African fluid bolus study: implications for practice

Mortality after emergency unit fluid bolus in febrile Ugandan children

OBJECTIVES

Pediatric fluid resuscitation in sub-Saharan Africa has traditionally occurred in inpatients. The landmark Fluid Expansion as Supportive Therapy (FEAST) trial showed fluid boluses for febrile children in this inpatient setting increased mortality. As emergency care expands in sub-Saharan Africa, fluid resuscitation increasingly occurs in the emergency unit. The objective of this study was to determine the mortality impact of emergency unit fluid resuscitation on febrile pediatric patients in Uganda.

METHODS

This retrospective cohort study used data from 2012-2019 from a single emergency unit in rural Western Uganda to compare three-day mortality for febrile patients that did and did not receive fluids in the emergency unit. Propensity score matching was used to create matched cohorts. Crude and multivariable logistic regression analysis (using both complete case analysis and multiple imputation) were performed on matched and unmatched cohorts. Sensitivity analysis was done separately for patients meeting FEAST inclusion and exclusion criteria.

RESULTS

The analysis included 3087 febrile patients aged 2 months to 12 years with 1,526 patients receiving fluids and 1,561 not receiving fluids. The matched cohorts each had 1,180 patients. Overall mortality was 4.0%. No significant mortality benefit or harm was shown in the crude unmatched (Odds Ratio [95% Confidence Interval] = 0.88 [0.61-1.26] or crude matched (1.00 [0.66-1.50]) cohorts. Adjusted cohort analysis (including both complete case analysis and multiple imputation) and sensitivity analysis of patients meeting FEAST inclusion and exclusion criteria all also failed to show benefit or harm. Post-hoc power calculations showed the study was powered to detect the absolute harm seen in FEAST but not the relative risk increase.

CONCLUSIONS

This study's primary finding is that fluid resuscitation in the emergency unit did not significantly increase or decrease three-day mortality for febrile children in Uganda. Universally aggressive or fluid-sparing emergency unit protocols are unlikely to be best practices, and choices about fluid resuscitation should be individualized.

Fluid Bolus Therapy in Pediatric Sepsis: Current Knowledge and Future Direction

Sepsis is a leading cause of morbidity and mortality in children with a worldwide prevalence in pediatric intensive care units of approximately 8%. Fluid bolus therapy (FBT) is a first line therapy for resuscitation of septic shock and has been a recommendation of international guidelines for nearly two decades. The evidence base supporting these guidelines are based on limited data including animal studies and case control studies. In recent times, evidence suggesting harm from fluid in terms of morbidity and mortality have generated interest in evaluating FBT. In view of this, studies of fluid restrictive strategies in adults and children have emerged. The complexity of studying FBT relates to several points. Firstly, the physiological and haemodynamic response to FBT including magnitude and duration is not well described in children. Secondly, assessment of the circulation is based on non-specific clinical signs and limited haemodynamic monitoring with limited physiological targets. Thirdly, FBT exists in a complex myriad of pathophysiological responses to sepsis and other confounding therapies. Despite this, a greater understanding of the role of FBT in terms of the physiological response and possible harm is warranted. This review outlines current knowledge and future direction for FBT in sepsis.

Predicting mortality in sick African children: the FEAST Paediatric Emergency Triage (PET) Score

BACKGROUND

Mortality in paediatric emergency care units in Africa often occurs within the first 24 h of admission and remains high. Alongside effective triage systems, a practical clinical bedside risk score to identify those at greatest risk could contribute to reducing mortality.

METHODS

Data collected during the Fluid As Expansive Supportive Therapy (FEAST) trial, a multi-centre trial involving 3,170 severely ill African children, were analysed to identify clinical and laboratory prognostic factors for mortality. Multivariable Cox regression was used to build a model in this derivation dataset based on clinical parameters that could be quickly and easily assessed at the bedside. A score developed from the model coefficients was externally validated in two admissions datasets from Kilifi District Hospital, Kenya, and compared to published risk scores using Area Under the Receiver Operating Curve (AUROC) and Hosmer-Lemeshow tests. The Net Reclassification Index (NRI) was used to identify additional laboratory prognostic factors.

RESULTS

A risk score using 8 clinical variables (temperature, heart rate, capillary refill time, conscious level, severe pallor, respiratory distress, lung crepitations, and weak pulse volume) was developed. The score ranged from 0-10 and had an AUROC of 0.82 (95 % CI, 0.77-0.87) in the FEAST trial derivation set. In the independent validation datasets, the score had an AUROC of 0.77 (95 % CI, 0.72-0.82) amongst admissions to a paediatric high dependency ward and 0.86 (95 % CI, 0.82-0.89) amongst general paediatric admissions. This discriminative ability was similar to, or better than other risk scores in the validation datasets. NRI identified lactate, blood urea nitrogen, and pH to be important prognostic laboratory variables that could add information to the clinical score.

