Pattern of Fluid Overload and its Impact on Mortality Among Mechanically Ventilated Children: Secondary Analysis of the ReLiSCh Trial

OBJECTIVES

To assess the pattern of fluid overload (FO) and its impact on mortality among mechanically ventilated children.

METHODS

In this secondary analysis of an open-label randomized controlled trial (ReLiSCh trial, October 2020-September 2021), hemodynamically stable mechanically ventilated children (n = 100) admitted to a tertiary level pediatric intensive care unit (PICU) in North India were enrolled. The primary outcome was pattern of FO (FO% >10% and cumulative FO% from day 1-7); and secondary outcomes were pattern of FO among survivors and non-survivors, and prescription practices of maintenance fluid.

RESULTS

The median (IQR) age was 3.5 (0.85-7.5) y and 57% were males. Common diagnoses were pneumonia (27%), scrub typhus (14%), Landry-Guillain-Barré syndrome (9%), dengue (8%), central nervous system infections (7%) and staphylococcal sepsis (6%). Common organ dysfunction included acute respiratory distress syndrome (ARDS) (41%), shock (38%), and acute kidney injury (AKI) (9%). The duration PICU stay was 11 (7-17) d and mortality was 12%. The FO% >10% was noted in 19% children; and there was significant increase in cumulative FO% from day 1-7 [1.2 (0.2-2.6)% to 8.5 (1.7-14.3)%, (p = 0.000)]. Among non-survivors, higher proportion had FO% >10% (66.7% vs. 12.5%, p 0.0001); and trend towards higher cumulative FO% on first seven days. From day 1-7, the percentage of maintenance fluid received increased from 60 (50-71)% to 70 (60-77)% (p = 0.691).

CONCLUSIONS

One-fifth of mechanically ventilated children had FO% >10% and there was significant increase in cumulative FO% from day 1-7. Non-survivors had significantly higher degree of FO.

Choice of creep or maintenance fluid type and their impact on total daily ICU sodium burden in critically ill patients: A systematic review and meta-analysis

PURPOSE

Maintenance and hidden/creep fluids are a major source of fluid and sodium intake in intensive care unit (ICU) patients. Recent research indicates that low versus high sodium content maintenance fluids could decrease fluid and sodium burden. We conducted a systematic review (SR) with meta-analysis to summarize the impact of maintenance fluid choice on total daily sodium in ICU patients.

MATERIALS AND METHODS

Systematic literature search in Pubmed, Embase, the Cochrane Library and the.

CLINICAL TRIALS REGISTRY

Only controlled clinical trials were included.

EXCLUSION CRITERIA

trials on resuscitation fluids, performed in the emergency department only and in pediatric patients. Primary objective was the reduction in mean total sodium intake with low versus high sodium content maintenance/creep fluids.

RESULTS

Five studies (1105 patients) were included. Heterogeneity was high.Risk of bias was moderate. Mean daily sodium reduction was 117 mmol (95%Confidence Interval [CI] -174; -59; p < 0.001) with low versus high sodium content maintenance/creep fluids. Incidence of hyperchloremia was lower (OR 0.26; 95%CI 0.1; 0.64) with low sodium. There were no differences in the incidences of hyper-/hyponatremia and fluid balances.

CONCLUSION

Using low sodium content maintenance/creep fluids substantially reduces daily sodium burden in adult ICU patients. Significant knowledge/research gaps exist regarding relevance and safety.

TRIAL REGISTRATION

PROSPERO 2022 CRD42022300577 (February 2022).

Restricted versus Usual/Liberal Maintenance Fluid Strategy in Mechanically Ventilated Children: An Open-Label Randomized Trial (ReLiSCh Trial)

OBJECTIVES

To assess the impact of restricted vs. usual/liberal maintenance fluid strategy on fluid overload (FO) among mechanically ventilated children.

