How is fecal osmotic gap calculated?
Stool osmotic gap is calculated as 290 mOsm/kg − 2 × (stool Na + stool K). 290 mOsm/kg is the presumed stool osmolality, and the measured concentration of sodium and potassium cations is doubled to account for the corresponding anions which must be present.
How is stool anion gap calculated?
The stool anion gap is calculated according to the formula: 290 – [(Na+K) X 2]. If the value is more than 100, osmolar diarrhea can be assumed to be present. If the value is less than 100, the diarrhea has a secretory origin.
What is normal stool Osmolarity?
Stool osmolality is measured in milliosmoles per kilogram (mOsm/kg). It normally ranges from 275 to 295 mOsm/kg. Stool osmolality less than 250 mOsm/kg may suggest factitious diarrhea.
How do you calculate serum osmolar gap?
The osmolality gap (OG) is an indication of unmeasured solute in the blood. It is determined by the measured osmolality (MO) minus the calculated osmolality (CO)….Osmolality Gap Calculator.
| Plasma sodium concentration: | mmol/L |
|---|---|
| Measured Osmolality, plasma: | mOsm/kg H2O |
| Measured ETOH, plasma: | mg/dL |
| Osmolality Gap: |
What is normal stool pH?
An acidic stool can indicate a digestive problem such as lactose intolerance, an infection such as E. coli or rotavirus, or overgrowth of acid-producing bacteria (such as lactic acid bacteria). The average pH for a healthy person has a reference range of 7.0 to 7.5.
How do you read stool electrolytes?
Normal stool has an alkaline pH. Sodium and potassium salts are the primary stool solutes. The sodium plus potassium concentration in stool usually ranges between 130 and 150 meq/L….Stool Electrolytes and pH.
| Laboratory test differentiation between secretory and osmotic diarrhea | ||
|---|---|---|
| Laboratory tests | Secretory | Osmotic |
| pH | Often >6.0 | Often <6.0 |
What does a high fecal osmolality mean?
A fecal sodium less than 60 mmol/L and an osmolal gap greater than 100 mOsm/kg suggest osmotic diarrhea. Fecal sodium greater than 150 mmol/L and osmolality greater than 400 mOsm/kg suggest contamination with concentrated urine.
What is osmolar gap test?
A serum osmolal gap (osmotic gap) may also be calculated. It is the difference between measured and calculated (estimated) osmolality results. In order to calculate the osmolal gap, tests for blood sodium, blood urea nitrogen (BUN), and glucose must be performed to calculate the expected osmolality.
What is a high osmolar gap?
An osmolal gap greater than 10 mOsm/kg indicates the presence of abnormal, unmeasured osmotically active molecules. The most common cause of an elevated osmolar gap is ingestion of an alcohol, including ethanol, methanol, ethylene glycol, diethylene glycol, propylene glycol, and isopropanol (isopropyl alcohol).
How do you read a stool test?
For a stool analysis, a stool sample is collected in a clean container and then sent to the laboratory. Laboratory analysis includes microscopic examination, chemical tests, and microbiologic tests. The stool will be checked for color, consistency, amount, shape, odor, and the presence of mucus.
What are stool electrolytes?
Sodium and potassium salts are the primary stool solutes. The sodium plus potassium concentration in stool usually ranges between 130 and 150 meq/L. Other cations, such as calcium and magnesium, are present at much lower concentrations.
What is a stool osmotic gap calculator?
Stool Potassium (mOsm/kg) Stool osmotic gap(Sg) Stool osmotic/osmolar gap is a calculation performed to distinguish among different causes of diarrhea. This calculator gives you the result whether it is osmotic diarrhea or secretory diarrhea.A low stool osmolal gap can imply secretory diarrhea, while a high gap can imply osmotic diarrhea.
What is the osmolar gap in diarrhea?
Osmolar gap Calculation. Stool osmotic/osmolar gap is a calculation performed to distinguish among different causes of diarrhea. This calculator gives you the result whether it is osmotic diarrhea or secretory diarrhea.A low stool osmolal gap can imply secretory diarrhea, while a high gap can imply osmotic diarrhea.
How do you calculate stool osmolarity?
The formula to calculate stool osmotic (osmolal gap) is: Stoop osmotic = Stool osmolarity – 2 x (stool Na + stool K) The normal fecal fluid values are: stool Na = 30 mEq/L, stool K = 75 mEq/L and stool osmolality/osmolarity = 290 – 300 mOsm/kg. The table below shows the result interpretation:
How do you calculate osmolality gap?
Osmolality Gap Calculator. The osmolality gap (OG) is an indication of unmeasured solute in the blood. It is determined by the measured osmolality (MO) minus the calculated osmolality (CO).