Timing of death in children referred for intensive care with severe sepsis: implications for interventional studies

2016 Update for the Rogers' Textbook of Pediatric Intensive Care: Recognition and Initial Management of Shock

OBJECTIVE

To review important articles in the field of pediatric shock and pediatric septic shock published subsequent to the Fifth Edition of the Rogers' Textbook of Pediatric Intensive Care.

DATA SOURCES

The U.S. National Library of Medicine PubMed (www.ncbi.nlm.nih.gov/pubmed) was searched for combination of the term "pediatric" and the following terms: "sepsis, septic shock, shock, antibiotics, extracorporeal membrane oxygenation, and steroid." The abstract lists generated by these searches were screened for potential inclusion. The authors were also aware of a number of key recent articles in pediatric shock, and these were also screened.

STUDY SELECTION AND DATA EXTRACTION

Promising articles published subsequent to the fifth edition of the textbook were included based on the consensus of the authors and via the peer review process.

DATA EXTRACTION

Articles were grouped by category. Each author was assigned categories and extracted data from articles in that category. All authors contributed to final review of extracted data.

DATA SYNTHESIS

Articles in the following categories were included: epidemiology and recognition of shock; laboratory markers of shock; antimicrobial therapy; vasoactive therapy; extracorporeal therapies; mortality patterns, prediction, and risk stratification; bundled approaches to shock recognition and management; and corticosteroid use.

CONCLUSION

Research efforts in pediatric shock have largely centered on pediatric septic shock, with significant progress in the understanding of sepsis epidemiology, the use of extracorporeal therapies in critically ill children with sepsis, the role of hyperlactatemia and risk stratification in pediatric septic shock, and the impact of bundled care for pediatric sepsis, including evaluation of individual bundle elements such as the optimal timing of antibiotic administration and vasoactive medication choice. A consistent theme in the literature is the beneficial role of a bundled approach to septic shock recognition and management to improve both care and outcomes.

Refractory septic shock in children: a European Society of Paediatric and Neonatal Intensive Care definition

Purpose

Although overall paediatric septic shock mortality is decreasing, refractory septic shock (RSS) is still associated with high mortality. A definition for RSS is urgently needed to facilitate earlier identification and treatment. We aim to establish a European society of paediatric and neonatal intensive care (ESPNIC) experts’ definition of paediatric RSS.

Methods

We conducted a two-round Delphi study followed by an observational multicentre retrospective study. One hundred and fourteen paediatric intensivists answered a clinical case-based, two-round Delphi survey, identifying clinical items consistent with RSS. Multivariate analysis of these items in a development single-centre cohort (70 patients, 30 % mortality) facilitated development of RSS definitions based on either a bedside or computed severity score. Both scores were subsequently tested in a validation cohort (six centres, 424 patients, 11.6 % mortality).

Results

From the Delphi process, the draft definition included evidence of myocardial dysfunction and high blood lactate levels despite high vasopressor treatment. When assessed in the development population, each item was independently associated with the need for extracorporeal life support (ECLS) or death. Resultant bedside and computed septic shock scores had high discriminative power against the need for ECLS or death, with areas under the receiver operating characteristics curve of 0.920 (95 % CI 0.89–0.94), and 0.956 (95 % CI 0.93–0.97), respectively. RSS defined by a bedside score equal to or higher than 2 and a computed score equal to or higher than 3.5 was associated with a significant increase in mortality.

Conclusions

This ESPNIC definition of RSS accurately identifies children with the most severe form of septic shock.

Electronic supplementary material

The online version of this article (doi:10.1007/s00134-016-4574-2) contains supplementary material, which is available to authorized users.

Exome Sequencing Reveals Primary Immunodeficiencies in Children with Community-Acquired Pseudomonas aeruginosa Sepsis

One out of three pediatric sepsis deaths in high income countries occur in previously healthy children. Primary immunodeficiencies (PIDs) have been postulated to underlie fulminant sepsis, but this concept remains to be confirmed in clinical practice. Pseudomonas aeruginosa (P. aeruginosa) is a common bacterium mostly associated with health care-related infections in immunocompromised individuals. However, in rare cases, it can cause sepsis in previously healthy children. We used exome sequencing and bioinformatic analysis to systematically search for genetic factors underpinning severe P. aeruginosa infection in the pediatric population. We collected blood samples from 11 previously healthy children, with no family history of immunodeficiency, who presented with severe sepsis due to community-acquired P. aeruginosa bacteremia. Genomic DNA was extracted from blood or tissue samples obtained intravitam or postmortem. We obtained high-coverage exome sequencing data and searched for rare loss-of-function variants. After rigorous filtrations, 12 potentially causal variants were identified. Two out of eight (25%) fatal cases were found to carry novel pathogenic variants in PID genes, including BTK and DNMT3B. This study demonstrates that exome sequencing allows to identify rare, deleterious human genetic variants responsible for fulminant sepsis in apparently healthy children. Diagnosing PIDs in such patients is of high relevance to survivors and affected families. We propose that unusually severe and fatal sepsis cases in previously healthy children should be considered for exome/genome sequencing to search for underlying PIDs.

