Restrictive versus Liberal Fluid Therapy for Major Abdominal Surgery.

BACKGROUND: Guidelines to promote the early recovery of patients undergoing major surgery recommend a restrictive intravenous-fluid strategy for abdominal surgery. However, the supporting evidence is limited, and there is concern about impaired organ perfusion. METHODS: In a pragmatic, international trial, we randomly assigned 3000 patients who had an increased risk of complications while undergoing major abdominal surgery to receive a restrictive or liberal intravenous-fluid regimen during and up to 24 hours after surgery. The primary outcome was disability-free survival at 1 year. Key secondary outcomes were acute kidney injury at 30 days, renal-replacement therapy at 90 days, and a composite of septic complications, surgical-site infection, or death. RESULTS: During and up to 24 hours after surgery, 1490 patients in the restrictive fluid group had a median intravenous-fluid intake of 3.7 liters (interquartile range, 2.9 to 4.9), as compared with 6.1 liters (interquartile range, 5.0 to 7.4) in 1493 patients in the liberal fluid group (P<0.001). The rate of disability-free survival at 1 year was 81.9% in the restrictive fluid group and 82.3% in the liberal fluid group (hazard ratio for death or disability, 1.05; 95% confidence interval, 0.88 to 1.24; P=0.61). The rate of acute kidney injury was 8.6% in the restrictive fluid group and 5.0% in the liberal fluid group (P<0.001). The rate of septic complications or death was 21.8% in the restrictive fluid group and 19.8% in the liberal fluid group (P=0.19); rates of surgical-site infection (16.5% vs. 13.6%, P=0.02) and renal-replacement therapy (0.9% vs. 0.3%, P=0.048) were higher in the restrictive fluid group, but the between-group difference was not significant after adjustment for multiple testing. CONCLUSIONS: Among patients at increased risk for complications during major abdominal surgery, a restrictive fluid regimen was not associated with a higher rate of disability-free survival than a liberal fluid regimen and was associated with a higher rate of acute kidney injury. (Funded by the Australian National Health and Medical Research Council and others; RELIEF ClinicalTrials.gov number, NCT01424150 .).

Risk factors for hyponatremia after hypotonic fluid infusion.

BACKGROUND: Hypotonic maintenance i.v. fluids (IVF) pose a higher risk of hyponatremia than isotonic maintenance IVF, but isotonic maintenance IVF can result in excess sodium (Na) load in children. This study analyzed the incidence and risk factors for hyponatremia in children given hypotonic fluids with different Na concentrations and different maintenance rates. METHODS: We performed a retrospective analysis using medical charts of children aged 3 months-15 years. The children were normonatremic (Na ≥135 mmol/L and <145 mmol/L) before IVF, and given IVF containing 35 mmol/L Na at a 100% maintenance rate (Na 35) or fluids containing 84 mmol/L Na at a 70% maintenance rate (Na 84) for 24-48 h. RESULTS: Of a total of 463 children, hyponatremia (Na <135 mmol/L) occurred in 46/275 children (17%) given Na 35, and 16/188 (9%) given Na 84 (P = 0.01). On multivariate logistic regression analysis, Na 35 (OR, 2.19; 95%CI: 1.04-4.62), low clinical dehydration scale (CDS) score before IVF (OR, 0.17; 95%CI: 0.06-0.49), and high body temperature 24-48 h after maintenance IVF (OR, 2.39; 95%CI: 1.79-3.18) were independent risk factors for hyponatremia. CONCLUSIONS: Maintenance IVF with low Na concentration at a 100% maintenance rate, low CDS before IVF, and a high body temperature 24-48 h after maintenance IVF are independent risk factors for hyponatremia.

The impact of intravenous isotonic and hypotonic maintenance fluid on the risk of delirium in adult postoperative patients: retrospective before-after observational study.

