Intravenous fluids for seriously ill children

Perioperative water and electrolyte balance and water homeostasis regulation in children with acute surgery

BACKGROUND

Hospital-acquired hyponatremia remains a feared event in patients receiving hypotonic fluid therapy. Our objectives were to assess post-operative plasma-sodium concentration and to provide a physiological explanation for plasma-sodium levels over time in children with acute appendicitis.

METHODS

Thirteen normonatremic (plasma-sodium ≥135 mmol/L) children (8 males), median age 12.3 (IQR 11.5-13.5) years participated in this prospective observational study (ACTRN12621000587808). Urine was collected and analyzed. Blood tests, including renin, aldosterone, arginine-vasopressin, and circulating nitric oxide substrates were determined on admission, at induction of anesthesia, and at the end of surgery.

RESULTS

On admission, participants were assumed to be mildly dehydrated and were prescribed 50 mL/kg of Ringer's acetate intravenously followed by half-isotonic saline as maintenance fluid therapy. Blood tests, urinary indices, plasma levels of aldosterone, arginine-vasopressin, and net water-electrolyte balance indicated that participants were dehydrated on admission. Although nearly 50% of participants still had arginine-vasopressin levels that would have been expected to produce maximum antidiuresis at the end of surgery, electrolyte-free water clearance indicated that almost all participants were able to excrete net free water. No participant became hyponatremic.

CONCLUSIONS

The use of moderately hypotonic fluid therapy after correction of extracellular fluid deficit is not necessarily associated with post-operative hyponatremia.

IMPACT

Our observations show that in acutely ill normonatremic children not only the composition but also the amount of volume infused influence on the risk of hyponatremia. Our observations also suggest that perioperative administration of hypotonic fluid therapy is followed by a tendency towards hyponatremia if extracellular fluid depletion is left untreated. After correcting extracellular deficit almost all patients were able to excrete net free water. This occurred despite nearly 50% of the cohort having high circulating plasma levels of arginine-vasopressin at the end of surgery, suggesting a phenomenon of renal escape from arginine-vasopressin-induced antidiuresis.

Isotonic versus Hypotonic Intravenous Maintenance Fluids in Children: A Randomized Controlled Trial

OBJECTIVE

To compare the incidence of hyponatremia during the first 48 h in hospitalized children receiving normal saline vs. N/2 saline as maintenance intravenous fluid.

METHODS

This open label, randomized controlled trial to compare the incidence of hyponatremia in hospitalized children receiving normal saline (0.9% sodium chloride in 5% dextrose) vs. N/2 saline (0.45% sodium chloride in 5% dextrose) as maintenance fluid was conducted from December 2014 through November 2015 in a tertiary care teaching hospital. Children between 1 mo and 18 y requiring maintenance intravenous fluids were randomized to receive normal saline with 5% dextrose (n = 75) or N/2 saline with 5% dextrose (n = 75).

RESULTS

Both groups were comparable for demographic variables and illness severity at baseline. Incidence of hyponatremia at 24 h of hospitalization was comparable between normal saline and N/2 saline group, 3(4%) vs. 6(8%) cases, respectively; p value 0.494. Mean serum sodium levels were marginally higher in normal saline group (138.3 ± 6.0 mEq/L) as compared with N/2 saline group (135.1 ± 4.4 mEq/L) (p value <0.01) at 24 h of hospitalization. Incidence of hyponatremia at 48 h and hypernatremia at 24 and 48 h was comparable in two groups.

CONCLUSIONS

The use of either N/2 saline or normal saline in sick children at standard maintenance fluid rates is associated with low but comparable incidence of hypo or hypernatremia in first 24 h of hospitalization. Both types of fluids appear acceptable in hospitalized sick children.

140 mmol/L of sodium versus 77 mmol/L of sodium in maintenance intravenous fluid therapy for children in hospital (PIMS): a randomised controlled double-blind trial

BACKGROUND

Use of hypotonic intravenous fluid to maintain hydration in children in hospital has been associated with hyponatraemia, leading to neurological morbidity and mortality. We aimed to assess whether use of fluid solutions with a higher sodium concentration reduced the risk of hyponatraemia compared with use of hypotonic solutions.

METHODS

We did a randomised controlled double-blind trial of children admitted to The Royal Children's Hospital (Melbourne, VIC, Australia) who needed intravenous maintenance hydration for 6 h or longer. With an online randomisation system that used unequal block sizes, we randomly assigned patients (1:1) to receive either isotonic intravenous fluid containing 140 mmol/L of sodium (Na140) or hypotonic fluid containing 77 mmol/L of sodium (Na77) for 72 h or until their intravenous fluid rate decreased to lower than 50% of the standard maintenance rate. We stratified assignment by baseline sodium concentrations. Study investigators, treating clinicians, nurses, and patients were masked to treatment assignment. The primary outcome was occurrence of hyponatraemia (serum sodium concentration <135 mmol/L with a decrease of at least 3 mmol/L from baseline) during the treatment period, analysed by intention to treat. The trial was registered with the Australian New Zealand Clinical Trials Registry, number ACTRN1260900924257.

