Somogyi effect and dawn phenomenon in diabetes

So I read a lot of interesting things today and I'm formulating questions based on it.

A person took too much insulin at night and went to sleep. He checks his morning blood sugar levels and it's elevated. Why?

It's because stress hormones were released while he was asleep which caused the hyperglycemia. (This is called Somogyi effect!)

Now, a person took his appropriate dose of insulin at night and went to sleep. He checks his morning blood sugar levels and it's elevated. What happened this time?

There is a normal hormone surge at 7 am (Growth hormone, cortisol, glucagon and epinephrine) which caused the hyperglycaemia. This is called dawn phenomenon.

How will you differentiate Somogyi effect from dawn phenomenon? Why is this clinically relevant?

I guess the person with Somogyi effect will have certain signs and symptoms related to hypoglycemia. For instance, night terrors. Right?

People with hypoglycemia don't wake up but have nightmares.

The 3 am glucose levels to be precise. It is low in Somogyi effect and maybe normal or high in dawn phenomenon. You'll decrease NPH insulin at night in the former and increase the NPH insulin dose in the latter. 

NPH is an intermediate acting insulin. NPH insulin is usually taken at night. Duration of action 7- 14 hours!

In Somogyi, the excess insulin caused hyperglycemia. So you'll decrease the dose.
And similarly, in dawn phenomenon, the inadequate dosing caused the hyperglycaemia, so you'll increase NPH insulin.

If you're under the impression that is inadequate insulin and if you increase the dose of insulin, you can put the patient into a hypoglycemic coma! This is why, recognising Somogyi effect is very important.

I didn't get the management.. How is the adequacy of insulin assessed? If a patient comes with morning hyperglycemia, will you order 3 am glucose levels?

Nope. That would be hectic too. You wanna decrease the dose and see if the patient improves. If the patient doesn't, it means it wasn't the dreaded Somogyi effect and it was just the regular dawn phenomenon, so you can go ahead and increase the dose.

You keep tailoring the dose to suit the patient. 

Study group discussion: Some virology review questions

Hey everyone! I have a major virology exam coming up, would you like to go over some review questions with me? :)

Yes!!!

Great! I'll start:

Yaay!

Heterophile antibodies are positive in which viral infection?

These are multiple choice questions, shall I write the choices?

No, write them only when we can't guess it.

Ok :)

EBV?

Yes!

Which test is positive and is used to diagnose when there is an EBV infection?

Infectious mononucleosis.. Presence of human anti sheep antibodies, I think.

Yes! The test has a specific name though, anyone know it?

Umm.. Monospot test?

Coombs test ??

Neither of those

Would you like the choices?

Okay

Paul-Bunnel Test
Coombs Test
Indirect IFA
Western Blot
ELISA

Paul Bunnell! I forgot that.. Thanks!
Ok, ready for a new question?

Yes!

Which test is used to determine the specific genotype of HPV?
Another question would be, what is the first test you used to check for the existence of an HPV infection?

First test is Pap smear. Correct!

We'll need choices for the genotype - I'm guessing PCR though.

Ok here are the choices:
Consensus PCR
Line Probe Assay
Western Blot
Pap Smear
Latex aglutination

Consensus PCR?

No, I initially thought that too.

I'd say the line probe.

It is LiPA!

Why is that?

It uses the reverse hybridization to id specific  hpv genotypes by detection of specific sequences in the l1 region of the HPV genome.

It is more specific than the PCR

I see.

While we're on the topic of HPV, what are the high risk genotypes? And the most common low risk genotypes?

High risk: 16, 18
Low risk: 4, 6, 11

16 and 18 is usually used in the vaccine as well!

This changes a lot from place to place though, my medical faculty is working on developing a vaccine specially for this area/country

Oh that's great.. I didn't know that thanks.

:) no problem!

You guys want some more questions?

Yes

What is the main cause of non-bacterial gastroenteritis epidemics?

Rotavirus

That is one the choices here, but it's actually not that

Ooh. It's the main cause in India!

Choices?

Rotavirus
Norovirus
Adenovirus
Enterovirus
Astrovirus

Rotavirus usually infects infants and younger children, if I'm not mistaken.

Yup. So it's something else in adults?

