FAQ: How to study for pg entrances while being in 3rd mbbs?
how to study for different pg entrance exams while in 3rd mbbs??solving mcqs or reading thoroughly is a good idea?please suggest some strategy.

hmmm -looks like ur the early bird- good good al lthe early birds in our batch got through first time- and their strategy was -finishing up harrison before final mbbs.
may be u can do the same.

ok. so as a third mbbs student, i should seriously aim at finishing Harrison before my final mbbs. my only doubt is how much will i retain after my internship?still, i guess, doing something is better than nothing. thanks for the tip.

reply
i think 1 shoud study psm thorouly & side by side complete few chapters of harrison bcz psm also forms good portions of prepg ques ,,,,,, am i right ,,,,help

First thing 2 read all textbooks right from first year. Then get good mcq books which standard mcqs as in exams. going for any mcq books will not help. I had talk with many seniors reason of failure wasnt lack of guidence but many of havent read textbooks & opted mcq books as shortcut. Well best luck for studies exam will automatically nice

1stly speakin of MCQ's i feel apt subject evaluation and proper grip over subjects prior to Final yr wil ensure confidence and zeal cos 1st to 3rd yr's subjects if weighed together wil equal the burden the final yr subjects possess!!!As our respected author said Patients wards and presentations come prior to sloving MCQ's and stuff like that.....2ndly coming to Harrisons its like a self limiting 4th grade carcinoma.....needs lot of monitoring and frequent revisions..One hell of a book where any1 can fall in love wit it but none can marry!!!!

hi everubody
as per my opinion we should start studying by entrance exam point of view instead of exam.
i think we should keep iii with us while studying any topic from any book n after complition of reading that topic we should slove all the mcqs related to that topic.
this will heip usdurig intenship to slove mcqs which already have been sloved by us and also it increases our confidance.

b thorough with the present subjects and read the books wich r suitable for entrance exams so that u will have no probs while reading for the entrance from the same books

i belive one needs a systemic approach to prep... first get complete knowledge regardin exams from seniors, sites like rxpg, coachin classes and wherever u may find em.... then make up a plan and follow third mbbs is a good time to start.... read gud standard books for clinicals.... and most importantly keep ur head strong... i am myself in third MBBS... perhaps we can share some of our thoughts amyloid.....

hey buddies i have gone through this discuccion...i am also a 3rd mbbs student.i started preparing for usmle and amc ...can any one tell me what is the better and the easy one among usmle and amc...on which one can i stress more???

me 3rd yr too
ive bought ashish anit arvind ... tryin to solve it as i read.... but i personally feel that 1st we shud make a stable data base of information of medicine in general... just solvin mcqs may be pointless.... how much can we remember out of that?

Nonparenteral medications
Capsules and unscored tablets are rounded to the nearest whole tablet. Scored tablets are rounded to the nearest 1/2 tablet. Liquid medications are rounded to one decimal place (tenths).

The dosage in which the drug is manufactured is considered a conversion factor; such as 1 tablet = 0.5 mg is 0.5 mg/tablet.

Ratio-proportions

Ratios indicate a relationship between two numbers with a colon between the numbers. The colon represents division. For example 3:4 = 3/4.

Proportions are equations containing ratios of equal value.
For example 3:4 = 6:8. This may also be written as fractions, 3/4=6/8.

Means are the two inner numbers, in this case 4 & 6.
Extremes are the two outer numbers, 3 and 8.

3 : 4 = 6 : 8

The product of the means (4 X 6) must equal the product of the extremes (3 X 8).

Therefore when you do not know one value (x), you can determine it, if the other three values are known.. When setting up a ratio, the known factor (on hand) is stated first, the desired is stated second. H = D x

3 : 4 = x : 8 multiply the means and
4x = 3 X 8 the extremes
4x = 24
x= 24 ¸ 4 = 6

If you set this up as a fraction:

3 = x cross multiply to obtain
4 8 the product of the means
4x = 3 X 8 = 24 and extremes
x = 24 ¸ 4 = 6

Example: Ordered: 600,000 units of penicillin po q6h
Available: 400,000 units per scored tablet
How many tablets will you administer?

