Protocol for a Randomized Controlled Trial to Evaluate a Permissive Blood Pressure Target Versus Usual Care in Critically Ill Children with Hypotension (PRESSURE).

OBJECTIVES: Management of hypotension is a fundamental part of pediatric critical care, with cardiovascular support in the form of fluids or vasoactive drugs offered to every hypotensive child. However, optimal blood pressure (BP) targets are unknown. The PRotocolised Evaluation of PermiSSive BP Targets Versus Usual CaRE (PRESSURE) trial aims to evaluate the clinical and cost-effectiveness of a permissive mean arterial pressure (MAP) target of greater than a fifth centile for age compared with usual care. DESIGN: Pragmatic, open, multicenter, parallel-group randomized control trial (RCT) with integrated economic evaluation. SETTING: Eighteen PICUs across the United Kingdom. PATIENTS: Infants and children older than 37 weeks corrected gestational age to 16 years accepted to a participating PICU, on mechanical ventilation and receiving vasoactive drugs for hypotension. INTERVENTIONS: Adjustment of hemodynamic support to achieve a permissive MAP target greater than fifth centile for age during invasive mechanical ventilation. MEASUREMENTS AND MAIN RESULTS: Randomization is 1:1 to a permissive MAP target or usual care, stratified by site and age group. Due to the emergency nature of the treatment, approaching patients for written informed consent will be deferred until after randomization. The primary clinical outcome is a composite of death and days of ventilatory support at 30 days. Baseline demographics and clinical status will be recorded as well as daily measures of BP and organ support, and discharge outcomes. This RCT received Health Research Authority approval (reference 289545), and a favorable ethical opinion from the East of England-Cambridge South Research Ethics Committee on May 10, 2021 (reference number 21/EE/0084). The trial is registered and has an International Standard RCT Number (reference 20609635). CONCLUSIONS: Trial findings will be disseminated in U.K. national and international conferences and in peer-reviewed journals.

International Consensus Criteria for Pediatric Sepsis and Septic Shock.

Importance: Sepsis is a leading cause of death among children worldwide. Current pediatric-specific criteria for sepsis were published in 2005 based on expert opinion. In 2016, the Third International Consensus Definitions for Sepsis and Septic Shock (Sepsis-3) defined sepsis as life-threatening organ dysfunction caused by a dysregulated host response to infection, but it excluded children. Objective: To update and evaluate criteria for sepsis and septic shock in children. Evidence Review: The Society of Critical Care Medicine (SCCM) convened a task force of 35 pediatric experts in critical care, emergency medicine, infectious diseases, general pediatrics, nursing, public health, and neonatology from 6 continents. Using evidence from an international survey, systematic review and meta-analysis, and a new organ dysfunction score developed based on more than 3 million electronic health record encounters from 10 sites on 4 continents, a modified Delphi consensus process was employed to develop criteria. Findings: Based on survey data, most pediatric clinicians used sepsis to refer to infection with life-threatening organ dysfunction, which differed from prior pediatric sepsis criteria that used systemic inflammatory response syndrome (SIRS) criteria, which have poor predictive properties, and included the redundant term, severe sepsis. The SCCM task force recommends that sepsis in children be identified by a Phoenix Sepsis Score of at least 2 points in children with suspected infection, which indicates potentially life-threatening dysfunction of the respiratory, cardiovascular, coagulation, and/or neurological systems. Children with a Phoenix Sepsis Score of at least 2 points had in-hospital mortality of 7.1% in higher-resource settings and 28.5% in lower-resource settings, more than 8 times that of children with suspected infection not meeting these criteria. Mortality was higher in children who had organ dysfunction in at least 1 of 4-respiratory, cardiovascular, coagulation, and/or neurological-organ systems that was not the primary site of infection. Septic shock was defined as children with sepsis who had cardiovascular dysfunction, indicated by at least 1 cardiovascular point in the Phoenix Sepsis Score, which included severe hypotension for age, blood lactate exceeding 5 mmol/L, or need for vasoactive medication. Children with septic shock had an in-hospital mortality rate of 10.8% and 33.5% in higher- and lower-resource settings, respectively. Conclusions and Relevance: The Phoenix sepsis criteria for sepsis and septic shock in children were derived and validated by the international SCCM Pediatric Sepsis Definition Task Force using a large international database and survey, systematic review and meta-analysis, and modified Delphi consensus approach. A Phoenix Sepsis Score of at least 2 identified potentially life-threatening organ dysfunction in children younger than 18 years with infection, and its use has the potential to improve clinical care, epidemiological assessment, and research in pediatric sepsis and septic shock around the world.