CONCLUSIONS

Eight clinical prognostic factors that could be rapidly assessed by healthcare staff for triage were combined to create the FEAST Paediatric Emergency Triage (PET) score and externally validated. The score discriminated those at highest risk of fatal outcome at the point of hospital admission and compared well to other published risk scores. Further laboratory tests were also identified as prognostic factors which could be added if resources were available or as indices of severity for comparison between centres in future research studies.

The passive leg raise test to predict fluid responsiveness in children--preliminary observations

OBJECTIVE

To assess whether the passive leg raising (PLR) test can predict fluid responsiveness in pediatric patients.

METHODS

This was a prospective observational study in a tertiary care pediatric center. Hemodynamic parameters including heart rate, stroke volume and cardiac output were assessed at baseline, after passive leg raising (PLR), at second baseline, and after volume loading (10 mL/kg normal saline in 10 min). Cutoff values of 7.5 and 10 % increase in cardiac index (CI) with passive leg raising were explored as predictors of volume loading response.

RESULTS

Overall, the changes in CI with passive leg raising varied widely and was a poor predictor of response to volume loading in children under 5 years of age. Of 40 patients, 23 had greater than 10 % increase in CI with PLR which predicted fluid responsiveness with a sensitivity of 94 % (95 % confidence interval 71,100) and specificity of 26 % (95 % confidence interval 10,48). Sensitivity was higher (100 % vs. 91 %) and specificity similar (27 % vs. 25 %) in predicting CI for those over 5 as compared to under 5 y, respectively. In patients over 5 y, simple linear regression revealed a positive correlation (R(2) = 21) while R(2) values were much lower (0-0.07) for those under 5 y.

CONCLUSIONS

Cardiac index changes after PLR varies widely in children and may be a poor predictor to volume loading in children under 5-y-old. However, in those over 5 y, PLR may be helpful in predicting fluid responsiveness in pediatric patients.

Immediate fluid management of children with severe febrile illness and signs of impaired circulation in low-income settings: a contextualised systematic review

OBJECTIVE

To evaluate the effects of intravenous fluid bolus compared to maintenance intravenous fluids alone as part of immediate emergency care in children with severe febrile illness and signs of impaired circulation in low-income settings.

DESIGN

Systematic review of randomised controlled trials (RCTs), and observational studies, including retrospective analyses, that compare fluid bolus regimens with maintenance fluids alone. The primary outcome measure was predischarge mortality.

DATA SOURCES AND SYNTHESIS

We searched PubMed, The Cochrane Library (to January 2014), with complementary earlier searches on, Google Scholar and Clinical Trial Registries (to March 2013). As studies used different clinical signs to define impaired circulation we classified patients into those with signs of severely impaired circulation, or those with any signs of impaired circulation. The quality of evidence for each outcome was appraised using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach. Findings are presented as risk ratios (RRs) with 95% CIs.

RESULTS

Six studies were included. Two were RCTs, one large trial (n=3141 children) from a low-income country and a smaller trial from a middle-income country. The remaining studies were from middle-income or high-income settings, observational, and with few participants (34-187 children).

SEVERELY IMPAIRED CIRCULATION

The large RCT included a small subgroup with severely impaired circulation. There were more deaths in those receiving bolus fluids (20-40 mL/kg/h, saline or albumin) compared to maintenance fluids (2.5-4 mL/kg/h; RR 2.40, 95% CI 0.84 to 6.88, p=0.054, 65 participants, low quality evidence). Three additional observational studies, all at high risk of confounding, found mixed effects on mortality (very low quality evidence).

ANY SIGNS OF IMPAIRED CIRCULATION

The large RCT included children with signs of both severely and non-severely impaired circulation. Overall, bolus fluids increased 48 h mortality compared to maintenance fluids with an additional 3 deaths per 100 children treated (RR 1.45, 95% CI 1.13 to 1.86, 3141 participants, high quality evidence). In a second small RCT from India, no difference in 72 h mortality was detected between children who received 20-40 mL/kg Ringers lactate over 15 min and those who received 20 mL over 20 min up to a maximum of 60 mL/kg over 1 h (147 participants, low quality evidence). In one additional observational study, resuscitation consistent with Advanced Paediatric Life Support (APLS) guidelines, including fluids, was not associated with reduced mortality in the small subgroup with septic shock (very low quality evidence).

SIGNS OF IMPAIRED CIRCULATION, BUT NOT SEVERELY IMPAIRED

Only the large RCT allowed an analysis for children with some signs of impaired circulation who would not meet the criteria for severe impairment. Bolus fluids increased 48 h mortality compared to maintenance alone (RR 1.36, 95% CI 1.05 to 1.76, high quality evidence).

CONCLUSIONS

Prior to the publication of the large RCT, the global evidence base for bolus fluid therapy in children with severe febrile illness and signs of impaired circulation was of very low quality. This large study provides robust evidence that in low-income settings fluid boluses increase mortality in children with severe febrile illness and impaired circulation, and this increased risk is consistent across children with severe and less severe circulatory impairment.