PURPOSE: To assess the impact of intravenous isotonic and hypotonic maintenance fluid on the risk of delirium in adult postoperative patients, we conducted retrospective before-after study in a tertiary teaching hospital. METHODS: We examined all adult patients admitted ICU after an elective operation for head and neck cancer, or esophageal cancer from February 2014 to January 2017. From February 2014 to July 2015, patients were administered hypotonic fluid (sodium; 35 mmol/L) as the National Institute for Health and Care Excellence (NICE) have recommended. From August 2015 to January 2017, patients were administered isotonic fluid (sodium; 140 mmol/L). We defined the incidence of delirium as the primary outcome. The delirium was defined as the Intensive Care Delirium Screening Checklist during the ICU stay ≥ 4. A propensity score-matched model was used to adjust confounders. RESULTS: As postoperative intravenous maintenance fluid, hypotonic fluid was administered to 119 patients and isotonic fluid was administered to 92 patients. Among those total cohorts, the incidence of postoperative delirium in the hypotonic group was 21.8%, which was significantly higher than that (9.8%) in the isotonic group (p = 0.019). After propensity score matching, we selected 77 patients in each group. The incidence of delirium during the ICU stay in the hypotonic group was 26.0%, which was significantly higher than the incidence of 11.7% in the isotonic group (p = 0.023). CONCLUSIONS: In this study, the use of postoperative hypotonic maintenance fluid was associated with a higher risk of postoperative delirium than that when isotonic maintenance fluid was used.

Comparison of the incidences of hyponatremia in adult postoperative critically ill patients receiving intravenous maintenance fluids with 140 mmol/L or 35 mmol/L of sodium: retrospective before/after observational study.

PURPOSE: The purpose of this study was to compare the incidences of hyponatremia in adult postoperative critically ill patients receiving isotonic and hypotonic maintenance fluids. METHODS: In this single-center retrospective before/after observational study, we included patients who had undergone an elective operation for esophageal cancer or for head and neck cancer and who received postoperative intensive care for >48 h from August 2014 to July 2016. In those patients, sodium-poor solution (35 mmol/L of sodium; Na35) had been administered as maintenance fluid until July 2015. From August 2015, the protocol for postoperative maintenance fluid was revised to the use of isotonic fluid (140 mmol/L of sodium; Na140). The primary outcome was the incidence of hyponatremia (<135 mmol/L) until the morning of postoperative day (POD) 2. RESULTS: We included 179 patients (Na35: 87 patients, Na140: 92 patients) in the current study. The mean volume of fluid received from ICU admission to POD 2 was not significantly different between the two groups (3291 vs 3337 mL, p = 0.84). The incidence of postoperative hyponatremia was 16.3% (15/92) in the Na140 cohort, which was significantly lower than that of 52.9% (46/87) in the Na35 group (odds ratio = 0.17, 95% confidence interval 0.09-0.35, p < 0.001]. The incidences of hypernatremia, defined as serum sodium concentration >145 mmol/L, were not significantly different between the two groups. CONCLUSION: In this study, the use of intravenous maintenance fluid with 35 mmol/L of sodium was significantly associated with an increased risk of hyponatremia compared to that with 140 mmol/L of sodium in adult postoperative critically ill patients.

Perioperative fluid management and postoperative hyponatremia in children.

Intravenous (IV) fluids are used ubiquitously when children undergo surgical procedures. Until recently, Holliday and Segar's guidelines for calculating maintenance fluids dictated fluid management strategies in postoperative pediatric patients. An increased recognition of hospital-acquired hyponatremia and its associated morbidity has led to a critical re-examination of IV fluid management in this population. Postsurgical patients are at high risk of developing hyponatremia due to the presence of non-osmotic stimuli for antidiuretic hormone release. Recent studies have established that, as they are administered in current practice, hypotonic maintenance fluids are associated with increased rates of hyponatremia. The best available data demonstrate that administration of isotonic fluid reduces hyponatremic risk. In this review, we discuss the collective data available on the subject and offer guidelines for fluid management and therapeutic monitoring.

Hypotonic versus isotonic fluids in hospitalized children: a systematic review and meta-analysis.

OBJECTIVE: To determine whether the use of hypotonic vs isotonic maintenance fluids confers an increased risk of hyponatremia in hospitalized children. STUDY DESIGN: A search of MEDLINE (1946 to January 2013), the Cochrane Central Registry (1991 to December 2012), Cumulative Index for Nursing and Allied Health Literature (1990 to December 2012), and Pediatric Academic Societies (2000-2012) abstracts was conducted using the terms "hypotonic fluids/saline/solutions" and "isotonic fluids/saline/solutions," and citations were reviewed using a predefined protocol. Data on the primary and secondary outcomes were extracted from original articles by 2 authors independently. Meta-analyses of the primary and secondary outcomes were performed when possible. RESULTS: A total of 1634 citations were screened. Ten studies (n = 893) identified as independent randomized controlled trials were included. Five studies examined subjects in the intensive care unit setting, including 4 on regular wards and 1 in a mixed setting. In hospitalized children receiving maintenance intravenous fluids, hyponatremia was seen more often in those receiving hypotonic fluids than in those receiving isotonic fluids, with an overall relative risk of 2.37 (95% CI, 1.72-3.26). Receipt of hypotonic fluids was associated with a relative risk of moderate hyponatremia (<130 mmol/L) of 6.1 (95% CI, 2.2-17.3). A subgroup analysis of hypotonic fluids with half-normal saline found a relative risk of hyponatremia of 2.42 (95% CI, 1.32-4.45). CONCLUSION: In hospitalized children in intensive care and postoperative settings, the administration of hypotonic maintenance fluids increases the risk of hyponatremia when compared with administration of isotonic fluids. For patients on general wards, insufficient data are available based on the reviewed studies, and individual risk factors must be assessed.

