Ventilator-free days (VFDs) are a commonly reported composite outcome measure in acute respiratory distress syndrome trials. VFDs combine survival and duration of ventilation in a manner that ...summarizes the "net effect" of an intervention on these two outcomes. However, this combining of outcome measures makes VFDs difficult to understand and analyze, which contributes to imprecise interpretations. We discuss the strengths and limitations of VFDs and other "failure-free day" composites, and we provide a framework for when and how to use these outcome measures. We also provide a comprehensive discussion of the different analytic methods for analyzing and interpreting VFDs, including Student's
tests and rank-sum tests, as well as competing risk regressions treating extubation as the primary outcome and death as the competing risk. Using simulations, we illustrate how the statistical test with optimal power depends on the relative contributions of mortality and ventilator duration on the composite effect size. Finally, we recommend a simple analysis and reporting framework using the competing risk approach, which provides clear information on the effect size of an intervention, a statistical test and measure of confidence with the ability to adjust for baseline factors and allow interim monitoring for trials. We emphasize that any approach to analyzing a composite outcome, including other "failure-free day" constructs, should also be accompanied by an examination of the components.
The paper is concerned with inference based on the mean function of a functional time series. We develop a normal approximation for the functional sample mean and then focus on the estimation of the ...asymptotic variance kernel. Using these results, we develop and asymptotically justify testing procedures for the equality of means in two functional samples exhibiting temporal dependence. Evaluated by means of a simulation study and application to a real data set, these two-sample procedures enjoy good size and power in finite samples.
OBJECTIVES:To determine prevalence of delirium in critically ill children and explore associated risk factors.
DESIGN:Multi-institutional point prevalence study.
SETTING:Twenty-five pediatric ...critical care units in the United States, the Netherlands, New Zealand, Australia, and Saudi Arabia.
PATIENTS:All children admitted to the pediatric critical care units on designated study days (n = 994).
INTERVENTION:Children were screened for delirium using the Cornell Assessment of Pediatric Delirium by the bedside nurse. Demographic and treatment-related variables were collected.
MEASUREMENTS AND MAIN RESULTS:Primary study outcome measure was prevalence of delirium. In 159 children, a final determination of mental status could not be ascertained. Of the 835 remaining subjects, 25% screened positive for delirium, 13% were classified as comatose, and 62% were delirium-free and coma-free. Delirium prevalence rates varied significantly with reason for ICU admission, with highest delirium rates found in children admitted with an infectious or inflammatory disorder. For children who were in the PICU for 6 or more days, delirium prevalence rate was 38%. In a multivariate model, risk factors independently associated with development of delirium included age less than 2 years, mechanical ventilation, benzodiazepines, narcotics, use of physical restraints, and exposure to vasopressors and antiepileptics.
CONCLUSIONS:Delirium is a prevalent complication of critical illness in children, with identifiable risk factors. Further multi-institutional, longitudinal studies are required to investigate effect of delirium on long-term outcomes and possible preventive and treatment measures. Universal delirium screening is practical and can be implemented in pediatric critical care units.
Septic shock impacts mortality, morbidity, and health care costs. A quality improvement (QI) initiative was launched to improve early recognition and timely treatment of patients with septic shock in ...a pediatric emergency department (PED). Our primary aim was to describe the longitudinal effectiveness of the program, iterative changes in clinical practice, and associated outcomes.
We implemented multiple interventions during our QI initiative (February 2007 to December 2014). Analysis of compliance and outcomes focused on a bundle consisting of: (1) timely antibiotics, (2) intravenous fluids (IVF) for rapid reversal of perfusion abnormalities and/or hypotension. Logistic regression was used to obtain adjusted odds ratios (ORs) for death and pediatric ICU (PICU) admission.
A total of 1380 patients were treated for septic shock; 93% met screening criteria at triage. Implementation of the various processes improved timely interventions. One example included implementation of a sepsis order set, after which the mean proportion of patients receiving timely antibiotics increased to its highest rate. The odds of death were 5 times as high for children who did not receive bundle-compliant care (OR, 5.0 95% Confidence Interval 1.9, 14.3) compared with those who did (OR, 0.20 95% Confidence Interval 0.07, 0.53). Among PICU admitted patients, the odds of mortality were greater for children who presented with abnormal mental status and a higher pediatric index of mortality 2 score.
QI methodology improved septic shock program goal adherence and decreased mortality without increasing PICU admissions or PED length of stay over the 8-year period, supporting continued emphasis on early recognition, timely IVF resuscitation, and antibiotic administration.