Adults aren't really effected, the one we're looking for can infect people from different ages.

It's actually Norovirus!

It is the leading cause of viral gastroenteritis in the world!

Never heard of it :O
Is it the same as Norwalk virus?

Yes! Norwalk virus is a species of this genus. It's responsible for almost 90% of viral gastroenteritis epidemics globally!

Woah. That's a lot.

Norovirus happens in outbreaks, and stays infectious for a long time on surfaces yes?

Yes, exactly.

It's a calcivirus! http://medicowesome.blogspot.in/2014/04/how-i-remember-that-norwalk-virus-is.html

Family : Calcivirus, Genus: Norovirus :)

I'm going to have to leave soon, would you like 1 or 2 more questions?

Yes!

Which one of the viruses listed below, has a non-segmented genome?

Orthomyxovirus
Reovirus
Coronavirus
Arenavirus
Bunyavirus

Coronavirus?

Correct!

Review question: Does anyone know the clinical significance of the segmented genome?

A segmented genome has evolutionary advantages! Like, reassortment!

Allows reassortment and thus new viral strains in mixing vessels. Eg avian influenza.

What is the cause of Roseola?

Human herpes virus 6 or 7

Correct!

Brilliante!

One last question before I leave for now? :)

Yep yep yep

What is the most common cause of bronchiolitis in newborns?

Oh oh I know this.

RSV

Respiratory synctitial virus.

Correct :)

That was good, thanks!

I love random review question sessions!

Do it more often!

I have to go now, my friends are coming over to study! This was great, talk to you soon!

I have hundreds of review questions for my exam! Great! Looking forward to it.

This review question session was held by Fidan :) Thanks!

Study tips: Anxiety for test day

This is my first time talking to anyone I follow on anywhere... Be it twitter or tumblr. I am not very involved in social media, but I guess I am a bystander.

I am messaging you because I am in a bit of a dilemma. I am writing my USMLE step 1 exam in 5 days. I have been studying for it, believe it or not, for 2 years.

In this time, I have been home, my parents looking after me after I had gone to a med school on the island. I suffer from text anxiety... So like in the middle of the exam my brain just gives up, I feel at loss of hope. I just get this overwhelming feeling of failure.

I have bought the exam twice now and my date is scheduled for the last day possible. My parents are just fed up and they want me to get moving with my life. I have inconveninced them.

I have written all the NBMEs and I have never got a score above 300. I study so hard, but I hate to memorize if that makes sense. I have watched all the Kaplan videos, all the DIT videos and I have completed both Q banks. I know everything, but when it comes to route memorization... I can't do it for some reason, because I have this fear of it even is going to stick. I don't know what to do and I hoped some wise words from you might help me. You have some awesome things to say and they helped me lurch back up on a low day. I am literally trying to fly the coop right now.

Hope I am not intruding with my story.

- Email from an awesomite

Hey!

I'm glad you chose to speak to me.

The USMLE step 1 exam is scary. And it gets scarier as it gets closer. I had scheduled it on the last day too! My mum needed to go abroad and I had inconvenienced her. I never scored above 300 either in my NBME. But I got a good score on my step.

I'm telling you this to assure you that this is normal. That many have gone through the feelings you're going through and have made it before you. That you're not alone. That there is always hope.

You made it through various exams as you got here. Let's do this and get done with it. You have studied and you can trust yourself in midst of self doubt. You can do this.

You shouldn't be afraid of consequences. You've given your best shot. You have worked hard. Be confident that it'll work out for you in the best possible way.

Now this is a personal belief - I believe that not all five fingers are the same. Everyone is unique. That you have your own limitations and strengths. So some will score better than you, some won't. Accept it.

Once you have done your preparations well and that there is not one more thing you could've done, you must not worry about the results. Everything happens for the best. There's a good reason behind why things don't work out the way we want to - we don't see it right now but it doesn't mean it's not there. So I'm content with the results even before they come out.

I also believe that scores don't matter. That you can do wonderful things with your life without the scores. Yes, a good score will help you feel good about yourself and open doors - but a fear of a bad score shouldn't fill you with despair. The little anxiety you get should help you work hard, not come in your way.

I understand your memorization dilemma. Remembering things comes to us with repetition whether we like it or not.