Postoperative decrease in plasma sodium concentration after infusion of hypotonic intravenous solutions in neonatal surgery.

BACKGROUND: Hypotonic i.v. solutions can cause hyponatraemia in the context of paediatric surgery. However, this has not been demonstrated in neonatal surgery. The goal of this study was to define the relationship between infused perioperative free water and plasma sodium in neonates. METHODS: Newborns up to 7 days old undergoing abdominal or thoracic surgery were included in this prospective, observational study. Collected data included type and duration of surgery, calculated i.v. free water intake, and pre- and postoperative plasma sodium. Statistical analyses were performed using the Pearson correlation, Mann-Whitney test, and receiver operating characteristic analysis with a 1000 time bootstrap procedure. RESULTS: Thirty-four subjects were included. Postoperative hyponatraemia occurred in four subjects (11.9%). The difference between preoperative and postoperative plasma sodium measurements (ΔNaP) correlated with calculated free water intake during surgery (r=0.37, P=0.03), but not with preoperative free water intake. Calculated operative free water intake exceeding 6.5 ml kg(-1) h(-1) was associated with ΔNaP≥4 mM with a sensitivity and specificity [median (95% confidence interval)] of 0.7 (0.9-1) and 0.5 (0.3-0.7), respectively. CONCLUSIONS: Hypotonic solutions and i.v. free water intake of more than 6.5 ml kg(-1) h(-1) are associated with reductions in postoperative plasma sodium measurements ≥4 mM. In the context of neonatal surgery, close monitoring of plasma sodium is mandatory. Routine use of hypotonic i.v. solutions during neonatal surgery should be questioned as they are likely to reduce plasma sodium.

Isotonic versus hypotonic solutions for maintenance intravenous fluid administration in children.

BACKGROUND: Maintenance intravenous fluids are frequently used in hospitalised children who cannot maintain adequate hydration through enteral intake. Traditionally used hypotonic fluids have been associated with hyponatraemia and subsequent morbidity and mortality. Use of isotonic fluid has been proposed to reduce complications. OBJECTIVES: To establish and compare the risk of hyponatraemia by systematically reviewing studies where isotonic is compared with hypotonic intravenous fluid for maintenance purposes in children.Secondly, to compare the risk of hypernatraemia, the effect on mean serum sodium concentration and the rate of attributable adverse effects of both fluid types in children. SEARCH METHODS: We ran the search on 17 June 2013. We searched the Cochrane Injuries Group Specialised Register, Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library), MEDLINE (OvidSP), Embase (OvidSP), and ISI Web of Science. We also searched clinical trials registers and screened reference lists. We updated this search in October 2014 but these results have not yet been incorporated. SELECTION CRITERIA: We included randomised controlled trials that compared isotonic versus hypotonic intravenous fluids for maintenance hydration in children. DATA COLLECTION AND ANALYSIS: At least two authors assessed and extracted data for each trial. We presented dichotomous outcomes as risk ratios (RR) with 95% confidence intervals (CIs) and continuous outcomes as mean differences with 95% CIs. MAIN RESULTS: Ten studies met the inclusion criteria, with a total of 1106 patients. The majority of the studies were performed in surgical or intensive care populations (or both). There was considerable variation in the composition of intravenous fluid, particularly hypotonic fluid, used in the studies. There was a low risk of bias for most of the included studies. Ten studies provided data for our primary outcome, a total of 449 patients in the analysis received isotonic fluid, while 521 received hypotonic fluid. Those who received isotonic fluid had a substantially lower risk of hyponatraemia (17% versus 34%; RR 0.48; 95% CI 0.38 to 0.60, high quality evidence). It is unclear whether there is an increased risk of hypernatraemia when isotonic fluids are used (4% versus 3%; RR 1.24; 95% CI 0.65 to 2.38, nine studies, 937 participants, low quality evidence), although the absolute number of patients developing hypernatraemia was low. Most studies had safety restrictions included in their methodology, preventing detailed investigation of serious adverse events. AUTHORS' CONCLUSIONS: Isotonic intravenous maintenance fluids with sodium concentrations similar to that of plasma reduce the risk of hyponatraemia when compared with hypotonic intravenous fluids. These results apply for the first 24 hours of administration in a wide group of primarily surgical paediatric patients with varying severities of illness.

