The normal sodium intake in adults is 50-100 mmol/24 hours, which should be accompanied by about 1.5 to 2.5 L (25 to 35 mL/kg/24h) of water
Chloride ions cause renal vasoconstriction and reduce glomerular filtration rate resulting in sodium retention
Because of the risk of inducing hyperchloraemic acidosis when crystalloid resuscitation or replacement is indicated, balanced salt solutions e.g. Ringer’s lactate/acetate or Hartmann’s solution should be used instead of 0.9% saline, except in cases of hypochloraemia e.g. from vomiting or gastric drainage.
*2) E
Solutions such as 4%/0.18% dextrose/saline and 5% dextrose are important sources of free water for maintenance, but should be used with caution as excessive amounts may cause dangerous hyponatraemia, especially in children and the elderly. These solutions are not appropriate for resuscitation or replacement therapy except in conditions of significant free water deficit e.g. diabetes insipidus.
*3) C
*4) D
*5) C
To meet maintenance requirements, adult patients should receive sodium 50-100 mmol/day, potassium 40-80 mmol/day in 1.5-2.5 litres of water by the oral, enteral or parenteral route. Additional amounts should only be given to correct deficit or continuing losses.