400,000 units : 1 tablet = 600,000 units : x
600,000 = 400,000x (multiply means
600,000 = x = 1.5 tablets & extremes)
400,000

OR set it up as a fraction

400,000 = 600,000
1 x

400,000x = 600,000
x = 600,000 = 1.5 tablets
400,000

When working with a complex fraction - either a fraction in the numerator or denominator - it helps to simplify the fraction. When dividing by a fraction, remember to invert and multiply.

The formula method:

D/H X Q = X

D - dosage desired or ordered
H - what is on hand (available)
Q - unit of measure that contains the available dose. When using solid products (tablets, capsules) Q is always 1 and can be eliminated. Q varies when using liquid measures.
X - the unknown dosage you need to administer

Example: Order: Potassium Chloride 20 mEq added to the IV.
Available: 40 mEq per 10cc.
How much potassium will you add?

D = 20 mEq H = 40 mEq Q = 10 cc

20 mEq X 10 cc = X
40 mEq
0.5 X 10 = X = 5 cc

It doesn't matter if you use ratios, fractions or the formula, the answer will be the same.

Points to remember:
The maximum number of tablets and capsules administered to achieve a desired dose is usually 3.
No more than 10% variation should exist between the dose ordered and the dose administered.
Make sure your answer seems reasonable. Think about whether the dose should be larger or smaller than what is available.

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Parenteral Medications

The same methods, ratio-proportion or formula, are used to determine the amount to be given.

Injectable medication guidelines:

Intradermal - the volume to be administered is 0.1 ml or less
Subcutaneous - the volume to be administer is 1.0 ml or less
Intramuscular - depends upon the size of the person
a. A healthy well developed person can tolerate 3.0 ml in large muscles - this does NOT include the deltoid.
b. For elderly, thin clients or children the total amount should not exceed 2.0 ml.
c. No more than 1.0 ml should be given to young children and older infants.
Calculating dosages in units (insulin, heparin, pitocin, vitamins, some antibiotics)

Example: Ordered: Heparin 8000 units subcutaneous q12h
Available: Heparin 10,000 units per ml
How much will you administer?

Formula: 8000 units X 1 ml = 0.8 ml
10,000 units

Ratio: 10,000 units : 1 ml = 8000 units : x
8000 units X 1 ml = 10,000 units x
8000 / 10,000 = x
0.8 ml = x

If the answer is greater than 1, you probably calculated the problem incorrectly. Rarely, the desired dose is large and you will have to administer it in more than one site.

Reconstituting powdered drugs:

Read the label for the amount of fluid to add, the type of fluid and the final concentration of the reconstituted fluid. The label will also tell you how long the mixture may be stored and what conditions are required for storage. The final volume will be larger than the amount of fluid you add because the powder will take up some room when diluted. If you are not given a final volume calculate the concentration based on the amount of fluid you added. You will calculate the amount to administer from the final concentration.

Insulin

Insulin is administered only using an insulin syringe. Most insulin vials contain 100 units/ml. Insulin may be administered subcutaneously, intramuscularly (rarely used) and intravenously.

Regular insulin is the only type that may be given IV since it does not contain any additives to prolong the action. Regular insulin is clear. If the vial is cloudy, it has been contaminated and should be discarded.

Longer acting insulin is cloudy and may have a precipitate on the bottom of the vial. Be sure to mix the vial well by rotating it between the hands.

Mixing regular insulin and a longer acting insulin in the same syringe.

Inject air into the longer acting insulin vial first - don't let the tip of the needle touch the surface of the fluid.
Using the same syringe, inject air into the regular insulin then invert the bottle and withdraw the correct amount of regular insulin. Remove air bubbles.
Still using the same syringe, withdraw the correct amount of the longer acting insulin. You cannot return any extra fluid withdrawn. If you withdraw too much, you must start over.

