Step 1 practice Qnz - 10 - USMLE Forums
 USMLE Forums         Your Reliable USMLE Online Community     Members     Posts
 Home USMLE Articles USMLE News USMLE Polls USMLE Books USMLE Apps
 USMLE Forums Step 1 practice Qnz - 10

 USMLE Step 1 Forum USMLE Step 1 Discussion Forum: Let's talk about anything related to USMLE Step 1 exam

#1
12-04-2010
 USMLE Forums Guru Steps History: Step 1 Only Posts: 487 Threads: 95 Thanked 1,500 Times in 361 Posts Reputation: 1510
Step 1 practice Qnz - 10

A 45 y/o woman is hospitalized after an automobile accident. The physician collects 1.44L of urine from the patient in a 24hr period. The clinical lab returns the following result.

Plasma creatinine con : 2.0 mg/ml
Plasma urea con : 15 umol/ml
Urine creatinine con : 100 mg/ml
Urine urea con : 160 umol/ml

What is the approx glomerular filtration Rate (GFR) in ml/min of this patient?

A) 10
B) 25
C) 50
D) 75
E) 100

....?

#2
12-04-2010
 USMLE Forums Guru Steps History: 1 + CS Posts: 438 Threads: 111 Thanked 241 Times in 138 Posts Reputation: 251

I think 50. I did it like this:
1.44L/24h is equivalent at 1440ml/24h wich is equivalent at 60ml/h wich is the same as saying 1ml/min. That's the V (urine flow).

Then you do the formula of Clearance of creatinine.

Cl: VxUrine concentration of creatinine
_________________________________
Plasma concentration of creatinie

Cl: 1x100
______
2

 The above post was thanked by: aktorque (12-04-2010), hope12 (05-03-2012)
#3
12-04-2010
 USMLE Forums Guru Steps History: Step 1 Only Posts: 487 Threads: 95 Thanked 1,500 Times in 361 Posts Reputation: 1510

Any one.... !!! come on guy...

#4
12-04-2010
 USMLE Forums Scout Steps History: --- Posts: 95 Threads: 30 Thanked 33 Times in 27 Posts Reputation: 43

 The above post was thanked by: aktorque (12-04-2010)
#5
12-04-2010
 USMLE Forums Guru Steps History: Step 1 Only Posts: 487 Threads: 95 Thanked 1,500 Times in 361 Posts Reputation: 1510

Quote:
 Originally Posted by evavar I think 50. I did it like this: 1.44L/24h is equivalent at 1440ml/24h wich is equivalent at 60ml/h wich is the same as saying 1ml/min. That's the V (urine flow). Then you do the formula of Clearance of creatinine. Cl: VxUrine concentration of creatinine _________________________________ Plasma concentration of creatinie Cl: 1x100 ______ 2 Answer is 50.
Thanks EVAVAR, Your explanation is very impressive. The answer is C) 50 ml/min.
#6
12-04-2010
 USMLE Forums Guru Steps History: 1 + CS Posts: 438 Threads: 111 Thanked 241 Times in 138 Posts Reputation: 251

 The above post was thanked by: aktorque (12-05-2010)

 Tags Physiology-, Renal-, Step-1-Questions

Message:
Options

## Register Now

In order to be able to post messages on the USMLE Forums forums, you must first register.
User Name:
Medical School
Choose "---" if you don't want to tell. AMG for US & Canadian medical schools. IMG for all other medical schools.
 AMG IMG ---
USMLE Steps History
What steps finished! Example: 1+CK+CS+3 = Passed Step 1, Step 2 CK, Step 2 CS, and Step 3.

Choose "---" if you don't want to tell.

 Not yet Step 1 Only CK Only CS Only 1 + CK 1 + CS 1+CK+CS CK+CS 1+CK+CS+3 ---
Favorite USMLE Books
 What USMLE books you really think are useful. Leave blank if you don't want to tell.
Location
 Where you live. Leave blank if you don't want to tell.

## Log-in

 Similar Threads Thread Thread Starter Forum Replies Last Post aktorque USMLE Step 1 Forum 5 12-01-2010 10:24 AM aktorque USMLE Step 1 Forum 8 11-30-2010 05:28 PM aktorque USMLE Step 1 Forum 4 11-30-2010 10:21 AM aktorque USMLE Step 1 Forum 5 11-18-2010 06:07 AM aktorque USMLE Step 1 Forum 4 11-18-2010 12:29 AM