Development and Validation of the Phoenix Criteria for Pediatric Sepsis and Septic Shock.

Importance: The Society of Critical Care Medicine Pediatric Sepsis Definition Task Force sought to develop and validate new clinical criteria for pediatric sepsis and septic shock using measures of organ dysfunction through a data-driven approach. Objective: To derive and validate novel criteria for pediatric sepsis and septic shock across differently resourced settings. Design, Setting, and Participants: Multicenter, international, retrospective cohort study in 10 health systems in the US, Colombia, Bangladesh, China, and Kenya, 3 of which were used as external validation sites. Data were collected from emergency and inpatient encounters for children (aged <18 years) from 2010 to 2019: 3 049 699 in the development (including derivation and internal validation) set and 581 317 in the external validation set. Exposure: Stacked regression models to predict mortality in children with suspected infection were derived and validated using the best-performing organ dysfunction subscores from 8 existing scores. The final model was then translated into an integer-based score used to establish binary criteria for sepsis and septic shock. Main Outcomes and Measures: The primary outcome for all analyses was in-hospital mortality. Model- and integer-based score performance measures included the area under the precision recall curve (AUPRC; primary) and area under the receiver operating characteristic curve (AUROC; secondary). For binary criteria, primary performance measures were positive predictive value and sensitivity. Results: Among the 172 984 children with suspected infection in the first 24 hours (development set; 1.2% mortality), a 4-organ-system model performed best. The integer version of that model, the Phoenix Sepsis Score, had AUPRCs of 0.23 to 0.38 (95% CI range, 0.20-0.39) and AUROCs of 0.71 to 0.92 (95% CI range, 0.70-0.92) to predict mortality in the validation sets. Using a Phoenix Sepsis Score of 2 points or higher in children with suspected infection as criteria for sepsis and sepsis plus 1 or more cardiovascular point as criteria for septic shock resulted in a higher positive predictive value and higher or similar sensitivity compared with the 2005 International Pediatric Sepsis Consensus Conference (IPSCC) criteria across differently resourced settings. Conclusions and Relevance: The novel Phoenix sepsis criteria, which were derived and validated using data from higher- and lower-resource settings, had improved performance for the diagnosis of pediatric sepsis and septic shock compared with the existing IPSCC criteria.

The rapid detection of respiratory pathogens in critically ill children.

PURPOSE: Respiratory infections are the most common reason for admission to paediatric intensive care units (PICU). Most patients with lower respiratory tract infection (LRTI) receive broad-spectrum antimicrobials, despite low rates of bacterial culture confirmation. Here, we evaluated a molecular diagnostic test for LRTI to inform the better use of antimicrobials. METHODS: The Rapid Assay for Sick Children with Acute Lung infection Study was a single-centre, prospective, observational cohort study of mechanically ventilated children (> 37/40 weeks corrected gestation to 18 years) with suspected community acquired or ventilator-associated LRTI. We evaluated the use of a 52-pathogen custom TaqMan Array Card (TAC) to identify pathogens in non-bronchoscopic bronchoalveolar lavage (mini-BAL) samples. TAC results were compared to routine microbiology testing. Primary study outcomes were sensitivity and specificity of TAC, and time to result. RESULTS: We enrolled 100 patients, all of whom were tested with TAC and 91 of whom had matching culture samples. TAC had a sensitivity of 89.5% (95% confidence interval (CI95) 66.9-98.7) and specificity of 97.9% (CI95 97.2-98.5) compared to routine bacterial and fungal culture. TAC took a median 25.8 h (IQR 9.1-29.8 h) from sample collection to result. Culture was significantly slower: median 110.4 h (IQR 85.2-141.6 h) for a positive result and median 69.4 h (IQR 52.8-78.6) for a negative result. CONCLUSIONS: TAC is a reliable and rapid adjunct diagnostic approach for LRTI in critically ill children, with the potential to aid early rationalisation of antimicrobial therapy.

Randomization to a Liberal Versus Conservative Oxygenation Target: Redox Responses in Critically Ill Children.

