-Phosphate is predominantly an intracellular ion that is critical for an array of cellular processes -Hypophosphatemia is most commonly seen in alcoholics, DKA, and sepsis: frequency rates of 40%-80% -Severe hypophosphatemia ( < 1.0 mg/dL) in the critically ill can manifest as widespread organ dysfunction: respiratory failure (diaphragmatic weakness), CHF (decreased myocardial contractility), rhabdomyolysis, arrhythmias, seizures, hemolysis, impaired hepatic function, and depressed WBC function -Severe hypophosphatemia should be treated with intravenous replacement: 0.08 - 0.16 mmol/kg over 2-6 hours -Be aware of complications from too rapid intravenous replacement: hypocalcemia, tetany, hypotension, volume excess, and metabolic acidosis