There's not much you can do 5 days before the exam. But if there are certain high yield facts that you know you have not memorized - You can store facts in your short term memory and then forget them forever. We are capable of it. So you can't memorize everything, but please do what you can!

On the exam day: Focus on the question. Don't let your mind wander - go into past disappointments or future failures. Stay there. Read the question. What's the best answer to this question? Hmm.. This is an interesting one. What could the answer to this be? What are they trying to tell me in this question? Oh I don't know about this - will read about it later. The hints they're giving me are awesome. Ooh. This is a tricky one! I likey! I love medicine and it's enough. I'm living my passion. I'm lucky to be here. And that positivity, I tell you, will pull you through and give you hope.

I'm glad the things I said helped you. I hope this does too.

You're not intruding, be free to message me whenever you like (:

I understand that you might not get the time to reply after reading this - so I'll hear from you after the step. All the very best to you. I'll pray that you do well.

Love,
IkaN

Study group discussion: Newer vaccines

Can anyone explain what newer vaccines mean? And which vaccines are included in this?

I think HPV is a newer vaccine.
The flu, hepatitis, rotavirus, pneumococcal & meningococcal are newer vaccines too... But this is in general stuff.
If you're looking for a definition, I don't know about that :/

Oh wait - I found a good link to newer vaccines.

These are 4 new vaccines added to the universal immunization programme (UIP) in India.
They are - Rotavirus, JE, injectable polio and rubella.

And here's more to it - If you're studying PSM in India :P

Vaccines against rotavirus, rubella and polio (injectable) will help the country meet its Millennium Development Goals 4 targets that include reducing child mortality by two-thirds by 2015, besides meeting meet global polio eradication targets. An adult vaccine against Japanese encephalitis will also be introduced in districts with high levels of the disease.

Okey. I was not sure if they were newly added or newly developed, that's why asked.

I think newly added - they had been developed long before, I suppose.

Yap same in our settings..They added rubella. And HPV for young females (Tanzania)

(India) What is the program called in your country, like is it UIP there too?

(Tanzania) Yap we use EPI.. Extended programme for immunization.

(India) We have that here too.. There's national, extended and universal.

(India) EPI was for six vaccine preventable diseases... Then it was updated to UIP with vaccination of mother with TT and vaccine spectrum for child was also extended. The one we use now is infact the UIP.

Nice. I didn't know the difference.

P.S. Thanks IkaN!

They give tetanus toxoid to preg mothers!?

Yep.

At first visit and I think two months later.

It's actually a viva question - When does immunization of the baby begin? The answer is in utero because tetanus given to the mum helps the baby before it's born.

Study group discussion: Why are they called false localizing signs?

This was discussed on our study group. I tried to explain it :D

Can anyone explain why bilateral grasp reflex and bilateral babinski sign are false localizing signs?

There are certain signs which makes you think lesion is at that level so you localize it there but the lesion may be at a different level. So you localized it falsely, just because of that sign. 

Study group discussion: Removal of antigens from RBC's

Did anybody know that we can remove A and B antigen? :O

From what kind of RBCs?

Didn't know!

Yes, I read a research while back. The idea was simple, the O group has no antigen naturally, so they thought about removing A and B antigen too.. They first used coffee beans to remove it but it required acidic pH that resulted in hemolysis, finally they found the glycosades in bettle to remove A and B..

Nice.

http://www.nature.com/nbt/journal/v25/n4/full/nbt1298.html
Link to a research using bacteria to remove ABO group.. :)

Study group discussion: Blood group doubts

Can a person with blood group
AB -ve be given A -ve and B -ve?

Yes.

AB blood group people are universal acceptors. Of course, you can give.

The problem of Rh negative is important when it is a woman. You can't give a Rh positive blood to an Rh negative female.

Is it because of any future pregnancies or something else?

The Rh negative woman will develop antibodies against Rh positive blood groups.

In successive pregnancy there's risk of erythroblastosis fetalis.

But isn't it also bad to give Rh + blood to anyone who is Rh -? I've heard you can't give positive blood to a negative male too.. Because of the tranfusion reaction following it na?

The important difference here is unlike the AB blood groups..
A patient who is of B blood group..He is missing the a antigen on the cell. Therefore, he has the a antibody in the plasma. But if the patient is Rh negative..He won't have the corresponding antibody.

