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Author 4 Posts
James
Senior Member

Topics: 14
Posts: 127
Posted 12/12/11 - 11:56 PM report   #1
Isopropyl alcohol: No acidosis but severe osmolar gap. Assay is difficult locally in most hospitals. Send out lab.

Methanol (methyl alcohol- gets metabolized to formic acid): Found in local made liquor and rubbing alcohol. Severe acidosis with increased anion gap. Can cause blindness. Actually the first line of treatment is IV Bicarbonate therapy because it prevents blindness due to methanol but in exams I have seen IV ETOH (alcohol) as the required answer because the bicarbonate is not a choice offered.

Paraldehyde: Typically presented as anion gap acidosis but normal osmolar gap.

Ethylene glycol: Gap acidosis + osmolar gap - but what distinguishes it from others is the presence of oxalate crystals in urinalysis.
James
Senior Member

Topics: 14
Posts: 127
Posted 12/12/11 - 11:58 PM report   #2
Urinalysis in different conditions


Condition Finding

Pre-renal state: Hyaline cast
ATN: Granular cast
Glomerulonephritis: RBC cast
Interstitial nephritis: WBC cast ± Eosinophils
CRF: Broad casts (most specific lab finding)
Ethylene glycol ingestion: Oxalate crystals
Retrograde ejaculation: Sperms in urine
James
Senior Member

Topics: 14
Posts: 127
Posted 12/12/11 - 11:59 PM report   #3
Anion gap is calculated as Na - (Cl + HCO3). If it is more than 12, it is abnormal and falls into the anion gap category.

Some conditions can cause a low anion gap to begin with e.g. Hypoalbuminemia, Lithium toxicity, IgG myeloma and some others that are not important (but all of these are either excess of positive ions or a lack of negative ions).

ANION GAP ACIDOSIS

Salicylate- also has respiratory alkalosis associated.
Lactate- can be due to many reasons e.g. infection, hypotension etc.
Uremia- Increased BUN/Cr, may have pericardial rub
Methanol- mediated through formic acid which causes blindness
Paraldehyde-
Ethylene glycol- look for oxalate crystals in urine
DKA- type 1 diabetic or first time diagnosed young patient, urine dip will show ketones & glucose

NON - ANION GAP ACIDOSIS

RTA-
Type1- Renal stones, distal type acidosis, hypokalemia, urine alwys alkalotic(>5.5)
Type2- No renal stones, Urine pH levels off and then becomes acidotic, Hypokalemia
Type3- Non existent (Category removed because found to be a type of type 2)
Type4- Hyperkalemia (associated with Diabetes, other states with hyporeninemic hypoaldosteronism)

Diarrhea- Low potassium too because it too is lost- also suspect a villous adenoma of colon.

Chloride infusion(NaCl)- In-patient setting.
James
Senior Member

Topics: 14
Posts: 127
Posted 12/13/11 - 12:01 AM report   #4
drugs that cause hyperkalemia in patients with renal failure.

Bactrim (Sulfamethoxazole/Trimethoprim), ACE inhibitors, NSAIDs, Spironolactone, K sparing diuretics, Heparin, Digoxin & ß-blockers.

Mechanisms

Decreased renal excretion: Bactrim, ACE inhibitors, NSAIDs, Spironolactone, K sparing diuretics

Release from cells: Digoxin & ß-blockers.

Causes hypoaldosteronism: Heparin. Decreased aldosterone prevents throwing out of potassium by the kidneys & colon.








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