RATIONALE: Optimal systemic oxygenation targets in pediatric critical illness are unknown. A U-shaped relationship exists between blood oxygen levels and PICU mortality. Redox stress or iatrogenic injury from intensive treatments are potential mechanisms of harm from hyperoxia. OBJECTIVES: To measure biomarkers of oxidative status in children admitted to PICU and randomized to conservative (oxygen-hemoglobin saturation [Sp o2 ] 88-92%) versus liberal (Sp o2 > 94%) peripheral oxygenation targets. DESIGN: Mechanistic substudy nested within the Oxygen in PICU (Oxy-PICU) pilot randomized feasibility clinical trial ( ClinicalTrials.gov : NCT03040570). SETTING: Three U.K. mixed medical and surgical PICUs in university hospitals. PATIENTS: Seventy-five eligible patients randomized to the Oxy-PICU randomized feasibility clinical trial. INTERVENTIONS: Randomization to a conservative (Sp o2 88-92%) versus liberal (Sp o2 > 94%) peripheral oxygenation target. MEASUREMENTS AND MAIN RESULTS: Blood and urine samples were collected at two timepoints: less than 24 hours and up to 72 hours from randomization in trial participants (March 2017 to July 2017). Plasma was analyzed for markers of ischemic/oxidative response, namely thiobarbituric acid-reactive substances (TBARS; lipid peroxidation marker) and ischemia-modified albumin (protein oxidation marker). Total urinary nitrate/nitrite was measured as a marker of reactive oxygen and nitrogen species (RONS). Blood hypoxia-inducible factor (HIF)-1a messenger RNA (mRNA) expression (hypoxia response gene) was measured by reverse transcription- polymerase chain reaction. Total urinary nitrate/nitrite levels were greater in the liberal compared with conservative oxygenation group at 72 hours (median difference 32.6 µmol/mmol of creatinine [95% CI 13.7-93.6]; p < 0.002, Mann-Whitney test). HIF-1a mRNA expression was increased in the conservative group compared with liberal in less than 24-hour samples (6.0-fold [95% CI 1.3-24.0]; p = 0.032). There were no significant differences in TBARS or ischemia-modified albumin. CONCLUSIONS: On comparing liberal with conservative oxygenation targets, we show, first, significant redox response (increase in urinary markers of RONS), but no changes in markers of lipid or protein oxidation. We also show what appears to be an early hypoxic response (increase in HIF-1a gene expression) in subjects exposed to conservative rather than liberal oxygenation targets.

Variation in Early Pediatric Intensive Care Management Strategies and Duration of Invasive Mechanical Ventilation for Acute Viral Bronchiolitis in the United Kingdom: A Retrospective Multicenter Cohort Study.

OBJECTIVES: Management of mechanically ventilated patients with bronchiolitis is not standardized and duration of mechanical ventilation has been shown to vary widely between centers. The aim of this study was to examine practice in a large number of U.K. PICUs with a view to identify if early management choices relating to fluid prescription, sedative agent use, and endotracheal tube (ETT) placement were associated with differences in duration of invasive mechanical ventilation (IMV). DESIGN: Retrospective multicenter cohort study. Primary outcome was duration of IMV. A hierarchical gamma generalized linear model was used to test for associations between practice variables (sedative and neuromuscular blocking agents, route of endotracheal intubation at 24 hr and fluid balance at 48 hr) and duration of IMV after adjustment for known confounders. SETTING: Thirteen U.K. PICUs. Duration of 2 months between November and December 2019. PATIENTS: Three hundred fifty infants receiving IMV for bronchiolitis. Excluded were patients receiving long-term ventilation, extracorporeal life support, or who died before separation from IMV. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: After adjustment for confounders, several variables were associated with an increase in the geometric mean duration of IMV (expressed as a percentage) including: nasal ETT use, 16% (95% CI, 1-32%); neuromuscular blockade use, 39% (95% CI, 21-61%); and fluid balance at 48 hr, 13% per 100 mL/kg positive fluid balance (95% CI, -1% to 28%). The association of sedative use varied with class of agent. The use of an alpha-2 agonist alone was associated with a reduction in duration of IMV by 19% in relation to no sedative agent (95% CI, -31 to -5%), whereas benzodiazepine uses alone or with alpha-2 agonist in combination were similar to using neither agent. CONCLUSIONS: Early management strategies for bronchiolitis were associated with the duration of IMV across U.K. centers after adjustment for confounders. Future work should prospectively assess the impact of fluid restriction, route of endotracheal intubation, and alpha-2 agonist use on duration of IMV in infants with bronchiolitis, with the aim of reducing seasonal bed pressure.

Criteria for Pediatric Sepsis-A Systematic Review and Meta-Analysis by the Pediatric Sepsis Definition Taskforce.

