Postoperative dysnatremia in infants after open‐heart surgery occurs frequently and is associated with prolonged intensive care length of stay

Abstract

Background Dysnatremia after surgery for congenital heart disease (CHD) is well known and has been associated with prolonged pediatric intensive care unit length of stay (PICU‐LOS). Fluctuations in plasma sodium levels occur perioperatively. The primary aim of the study was to evaluate the occurrence of dysnatremia during the first 48 h after surgery and whether it was associated with PICU‐LOS. The secondary aim was to evaluate if the degree of sodium fluctuations was associated with PICU‐LOS. Methods A retrospective observational, single‐center study including infants undergoing surgery for CHD. The highest and lowest plasma sodium value was registered for the prespecified time periods. PICU‐LOS was analyzed in relation to the occurrence of dysnatremia and the degree of plasma sodium fluctuations. The occurrence of dysnatremia was evaluated in relation to surgical procedure and fluid administration. Results Two hundred and thirty infants who underwent 249 surgical procedures were included. Dysnatremia developed in more than 60% within 48 h after surgery. Infants with normonatremia had a 40%–50% shorter PICU‐LOS among children in RACHS‐1 category 3–6, compared with infants developing either hypo‐ or hyper‐/hyponatremia within 48 h after surgery (p = .006). Infants who had a decline of plasma sodium >11 mmol/L had almost double the PICU‐LOS compared to those with a decline of <8 mmol/L. Conclusion Dysnatremias were common after surgery for CHD and associated with prolonged PICU‐LOS. The degree of decline in plasma sodium was significantly associated with PICU‐LOS. Fluid administration both in terms of volume and components (blood products and crystalloids) as well as diuresis were related to the occurrence of dysnatremias.

Postoperative free water administration is associated with dysnatremia after congenital heart disease surgery in infants

“…Previous studies in pediatric patients have either focused on only hyponatremia, 9,10 the occurrence and outcome of dysnatremia, 7 or a limited observation period like intraoperatively 6 . We have previously shown that the individual patient's sodium levels are highly variable and may change markedly over time and some patients even develop both hypo‐ and hypernatremia during the perioperative days 8 . Risk factors for perioperative dysnatremia remain poorly understood in this context.…”

“…6 We have previously shown that the individual patient's sodium levels are highly variable and may change markedly over time and some patients even develop both hypo-and hypernatremia during the perioperative days. 8 Risk factors for perioperative dysnatremia remain poorly understood in this context. Postoperative hypernatremia has previously been associated with prolonged CPB duration and the administration of sodium-rich fluids like sodiumbicarbonate.…”

“…[18][19][20] European consensus statement recommends the use of isotonic fluids with 1%-2.5% of glucose intraoperatively in all pediatric patients. 21 However, the use of cardiopulmonary bypass in CHD surgery has led to concerns regarding the development of hypernatremia, as it has been associated with prolonged bypass time [6][7][8] and administration of sodium-containing solutions. 6,7 As the overall fluid administration regimens are vastly different in pediatric patients undergoing CHD surgery with cardiopulmonary bypass compared with major noncardiac surgery.…”

Dysnatremia in children, why is it so hard to stay normal?

“…In a recent article by Kronborg et al, the impact of sodium swings on outcome in children after cardiac surgery was well illustrated. 7 Not surprisingly, dysnatremia, that is, the presence of anything but normal plasma sodium, was a common finding after surgery for congenital heart disease and linked to the amount of fluid given. What was particularly interesting was that shifts in sodium and not just the occurrence of a low or high value was also associated with prolonged hospital length of stay, again emphasizing the importance of maintaining homeostasis.…”

“…This relation is also true in pediatric cardiac surgery patients, a fragile group often subjected to large fluid shifts and a useful cohort to study with regards to fluid balance and electrolyte disturbances. In a recent article by Kronborg et al, the impact of sodium swings on outcome in children after cardiac surgery was well illustrated 7 . Not surprisingly, dysnatremia, that is, the presence of anything but normal plasma sodium, was a common finding after surgery for congenital heart disease and linked to the amount of fluid given.…”