PAINE #PANCE Pearl – Renal



Question

 

In an oliguric patient, what is the first step in differentiating between prerenal and intrinsic renal causes?

 



Answer

 

The fractional excretion of sodium (FENa) can help differentiate prerenal from intrinsic renal causes in patient with oliguria.  If the FENa is < 1%, it suggests prerenal and if it is > 2%, it suggests intrinsic renal causes.  There are many limitations to using this calculation, but it is a good first step in determining the cause of a patient’s oliguria.  Other laboratory studies, such as BUN/Cr, can be useful as well.

 

Image result for fractional excretion of sodium

Ep-PAINE-nym



Bowman’s Capsule

 

Other Known AliasesCapsula glomeruli, glomerular capsule

DefinitionDouble walled, cup-like capsule surrounding the glomerulus

Image result for bowman's capsule

Clinical SignificanceIt is made up of two poles: a vascular pole (afferent and efferent arterioles) and a urinary pole (proximal convoluted tubule). Within the capsule, there is a parietal layer and visceral layer with a space in between.  This is where ultrafiltration takes place and urine is filtered from the blood.

History – Named after Sir William Bowman (1816-1892), who was an English ophthalmologist, histologist, and anatomist, and first identified this structure in 1841.  He published his findings at the age of 25 and was awarded The Royal Medal by the Royal Society of  London.

He was well known for his extensive use microscopes in visualizing structures of the human body and publishing two works with his mentor, Robert Bentley Todd, entitled “Physiological Anatomy and Physiology of Man” and “Cyclopaedia of Anatomy and Physiology”.

William Bowman.jpg

The Cyclopaedia Of Anatomy And Physiology


References

  1. Firkin BG and Whitwirth JA.  Dictionary of Medical Eponyms. 2nd ed.  New York, NY; Parthenon Publishing Group. 1996.
  2. Bartolucci S, Forbis P.  Stedman’s Medical Eponyms.  2nd ed.  Baltimore, MD; LWW.  2005.
  3. Yee AJ, Pfiffner P. (2012).  Medical Eponyms (Version 1.4.2) [Mobile Application Software].  Retrieved http://itunes.apple.com.
  4. Whonamedit – dictionary of medical eponyms. http://www.whonamedit.com
  5. Bowman W.  On the Structure and Use of the Malpighian Bodies of the Kidney.  Phil Trans R Soc Lond.  1842;132:57-80
  6. Eknoyan G. Sir William Bowman: his contributions to physiology and nephrology. Kidney international. 1996; 50(6):2120-8. [pubmed]
  7. Galst JM. Sir William Bowman (1816-1892). Archives of ophthalmology (Chicago, Ill. : 1960). 2007; 125(4):459. [pubmed]

Ep-PAINE-nym



Gerota’s Fascia

 

Other Known AliasesRenal fascia

DefinitionConnective tissue layers covering the kidneys and adrenal glands

Clinical Significance This connective tissue encapsulates these organs and must be excised to perform nephrectomies and adrenalectomies.  It has 4 attachments:

  • Anterior attachment – Connects the anterior layer of the renal fascia of the opposite kidney.
  • Posterior attachment – Connects the psoas fascia and the body of the vertebrae.
  • Superior attachment – The anterior and posterior layers fuse at the upper pole of the kidney and then split to enclose the adrenal gland. At the upper part of the adrenal gland they again fuse to form the suspensory ligament of the adrenal gland and fuse with the diaphragmatic fascia.
  • Inferior attachment – The posterior layer descends downwards and fuses with the iliac fascia. The anterior layer blends with the connective tissue of the iliac fossa.

History – Named after Dimitrie D. Gerota (1867-1939), who was a Romanian physician and professor of surgical anatomy and experimental surgery at the University of Bucharest.  He was also the first radiologist in Romania and developed a method for injecting lymphatic vessels known as “The Gerota Method”

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References

  1. Firkin BG and Whitwirth JA.  Dictionary of Medical Eponyms. 2nd ed.  New York, NY; Parthenon Publishing Group. 1996.
  2. Bartolucci S, Forbis P.  Stedman’s Medical Eponyms.  2nd ed.  Baltimore, MD; LWW.  2005.
  3. Yee AJ, Pfiffner P. (2012).  Medical Eponyms (Version 1.4.2) [Mobile Application Software].  Retrieved http://itunes.apple.com.
  4. Whonamedit – dictionary of medical eponyms. http://www.whonamedit.com