And if that person is given rh+ blood won't their body produce anti D antibodies? Since D is an antigen?

A Rh negative person will only form antibodies when exposed to RBC which are Rh positive.

So even in males antibodies will be formed. And haemolysis and consequent reactions will be there?

Yes.

So it shouldn't be preferable to give Rh + blood to anyone who is Rh - regardless of gender.

Theoretically.

Yes! Therefore, we ask for previous blood transfusions.

But in cases of emergency. You first go for O negative blood. If not available.. Even of positive can be used.

So if we would have to do a list
1. O Rh negative
2. O Rh positive

But especially in cases of women.. You have to be super cautious not to use a positive blood group if she is a negative.

You have a patient with A rh- blood who is in need of urgent transfusion. And you have two possible donors: An O Rh -  person and a A Rh + person. Which one do you choose?

O negative.

You can't give positive to a negative person!

Yeah since its a universal donor. And the Rh is same.

But O negative blood is reserved for emergencies..So it depends on the availability. If you manage to get hole of the same group..like A+ for an A+ That one is preferred

You preserve O - cause in emergencies there is hardly any time for blood group testing

Fair enough.

Treat positive as an antigen. You don't wanna create unnecessary antibodies in anyone because it increases the risk of organ rejection in the future. So regardless of the sex, you wanna properly match the blood.

Also future blood transfusions can be an issue.. Due to undue antibodies.

If you have no choice which antigen is worse the Rh, or the blood group?

The blood group.

They will cause an immediate reaction which is fatal.

Okay thanks! :)

As I said antibodies to Rh are not preformed.. They take time to form.

Oh I wasn't aware of that distinction. Thanks again.

Got a question. Would the anti A and anti B in O group prove antigenic to the patient? Of course, if he is either B or A respectively or AB

You mean to ask If the antibodies against A and B of O donor, will effect A B and AB recipient?

Yes, exactly.

No, I guess..

But why?

I think they are not in a significant quantity.

Because they are not yet exposed to A and B antigen when they were in donor.

In contrast, if mismatch occurs, the patient's body will produce numerous antibodies against the donor blood.

If I were to guess, I'd say once they leave their own system (the donor) they lose ability to mature into active antibodies.

They are not really viable ones the blood is collected from the donor. However we still have minor cross matching for that.

We had a discussion on that before!

Here it is:
O negative blood group  http://medicowesome.blogspot.com/2015/02/study-group-discussion-o-negative-blood.html

Oh.

The discussion is good. Thanks!

Study group experience #11

Here's everything we learnt (50 posts pending though)

Multiple myeloma and tumor lysis syndrome (USMLE oriented case)

ACE inhibitors 

Calcium channel blockers 

Antihypertensives - Arteriolar, venous and arteriovenodilators

Teratogenic effects of warfarin

Induction of enzymes by barbiturates 
Fluoroquinolones

Tetracyclines

Sulfonamides, Trimethoprim Sulfamethoxazole and other sulfa drugs 

Anti-tubercular drugs 

Anti-viral drugs used in herpes 

JVP in pulmonary hypertension and tricuspid regurgitation 

Extra books for USMLE 

Physiology books 

Embryology and gestational trophoblastic disease 

Normal movements in brain dead patients

Preganglionic and postganglionic fibers 

Vitamin B12 deficiency

I don't have a lot to say this week. I hope you're having fun reading the discussions!

-IkaN

Study group discussion: Calcium channel blockers

Which calcium channel blockers are not given in CHF?

Verapamil

Diltiazem

Correct. And why?

Decrease contractility.

Correct. They are negative dromotropic and negative ionotropic.

So in which conditions do you give verapamil and diltiazim?

Hypertension?

It's not hypertension. For hypertension you use dipines.

CCB are class 4 antiarrhythmics. So they are used in arrhythmias of atrial origin.

Remember.. The dipines act predominantly on vessels.. Hence they are preferred in hypertension.

Verapamil and diltiazem on the other hand act equally on heart as well as vessels.

Unstable angina?

They are used in unstable angina correct!

Which type of calcium channels do CCB act?

L type

First choice drug in hypertensive crisis?

