome.blogspot.ae/2014/12/how-to-make-concise-medical-notes.html

I used to draw a lot of flow charts in physiology..and Youtube, try subscribing to armando hasudungan or medcram..They have nice videos!

Study group discussion: Enzymes checked through RBCs

Why is LDH non specific for MI?

LDH is elevated in many other diseases too!!

There is a much more specific reason for it.

The LDH -2 isoform is present in RBC, any sort of slight hemolysis will increase it as well.

Oh that's why! Didn't have the faintest idea.

Great!! So LDH -2 Isoform is also the one for MI?

Nope it's LDH-1.

But no one gets the specific enzyme type. Too expensive I guess.

I guess electrophorectically you can't differentiate both. Maybe.

Which poisoning is checked through RBC?
Lead!
Basophilic strippling.

Yes, one more!

Cobalt.

Which other poison then?

OPP. Organophosphorous poisoning.

How?

You check the acetylcholinesterase levels in mature RBC.

Which vitamin levels can be checked through RBCs?
Hint: A vitamin that affects enzymes.

Transketolase, Vitamin B1 deficiency.

How does it affect the RBC the transketolase?

Umm it's just a level that can be checked through RBCs. I don't think they do it in clinical practice.

Study group discussion: Mitral stenosis auscultatory findings

What is the characteristic feature of mitral stenosis? In terms of murmur? And echo findings?

Opening snap.
Enlarged  left atria.
Mid diastolic murmur.
Left heart failure.. Left atrial enlargement.
Sam of mitral leaflet.

Also one more auscultatory finding.

Loud S1

Correct!

One more!

Pre systolic accentuation.

Yes!

Advanced stage S 1 goes soft.

What happens to this murmur in cases of atrial fibrillation?

Disappear.

What disappears?

Psa.

Correct. Now tell me why?

Because presystolic accentuation is due to contraction of the atria.

May be bcoz atria are in tremora!

Correct. The final phase of atrial contraction is absent in afib.

Which auscultatory finding indicates the severity of the disease?

Length of murmur. The longer, the more severe the disease.

Opening snap moves closer to s2 as the severity increases.

When I said OS S2 interval, the examiner wasn't convinced.
I checked..and then I read somewhere about the length of murmur. You see..As the level of stenosis increases..Blood takes a longer time to enter from atria to ventricles. Hence, the length of murmur.

Maybe it's not anymore. I read a research publication on it.. It's not OS A2 anymore. But let's not confuse exam going students :P

Haha. Could be the length of the murmur!
It could be our PG question :O

Here's the paper for those who are interested http://www.ncbi.nlm.nih.gov/pmc/articles/PMC487332/

Interesting.

Study group discussion: What is the kussmaul's sign? Is it seen in cardiac tamponade?

Kassmaul sign is never found in cardiac tamponade

i.e inspiratory rise in jvp is not present in cardiac tamponade

Kussmaul sign is present in cardiac tamponade. That's what was explained.

Bt kussmaul sign absent in cardiac tamponade.I will recheck my sources for the kussmaul sign
Okay i saw..increased jvp is present and it is common in cardiac tamponade

overall JVP rises bt inspiratory rise is nt dere
I had read somewhere

kussmaul's which is an inspiratory increase is also present..but it is more pathognomic sign of constrictive pericarditis. 
Hence, its not a sure sign of cardiac tamponade

We need harrison for this. Could you check?

On it B)

The table in Harrison says Kussmaul's sign is absent in tamponade. 

A positive Kussmaul sign (seebelow) is rare in cardiac tamponade. 
-Harrison

(***the table in harrison says it is absent, but the text says it is rare***)

So I guess we ain't wrong after all (:

Yaay!

during inspiration there is  RV enlargement to accommodate more blood and in cardiac tamponade it can’t dilate more due to the blood enveloping around it so it pushes the septum and dilates....dilatation causes decrease pressure of right atrium and hence decrease in JVP

I have read about the septum being pushed to the left

Ya septum is pushed to left

The abrupt x descent in jvp shows that  pressure is increased

Ya pushed to left

There are a couple of mcq's asked on the same topic many a times

In tamponade diastole filling affected so it is transmitted in jugular vein , and presence or absence of JVP is indicative of degree of tamponade severity
Pressure

Rapid 'Y' Decent Seen In Constrictive Pericarditis Is Called As Friedreich's sign

So the conclusion we can draw is, it might be present in cardiac tamponade but in rare cases. Kussmauls sign is more pathognomic of constrictive pericarditis and very non specific sign for cardiac tamponade.