OBJECTIVE: To determine the associations of demographic, clinical, laboratory, organ dysfunction, and illness severity variable values with: 1) sepsis, severe sepsis, or septic shock in children with infection and 2) multiple organ dysfunction or death in children with sepsis, severe sepsis, or septic shock. DATA SOURCES: MEDLINE, Embase, and the Cochrane Central Register of Controlled Trials were searched from January 1, 2004, and November 16, 2020. STUDY SELECTION: Case-control studies, cohort studies, and randomized controlled trials in children greater than or equal to 37-week-old postconception to 18 years with suspected or confirmed infection, which included the terms "sepsis," "septicemia," or "septic shock" in the title or abstract. DATA EXTRACTION: Study characteristics, patient demographics, clinical signs or interventions, laboratory values, organ dysfunction measures, and illness severity scores were extracted from eligible articles. Random-effects meta-analysis was performed. DATA SYNTHESIS: One hundred and six studies met eligibility criteria of which 81 were included in the meta-analysis. Sixteen studies (9,629 patients) provided data for the sepsis, severe sepsis, or septic shock outcome and 71 studies (154,674 patients) for the mortality outcome. In children with infection, decreased level of consciousness and higher Pediatric Risk of Mortality scores were associated with sepsis/severe sepsis. In children with sepsis/severe sepsis/septic shock, chronic conditions, oncologic diagnosis, use of vasoactive/inotropic agents, mechanical ventilation, serum lactate, platelet count, fibrinogen, procalcitonin, multi-organ dysfunction syndrome, Pediatric Logistic Organ Dysfunction score, Pediatric Index of Mortality-3, and Pediatric Risk of Mortality score each demonstrated significant and consistent associations with mortality. Pooled mortality rates varied among high-, upper middle-, and lower middle-income countries for patients with sepsis, severe sepsis, and septic shock (p < 0.0001). CONCLUSIONS: Strong associations of several markers of organ dysfunction with the outcomes of interest among infected and septic children support their inclusion in the data validation phase of the Pediatric Sepsis Definition Taskforce.

Machine learning model for early prediction of acute kidney injury (AKI) in pediatric critical care.

BACKGROUND: Acute kidney injury (AKI) in pediatric critical care patients is diagnosed using elevated serum creatinine, which occurs only after kidney impairment. There are no treatments other than supportive care for AKI once it has developed, so it is important to identify patients at risk to prevent injury. This study develops a machine learning model to learn pre-disease patterns of physiological measurements and predict pediatric AKI up to 48 h earlier than the currently established diagnostic guidelines. METHODS: EHR data from 16,863 pediatric critical care patients between 1 month to 21 years of age from three independent institutions were used to develop a single machine learning model for early prediction of creatinine-based AKI using intelligently engineered predictors, such as creatinine rate of change, to automatically assess real-time AKI risk. The primary outcome is prediction of moderate to severe AKI (Stage 2/3), and secondary outcomes are prediction of any AKI (Stage 1/2/3) and requirement of renal replacement therapy (RRT). Predictions generate alerts allowing fast assessment and reduction of AKI risk, such as: "patient has 90% risk of developing AKI in the next 48 h" along with contextual information and suggested response such as "patient on aminoglycosides, suggest check level and review dose and indication". RESULTS: The model was successful in predicting Stage 2/3 AKI prior to detection by conventional criteria with a median lead-time of 30 h at AUROC of 0.89. The model predicted 70% of subsequent RRT episodes, 58% of Stage 2/3 episodes, and 41% of any AKI episodes. The ratio of false to true alerts of any AKI episodes was approximately one-to-one (PPV 47%). Among patients predicted, 79% received potentially nephrotoxic medication after being identified by the model but before development of AKI. CONCLUSIONS: As the first multi-center validated AKI prediction model for all pediatric critical care patients, the machine learning model described in this study accurately predicts moderate to severe AKI up to 48 h in advance of AKI onset. The model may improve outcome of pediatric AKI by providing early alerting and actionable feedback, potentially preventing or reducing AKI by implementing early measures such as medication adjustment.

Perspective of the Surviving Sepsis Campaign on the Management of Pediatric Sepsis in the Era of Coronavirus Disease 2019.