Na nitropruside

Correct Priyanka

Now tell me why?

Marked fall in BP in a few mins.

There is one more reason.

Equal arterial as well as venous dilator!

Brilliant!

Study group discussion: Antihypertensives - Arteriolar, venous and arteriovenodilators

Tell me the drugs which are:
a. Specific venodilators
b. Arteriodilators
c. Arteriovenodilators

Arteriolar- hydralazine and minoxidil.

Correct!

Venodilators - GTN?

Actually, that is a googly question. There are no specific venodilators. Nitrates dilate the veins more.. But they dilate arteries too.

Cool.

What about arteriovenous dilators?
There are three classes to them!

Na nitroprusside.

Correct! Sodium nitroprusside it is.

Plasma kinins.

And by using what you make the kinins available to act on your blood vessels? Cause normally they are degraded.

ACEIs

Bingo!

Which receptors are responsible for vasoconstriction?

The autonomic nervous system ones! The alpha 1 blockers are the third class.

Last question. Nitrates act on veins more than arteries. Tell me which drugs act on arteries more than veins?

The calcium channel blockers, of course.

Study group discussion: Induction of enzymes by barbiturates

Why do barbiturates lead to hypertrophy of smooth ER and why do we need to increase the dose?

Barbiturates are CYP450 oxidase inducers. This enzyme is produced by smooth ER.. So there will be hypertrophy.

Ok agreed. But how the person becomes tolerant to the drug?

It is because the hypertrophied smooth ER metabolises the drug more causing adaptation.

Study group discussion: Teratogenic effects of warfarin

Random review questions! 

A baby is found to have stippled epiphysis, microcephaly and optic atrophy. Which drug was the mother exposed to during pregnancy which resulted in the birth defect?

Alcohol?

Alcohol will cause microcephaly, not the other two findings.

Steroids in the first trimester?

Umm no. Steroids cause cleft palate and cataract.

Phenytoin?

Again, phenytoin will cause microcephaly, not the other two defects.

Hint: The woman said she had developed joint pain when she was young. She also had skin rash and breathlessness on activity. That's why, the doctor prescribed her monthly injections.

So she had acute rheumatic fever?

Yes, she did!

So rheumatic fever patients become breathless during pregnancy. Why?

Penicillin?

It's not penicillin that caused the defect. It was some other drug!

Tetracycline?

Nope. Tetracyclines cause discoloration of teeth. She wasn't on antibiotics.

She also said that she consumed oral tablets during pregnancy.

Heparin or warfarin!

Warfarin correct! Heparin ain't teratogenic.

She was on a blood thinner, because of mitral stenosis due to RHD, probably wasn't informed that her medication should be changed during pregnancy.

Oh and can any guess why the neonate developed the Optic atrophy?

Warfarin makes the fetus susceptible to intraventricular hemorrhage. That's why the optic atrophy!

It's been suggested that warfarin causes repeated intracerebral hemorrhages which causes Optic atrophy, microcephaly and mental retardation.

Here's another cool fact - warfarin in early trimesters cause nasal hypoplasia and stippled epiphyses, and if taken in later trimesters cause the CNS defects.

This is so cool.

The mechanism of the first trimester defects are - Warfarin blocks protein C and S.. Which is essential in bone formation of the baby. Hence, you get nasal hypoplasia and epiphysial problems.

(UPDATE: This syndrome caused by warfarin is NOT called contradi syndrome. It's similar to Conradi-Hünermann syndrome, a rare genetic disorder characterized by skeletal malformations, skin abnormalities, cataracts and short stature.)

I got a doubt - What monthly injections was the lady taking?

Well, she was taking rheumatic fever prophylaxis. Benzathine penicillin intramuscular injections to be precise!

Study group discussion: Preganglionic and postganglionic fibers

What is importance of preganglionic and postganglionic fibers in our CNS?

The length of them? It differs from the parasympathetic and sympathtic!

Neurotransmitters of postganglionic varies by parasympathetic and sympathetic.

Parasympathetic: Cholinergic such as acetylcholine.
Sympathetic: Adrenergic such as epinephrine and norepinephrine.

Yes, and preganglionic neurotransmitters of both sympathetic and parasympathetic is Acetylcholine.