Condition category
Date applied
Date assigned
Last edited
Prospectively registered
Overall trial status
Recruitment status
Publication status

Plain English Summary

Not provided at time of registration

Trial website

Contact information



Primary contact

Dr Rafael Krmar


Contact details

Department of Pediatrics
Karolinska University Hospital
S-141 86 Stockholm
S-141 86

Additional identifiers

EudraCT number number

Protocol/serial number

Clinical Trial register database registry number ( CT20110060

Study information

Scientific title

The efficacy of hypotonic and near-isotonic saline for parenteral fluid therapy given at low maintenance rate in preventing significant change in plasma sodium in post-operative paediatric patients: a prospective randomised non-blinded study


Study hypothesis

Hyponatremia is the most frequent electrolyte abnormality observed in post-operative paediatric patients receiving intravenous maintenance fluid therapy. If plasma sodium concentration (p-Na+) declines to levels below 125 mmol/L in < 48 h, transient or permanent brain damage may occur.

There is an intense debate as to whether the administered volume (full rate vs. restricted rate of infusion) and the composition of solutions used for parenteral maintenance fluid therapy (hypotonic vs. isotonic solutions) contribute to the development of hyponatremia. Lines of evidence indicates that post-operative hyponatremia would be the result of dilution of body solutes, i.e. an excess of water in relation to the existing sodium stores rather than to an increase in urinary sodium excretion. This phenomenon might occur whenever antidiuretic hormone levels are increased, like in clinical conditions such as surgery.

Our hypothesis is that regardless of the parenteral fluid therapy to be administered, on the condition that the patient’s extracellular fluid compartment is preserved and the urinary dilution capacity is suspected to be impaired by non-osmotic stimulated antidiuretic hormone activity, hyponatremia will not develop if fluid therapy is given at low maintenance rate i.e. approximately 3/4 of the average maintenance allowance.

Please note that as of 20/06/2011 the anticipated start and end dates of this trial have been updated. The previous dates were as follows:
Previous anticipated start date: 04/07/2011
Previous anticipated end date: 03/12/2012

Ethics approval

The study protocol has been approved by the Medical Ethics Committee at Karolinska University Hospital, Stockholm, Sweden on 1st November 2010, Protocol No. 2010/2:9

Study design

Prospective randomised non-blinded study

Primary study design


Secondary study design

Randomised controlled trial

Trial setting


Trial type


Patient information sheet

Not available in web format, please use the contact details below to request a patient information sheet


Emergency intervention for treatment of acute appendicitis in children and adolescents


As of 19/04/2012 the status of this record was changed to 'stopped' due to low patient recruitment rate. The trial officially stopped on 18/04/2012.

Eligible patients will be randomly assigned to receive one of the following :
Eelectrolyte/glucose combinations as parenteral maintenance fluid therapies during the 24 h following surgery:
1. 0.23% sodium chloride (40 mmol/L Na+ + 20 mmol/L K+ + 60 mmol/L Cl­; extempore solution) in 5% glucose
2. 0.40% sodium chloride (70 mmol/L Na+ + 45 mmol/L Cl­ + 25 mmol/L acetate; B. Braun Melsungen AG, Melsungen, Germany) in 2.5% glucose
3. 0.81% sodium chloride (140 mmol/L Na+ + 4 mmol/L K+ + 1 mmol/L Ca2+ + 1 mmol/L Mg2+ + 118 mmol/L Cl­ + 30 mmol/L acetate; Serumwerk Bernburg AG, Bernburg, Germany) in 1% glucose (the chemical symbols K+, Cl-, Ca2+, and Mg2+ refer to potassium, chloride, calcium, and magnesium, respectively)

The fluid needs for parenteral therapy will be estimated based on metabolic requirements of the body, i.e. expenditure of energy, as described by Holliday and Segar where daily caloric expenditure is equal to 100 cal/kg BW up to 10 kg, 1000 cal + 50 cal/kg BW from 11 to 20 kg and 1500 cal + 20 cal/kg BW over 20 kg. Since prescription of intravenous fluid therapy given at full maintenance rate may be potentially dangerous when renal water excretion is limited by excess antidiuretic hormone, parenteral fluid therapy will be given at a lower rate than the recommended average maintenance rate. In accordance with our local care guidelines for parenteral fluid therapy following surgical procedures, approximately 3/4 of the average maintenance allowance, percentage of the average maintenance rate will be prescribed to all participants for the first 24 h post-operatively.

