Intravenous fluids provide daily maintenance requirements of electrolytes and prevent volume depletion or dehydration. This is essential in successful treatment of surgical pediatric patients.

Fluids must maintain volume requirements, replete electrolyte and fluid deficits, and restore ongoing losses. However, maintenance requirements differ based on age.

Assessment of fluid status depends on the degree of dehydration:

Signs of moderate fluid loss: irritability, dry mucous membranes, oliguria, increased thirst, depressed fontanelle, decreased tears, cool pale skin, delayed capillary refill (>2), and decreased skin turgor.

Signs of severe fluid loss: decreased blood pressure, marked tachycardia, cool cyanotic or mottled skin, parched mucous membranes, sunken fontanelle, very delayed capillary refill (>3), and absent tears.

The goal of fluid therapy is to preserve normal fluid volume and electrolyte composition of the body.

Maintenance therapy covers ongoing sensible and insensible losses of volume due to physiologic processes such as respiration, urination, defecation, and sweating. These requirements vary depending on the setting and age of the child.

Replacement therapy replenishes acute losses of water and/or electrolytes due to illness.

Fluid replacement corrects the deficit depending on the degree of loss. These are given in addition to maintenance requirements.

Add to maintenance fluids for any losses from dehydration (Table 2.1).

Although, historically, hospitalized children received hypotonic fluids with electrolyte additives, current literature asserts that isotonic saline solutions are preferred in hospitalized children. Administration of hypotonic fluids increase the risk of inappropriate antidiuretic hormone (ADH) release and hyponatremia compared with administration of isotonic fluids.³