Severe acute respiratory syndrome coronavirus 2 is a novel cause of organ dysfunction in children, presenting as either coronavirus disease 2019 with sepsis and/or respiratory failure or a hyperinflammatory shock syndrome. Clinicians must now consider these diagnoses when evaluating children for septic shock and sepsis-associated organ dysfunction. The Surviving Sepsis Campaign International Guidelines for the Management of Septic Shock and Sepsis-associated Organ Dysfunction in Children provide an appropriate framework for the early recognition and initial resuscitation of children with sepsis or septic shock caused by all pathogens, including severe acute respiratory syndrome coronavirus 2. However, the potential benefits of select adjunctive therapies may differ from non-coronavirus disease 2019 sepsis.

Surviving Sepsis Campaign International Guidelines for the Management of Septic Shock and Sepsis-Associated Organ Dysfunction in Children.

OBJECTIVES: To develop evidence-based recommendations for clinicians caring for children (including infants, school-aged children, and adolescents) with septic shock and other sepsis-associated organ dysfunction. DESIGN: A panel of 49 international experts, representing 12 international organizations, as well as three methodologists and three public members was convened. Panel members assembled at key international meetings (for those panel members attending the conference), and a stand-alone meeting was held for all panel members in November 2018. A formal conflict-of-interest policy was developed at the onset of the process and enforced throughout. Teleconferences and electronic-based discussion among the chairs, co-chairs, methodologists, and group heads, as well as within subgroups, served as an integral part of the guideline development process. METHODS: The panel consisted of six subgroups: recognition and management of infection, hemodynamics and resuscitation, ventilation, endocrine and metabolic therapies, adjunctive therapies, and research priorities. We conducted a systematic review for each Population, Intervention, Control, and Outcomes question to identify the best available evidence, statistically summarized the evidence, and then assessed the quality of evidence using the Grading of Recommendations Assessment, Development, and Evaluation approach. We used the evidence-to-decision framework to formulate recommendations as strong or weak, or as a best practice statement. In addition, "in our practice" statements were included when evidence was inconclusive to issue a recommendation, but the panel felt that some guidance based on practice patterns may be appropriate. RESULTS: The panel provided 77 statements on the management and resuscitation of children with septic shock and other sepsis-associated organ dysfunction. Overall, six were strong recommendations, 52 were weak recommendations, and nine were best-practice statements. For 13 questions, no recommendations could be made; but, for 10 of these, "in our practice" statements were provided. In addition, 49 research priorities were identified. CONCLUSIONS: A large cohort of international experts was able to achieve consensus regarding many recommendations for the best care of children with sepsis, acknowledging that most aspects of care had relatively low quality of evidence resulting in the frequent issuance of weak recommendations. Despite this challenge, these recommendations regarding the management of children with septic shock and other sepsis-associated organ dysfunction provide a foundation for consistent care to improve outcomes and inform future research.

Mortality and morbidity in community-acquired sepsis in European pediatric intensive care units: a prospective cohort study from the European Childhood Life-threatening Infectious Disease Study (EUCLIDS).

BACKGROUND: Sepsis is one of the main reasons for non-elective admission to pediatric intensive care units (PICUs), but little is known about determinants influencing outcome. We characterized children admitted with community-acquired sepsis to European PICUs and studied risk factors for mortality and disability. METHODS: Data were collected within the collaborative Seventh Framework Programme (FP7)-funded EUCLIDS study, which is a prospective multicenter cohort study aiming to evaluate genetic determinants of susceptibility and/or severity in sepsis. This report includes 795 children admitted with community-acquired sepsis to 52 PICUs from seven European countries between July 2012 and January 2016. The primary outcome measure was in-hospital death. Secondary outcome measures were PICU-free days censured at day 28, hospital length of stay, and disability. Independent predictors were identified by multivariate regression analysis. RESULTS: Patients most commonly presented clinically with sepsis without a source (n = 278, 35%), meningitis/encephalitis (n = 182, 23%), or pneumonia (n = 149, 19%). Of 428 (54%) patients with confirmed bacterial infection, Neisseria meningitidis (n = 131, 31%) and Streptococcus pneumoniae (n = 78, 18%) were the main pathogens. Mortality was 6% (51/795), increasing to 10% in the presence of septic shock (45/466). Of the survivors, 31% were discharged with disability, including 24% of previously healthy children who survived with disability. Mortality and disability were independently associated with S. pneumoniae infections (mortality OR 4.1, 95% CI 1.1-16.0, P = 0.04; disability OR 5.4, 95% CI 1.8-15.8, P < 0.01) and illness severity as measured by Pediatric Index of Mortality (PIM2) score (mortality OR 2.8, 95% CI 1.3-6.1, P < 0.01; disability OR 3.4, 95% CI 1.8-6.4, P < 0.001). CONCLUSIONS: Despite widespread immunization campaigns, invasive bacterial disease remains responsible for substantial morbidity and mortality in critically ill children in high-income countries. Almost one third of sepsis survivors admitted to the PICU were discharged with some disability. More research is required to delineate the long-term outcome of pediatric sepsis and to identify interventional targets. Our findings emphasize the importance of improved early sepsis-recognition programs to address the high burden of disease.