For further information regarding sample size calculation, which is based on an hypothetical condition, please contact

Intervention type



Not Applicable

Drug names

Primary outcome measure

To evaluate whether the post-operative prescription of either hypotonic (0.23% and 0.40% sodium chloride) or near-isotonic (0.81% sodium chloride) fluid therapy given at low maintenance rate in otherwise healthy children with normal post-operative p-Na+ are equally effective in maintaining p-Na+ within the normal range 24 h postoperatively

Secondary outcome measures

To determine water and electrolyte-balance during the administration of the investigational parenteral maintenance fluids as well as to investigate known regulatory hormones involved in the homeostatic control of water balance. We will also seek to determine how frequently p-Na+ should be monitored during the 24 h post-operative period.

Overall trial start date


Overall trial end date


Reason abandoned (if study stopped)

Prematurely stopped due to a low patient recruitment rate


Participant inclusion criteria

1. Male and female children and adolescents aged between 1 and 14 years old whose post-operative p-Na+ are within the normal range (local reference range: 135 – 147 mmol/L)
2. Children and adolescents undergoing emergency intervention for treatment of acute appendicitis either as an open or laparoscopic procedure will be considered to be potentially eligible
To qualify for randomisation, the participants are required to have a complicated appendicitis, i.e. gangrenous or perforated, either with generalised or localised peritonitis of such a degree that the surgeon considers oral feeding unsuitable for at least 24 hours following the surgery. Consequently, the randomisation will be performed post-operatively and on the basis of intra-operative findings.

We infer that in our study population, the prescription of parenteral fluid therapy for the immediate 24 hours post-operative period might be justified and that by delaying oral fluid therapy intake, in any particular case, will do no harm to the patient.

Participant type


Age group




Target number of participants

The number of patients per study arm needed to fulfill the power goal of the study will be 17 patients.

Participant exclusion criteria

1. Any clinical condition, such as renal disease, acute or chronic lung inflammation, pituitary or hypothalamic disease and adrenal insufficiency that eventually can lead to electrolyte and water imbalance
2. Any patient whose p-Na+ is < 130 mmol/L after the initiation of parenteral maintenance fluid therapy, will be withdrawn from the study and treated accordingly at the discretion of the anaesthesiologist responsible for the patient’s care

Recruitment start date


Recruitment end date



Countries of recruitment


Trial participating centre

Department of Pediatrics
S-141 86

Sponsor information


Karolinska University Hospital (Sweden)

Sponsor details

Department of Pediatric Anesthesia and Intensive Care
Karolinska University Hospital
S-171 76

Sponsor type

Hospital/treatment centre



Funder type


Funder name

Investigator initiated and funded (Sweden)

Alternative name(s)

Funding Body Type

Funding Body Subtype


Results and Publications

Publication and dissemination plan

Not provided at time of registration

Intention to publish date

Participant level data

Not provided at time of registration

Basic results (scientific)

Publication list

2011 protocol in
2019 results in (added 09/07/2020)

Publication citations

  1. Protocol

    Fläring U, Lönnqvist PA, Frenckner B, Svensson JF, Ingolfsson I, Wallensteen L, Stigzelius S, Kowalski J, Krmar RT, The efficacy of hypotonic and near-isotonic saline for parenteral fluid therapy given at low maintenance rate in preventing significant change in plasma sodium in post-operative pediatric patients: protocol for a prospective randomized non-blinded study., BMC Pediatr, 2011, 11, 61, doi: 10.1186/1471-2431-11-61.

Additional files

Editorial Notes

09/07/2020: Publication reference added.