Multicenter, Randomized, Controlled clinical trial.~The purpose of this study is to determine if isotonic solutions reduce the risk of hospital acquired hyponatremia compared with hypotonic solutions~This study will include 150 patients in 2 groups according to these type of pathology: group 1: medical conditions which includes respiratory problems (pneumonia, bronchiolitis, acute asthma attack) and acute gastrointestinal problems (bacterial or viral gastroenteritis) and group 2: surgical conditions (pre, peri or postoperative patients will be included). Each group will be randomized to receive 3 types of interventions: 0.3% Saline (hypotonic solution), 0.45% Saline (hypotonic solution) or 0.9% Saline (isotonic solution). In non-dehydrated patients the daily total volume of liquid infused will be determined by the volumetric Holliday- Segar* formula and the daily total volume will be calculated by adding the maintenance requirements (using the Holliday Segar formula) to the fluid deficit (according to percent of estimated weight**) in dehydrated patients.~The glucose concentrations in the first group will be 3.3%, and in group 2 and 3 will be 5%. The potassium concentration will be 20mEq/L in all groups. Blood samples will be collected before, 8 hours and 24 hours after the start of intravenous fluid, for the analysis of sodium, potassium, glucose, urea and creatinine. The adverse clinical outcomes at 8 and 24 hours of the start of intravenous fluid will also be recorded. The sodium plasma level, the incidence of hyponatremia and the adverse clinical outcomes will be compared.~*0-10 kilogram (kg): 100ml/kg per day; 10-20 kg: 1000 ml + 50 ml/kg/day over 10 kg; >20 kg: 1500 ml + 20ml/ kg over 20kg~** In patients under 10 kg correspond to a loss of 5% (50 mL/kg) in mild dehydration and 10% in moderate dehydration. In 10 kg or more: 3% (30 mL/kg) in mild dehydration and 6% (60 mL/kg) in moderate dehydration.
The purpose of this study is to determine if isotonic solutions reduce the risk of hospital acquired hyponatremia compared with hypotonic solutions.