A clinical prediction model to identify patients at high risk of hemodynamic instability in the pediatric intensive care unit.

BACKGROUND: Early recognition and timely intervention are critical steps for the successful management of shock. The objective of this study was to develop a model to predict requirement for hemodynamic intervention in the pediatric intensive care unit (PICU); thus, clinicians can direct their care to patients likely to benefit from interventions to prevent further deterioration. METHODS: The model proposed in this study was trained on a retrospective cohort of all patients admitted to a tertiary PICU at a single center in the United States, and validated on another retrospective cohort of all patients admitted to the PICU at a single center in the United Kingdom. The PICU clinical information system database (Intellivue Clinical Information Portfolio, Philips, UK) was interrogated to collect physiological and laboratory data. The model was trained using a variant of AdaBoost, which learned a set of low-dimensional classifiers, each of which was age adjusted. RESULTS: A total of 7052 patients admitted to the US PICU was used for training the model, and a total of 970 patients admitted to the UK PICU was used for validation. On the training/validation datasets, the model showed better prediction of hemodynamic intervention (area under the receiver operating characteristic (AUROC) = 0.81/0.81) than systolic blood pressure-based (AUCROC = 0.58/0.67) or shock index-based (AUCROC = 0.63/0.65) models. Both of these models were age adjusted using the same classifier. CONCLUSIONS: The proposed model reliably predicted the need for hemodynamic intervention in PICU patients and provides better classification performance when compared to systolic blood pressure-based or shock index-based models alone. This model could readily be built into a clinical information system to identify patients at risk of hemodynamic instability.

Attitudes towards fever amongst UK paediatric intensive care staff.

The role played by fever in the outcome of critical illness in children is unclear. This survey of medical and nursing staff in 35 paediatric intensive care units and transport teams in the United Kingdom and Ireland established attitudes towards the management of children with fever. Four hundred sixty-two medical and nursing staff responded to a web-based survey request. Respondents answered eight questions regarding thresholds for temperature control in usual clinical practice, indications for paracetamol use, and readiness to participate in a clinical trial of permissive temperature control. The median reported threshold for treating fever in clinical practice was 38 °C (IQR 38-38.5 °C). Paracetamol was reported to be used as an analgesic and antipyretic but also for non-specific comfort indications. There was a widespread support for a clinical trial of a permissive versus a conservative approach to fever in paediatric intensive care units. Within a trial, 58% of the respondents considered a temperature of 39 °C acceptable without treatment. CONCLUSIONS: Staff on paediatric intensive care units in the United Kingdom and Ireland tends to treat temperatures within the febrile range. There was a willingness to conduct a randomized controlled trial of treatment of fever. What is known: • The effect of fever on the outcome in paediatric critical illness is unknown. • Paediatricians have traditionally been reluctant to allow fever in sick children. What is new: • Paediatric intensive care staff report a tendency towards treating fever, with a median reported treatment threshold of 38 °C. • There is widespread support amongst PICU staff in the UK for a randomized controlled trial of temperature in critically ill children. • Within a trial setting, PICU staff attitudes to fever are more permissive than in clinical practice.

The Impact of Chronic Health Conditions on Length of Stay and Mortality in a General PICU.

