Published online Nov 4, 2014. doi: 10.5492/wjccm.v3.i4.95
Revised: September 13, 2014
Accepted: October 23, 2014
Published online: November 4, 2014
For more than 50 years, hypotonic fluids (crystalloids) have been the standard for maintenance fluid used in children. In the last decade, several studies have evaluated the risk of hyponatremia associated with the use of hypotonic vs isotonic fluids, which has lead to an intense debate. Children undergoing surgery have several stimuli for release of antidiuretic hormone, which controls renal water handling, including pain, nausea, vomiting, narcotic use and blood loss. The body’s primary defense against the development of hyponatremia is the ability of the kidneys to excrete free water and dilute urine. Increased levels of antidiuretic hormone can result in hyponatremia, defined as a plasma sodium level < 136 mmol/L, which causes cells to draw in excess water and swell. This manifests as central nervous system symptoms such as lethargy, irritability and seizures. The risk for symptomatic hyponatremia is higher in children than in adults. It represents an emergency condition, and early diagnosis, prompt treatment and close monitoring are essential to reduce morbidity and mortality. The widespread use of hypotonic fluids in children undergoing surgery is a matter of concern and more focus on this topic is urgently needed. In this paper, we review the literature and describe the impact of perioperative hyponatremia in children.
Core tip: Hospital-acquired hyponatremia is common, particularly among children undergoing surgery. These children tend to develop hyponatremic encephalopathy at higher serum sodium concentrations than adults and they have a poorer prognosis. As the risk is increased by the use of hypotonic fluids, intraoperative fluids for children should be isotonic. Symptomatic hyponatremia should be corrected with 3% sodium chloride and close monitoring of the patient and serum sodium level is mandatory to prevent brain herniation and neurologic damage from cerebral ischemia.