OBJECTIVES:In-hospital pediatric sepsis mortality has decreased substantially, but long-term mortality and morbidity among children initially surviving sepsis, is unknown. Accordingly, the Life After ...Pediatric Sepsis Evaluation investigation was conducted to describe the trajectory of mortality and health-related quality of life morbidity for children encountering community-acquired septic shock.
DESIGN:Prospective, cohort-outcome study, conducted 2013–2017.
SETTING:Twelve academic PICUs in the United States.
PATIENTS:Critically ill children, 1 month to 18 years, with community-acquired septic shock requiring vasoactive-inotropic support.
INTERVENTIONS:Demographic, infection, illness severity, organ dysfunction, and resource utilization data were collected daily during PICU admission. Serial parent proxy-report health-related quality of life assessments were obtained at baseline, 7 days, and 1, 3, 6, and 12 months following PICU admission utilizing the Pediatric Quality of Life Inventory or Stein-Jessop Functional Status Scale.
MEASUREMENTS AND MAIN RESULTS:Among 389 children enrolled, mean age was 7.4 ± 5.8 years; 46% were female; 18% were immunocompromised; and 51% demonstrated chronic comorbidities. Baseline Pediatric Overall Performance Category was normal in 38%. Median (Q1–Q3) Pediatric Risk of Mortality and Pediatric Logistic Organ Dysfunction scores at PICU admission were 11.0 (6.0–17.0) and 9.0 (6.0–11.0); durations of vasoactive-inotropic and mechanical ventilation support were 3.0 days (2.0–6.0 d) and 8.0 days (5.0–14.0 d); and durations of PICU and hospital stay were 9.4 days (5.6–15.4 d) and 15.7 days (9.2–26.0 d). At 1, 3, 6, and 12 months following PICU admission for the septic shock event, 8%, 11%, 12%, and 13% of patients had died, while 50%, 37%, 30%, and 35% of surviving patients had not regained their baseline health-related quality of life.
CONCLUSIONS:This investigation provides the first longitudinal description of long-term mortality and clinically relevant, health-related quality of life morbidity among children encountering community-acquired septic shock. Although in-hospital mortality was 9%, 35% of survivors demonstrated significant, health-related quality of life deterioration from baseline that persisted at least 1 year following hospitalization for septic shock.
OBJECTIVES:A companion article reports the trajectory of long-term mortality and significant health-related quality of life disability among children encountering septic shock. In this article, the ...investigators examine critical illness factors associated with these adverse outcomes.
DESIGN:Prospective, cohort-outcome study, conducted 2013–2017.
SETTING:Twelve United States academic PICUs.
PATIENTS:Critically ill children, 1 month to 18 years, with community-acquired septic shock requiring vasoactive-inotropic support.
INTERVENTIONS:Illness severity, organ dysfunction, and resource utilization data were collected during PICU admission. Change from baseline health-related quality of life at the month 3 follow-up was assessed by parent proxy-report employing the Pediatric Quality of Life Inventory or the Stein-Jessop Functional Status Scale.
MEASUREMENTS AND MAIN RESULTS:In univariable modeling, critical illness variables associated with death and/or persistent, serious health-related quality of life deterioration were candidates for multivariable modeling using Bayesian information criterion. The most clinically relevant multivariable models were selected among models with near-optimal statistical fit. Three months following septic shock, 346 of 389 subjects (88.9%) were alive and 43 of 389 had died (11.1%); 203 of 389 (52.2%) had completed paired health-related quality of life surveys. Pediatric Risk of Mortality, cumulative Pediatric Logistic Organ Dysfunction scores, PICU and hospital durations of stay, maximum and cumulative vasoactive-inotropic scores, duration of mechanical ventilation, need for renal replacement therapy, extracorporeal life support or cardiopulmonary resuscitation, and appearance of pathologic neurologic signs were associated with adverse outcomes in univariable models. In multivariable regression analysis (odds ratio 95% CI), summation of daily Pediatric Logistic Organ Dysfunction scores, 1.01/per point (1.01–1.02), p < 0.001; highest vasoactive-inotropic score, 1.02/per point (1.00–1.04), p = 0.003; and any acute pathologic neurologic sign/event, 5.04 (2.15–12.01), p < 0.001 were independently associated with death or persistent, serious deterioration of health-related quality of life at month 3.
CONCLUSIONS AND RELEVANCE:Biologically plausible factors related to sepsis-associated critical illness organ dysfunction and its treatment were associated with poor outcomes at month 3 follow-up among children encountering septic shock.
