Why are hypotonic fluids used?
Hypotonic fluids are still the parenteral fluid most commonly administered to both pediatric and adult hospitalized patients. The pediatric literature specifically addresses the topic of maintenance parenteral fluid therapy and recommends hypotonic fluid.14 The adult literature does not specifically address maintenance parenteral therapy but does make recommendations for hypotonic fluids in total parenteral nutrition and in the perioperative setting.15, 16 We queried the adult inpatient pharmacy of the University of Pittsburgh Medical Center, and found that 0.45% NaCl with 20 mmol/l potassium chloride in 5% dextrose is the most commonly prescribed fluid for parenteral therapy. This practice seems to be common for adult patients throughout the world. The WHO recommends using 5% dextrose in water in the postoperative setting for one-third of maintenance fluids in patients unable to drink.17 In the UK, 0.18% NaCl in 4% dextrose is the most commonly used parenteral fluid.18, 19, 20 In a Br