Effects of sodium hyaluronate on wavefront aberrations in dry eye patients.

PURPOSE: To investigate the effects of a single instillation of hypotonic 0.18% sodium hyaluronate artificial tears on wavefront aberrations in dry eye patients. METHODS: Fifty patients with dry eye were recruited into this single-center, prospective, double-masked, randomized controlled trial. Patients were randomly assigned to receive one drop of preservative-free, hypotonic 0.18% sodium hyaluronate (treatment) in one eye and one drop of sterile 0.9% sodium chloride solution (control) in the other eye. Ocular aberrations evaluated by a Hartmann-Shack aberrometer and severity of dry eye symptoms graded by a questionnaire (at baseline, 1, 10, 30, 60, and 120 minutes after instillation) were the main outcome measures. RESULTS: After a single instillation of one drop of the allocated eye drops, there were no statistically significant differences between the treatment and control groups in total higher-order aberrations, coma, and spherical aberrations during the study period (p = 0.40, 0.57, and 0.16, respectively). Although a statistically significant (p = 0.04) decrease from baseline in spherical aberrations was noted in the treatment group at 1 minute following instillation, it gradually increased back to baseline values at later time points. A statistically significant diminishment of dry eye symptoms compared with the placebo was reported at all time points by the treatment group (p < 0.001). CONCLUSIONS: A single instillation of hypotonic 0.18% sodium hyaluronate eye drops is safe and effective in alleviating subjective dry eye symptoms; however, it does not appear to affect higher-order aberrations in moderate to severe dry eye patients.

Intravenous maintenance fluids revisited.

Intravenous maintenance fluid therapy aims to replace daily urinary and insensible losses for ill children in whom adequate enteric administration of fluids is contraindicated or infeasible. The traditional determination of fluid volumes and composition dates back to Holliday and Segar's seminal article from 1957, which describes the relationship between weight, energy expenditure, and physiologic losses in healthy children. Combined with estimates of daily electrolyte requirements, this information supports the use of the hypotonic maintenance fluids that were widely used in pediatric medicine. However, using hypotonic intravenous fluids in a contemporary hospitalized patient who may have complex physiologic derangements, less caloric expenditure, decreased urinary output, and elevated antidiuretic hormone levels is often not optimal; evidence over the last 2 decades shows that it may lead to an increased incidence of hyponatremia. In this review, we present the evidence for using isotonic rather than hypotonic fluids as intravenous maintenance fluid.

[Some clinical aspects of sodium homeostasis disorders]. / A nátriumháztartás zavarainak néhány klinikai vonatkozása.

In this review three major issues of sodium homeostasis are addressed. Specifically, volume-dependent (salt-sensitive) hypertension, sodium chloride content of maintenance fluid and clinical evaluation of hyponatremia are discussed. Regarding volume-dependent hypertension the endocrine/paracrine systems mediating renal sodium retention, the relationship between salt intake, plasma sodium levels and blood pressure, as well as data on the dissociation of sodium and volume regulation are presented. The concept of perinatal programming of salt-preference is also mentioned. Some theoretical and practical aspects of fluid therapy are summarized with particular reference to using hypotonic sodium chloride solution for maintenance fluid as opposed to the currently proposed isotonic sodium chloride solution. Furthermore, the incidence, the aetiological classification and central nervous system complications of hyponatremia are presented, too. In addition, clinical and pathophysical features of hyponatremic encephalophathy and osmotic demyelinisation are given. The adaptive reactions of the brain to hypotonic stress are also described with particular emphasis on the role of brain-specific water channel proteins (aquaporin-4) and the benzamil-inhibitable sodium channels. In view of the outmost clinical significance of hyponatremia, the principles of efficient and safe therapeutic approaches are outlined.

Intravenous fluid management for the acutely ill child.