Yes!

Study group experience #8

Here's what we learnt!

Thyroid, weight and ophthalmoplegia 

Competitive and non competitive inhibition 

Classification of enzymes

Alcohol and liver enzymes 

High output cardiac failure and beri beri

Cardiac biomarkers 

Vasculitis (Question and answer discussion. Must read!)

Kawasaki disease quiz!

Anti-phospholipid antibody syndrome 
Systemic Lupus Erythematosus

Acute myelogenous leukemia 

Pharmacological treatment of UTI in pregnancy

Colored side effects 

Typhoid 

Malaria 

As you all can guess, we discuss A LOT and I can't seem to keep up with it. So I'm planning to post one or two posts per day. The number of blogs per day will reduce but I'll post all the topics eventually, I promise! Maybe we'll post a weekly study group experience of 15 topics or something. Let's see!

How to join the study group

Study group discussion: Colored side effects

Which drug causes Red Man syndrome? Why?

Vancomycin!

The antibiotic causes histamine release - which causes flushing.

Which drug causes Grey baby syndrome? Why?

Chloramphenicol.

Due to a lack of glucuronidation reactions occurring in the baby, thus leading to an accumulation of toxic chloramphenicol metabolites. The UDP-glucuronyl transferase enzyme system of infants, especially premature infants, is immature and incapable of metabolizing the excessive drug load.

Which drug causes Blue man syndrome? Why?

Amiodarone.

Amiodarone is anti-arrhythmic drug which contains iodine, it's because of that the iodine accumulated in the skin gives the blue color.

Which drug causes blue halo effect?

Sildenafil. 

Which substance makes us look yellow? (It is something which you eat. It is a differential diagnosis for jaundice.)

Excess carotene... Especially, from carrots. But the sclera is spared.. So thats how you know its not jaundice.

Orange urine and tears? Side effect of?

Rifampicin!

Which drug cause blue urine?

Methylene blue.

Study group discussion: Acute myelogenous leukemia

A 67-year-old man presents to his physician with a 10-day history of fatigue, bleeding gums, cellulitis, and a recent weight loss of 9 kg (20 lb). On physical examination, the patient is pale but has no evidence of lymphadenopathy or hepatosplenomegaly. Results of a complete blood count are as follows: WBC count: 18,300/mm3 (75% blastocytes, 20% lymphocytes) Hemoglobin: 9.1 g/dL Hematocrit: 29% Platelet count: 98,000/mm3 diagnosis?

He has acute myelogenous leukemia. It's acute because of the blasts.

Yes, acute myelogenous leukemia.

What could be find in marrow biopsy?

Lots of cells! Sometimes there could be fibrosis though which would lead to a dry tap.

Can anyone tell why the platelet count is affected? (Conceptual review question)

Isn't it in normal limits? 100k-150k?

Then why did he have bleeding gums?

Megakaryocyte lineage affected.

Yup the excessive growth of myeloid series doesn't not allow growth of megakaryocyte.

It is AML M5.

Isn't the bleeding gums due to thrombocytopenia?

I have seen a patient with type 5 AML in my hospital. They don't have bleeding gums. Rather a swelling of gums due to infiltration of leukemic cells. Gingival infiltration it's called I think.

Chloroma.

What's chloroma?

Infiltration of leukaemic cells in soft tissues.

That happens in ALL too, right? The infiltration of leukaemic cells into tissues?

Yes, I think.

I had seen a picture with a child having a chloroma of the orbit.

I thought the WBC count goes in lakhs in AML.

The count doesn't really help because sometimes the counts are comparable to a normal infection.

Oh.

What do we use for differentiating leukemia from infection?

The LAP.

What are the other causes of leukemoid reaction?

The major causes of leukemoid reactions are severe infections, intoxications, malignancies, severe hemorrhage, or acute hemolysis.
Source: http://www.ncbi.nlm.nih.gov/pubmed/16962944

Study group discussion: Pharmacological treatment of UTI in pregnancy

Sharing some of the knowledge I learnt!

So what is the treatment of Urinary tract infection?

Antibiotic according to urine  culture report.

Yeah what's the most common cause?

E.coli

So what the treatment prescribed?

Norfloxacin. It's excreted unchanged in the urine.

The most commonly is trimethoprim sulfamethoxazole. But that's in case of chronic uti, right?

So the question I wanted to ask is what would you prescribe in a pregnant lady? Which drug.. Sulphamethoxazole and trimethoprim?