OBJECTIVES: Each year approximately 20,000 children are admitted to PICUs across the United Kingdom. It is highlighted in several international studies that 40-70% of children admitted to PICUs have at least one chronic health condition that leads to increased length of stay and higher mortality rates. The prevalence of chronic health conditions in children admitted to U.K. PICUs is unknown. The purpose of this study was to use existing clinical data to explore the prevalence and impact of chronic health conditions on length of stay and mortality in a tertiary U.K. PICU. DESIGN: Single-centre retrospective observational cohort study. SETTING: Single, tertiary referral PICU. PATIENTS: One thousand one hundred ninety-seven children 0-18 years old admitted between March 1, 2009, and February 28, 2013. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Data were derived from the unit's data submitted to the Paediatric Intensive Care Audit Network, the U.K. national PICU dataset. Data included demographics, diagnosis, Pediatric Index of Mortality-2 score, PICU interventions, PICU outcomes, chronic health condition etiologies, admission, and discharge dates and times. In total, 554 of 1,197 (46.3%) had at least one chronic health condition. Of 554, 371 patients (67.1%) presented with a single chronic health condition, 126 (22.6%) with two chronic health conditions, and 57 (10.3%) with at least three chronic health conditions to a maximum of four chronic health conditions. There was a statistically significant difference in length of stay in those with a chronic health condition compared with those without (medians, 4 vs 3 d [interquartile range, 1-7 d]; Mann-Whitney U test, p < 0.001). The length of stay also increased significantly according to the number of chronic health conditions (Kruskal-Wallis test, p < 0.001). Mortality was significantly different between those with and without chronic health conditions (8.8% vs 5.4%; chi-square test, p = 0.024). Having two or at least three chronic health conditions significantly increased mortality compared with no chronic health conditions (odds ratio, 2.3 [CI, 1.2-4.55]; p = 0.013 and 2.95 [CI, 1.28-6.8]; p = 0.011), respectively. CONCLUSIONS: The increasing number of chronic healthcare conditions is associated with length of stay and mortality.

Admission Plasma Troponin I Is Associated With Mortality in Pediatric Intensive Care.

OBJECTIVES: Assessment of whether admission plasma troponin I level is associated with mortality or requirement for vasoactive drugs in pediatric intensive care. DESIGN: Retrospective cohort study. SETTING: Single centre, tertiary referral general PICU, without a cardiac surgical program. PATIENTS: Three hundred and nineteen patients 0-18 years old in two cohorts. Cohort 1 was admitted between January 2009 and September 2012 and the cohort 2 between April 2014 and April 2015. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Plasma troponin I was measured in patients in cohort 1 only if the attending physician ordered the test due to clinical concern regarding myocardial injury. The second cohort had plasma troponin I routinely measured at admission. The primary outcome was death during PICU admission, and the secondary outcome was maximum inotrope requirement during PICU stay, measured by Vasoactive Inotrope Score. Plasma troponin I was a discriminator for mortality in both cohorts (area under the receiver-operating characteristic curve of 0.73 and 0.86 in cohorts 1 and 2, respectively). In an adjusted analysis using Cox regression, accounting for Pediatric Index of Mortality 2 risk of mortality and age, elevated plasma troponin I was significantly associated with death in both cohorts (hazard ratio, 4.99; p = 0.033; hazard ratio, 10.5; p = 0.026 in cohorts 1 and 2, respectively). Elevated plasma troponin I was only associated with increased Vasoactive Inotrope Score following multivariate analysis in the cohort 2. CONCLUSIONS: Detectable plasma troponin I at admission to PICU is independently associated with death. The utility of troponin I as a stratification biomarker requires further evaluation.

Metabolic Profiling of Children Undergoing Surgery for Congenital Heart Disease.

OBJECTIVE: Inflammation and metabolism are closely interlinked. Both undergo significant dysregulation following surgery for congenital heart disease, contributing to organ failure and morbidity. In this study, we combined cytokine and metabolic profiling to examine the effect of postoperative tight glycemic control compared with conventional blood glucose management on metabolic and inflammatory outcomes in children undergoing congenital heart surgery. The aim was to evaluate changes in key metabolites following congenital heart surgery and to examine the potential of metabolic profiling for stratifying patients in terms of expected clinical outcomes. DESIGN: Laboratory and clinical study. SETTING: University Hospital and Laboratory. PATIENTS: Of 28 children undergoing surgery for congenital heart disease, 15 underwent tight glycemic control postoperatively and 13 were treated conventionally. INTERVENTIONS: Metabolic profiling of blood plasma was undertaken using proton nuclear magnetic resonance spectroscopy. A panel of metabolites was measured using a curve-fitting algorithm. Inflammatory cytokines were measured by enzyme-linked immunosorbent assay. The data were assessed with respect to clinical markers of disease severity (Risk Adjusted Congenital heart surgery score-1, Pediatric Logistic Organ Dysfunction, inotrope score, duration of ventilation and pediatric ICU-free days). MEASUREMENTS AND MAIN RESULTS: Changes in metabolic and inflammatory profiles were seen over the time course from surgery to recovery, compared with the preoperative state. Tight glycemic control did not significantly alter the response profile. We identified eight metabolites (3-D-hydroxybutyrate, acetone, acetoacetate, citrate, lactate, creatine, creatinine, and alanine) associated with surgical and disease severity. The strength of proinflammatory response, particularly interleukin-8 and interleukin-6 concentrations, inversely correlated with PICU-free days at 28 days. The interleukin-6/interleukin-10 ratio directly correlated with plasma lactate. CONCLUSIONS: This is the first report on the metabolic response to cardiac surgery in children. Using nuclear magnetic resonance to monitor the patient journey, we identified metabolites whose concentrations and trajectory appeared to be associated with clinical outcome. Metabolic profiling could be useful for patient stratification and directing investigations of clinical interventions.

