PAINE #PANCE PEARL – Endocrine



Question

 

58yo male, with DMI controlled with insulin, has blood glucose measurements in the morning of 205-272 mg/dL for the past week.  He reports that his evening blood glucose measurements before bed range from 103-127 mg/dL.  What are two potential causes of these findings?

#43 – ABG Interpretation



Ground Rules

  1. Accurate assessment of a patient’s acid/base status requires a measurement of arterial pH and PCO2
    1. bedside analyzers directly measure these and then use the Henderson-Hasselbach equation to calculate the HCO3-
    2. You can use venous blood, but must make adjustments:
      1. pH is 0.03-0.04 lower than arterial
      2. PCO2 is 7-8 mmHg higher than arterial
      3. HCO3- is 2 mEq/L higher than arterial
    3. A primary disturbance is usually accompanied by a compensatory response, but does not fully correct the pH


There are four main ways pH can change:

  • Metabolic Alkalosis
    • increase in HCO3- and increase in pH
  • Metabolic Acidosis
    • Decrease in HCO3- and decrease in pH
  • Respiratory Alkalosis
    • Decrease in PCO2 and increase in pH
  • Respiratory Acidosis
    • Increase in PCO2 and decrease in pH

 

 

Remember, that the lungs can compensate considerable FASTER than the kidneys.

  • Lungs can excrete 12 moles of acid per day as CO2
  • Kidneys can excrete 0.1 moles of acid per day as ammonia, but can secrete HCO3- to buffer

 


Respiratory Acidosis

  • Decrease in minute ventilation (TV x RR)
  • Causes
    • Normal Lungs
      • CNS depression (drugs, head trauma)
      • Neuromuscular impairment (GBS, MG)
      • Thoracic restriction
    • Abnormal Lungs
      • Obstruction
      • Alveoli dysfunction (ARDS)
      • Perfusion defect (cardiac arrest, PTE)
  • Compensation
    • Acute
      • Increase of 10 mmHg of PaCO2 will increase serum HCO3- by 1 mEq/L
    • Chronic
      • Increase of 10 mmHg of PaCO2 will increase serum HCO3- by 3 mE1/L

Respiratory Alkalosis

  • Increase in minute ventilation (TV x RR)
  • Causes
    • Cardiac
    • Hypoxemia
    • Anemia
    • Medications
    • Pregnancy
    • Iatrogenic
    • Obstruction
    • Neurologic
    • Stress
  • Compensation
    • Acute
      • Decrease of 10 mmHg of PaCO2 will decrease serum HCO3- by 2 mEq/L
    • Chronic
      • Decrease of 10 mmHg of PaCO2 will decrease serum HCO3- by 4 mEq/L

If the condition is 100% acute respiratory, then the pH will change 0.08 for every 10 mmHg change in PaCO2



Metabolic Acidosis

  • Decreased pH due to decreased HCO3-
  • First step after determining that a patient has a metabolic acidosis is to calculate the anion gap
  • High Anion Gap Metabolic Acidosis (HAGMA)
    •  Causes
      • Carbon monoxide, cyanide
      • Aminoglycosides
      • Theophyline, toluene
      • Methanol
      • Uremia
      • Diabetic ketoacidosis
      • Propylene glycol
      • Inborn errors of metabolism
      • Lactic acidosis
      • Ethylene glycol, ethanol
      • Salicylates

  • Calculating a Delta Gap

  • Normal Anion Gap Metabolic Acidosis (NAGMA)
    • Causes
      • Ureteric diversion
      • Small bowel fistulae
      • Excessive saline
      • Diarrhea
      • Carbonic anhydrase inhibitors
      • Renal tubular acidosis
      • Adrenal insufficiency
      • Pancreatic fistulae

  • Respiratory Compensation
    • Expected PaCO2 = 8 + (1.5 x HCO3-) ± 2

Metabolic Alkalosis

  • Increased pH due to increased HCO3-
  • Causes
    • Contraction
    • Licorice
    • Endocrine
    • Vomiting
    • Excessive NG suction
    • Ringer’s solution
    • Post-hypercapnia
    • Diuretics
  • Respiratory Compensation
    • Expected PaCO2 = 20 + (0.7 x HCO3-) ± 5 

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



Peyronie’s Disease

 

Other Known Aliasesnone

 

Definitionan acquired, localized fibrotic disorder of the tunica albuginea where thick, fibrous plaques compress the corpora cavernosa

 

Image result for peyronie's disease

 

Clinical Significance The pathogenesis of Peyronie’s disease is unknown and is postulated to be multifactorial.  Patients experience pain, penile deformity, and sexual dysfunction

 

History – Named after François de la Peyronie (1678-1747), who was a French surgeon and received his medical training as a barber-surgeon in Montpellier in 1695.  He continued his academic career teaching and practicing surgery and anatomy throughout France.  In 1736, he was appointed first-surgeon to King Louis XV and was instrumental in organizing formal training in the surgical arts and was a major force in the creation of the 1743 law that banned barbers from practicing surgery.  Also in 1743, he first described the eponymous disease in a book on ejaculation dysfunction where described “indurations of the cavernous bodies like rosary beads” leading to penile curvature.  His last name, lapeyronie, means litter stone because his father was a stone cutter.  Its a shame he didn’t pursue management of kidney stones as his claim to fame.

 

 

 


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. Up To Date. www.uptodate.com
  6. Fischer LP, Ferrandis JJ, Blatteau JE. [François de Lapeyronie, from Montpellier (1678-1747). “Surgery restorer” and universal spirit. The soul, Musc, rooster eggs]. Histoire des sciences medicales. ; 43(3):241-8. [pubmed]

Ep-PAINE-nym



Maisonneuve Fracture

 

Other Known Aliasesnone

 

Definitionspiral fracture of the proximal third of the fibula caused by pronation with external rotation

 

Image result for maisonneuve

Clinical SignificanceThis injury is a sequelae of significant ankle trauma with disruption of the distal tibiofibular syndesmosis and can be unstable.  It is also one of the criteria of the Ottawa Rules of the Ankle so you don’t miss these

 

History – Named after Jules Germain François Maisonneuve (1809-1897), a French surgeon who studied under Guillaume Dupuytren in the mid-1800s.  He first reported this injury pattern in 1840 in the article entitled Recherches sur la fracture du Péroné.  He was also the first surgeon to advocate the use of external fixation in the management of ankle fractures


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. Up To Date. www.uptodate.com
  6. Maisonneuve, J. G. (1840). Recherches sur la fracture du péroné. Paris. France: Loquin & Cie.

PAINE #PANCE Pearl – Musculoskeletal



Question

 

What rheumatologic disease can be summed up the phrase “can’t see, can’t pee, can’t climb a tree”?

 



Answer

 

The triad of ocular symptoms (conjunctivitis, uveitis, episcleritis, keratitis), genitourinary symptoms (dysuria, urethritis, cervicitis) and musculoskeletal symptoms (arthritis, enthesitis, dactylitis) are diagnostic of reactive arthritis.

 

Image result for cant see cant pee cant climb a tree