No. Its a PABA agonist.. Will inhibit folate synthesis. Risk factor for NTD.

NTD means?

Ntd-neural tube defects.

Amoxicillin and ampicillin. Those are the ones preferred for any infection.

Nitrofurantoin too.

That's prophylactically. Atleast that's what we were taught.

Even nalidixic acid.

Yeah! Not to give TMP-SMX that's what was the main point I wanted to convey.

Study group discussion: Thyroid, weight and ophthalmoplegia

We were told by our Pediatrics teacher that thyroid status and weight changes are not related. Weight gain in hypothyroidism, in fact due to myxoedema and not due to slow metabolism.
But almost every other book I read say weight changes are a part of symptomatology of thyroid disorders.
Would someone enlighten me about this?

In myxedema there is reduced breakdown of glycosoamimoglycans. Plus there is free fluid retention. A lot of factors come into play. I'll look it up and send a good resource on it.

And haan..also iy read in a book..that in thyrotoxicosis..30% of patients will have weight gain. So therefore, maybe the weight status are not characteristic to changes in thyroid profile.

Maybe.

The cause of the weight gain in hypothyroid individuals is also complex, and not always related to excess fat accumulation. Most of the extra weight gained in hypothyroid individuals is due to excess accumulation of salt and water.
Source: http://www.thyroid.org/weight-loss-and-thyroid

So, 'obesity' should not ideally be mentioned in symptoms of hypothyroidism?

Weight gain should be mentioned
Along with the various other signs and symptoms. The complete clinical picture is specific to thyroid diseases.

The mechanism maybe varied but weight gain is a symptom and should always be a differential for hypothyroidism.

Yup.

Also, in Grave's ophthalmopathy, GSGs are deposited in the retro orbital space. Shouldn't this be seen instead in hypothyroidism where there is reduced breakdown of GSGs?

It's because of autoimmunity
The antibodies stimulate deposition of GAGs. Has nothing to do with the effect of thyroid hormones. That's why, ophthalmoplegia can not be treated by anti thyroid medications.

Oh!

What is the treatment of ophthalmoplegia in Grave's?

It is symptomatic. Lubricants, steroids is all what we can prescribe.

Yes, steroids. To suppress the immune system.

Steroids are especially given in retinal pathologies.

What about a permanent cure?

I don't know about any permanent cure.

It's radioactive iodine 131 or thyroidectomy.

Permanent cure for opthalmopathy?

Hemithyroidectomy. Or if the graves is not too bad, we can give thyroid peroxidase inhibitors? And sometimes it will resolve by itself?
I was told the retro-orbital lipofibroblasts requires surgical removal of the mass behind the eye, but the lid lag will resolve once the thyrotoxicosis resolves?

Yes.

There are different surgeries for the opthalmoplegia..Don't remember the names.

Study group discussion: Cardiac biomarkers

Which all troponins are used as cardiac biomarkers?

I and T.

Troponin- T type 2.

Correct!

Which biomarker is used to differentiate breathlessness of cardiac origin from that of COPD?

BNP.

Correct!

BNP?
Brain natriuretic peptide.

Woah. I didn't know this.

Yeah. BNP is a marker for heart failure.

It's also used to monitor COPD patients.. That is the levels will increase if there is cor pulmonale

Also pro BNP.

BNP is present in ventricles. The ANP (Atrial natriuretic peptide) version in atria.

Amazing!

Study group discussion: Alcohol and liver enzymes

Which is the most sensitive enzyme for alcohol abuse?

Gamma glutamyl transaminase (GGT). 

What is the ALT:AST ratio specific for alcoholic hepatitis? 

1:2

2:1 is AST ALT. That was the catch if you got it wrong! Scotch and tonic is the mnemonic!

Which is more specific for liver disease.. ALT or AST?

ALT.

Why? 

ALT is more specific for liver disease than AST because AST is found in more types of cell (e.g. heart, intestine, muscle).

Kawasaki disease mnemonic and notes

Kawasaki, a Japanese name, reminds me of anime!

So I drew this anime character, having Kawasaki's disease. Can you label the 5 things she'll have besides the fever to make a clinical diagnosis of the disease?

Study group discussion: Vasculitis

This review question session was held by Sakkan!

Examples of large, medium and small arteries?

Large arteries: Aorta, pulmonary. Also, the major branches of aorta are large arteries - Brachiocephalic, common carotid and subclavian.

Mediucm sized arteries: Brachial and temporal, femoral are medium.

Small sized artery: Digitalis artery.

