What is the cause of ARF here? - USMLE Forums
USMLE Forums Logo
USMLE Forums         Your Reliable USMLE Online Community     Members     Posts
Home
USMLE Articles
USMLE News
USMLE Polls
USMLE Books
USMLE Apps
Go Back   USMLE Forums > USMLE Step 2 CK Forum

USMLE Step 2 CK Forum USMLE Step 2 CK Discussion Forum: Let's talk about anything related to USMLE Step 2 CK exam


Reply
 
Thread Tools Search this Thread Display Modes
  #1  
Old 04-11-2010
USMLE Forums Scout
 
Steps History: Not yet
Posts: 97
Threads: 52
Thanked 135 Times in 49 Posts
Reputation: 135
Question What is the cause of ARF here?

A 72-year-old woman undergoes three-vessel coronary artery bypass graft for coronary artery disease. Her postoperative course is complicated by wound infection leading to sepsis with multidrug-resistant Klebsiella. Her sepsis is difficult to manage, and she is on pressors, fluids, and antibiotics for several days before becoming afebrile and hemodynamically stable. Her creatinine rises postoperatively, and on postoperative day 4 electrolytes show blood urea nitrogen (BUN) of 34 mg/dL and creatinine of 2.6 mg/dL. Urine Na is 46 mEq/L, fractional excretion of sodium is calculated as 2.1%, and urine osmolarity is 310 mOsm/kg. Urinalysis shows muddy brown granular casts. Over the next week, her creatinine continues to rise despite aggressive fluid management; however, she continues to make small amounts of urine, and BUN and creatinine gradually return to normal over the next few weeks. What is the most likely pathogenesis of this woman’s acute renal failure?
(A) Allergic reaction to dobutamine
(B) Autoimmune glomerular destruction
(C) Hypovolemic shock
(D) Ischemic tubular injury
(E) Klebsiella infection of the kidney
Reply With Quote Quick reply to this message



  #2  
Old 04-13-2010
USMLE Forums Scout
 
Steps History: Step 1 Only
Posts: 17
Threads: 1
Thanked 3 Times in 3 Posts
Reputation: 13
Default Answer is d

This is ATN I guess which is answer D
Reply With Quote Quick reply to this message
  #3  
Old 04-15-2010
USMLE Forums Scout
 
Steps History: Not yet
Posts: 97
Threads: 52
Thanked 135 Times in 49 Posts
Reputation: 135
Smile Correct answer is D

Yes Idaho you are right.
This woman most likely has acute tubular necrosis (ATN), which presents with a picture of acute renal failure, often following sepsis, hypotension, or other ischemic insult. Although prerenal failure can also result from these, it resolves more rapidly with fluid administration, and presents with a prerenal picture, including BUN:creatinine ratio > 20:1 and FeNa < 1%. ATN, in ontrast, lasts longer, with creatinine elevation often persisting for several weeks, and presents with signs of renal failure such as elevated BUN and creatinine, FeNa > 2%, and low urine osmolarity due to impaired urine concentrating ability despite hypovolemia. Muddy brown casts on urinalysis are characteristic of ATN.
Reply With Quote Quick reply to this message



Reply

Tags
Internal-Medicine-, Nephrology-, Step-2-Questions

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the USMLE Forums forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.
User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:
Medical School
Choose "---" if you don't want to tell. AMG for US & Canadian medical schools. IMG for all other medical schools.
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.

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

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.



Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes


RSS Feed
Find Us on Facebook
vBulletin Security provided by vBSecurity v2.2.2 (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.

USMLE® & other trade marks belong to their respective owners, read full disclaimer
USMLE Forums created under Creative Commons 3.0 License. (2009-2014)