Association of Fluid Accumulation with Clinical Outcomes in Critically Ill Children with Severe Sepsis

Objective

To evaluate whether early and acquired daily fluid overload (FO), as well as fluctuations in fluid accumulation, were associated with adverse outcomes in critically ill children with severe sepsis.

Methods

This study enrolled 202 children in a pediatric intensive care unit (PICU) with severe sepsis. Early fluid overload was defined as ≥5% fluid accumulation occurring in the first 24 hours of PICU admission. The maximum daily fluid accumulation ≥5% occurring during the next 6 days in patients with at least 48 hours of PICU stay was defined as PICU-acquired daily fluid overload. The fluctuation in fluid accumulation was calculated as the difference between the maximum and the minimum daily fluid accumulation obtained during the first 7 days after admission.

Results

Of the 202 patients, 61 (30.2%) died during PICU stay. Among all patients, 41 (20.3%) experienced early fluid overload, including 9 with a FO ≥10%. Among patients with at least 48 hours of PICU stay (n = 154), 36 (23.4%) developed PICU-acquired daily fluid overload, including 2 with a FO ≥10%. Both early fluid overload (AOR = 1.20; 95% CI 1.08–1.33; P = 0.001; n = 202) and PICU-acquired daily fluid overload (AOR = 5.47 per log increase; 95% CI 1.15–25.96; P = 0.032; n = 154) were independent risk factors associated with mortality after adjusting for age, illness severity, etc. However, fluctuations in fluid accumulation were not associated with mortality after adjustment. Length of PICU stay increased with greater fluctuations in fluid accumulation in all patients with at least 48 hours of PICU stay (FO <5%, 5%-10% vs. ≥10%: 4 [3–8], 7 [4–11] vs. 10 [6–16] days; P <0.001; n = 154) and in survivors (4 [3–8], 7 [5–11] vs. 10 [5–15] days; P <0.001; n = 121). Early fluid overload achieved an area under-the-receiver-operating-characteristic curve of 0.74 (95% CI 0.65–0.82; P <0.001; n = 202) for predicting mortality in patients with severe sepsis, with a sensitivity of 67.2% and a specificity of 80.1% at the optimal cut-off value of 2.65%.

Conclusions

Both early and acquired daily fluid overload were independently associated with PICU mortality in children with severe sepsis.

Comparison of Pediatric Severe Sepsis Managed in U.S. and European ICUs

OBJECTIVES

Pediatric severe sepsis remains a significant global health problem without new therapies despite many multicenter clinical trials. We compared children managed with severe sepsis in European and U.S. PICUs to identify geographic variation, which may improve the design of future international studies.

DESIGN

We conducted a secondary analysis of the Sepsis PRevalence, OUtcomes, and Therapies study. Data about PICU characteristics, patient demographics, therapies, and outcomes were compared. Multivariable regression models were used to determine adjusted differences in morbidity and mortality.

SETTING

European and U.S. PICUs.

PATIENTS

Children with severe sepsis managed in European and U.S. PICUs enrolled in the Sepsis PRevalence, OUtcomes, and Therapies study.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

European PICUs had fewer beds (median, 11 vs 24; p < 0.001). European patients were younger (median, 1 vs 6 yr; p < 0.001), had higher severity of illness (median Pediatric Index of Mortality-3, 5.0 vs 3.8; p = 0.02), and were more often admitted from the ward (37% vs 24%). Invasive mechanical ventilation, central venous access, and vasoactive infusions were used more frequently in European patients (85% vs 68%, p = 0.002; 91% vs 82%, p = 0.05; and 71% vs 50%; p < 0.001, respectively). Raw morbidity and mortality outcomes were worse for European compared with U.S. patients, but after adjusting for patient characteristics, there were no significant differences in mortality, multiple organ dysfunction, disability at discharge, length of stay, or ventilator/vasoactive-free days.

CONCLUSIONS

Children with severe sepsis admitted to European PICUs have higher severity of illness, are more likely to be admitted from hospital wards, and receive more intensive care therapies than in the United States. The lack of significant differences in morbidity and mortality after adjusting for patient characteristics suggests that the approach to care between regions, perhaps related to PICU bed availability, needs to be considered in the design of future international clinical trials in pediatric severe sepsis.

Pediatric sepsis

PURPOSE OF REVIEW

Sepsis is the leading cause of pediatric death worldwide. In the United States alone, there are 72 000 children hospitalized for sepsis annually with a reported mortality rate of 25% and an economic cost estimated to be $4.8 billion. However, it is only recently that the definition and management of pediatric sepsis has been recognized as being distinct from adult sepsis.

RECENT FINDINGS

The definition of pediatric sepsis is currently in a state of evolution, and there is a large disconnect between the clinical and research definitions of sepsis which impacts the application of research findings into clinical practice. Despite this, it is the speed of diagnosis and the timely implementation of current treatment guidelines that has been shown to improve outcomes. However, adherence to treatment guidelines is currently low and it is only through the implementation of protocols that improved care and outcomes have been demonstrated.

SUMMARY

The current management of pediatric sepsis is largely based on adaptations from adult sepsis treatment; however, distinct physiology demands more prospective pediatric trials to tailor management to the pediatric population. Adherence to current and emerging practice guidelines will require that protocolized care pathways become a commonplace.