A patient comes with rhinitis and dyspnea, he also complains of hematuria. Which is the most probable vasculitis?

Study group discussion: Classification of enzymes

Which class of enzymes does carboxylase come under? (IUMB class for enzymes, 1 to 6.)

It belongs to transferases... Because you transfer a CO2 compound. 

Study group discussion: Competitive and non competitive inhibition

Define Km value of an enzyme.

In types of enzyme inhibition..Where does the value km and where does the value Vmax decrease?

It is the substrate concentration at which reaction rate is half the maximum rate.

Study links!
http://medicowesome.blogspot.ae/2013/12/competitive-and-non-competitive.html

http://medicowesome.blogspot.ae/2013/11/competitive-vs-non-competitive.html

In types of enzyme inhibition..Where does the value km and where does the value Vmax decrease?

Vmax decreases in non competitive inhibiton.

Kmax in competitive.

There is one more thing.. Uncompetitive inhibition.
Anybody knows about that?

Some placental enzyme inhibited by phenylalanine. Donno for sure.

Biochemistry.. It's fun when you have recently read it.

Study group discussion: Malaria

Review questions! Which are the types of parasites for malaria?

Plasmodium species!
Vivax, falciparum, ovale, malariae.

One more.
Plasmodium knowelsi.

How do you differentiate cause of malaria based on the fever

It's quartan in malarie.. After every third day.
It's tertian in the rest of them.. Every alternate day.

What's algid malaria?
Circulatory collapse

Fever and shock. That's algid malaria.

Which are the rapid diagnostic test for malaria?
Dip stick test
Pfhrp
Pfldh

Of HRP and LDH , which is specific for falciparum malaria?
HRP?

True.
LDH just shows infection with plasmodium. Not which sub type.

But what was the significance of LDH? I read somewhere it's super important.

It detects all other forms. Hrp is just to check whether it is falci or not.

Which forms have a latent phase in liver?
P. vivax & P. ovale

What is the clinical significance of liver forms?
They remain dormant in ovale & vivax, also known as hypnozoites & they cause relapse.
Yes.

Drug of choice for relapse?
Primaquine!

Why do we give primaquine in P. Falciparum malaria?

To destroy gametes!

Yes. Gametocides. It helps in control of spread. 45 mg is gametocidal.

Which test is more preferred if you are suspecting relapse?
Peripheral blood smear is preferred.

Correct!
Why don't you perform rapid diagnostic test when you are suspecting a relapse for malaria?

You don't do rapid diagnostic test cause.. These remain positive several weeks after an initial infection.
So it will show positive even if it's fever for some other cause.

I was asked this in viva, why we combine chloroquine and primaquine in combination?

In Vivax, primaquine is used for hypnozoites.

Which is the gold standard for detecting malaria?
Gold standard is that centrifuge thing.
QBC? Quantitative Buffy Coat? We add acridine orange?

Hmm. Peripheral blood smear is gold standard. Never heard of buffy test. Could be because in the buffy coat what you get is WBC's in maximal amount. Plasmodium are within RBC.

How will you diagnose cerebral malaria?

You can't diagnose malaria by CSF.
It's on clinical symptoms. Based on altered sensorium and coma you diagnose it.

Interesting.

But first you infuse glucose to rule out hypoglycaemia..If the patient fails to improve then its  cerebral malaria.

Yes, I remember that.

Which anti malarial drug can cause hypoglycaemia?

Quinine and chloroquine too.

Correct!

Introduction to the new author

Greetings mortals

I am sakkan. I am new here

New as in, I have just recently taken up blogging seriously. And as ikan told me..”welcome to everyday blooging “ =D

Its fun

Hobbies include. 

I am a passionate reader of fantasy novels.

 I like food, but I wont call myself passionate about it, cause I have to watch those calories.

I like sitting on a bench facing a park, with a cool breeze. That’s peace

I like knowing the why behind everything. Its very hard for me to remember things if I don’t understand whats going on.

 This blog has provided me a portal to be more demanding of those answers.

I have a couple of groups to my whatsapp. From junior college, medical college, classes. But truth be told none of them is as humongamous as the medicowesome study group. Diversity, sharing, thoughts, questions and most of all answers, and everybody just jumps in to answer your questions. It feels like a tiny virtual world of awesomites who just care to learn and nothing else.

p.s ‘ the word humongamous- cause even enormous seemed small to describe you guys’

hope we provide you with as much of knowledge through this blog, in equivalence to what you guys have provided us.

thank you

-sakkan