METHODS

This open-label randomized controlled trial was conducted over a period of 1 y (October 2020-September 2021) in a Pediatric intensive care unit (PICU) in North India. Hemodynamically stable mechanically ventilated children were randomized to 40% (restricted group, n = 50) and 70-80% (usual/liberal group, n = 50) of maintenance fluids. The primary outcome was cumulative fluid overload percentage (FO%) on day 7. Secondary outcomes were FO% >10%; vasoactive inotropic score, sequential organ failure assessment score, pediatric logistic organ dysfunction score and oxygenation index from day 1-7; ventilation free days (VFDs) and PICU free days (PFDs) through day 28; and mortality.

RESULTS

The restricted group had statistically non-significant trend towards lower cumulative FO% at day 7 [7.6 vs. 9.5, p = 0.40]; and proportion of children with FO% >10% (12% vs. 26%, p = 0.21) as compared to usual/liberal group. The increase in FO% from day 1-7 was significant in usual/liberal group as compared to restricted group (p <0.001 and p = 0.134, respectively). Restricted group received significantly lower amount of fluid in the first 5 d; had significantly higher VFDs (23 vs. 17 d, p = 0.008) and PFDs (19 vs. 15 d, p = 0.007); and trend towards lower mortality (8% vs. 16%, p = 0.21).

CONCLUSIONS

Restricted as compared to usual/liberal maintenance fluid strategy among mechanically ventilated children was associated with a trend towards lower rate and severity of FO and mortality; and significantly lower fluid volume received, and higher VFDs and PFDs.

Intermittent boluses of balanced salt solution for post-operative intravenous hydration following elective major abdominal and thoracic surgery in children

PURPOSE

Maintenance fluids following major operations in children are typically administered with a continuous rate. We hypothesized that administering fluids as intermittent boluses is more physiologic and could limit post-operative fluid volume, thereby avoiding harmful effects of excess fluid.

METHODS

We retrospectively reviewed children aged 1-21 admitted after an elective major abdominal or thoracic operation from 2015 to 2021. We excluded non-elective operations and patients receiving peri-operative enteral or parenteral nutrition. We analyzed total fluid volume at 0-24, 24-48, 48-72, and 72-96 h, time to regular diet and discharge, and end-organ complications.

RESULTS

We identified 363 patients, of which 108 received intermittent boluses and 255 continuous fluids. Bolus group patients received significantly less fluid up to 72 h post-operatively with average rates of 0.49 mL/kg/h vs 0.86 mL/kg/h at 0-24 h (p << 0.01), 0.57 mL/kg/h vs 1.46 mL/kg/h at 24-48 h (p << 0.01), and 0.50 vs 0.92 mL/kg/h at 48-72 h (p << 0.01). Additionally, the bolus group maintained adequate urine output, tolerated a regular diet sooner (2.08 days vs 2.51 days; p = 0.0023) and averaged a shorter hospital stay (3.12 vs 4.14 days; p = 0.004). There was no difference in adverse effects between the two groups.

CONCLUSION

Utilizing intermittent boluses reduces the volume of maintenance fluids administered and may lead to a faster time to regular diet and discharge.

LEVEL OF EVIDENCE

IV.

TYPE OF STUDY

Retrospective review.

Fluid therapy in mechanically ventilated critically ill children: the sodium, chloride and water burden of fluid creep

Background

Fluid therapy is a cornerstone of pediatric intensive care medicine. We aimed at quantifying the load of water, sodium and chloride due to different fluid indications in our pediatric intensive care unit (PICU). We were particularly interested in the role of fluid creep, i.e. fluid administered mainly as the vehicle for drugs, and the association between sodium load and water balance.

Methods

Critically ill children aged ≤3 years and invasively ventilated for ≥48 h between 2016 and 2019 in a single tertiary center PICU were retrospectively enrolled. Need for renal replacement therapy, plasmapheresis or parenteral nutrition constituted exclusion criteria. Quantity, quality and indication of fluids administered intravenously or enterally, urinary output and fluid balance were recorded for the first 48 h following intubation. Concentrations of sodium and chloride provided by the manufacturers were used to compute the electrolyte load.

