RESUMO
Fluid replacement therapy for pediatric patients in the past 50 years has meant the infusion of hypotonic solutions in amounts calculated using the Holliday-Segar formula. Recent studies have focused attention on the incidence of postoperative hyponatremia and associated morbidity and mortality rates, generating debate on the advisability of perioperative fluid therapy and calling into question both the effectiveness of this strategy and the quantities used. We report 3 cases of hyponatremic encephalopathy in children following different types of minor surgery. Free water excretion by the kidneys is known to be a conditioning factor in this therapy, yet the ideal way to provide pediatric fluid therapy is still hotly debated. The question cannot be resolved until large randomized clinical trials are carried out to compare the use of hypotonic and isotonic solutions. Some general recommendations can be offered, however, in the interest of lowering the incidence of electrolyte disturbances and diminishing their repercussions.