Fluid overload at 48 hours is associated with respiratory morbidity but not mortality in a general PICU: retrospective cohort study.

OBJECTIVE: Recent evidence suggests that fluid overload may be deleterious to critically ill children. The purpose of this study was to investigate the association of early fluid overload with respiratory morbidity and mortality in patients admitted to a general PICU. DESIGN: Retrospective cohort study. SETTING: Single, tertiary referral PICU. PATIENTS SIX HUNDRED THIRTY-SIX: patients aged 0-16 years invasively ventilated at 48 hours post admission, admitted between April 1, 2009, and March 31, 2013. MEASUREMENTS AND MAIN RESULTS: Data collected included demographics, diagnosis, Pediatric Index of Mortality 2 score, and fluid overload percent at 48 hours from admission. Fluid overload percent was calculated as (cumulative fluid in - cumulative fluid out (L))/hospital admission weight (kg) × 100%. Outcome measures were oxygenation index at 48 hours from admission, death, and invasive ventilation days in survivors. Data are reported as median (interquartile range) and were analyzed using nonparametric tests. The median age was 1.05 years (0.3-4.2 yr). Fifty-three patients (8%) died. Median duration of ventilation in survivors was 5 days (3-8 d). Fluid overload percent correlated significantly with oxygenation index (Spearman ρ, 0.318; p < 0.0001) and with invasive ventilation days in survivors (Spearman ρ, 0.274; p < 0.0001). There was no significant difference in fluid overload percent between survivors and nonsurvivors. Regression analysis demonstrated that fluid overload percent was a significant predictor of both oxygenation index at 48 hours (p < 0.001) and invasive ventilation days (p = 0.002). CONCLUSIONS: Fluid overload at 48 hours was associated with oxygenation index at 48 hours and invasive ventilation days in survivors in a general PICU population. There was no association of fluid overload at 48 hours with mortality.

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

OBJECTIVE: Early deaths in pediatric sepsis may limit the impact of therapies that can only be provided on PICUs. By introducing selection and survivorship biases, these very early deaths may also undermine the results of trials that employ standard consent procedures. We hypothesized that: 1) the majority of deaths in children with severe sepsis occur very early, within 24 hours of referral to PICU; and 2) a significant proportion of deaths occur before PICU admission. DESIGN, SETTING, AND PATIENTS: We studied consecutive referrals of newborns through to 16 years of age, between 2005 and 2011 to the Children's Acute Transport Service, the North Thames regional pediatric intensive care transport service, with a working diagnosis of "sepsis," "severe sepsis," "meningococcal sepsis," or "septic shock." INTERVENTIONS: The primary outcome measure was the proportion of deaths within 24 hours of referral. Survival distributions of previously healthy children were compared with those with significant comorbidities. MEASUREMENTS AND MAIN RESULTS: Thirteen thousand four hundred and nine referrals were made to Children's Acute Transport Service, of whom 703 (5%) met inclusion criteria. Data on survival to 1 year were available in 627 of 703 patients (89%). One hundred thirty children (130/627; 21%; 95% CI, 18-24%) died in the first year. A higher proportion of children with comorbidity cases (46/85, 54%, 44-64) died compared with previously healthy cases (84/542; 16%; 13-19; p < 0.0005, Fisher exact test). Seventy-one deaths occurred within 24 hours of PICU referral (71/130, 55%, 46-63). The timing of death differed with comorbidity. Similar proportions of children survived to 24 hours (previously healthy children 90% vs children with comorbidity 83%, p = 0.06). However, deaths after 24 hours were infrequent among previously healthy cases (28/84 deaths, 33%, 24-44%) compared with children with comorbidity cases (31/46 deaths, 66%, 53-79%) (p < 0.001, Fisher exact test). CONCLUSIONS: This majority of deaths among children referred for pediatric intensive care with for severe sepsis occur within 24 hours. This has important implications for future clinical trials and quality improvement initiatives aimed at improving sepsis outcomes.