Results

Forty-three patients (median 7 months (IQR 3–15)) were enrolled. Patients received 1004 ± 284 ml of water daily (153 ± 36 ml/kg/day), mainly due to enteral (39%), creep (34%) and maintenance (24%) fluids. Patients received 14.4 ± 4.8 mEq/kg/day of sodium and 13.6 ± 4.7 mEq/kg/day of chloride, respectively. The majority of sodium and chloride derived from fluid creep (56 and 58%). Daily fluid balance was 417 ± 221 ml (64 ± 30 ml/kg/day) and was associated with total sodium intake (r² = 0.49, p < 0.001).

Conclusions

Critically ill children are exposed, especially in the acute phase, to extremely high loads of water, sodium and chloride, possibly contributing to edema development. Fluid creep is quantitatively the most relevant fluid in the PICU and future research efforts should address this topic in order to reduce the inadvertent water and electrolyte burden and improve the quality of care of critically ill children.

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.

Maintenance fluid therapy and fluid creep impose more significant fluid, sodium, and chloride burdens than resuscitation fluids in critically ill patients: a retrospective study in a tertiary mixed ICU population

PURPOSE

Research on intravenous fluid therapy and its side effects, volume, sodium, and chloride overload, has focused almost exclusively on the resuscitation setting. We aimed to quantify all fluid sources in the ICU and assess fluid creep, the hidden and unintentional volume administered as a vehicle for medication or electrolytes.

METHODS

We precisely recorded the volume, sodium, and chloride burdens imposed by every fluid source administered to 14,654 patients during the cumulative 103,098 days they resided in our 45-bed tertiary ICU and simulated the impact of important strategic fluid choices on patients' chloride burdens. In septic patients, we assessed the impact of the different fluid sources on cumulative fluid balance, an established marker of morbidity.

RESULTS

Maintenance and replacement fluids accounted for 24.7% of the mean daily total fluid volume, thereby far exceeding resuscitation fluids (6.5%) and were the most important sources of sodium and chloride. Fluid creep represented a striking 32.6% of the mean daily total fluid volume [median 645 mL (IQR 308-1039 mL)]. Chloride levels can be more effectively reduced by adopting a hypotonic maintenance strategy [a daily difference in chloride burden of 30.8 mmol (95% CI 30.5-31.1)] than a balanced resuscitation strategy [daily difference 3.0 mmol (95% CI 2.9-3.1)]. In septic patients, non-resuscitation fluids had a larger absolute impact on cumulative fluid balance than did resuscitation fluids.

CONCLUSIONS

Inadvertent daily volume, sodium, and chloride loading should be avoided when prescribing maintenance fluids in view of the vast amounts of fluid creep. This is especially important when adopting an isotonic maintenance strategy.

The effect of NaCl 0.9% and NaCl 0.45% on sodium, chloride, and acid-base balance in a PICU population

OBJECTIVES

To study the effect of two intravenous maintenance fluids on plasma sodium (Na), and acid-base balance in pediatric intensive care patients during the first 24h of hospitalization.

METHODS

A prospective randomized controlled study was performed, which allocated 233 patients to groups: (A) NaCl 0.9% or (B) NaCl 0.45%. Patients were aged 1 day to 18 years, had normal electrolyte concentrations, and suffered an acute insult (medical/surgical).

MAIN OUTCOME MEASURED

change in plasma sodium. Parametric tests: t-tests, ANOVA, X(2) statistical significance level was set at α=0.05.

RESULTS

Group A (n=130): serum Na increased by 2.91 (±3.9)mmol/L at 24h (p<0.01); 2% patients had Na higher than 150 mmol/L. Mean urinary Na: 106.6 (±56.8)mmol/L. No change in pH at 0 and 24h. Group B (n=103): serum Na did not display statistically significant changes. Fifteen percent of the patients had Na<135 mmol/L at 24h. The two fluids had different effects on respiratory and post-operative situations.

CONCLUSIONS

The use of saline 0.9% was associated with a lower incidence of electrolyte disturbances.