29 de August de 2004

International Classification of Diseases

www.wolfbane.com/icd/icd10h.htm -

SUMMARY:

Hyperaldosteronism

1. Epidemiology
   1. Represents under 1% of Hypertension causes
   2. Peak age 30-50 years
   3. Most patients are women
2. Pathophysiology
   1. Inappropriate Aldosterone Hypersecretion
      1. Primary Hyperaldosteronism (See Causes below)
         1. Increased aldosterone is initiating event
         2. Results in sodium retention and volume increase
         3. Renin decreases
      2. Secondary Hyperaldosteronism (See Causes below)
         1. Decreased circulating volume is initiating event
         2. Results in increased renin and aldosterone
         3. Results in sodium retention
   2. Physiologic response to Aldosterone Excess
      1. Increased renal distal tubular sodium reabsorption
         1. Increased total body sodium content
         2. Increased water retention
      2. Escape phenomenon
         1. Compensatory increased ANF secretion
         2. Hypertension may not be solely volume expansion
      3. Increased peripheral vascular resistance
         1. Hypokalemia: Potassium lost in distal renal tubule
         2. Alkalosis: Ammoniagenesis
      4. Hydrogen ion loss (avid sodium retention)
      5. Polyuria: Decreased renal concentrating ability
      6. Plasma renin suppressed
         1. Unresponsive to intravascular volume depletion
3. Causes
   1. Primary Hyperaldosteronism (Conn's Disease)
      1. Solitary adrenal adenomas (80-90%)
      2. Bilateral adrenal hyperplasia (10-20%)
         1. Idiopathic hyperaldosteronism
         2. Accounts for 50% of cases at some referral centers
      3. Adrenal Carcinoma (rare)
      4. Unilateral Adrenal Hyperplasia (very rare)
   2. Secondary Hyperaldosteronism
      1. Hypertensive States
         1. Primary Reninism (rare renin producing tumor)
         2. Secondary reninism due to decreased renal perfusion
      2. Edematous States
         1. Cirrhosis
         2. Nephrotic Syndrome
4. Symptoms
   1. Often Asymptomatic
   2. Frontal Headache
   3. Muscle weakness to flaccid paralysis (Hypokalemia)
   4. Polyuria and Polydipsia (carbohydrate intolerance)
5. Signs
   1. Hypertension
      1. May be severe
      2. Rarely malignant
   2. Motor Exam with decreased muscle strength
6. Labs
   1. Serum Electrolytes
      1. Serum Potassium decreased (Hypokalemia)
      2. Serum Sodium increased (Mild)
      3. Metabolic Acidosis
   2. Aldosterone to PRA ratio over 20-25
      1. Definately significant if ratio >100
      2. Aldosterone high and plasma renin low
   3. Saline suppression
      1. IVF: 300-500 cc/hour for 4 hours
      2. Normal response
         1. Aldosterone usually under 0.28
         2. Renin usually suppressed
7. Differential Diagnosis: Hypertension with Hypokalemia
   1. Cushing's Disease
      1. Low Aldosterone and Low Plasma Renin
   2. Renal Artery Stenosis or other renal cause
      1. High Aldosterone and High Plasma Renin
8. Management
   1. Adrenal Adenoma
      1. Surgical excision
   2. Adrenal Hyperplasia
      1. Spironolactone

Source: http://www.fpnotebook.com/END2.htm

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