hypertonic: osmolar gap, other osmotically acive osmoles in the blood. mannitol, glucose, contrast dye ethanol, methanol, ethylene glycol (increase tonicty of ECF). water will come out of ICF into ECF and dilute the Na. glucose/4+ measured sodium (corrected sodium, idea of what the sodium shoudl reflect)
Corrected sodium concentration (mmol/L) = measured sodium (mmol/L) + (0.3 x [serum glucose {mmol/L} – 5.5])