PURPOSE OF REVIEW: To review the principles of prescribing intravenous fluids (IVFs) to the acutely ill child and of adjusting sodium composition and fluid rate to prevent disorders in serum sodium or volume status from occurring. RECENT FINDINGS: Recent data have revealed that the historic approach of administering hypotonic IVFs results in a high incidence of hospital-acquired hyponatremia in children. The majority of hospitalized children requiring IVFs are at risk for developing hyponatremia from numerous stimuli for arginine vasopressin (AVP) production, such as volume depletion, pain, stress, nausea, vomiting, respiratory or central nervous system (CNS) disorders, or the postoperative state. Multiple recent prospective studies in over 600 children have demonstrated that hypotonic fluids cause acute hyponatremia, whereas 0.9% sodium chloride (NaCl) effectively prevents it. 0.9% NaCl is the most appropriate IVF for the majority of hospitalized children. Fluid and sodium restriction will be needed for children with edematous or oliguric states and hypotonic fluids needed for children with urinary or extra-renal free water losses or hypernatremia. SUMMARY: Hypotonic fluids should not be administered routinely in children due to the risk of hospital-acquired hyponatremia. 0.9% NaCl is the preferred IVF for the vast majority of hospitalized children.

The relationship between arginine vasopressin levels and hyponatremia following a percutaneous renal biopsy in children receiving hypotonic or isotonic intravenous fluids.

Post-operative hyponatremia is a common complication in children which results from hypotonic fluid administration in the presence of arginine vasopressin (AVP) excess. We evaluated the relationship between the change in serum sodium and AVP levels following percutaneous renal biopsy in children receiving either hypotonic or isotonic fluids. This study was prompted after we encountered a patient who developed near-fatal hyponatremic encephalopathy following a renal biopsy while receiving hypotonic fluids. The relationship between the change in serum sodium and AVP levels was evaluated prior to (T0) and at 5 h (T5) following a percutaneous renal biopsy in 60 children receiving either hypotonic (0.6% NaCl, 90 mEq/L) or isotonic fluids (0.9% NaCl, 154 mEq/L). The proportion of patients with elevated AVP levels post-procedure was similar between those receiving 0.6 or 0.9% NaCl (30 vs. 26%). Patients receiving 0.6% NaCl with elevated AVP levels experienced a fall in serum sodium of 1.9 ± 1.5 mEq/L, whereas those receiving 0.9% NaCl had a rise in serum sodium of 0.85 ± 0.34 mEq/L with no patients developing hyponatremia. There were no significant changes in serum sodium levels in patients with normal AVP concentrations post-procedure in either group. In conclusion, elevated AVP levels were common among our patients following a percutaneous renal biopsy. Isotonic fluids prevented a fall in serum sodium and hyponatremia, while hypotonic fluids did not.

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.

Incidence of hyponatremia in children with gastroenteritis treated with hypotonic intravenous fluids.

Hypotonic saline solutions have been used for over five decades to treat children with diarrheal dehydration. However, concern has recently been raised about the potential for iatrogenic hyponatremia as a result of this therapy. We reviewed the medical records of 531 otherwise healthy children with gastroenteritis who had been admitted to the hospital for intravenous fluid therapy. We retrospectively collected data on 141 of these children who had received two serum electrolytes (one upon admission and the other 4-24 h thereafter). The remaining 390 children were excluded because their charts lacked the required data. We analyzed data in 124 of these 141 patients whose initial serum sodium (Na) level was between 130-150 mEq/l and excluded 17 patients whose admission serum sodium fell outside this range. All patients were treated with intravenous hypotonic fluids (5% dextrose in 0.2% saline, n = 4; 5% dextrose in 0.3% saline, n = 102; 5% dextrose in 0.45% saline, n = 18 patients) as maintenance fluid therapy or maintenance fluid plus deficit therapy; 100 of these children had received an initial saline bolus of 21.05 +/- 8.5 ml/kg upon admission. The serum Na level decreased by 1.7 +/- 4.3 mEq/l in the whole group. Of the 97 children with isonatremia (Na 139.5 +/- 2.7 mEq/l) on admission, 18 (18.5%) developed mild hyponatremia (Na 133.4 +/- 0.9 mEq/l, range 131-134), with a decrease in serum Na of 5.7 +/- 3.1 mEq/l, and 79 remained isonatremic (Na 138.3 +/- 2.7 mEq/l), with a decrease in serum Na of 1.8 +/- 3.4 mEq/l (p < 0.0005). There was no significant difference in type, rate, or amount of intravenous fluid or saline bolus (26.1 +/- 10.4 vs. 20.2 +/- 8.6 ml/kg, respectively) administered in these two groups. Children who became hyponatremic were older (5.8 +/- 2.7 years) than those who remained isonatremic (2.8 +/- 3.1 years) (p < 0.0005), but there was no statistical difference in gender, degree of dehydration, and severity of metabolic acidosis between the two groups. Although serum Na increased by 3.9 +/- 2.5 mEq/l in 19 patients with mild hyponatremia upon admission (Na 132.8 +/- 1.3 to 136.7 +/- 2.6 mEq/l) and 73% of these became isonatremic, hypotonic saline solutions have the potential to cause hyponatremia in children with gastroenteritis and isonatremic dehydration.

