osmolal

Serum osmolal gap in clinical practice: usefulness and limitations.

In cases of suspected pseudohyponatremia, direct ion-selective electrode methods or osmolal gap calculations can be helpful for laboratory management (5).

Patients with recent history of ingesting toxic amounts of methanol and having osmolal gap of more than 10 mOsm/kg H2O were included.

Laboratory testing and diagnosis are based on the presence of high anion gap metabolic acidosis, the presence of a serum osmolal gap (the difference between measured and calculated osmolality > 10), and measuring the levels of toxic alcohols (used for confirmation; typically, this testing is not time sensitive, and the treatment should not be withheld in any patient suspected of having toxic alcohol ingestion).

Measurements of lactate, urea, other electrolytes and albumin and calculation of the anion and osmolal gaps would be recommended to access their influence.

This was supported by the evidence of a high plasma osmolal gap, which is the difference between the measured plasma osmolality in the laboratory and calculated plasma osmolality.

The questions relate to topics like acid-base disturbances, sodium concentration disorders, the utility of urine anion and osmolal gaps, the use of bicarbonate to treat metabolic acidosis, the use phosphorus binders to treat hyperphosphatemia, the interpretation of changes in plasma creatinine, the urine-to-plasma creatinine ratio, acute renal failure vs.

In case the contrast study was deemed necessary by the clinician, the contrast investigations were performed using low osmolal nonionic contrast media after premedication with steroids as per guidelines.

Urinary electrolytes and osmolal gap may be useful in assessment of metabolic alkalosis and normal AG metabolic acidosis.

The American Academy of Toxicology recommends treatment with ethanol (or fomepizole if available) in the presence of a methanol level >20 mg/dl, a documented history of methanol ingestion with a serum osmolal gap >10 mOsm/l or strong clinical suspicion of methanol poisoning with at least two of the following: arterial pH <7.3, serum HCO3 <20 mEq/l and osmolal gap >20 mOsm/[l.sup.2].

Clinical use of anion and osmolal gaps in veterinary medicine.