Infusion of 1–1.5 litres of 0.9% saline in the first hour is appropriate in most cases, though colloid should be considered if the systolic blood pressure is ,100 mm Hg. Rates can be adjusted according to requirements subsequently (hydration status, electrolytes, urinary output) but will usually be in the region of 250–1000 ml/hour for the next four hours (4–14 ml/kg/hour). If corrected sodium concentrations are high (.155 mmol/l) after the initial 1–2 litres of 0.9% saline, then 0.45% saline should be considered with close monitoring of electrolytes.5 37European guidelines34 are more circumspect about the use of hypo-osmolar solutions than the new American Position Statement and Technical Review5 35and recommend that, if used at all, no more than one litre of 0.45% saline should be given over eight hours.34 Once plasma glucose falls to ,14 mmol/l then 5% dextrose (10% dextrose if less fluid/more insulin required) should be started at 100–125 ml/hour and 0.9% saline continued at a slower rate to complete rehydration and electrolyte replacement. The recommendations of the American Diabetes Association2 suggest that effective serum osmolality should not change by .3 mOsm/kg/hour and, although this may be hard to ensure, osmolality should be monitored regularly.