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.

Hospital-acquired hyponatremia in postoperative pediatric patients: prospective observational study.

OBJECTIVE: To establish the incidence and factors associated with hospital-acquired hyponatremia in pediatric surgical patients who received hypotonic saline (sodium 40 mmol/L plus potassium 20 mmol/L) at the rate suggested by the Holliday and Segar's formula for calculations of maintenance fluids. DESIGN: Prospective, observational, cohort study. SETTING: Pediatric intensive care unit. PATIENTS: : Eighty-one postoperative patients. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Incidence and factors associated with hyponatremia (sodium < or = 135 mmol/L). Univariate analysis was conducted post surgery at 12 hrs and at 24 hrs. Mean values were compared with independent t test samples. Receiver operating characteristics curve analysis was performed in variables with a p <.05, and relative risks were calculated. Eighty-one patients were included in the study. The incidence of hyponatremia at 12 hrs was 17 (21%) of 81 (95% confidence interval, 3.7-38.3); at 24 hrs, it was was 15 (31%) of 48 (95% confidence interval, 11.4-50.6). Univariate analysis at 12 hrs showed that hyponatremic patients had a higher sodium loss (0.62 mmol/kg/hr vs. 0.34 mmol/kg/hr, p = .0001), a more negative sodium balance (0.39 mmol/kg/hr vs. 0.13 mmol/kg/hr, p < .0001), and a higher diuresis (3.08 mL/kg/hr vs. 2.2 mL/kg/hr, p = .0026); relative risks were 11.55 (95% confidence interval, 2.99-44.63; p = .0004) for a sodium loss >0.5 mmol/kg/hr; 10 (95% confidence interval, 2.55-39.15; p = .0009) for a negative sodium balance >0.3 mmol/kg/hr; and 4.25 (95% confidence interval, 1.99-9.08; p = .0002) for a diuresis >3.4 mL/kg/hr. At 24 hrs, hyponatremic patients were in more positive fluid balance (0.65 mL/kg/hr vs. 0.10 mL/kg/hr, p = .0396); relative risk was 3.25 (95% confidence interval, 1.2-8.77; p = .0201), for a positive fluid balance >0.2 mL/kg/hr. CONCLUSIONS: The incidence of hyponatremia in this population was high and progressive over time. Negative sodium balance in the first 12 postoperative hours and then a positive fluid balance could be associated with the development of postoperative hyponatremia.

Effect of intraoperative Hartmann's versus hypotonic solution administration on FLACC pain scale scores in children: A prospective randomized controlled trial.

BACKGROUND: In healthy children, an isotonic solution containing no glucose or a small amount of glucose (1-2%) has been recommended as an intraoperative maintenance fluid due to the potential risk of hyponatremia associated with hypotonic solutions. However, a hypotonic solution with glucose is still widely used as a maintenance fluid for pediatric anesthesia. We speculated that the hypotonic solution may worsen postoperative discomfort and irritability in pediatric patients due to hyponatremia. PATIENTS AND METHODS: In the current study, we compared the post-operative Face, Legs, Activity, Cry, Consolability(FLACC) scale scores of pediatric patients aged 3-10 years who received either a 1:2 dextrose solution or Hartmann's solution during Nuss Bar removal. RESULTS: The FLACC scale score in the post-anesthesia care unit was higher in the 1:2 dextrose solution group(HYPO) (n = 20) than in the Hartmann's solution group(ISO) (n = 20) (6.30 vs 4.70, p = 0.044, mean difference and 95% Confidence Interval(CI) was 1.6 (0.04 to 3.16)). We also compared opioid consumption at the post-anesthesia care unit. Total dose of fentanyl per body weight in the post-anesthesia care unit was also higher in the HYPO (0.59 vs 0.37 mcg/kg, p = 0.042, mean difference and 95% CI was 0.22 mcg/kg (0.030 to 0.402)). CONCLUSIONS: Intraoperative use of the hypotonic solution in children causes increased FLACC scale scores, leading to higher opioid consumption in post-anesthesia care unit.