FINDINGS

Between Feb 2, 2010, and Jan 29, 2013, we randomly assigned 690 patients. Of these patients, primary outcome data were available for 319 who received Na140 and 322 who received Na77. Fewer patients given Na140 than those given Na77 developed hyponatraemia (12 patients [4%] vs 35 [11%]; odds ratio [OR] 0·31, 95% CI 0·16-0·61; p=0·001). No clinically apparent cerebral oedema occurred in either group. Eight patients in the Na140 group (two potentially related to intravenous fluid) and four in the Na77 group (none related to intravenous fluid) developed serious adverse events during the treatment period. One patient in the Na140 had seizures during the treatment period compared with seven who received Na77.

INTERPRETATION

Use of isotonic intravenous fluid with a sodium concentration of 140 mmol/L had a lower risk of hyponatraemia without an increase in adverse effects than did fluid containing 77 mmol/L of sodium. An isotonic fluid should be used as intravenous fluid for maintenance hydration in children.

FUNDING

National Health and Medical Research Council, Murdoch Childrens Research Institute, The Royal Children's Hospital, and the Australian and New Zealand College of Anaesthetists.

A randomized controlled trial of isotonic versus hypotonic maintenance intravenous fluids in hospitalized children

Background

Isotonic saline has been proposed as a safer alternative to traditional hypotonic solutions for intravenous (IV) maintenance fluids to prevent hyponatremia. However, the optimal tonicity of maintenance intravenous fluids in hospitalized children has not been determined. The objective of this study was to estimate and compare the rates of change in serum sodium ([Na]) for patients administered either hypotonic or isotonic IV fluids for maintenance needs.

Methods

This was a masked controlled trial. Randomization was stratified by admission type: medical patients and post-operative surgical patients, aged 3 months to 18 years, who required IV fluids for at least 8 hours. Patients were randomized to receive either 0.45% or 0.9% saline in 5.0% dextrose. Treating physicians used the study fluid for maintenance; infusion rate and the use of additional fluids were left to their discretion.

Results

Sixteen children were randomized to 0.9% saline and 21 to 0.45% saline. Baseline characteristics, duration (average of 12 hours) and rate of study fluid infusion, and the volume of additional isotonic fluids given were similar for the two groups. [Na] increased significantly in the 0.9% group (+0.20 mmol/L/h [IQR +0.03, +0.4]; P = 0.02) and increased, but not significantly, in the 0.45% group (+0.08 mmol/L/h [IQR -0.15, +0.16]; P = 0.07). The rate of change and absolute change in serum [Na] did not differ significantly between groups.

Conclusions

When administered at the appropriate maintenance rate and accompanied by adequate volume expansion with isotonic fluids, 0.45% saline did not result in a drop in serum sodium during the first 12 hours of fluid therapy in children without severe baseline hyponatremia. Confirmation in a larger study is strongly recommended.

Clinical Trial Registration Number

NCT00457873 (http://www.clinicaltrials.gov/)

Hypotonic versus isotonic maintenance fluids in critically ill children: a multicenter prospective randomized study

AIM

Study the influence of hypotonic (HT) and isotonic (IT) maintenance fluids in the incidence of dysnatraemias in critically ill children.

METHODS

Prospective, randomized study conducted in three paediatric intensive care units (PICU). One hundred and twenty-five children requiring maintenance fluid therapy were included: 62 received HT fluids (50-70 mmol/L tonicity) and 63 IT fluids (156 mmol/L tonicity). Age, weight, cause of admission, sodium and fluid intake, and diuresis were collected. Blood electrolytes were measured on admission, 12 and 24 h later.

RESULTS

Blood sodium levels at 12 h were 133.7±2.7 mmol/L in HT group vs. 136.8±3.5 mmol/L in IT group (p=0.001). Adjusted for age, weight and sodium level at PICU admission, the blood sodium values of patients receiving HT fluids decrease by 3.22 mmol/L (CI: 4.29/2.15)(p=0.000). Adjusted for age, weight and hyponatraemia incidence at admission, patients receiving HT fluids increased the risk of hyponatraemia by 5.8-fold (CI: 2.4-14.0) during the study period (p=0.000).

CONCLUSIONS

Hypotonic maintenance fluids increase the incidence of hyponatraemia because they decrease blood sodium levels in normonatraemic patients. IT maintenance fluids do not increase the incidence of dysnatraemias and should be considered as the standard maintenance fluids.

Perioperative crystalloid and colloid fluid management in children: where are we and how did we get here?

It has been more than 50 yr since the landmark article in which Holliday and Segar (Pediatrics 1957;19:823-32) proposed the rate and composition of parenteral maintenance fluids for hospitalized children. Much of our practice of fluid administration in the perioperative period is based on this article. The glucose, electrolyte, and intravascular volume requirements of the pediatric surgical patient may be quite different than the original population described, and consequently, use of traditional hypotonic fluids proposed by Holliday and Segar may cause complications, such as hyperglycemia and hyponatremia, in the postoperative surgical patient. There is significant controversy regarding the choice of isotonic versus hypotonic fluids in the postoperative period. We discuss the origins of perioperative fluid management in children, review the current options for crystalloid fluid management, and present information on colloid use in pediatric patients.