Lamotrigine: A depression mood stabilizer

Lamotrigine is used primarily as an anticonvulsant for the treatment of generalized and partial seizures and is effective for treating focal epilepsies in the presence or absence of secondary generalization.

Photophobia vs blepharospasm

Both have the same presentation of tight lid closure.

In dark, blepharospasm won't be completely abolished while photophobia would.

Anaesthetisation(topical) reduces greatly the blepharospasm but not photophobia.

-Sushrut

Definition of generalized convulsive status epilepticus

Hi everyone,

Historically, the International League Against Epilepsy (ILAE) and others defined status epilepticus as a single epileptic seizure of >30 minutes duration or a series of epileptic seizures during which function is not regained between ictal events in a 30-minute period.

However, a 30-minute definition is neither practical nor appropriate in clinical practice.

Glucagon-like peptide-1 (GLP-1) receptor agonists

Hello everyone!

Let's talk about glucagon-like peptide-1 (GLP-1) receptor agonists today!

Tetralogy of Fallot: The Basics

Hey guys, this post highlights the important points discussed in the accompanying video.

Fuch's s in Ophthalmology

Following this are ascribed to Fuch

1. Fuch's heterochromic iridocyclitis
2. Fuch's corneal endothelial dystrophy
3. Gyrate atrophy of the choroid
4. Ciliary body adenoma

-Sushrut

Leptospirosis

Rats, rains, ricefields? Ring any bells? Sewer workers coming in with jaundice and fever? Still no?
Assam/Odisha/Kerala floods?

No Vitamin A in Stargardt's disease

In lipofuscinoses like Stargardt's, fundus flavimaculatus, and Best's disease spectrum, Vitamin A and related compounds are avoided as the metabolites of those is what causes the disease in the first place. Usually, Vitamin A is prescribed empirically by general ophthalmologists for degenerative diseases of the retina.

-Sushrut

Age related macular degeneration- some facts

1. Dry AMD is the most common form, but wet AMD is responsible for 90% of the cases of visual loss.

2. Type 1 choroidal neovascular membrane is 'occult' and type 2 is 'classic'. This might be counter intuitive to remember.

3. In the genome, except for chromosome nos 7,11,13,21, and the Y chromosomes, all the other harbour genetic loci for AMD!

4. Hypermetropic eyes are at a greater risk of AMD. This, again is counterintuitive as myopic eyes are usually more prone to degenerative conditions.

5.Another, (sort of) counter intuitive fact is that 'hard' drusens do not lead to macular degeneration while 'soft' drusens precede macular degeneration.

6.Beta carotene, a treatment modality for AMD increases the risk of carcinoma of the lung in smokers as well as non smokers. Zinc causes genitourinary complications- UTIs, prostatic hyperplasia, and in women,stress incontinence. Also, zinc is ineffective in the prevention of advanced AMD. These results are from the two RCTs- AREDS 1 and 2 .

-Sushrut

Calcium channel blockers for vasospastic angina

Hey everyone!

I was reading about calcium channel blockers for vasospastic angina and it was a good refresher to know that even though they belong to the same class, they act by different mechanisms.

Dihydropyridines block slow calcium channels.

They vasodilate coronary arteries, reduce coronary resistance, increase coronary blood flow, and may enhance the development of coronary collaterals.

The vasodilatation and increase in coronary artery blood flow result from the blockade of calcium influx as well as an increase the levels of nitric oxide and bradykinin.

They can cause reflex tachycardia.

Verapamil has different physiologic effects from the dihydropyridines because of a different interaction with the calcium channels.

Verapamil is effective in angina because it decreases myocardial oxygen demand by acting as a negative inotrope and chronotrope and by lowering the systemic blood pressure.

Changes in contractility are minimal in patients without heart disease; however, verapamil can exacerbate heart failure in patients with cardiac dysfunction due to its negative inotropic activity.

Diltiazem is a potent coronary but a mild arterial vasodilator, producing improved blood flow through coronary epicardial vessels, collaterals, and normal and ischemic myocardium, as well as lowering mean arterial pressure.

That's all!

-IkaN

Inferior wall MI and Bezold-Jarisch reflex

Hello everyone!

Acute myocardial infarction (AMI), especially of the inferior left ventricular wall, is often associated with transient hypotension and sinus bradycardia.

Ever wondered... Why?

Kleihauer–Betke test

Kleihauer–Betke test: KB test.

1) Why do we do this test?

- To calculate Fetal RBCs in blood. This helps us to measure amount of Anti-D required to neutralize it.

2) How do we do it?

- Basically, we are going to take blood sample and add acid to it and measure red blood cells under microscope.

3) How do you differentiate Fetal and Maternal blood?

- Fetal RBCs are acid resistant. Adding acid in the preparation leads to lysis of the Maternal RBCs.

4) What are important points regarding this test that should be kept in mind while solving MCQs?

- Do not confuse it with APT test. APT is done in Alkali and it is a Qualitative test. It helps in differentiating Maternal and Fetal blood only. On the other hand, in KB test (Also know as Acid dilution test), we use Acid and we quantify Fetal blood.

- Minimum dose even after KB test is 300 microgram.

5) How do we calculate amount of Anti-D required to neutralize Fetal RBCs?

- If 20 RBCs in HPF are seen, then it means 1 ml Fetal blood is in circulation.

-‎1 ml fetal blood requires 10 microgram of Anti-D for neutralization

6) What if they don't mention "Fetal RBCs" and instead, mention "Fetal blood" in the question?

- Here is a trick. Always remember, 1 ml Fetal blood has 0.5 ml Fetal RBCs.

Applied calculations:

Q1) A Multigravida with twin pregnancy has 20 ml Fetal RBCs. How much Anti-D will be required to neutralize it?

(Take a deep breath. You don't need to worry about twin pregnancy. All the important points are already covered in above segment)

- 20 ml Fetal RBCs = 40 ml Fetal blood.
- ‎1 ml Fetal blood = 10 micrograms Anti-D

Answer = 400 micrograms Anti-D

400 micrograms is the enough amount of blood given to neutralize 40 ml fetal blood or 20 ml Fetal RBCs.
‎
(Done easily? Perfect ! Let's level up.
I want you to go through blog once again before heading down.)

Q2) This time patient comes with same clinical presentation but with 20 ml fetal blood.

- 1 ml fetal blood = 10 micrograms of the Anti-D
- ‎20 ml Fetal blood will require 200 micrograms Anti-D.

Perfect. We calculated correctly but my question is - Will you administer 200 micrograms Anti-D to the patient showing 20 ml Fetal blood to neutralize it?

Answer is big 'NO'.

Go back to bullet (4) point 2:

Minimum amount is still 300 micrograms after KB test. So you cannot administer 200 micrograms. You have to give 300 micrograms.

I hope this blog is better than my previous blogs. Any important points you have regarding KB test, do comment in comment box

That's it

-Demotional bloke

Interesting retinal peculiarities

1. The respiratory rate of the retina is twice that of the brain.

2. The retina does not require insulin for glucose to enter the cells!

3. In the retina, glycolysis occurs despite having sufficient oxygen supply.

4. The retina is not just a sensory organ. Much of the image processing occurs at the retinal level itself.

-Sushrut