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Intravenous calculations

Drop factor - IV tubing has a drip chamber that is used to count drops (gtts) per minute. Each tubing is labeled with the number of drops per milliliter (drop factor).

Macrodrop tubing - has a drop factor of 10, 15 or 20 gtts/ml (drops per milliliter).

Microdrip tubing - has a drop factor of 60 gtts/ml.

Formula for calculating IV flow rate:

V1 X V2 = gtt/min V1 - volume to infuse
T1 T2 T1 - time to infuse (hours or minutes)
V2 - drop factor
T2 - time in minutes - this number is
always 60 (minutes/hour) unless
you are going to infuse for less
than 60 minutes

Example: Ordered: D5W 1000 ml to infuse in 6 hours.
The drop factor of your tubing is 10 gtts/ml.
How many gtts/min will you infuse?

V1=1000 ml V2=10 gtts/ml T1= 6 hr T2 = 60 min/hr

1000 ml X 10 gtt/ml = 1000 X 1 = 1000 = 27.8 = 28 gtts/min
6 hr 60 min/hr 6 6 36

The same formula may be used to calculate drop rates for fluids administered in less than 1 hour:

Example: Ordered: Gentamycin 40 mg/100 ml IVPB q 6h
Drop factor 15 gtts/ml
Your drug book says you can give this in 45 min
How many gtts/min will you infuse the Gentamycin

100 ml X 15 gtts/ml = 100 X 1 = 33 gtts/min
1 hr 45 min/hr 3

You may only give 32 gtts/min because it is easier to count for 15 seconds (8 gtts every 15 seconds = 32 gtts/min).

When using an IV pump, the rate is in ml/hr. Therefore, you do not need to determine a drop factor.

Example: Infuse Ancef 1 g/50 ml IVPB q6h. The IV handbook states this can be given in 20 minutes. What rate will you set on the IV pump?

50 ml X 60 min = 50 X 3 = 150 ml/hr
20 min 1 hr

You need to give 50 ml in 20 minutes. But you have to convert the minutes to hours.

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Pediatric calculations

Accurate doses are especially important in giving medications to infants and children because even small errors can be dangerous due to their small body size.

Two methods are used to calculate pediatric dosages:

According to the weight in kilograms (kg)
According to the child's body surface area (BSA)

Calculations based on body weight

The first step is to convert the child's body weight into kg. The formula is 2.2 lb. = 1 kg.
The second step is to calculate the medication dose.
a. Calculate the daily dose
b. Divide the daily dose by the number of doses to
be administered.
c. Use either the ratio-proportion or formula
method to calculate the number of tablets/
capsules or volume to be administered with
each dose.
Example: A child weighing 76 lbs. is ordered to receive 150 mg of Clindamycin q6h. The pediatric drug handbook states the recommended dose is 8-20 mg/kg/day in four divided doses. The Clindamycin is supplied in 100 mg scored tablets.

1. What is the weight in kg?

76 lbs. ¸ 2.2 kg/lb. = 34.5 kg

2. What is the safe total daily dose?

Minimum: 8 mg/kg/day X 34.5 kg = 276 mg/day
Maximum: 20 mg/kg/day X 34.5 kg = 690 mg/day

3. Is this a safe dose?

150 mg/dose X 4 doses/day = 600 mg/day

Yes this is within the recommended safe range.

4. Calculate the number of tablets to give.

100 mg : 1 tablet = 150 mg : x (multiply means
100 x = 150 & extremes)
x = 1.5 tablets

Calculations based on Body Surface Area (BSA)

BSA is determined from a nomogram using the child's height and weight.
When you know the child's BSA the dosage is determined by multiplying the BSA by the recommended dose.
To determine whether the dose is safe, compare the ordered dose and the calculation based upon the BSA.
The formula for calculating child's dosage is

Child's BSA X adult dosage
1.7 M2

Example: The child has a BSA of 0.67 M2. the adult dose is 40 mg. The physician ordered 8 mg. Is the dosage correct?

0.67 X 40 = 26.8 = 15.8 mg No, the dose is
1.7 1.7 too small.