Thrombotic microangiopathy-induced thrombocytopenia-associated multiple organ failure and hyperinflammatory macrophage activation syndrome are important causes of late pediatric sepsis mortality that ...are often missed or have delayed diagnosis. The National Institutes of General Medical Science sepsis research working group recommendations call for application of new research approaches in extant clinical data sets to improve efficiency of early trials of new sepsis therapies. Our objective is to apply machine learning approaches to derive computable 24-h sepsis phenotypes to facilitate personalized enrollment in early anti-inflammatory trials targeting these conditions.
We applied consensus, k-means clustering analysis to our extant PHENOtyping sepsis-induced Multiple organ failure Study (PHENOMS) dataset of 404 children. 24-hour computable phenotypes are derived using 25 available bedside variables including C-reactive protein and ferritin.
Four computable phenotypes (PedSep-A, B, C, and D) are derived. Compared to all other phenotypes, PedSep-A patients (n = 135; 2% mortality) were younger and previously healthy, with the lowest C-reactive protein and ferritin levels, the highest lymphocyte and platelet counts, highest heart rate, and lowest creatinine (p < 0.05); PedSep-B patients (n = 102; 12% mortality) were most likely to be intubated and had the lowest Glasgow Coma Scale Score (p < 0.05); PedSep-C patients (n = 110; mortality 10%) had the highest temperature and Glasgow Coma Scale Score, least pulmonary failure, and lowest lymphocyte counts (p < 0.05); and PedSep-D patients (n = 56, 34% mortality) had the highest creatinine and number of organ failures, including renal, hepatic, and hematologic organ failure, with the lowest platelet counts (p < 0.05). PedSep-D had the highest likelihood of developing thrombocytopenia-associated multiple organ failure (Adj OR 47.51 95% CI 18.83-136.83, p < 0.0001) and macrophage activation syndrome (Adj OR 38.63 95% CI 13.26-137.75, p < 0.0001).
Four computable phenotypes are derived, with PedSep-D being optimal for enrollment in early personalized anti-inflammatory trials targeting thrombocytopenia-associated multiple organ failure and macrophage activation syndrome in pediatric sepsis. A computer tool for identification of individual patient membership ( www.pedsepsis.pitt.edu ) is provided. Reproducibility will be assessed at completion of two ongoing pediatric sepsis studies.
Illness severity scores predict mortality following pediatric critical illness. Given declining PICU mortality, we assessed the ability of the Pediatric Risk of Mortality-III (PRISM) and Pediatric ...Logistic Organ Dysfunction-2 (PELOD) scores to predict morbidity outcomes.
Among 359 survivors <18 years in the Life After Pediatric Sepsis Evaluation multicenter prospective cohort study, we assessed functional morbidity at hospital discharge (Functional Status Scale increase ≥3 points from baseline) and health-related quality of life (HRQL; Pediatric Quality of Life Inventory or Functional Status II-R) deterioration >25% from baseline at 1, 3, 6, and 12 months post-admission. We determined discrimination of admission PRISM and admission, maximum, and cumulative 28-day PELOD with functional and HRQL morbidity at each timepoint.
Cumulative PELOD provided the best discrimination of discharge functional morbidity (area under the receive operating characteristics curve AUROC 0.81, 95% CI 0.76-0.87) and 3-month HRQL deterioration (AUROC 0.71, 95% CI 0.61-0.81). Prediction was inferior for admission PRISM and PELOD and for 6- and 12-month HRQL assessments.
Illness severity scores have a good prediction of early functional morbidity but a more limited ability to predict longer-term HRQL. Identification of factors beyond illness severity that contribute to HRQL outcomes may offer opportunities for intervention to improve outcomes.
Illness severity scores are commonly used for mortality prediction and risk stratification in pediatric critical care research, quality improvement, and resource allocation algorithms. Prediction of morbidity rather than mortality may be beneficial given declining pediatric intensive care unit mortality. The PRISM and PELOD scores have moderate to good ability to predict new functional morbidity at hospital discharge following pediatric septic shock but limited ability to predict health-related quality of life outcomes in the year following PICU admission. Further research is needed to identify additional factors beyond illness severity that may impact post-discharge health-related quality of life.
Medical management, primarily a fat-modified diet (FMD), is the mainstay of treatment for most patients with chylothorax. Duration of FMD is traditionally reported as 6 weeks, but no studies have ...demonstrated the shortest effective duration that prevents recurrence of chylothorax. The aim of this study was to decrease FMD duration to 2 weeks in children with postoperative chylothorax without a significant increase in recurrence.
This single-center study included pediatric (aged <18 years) patients in whom chylothorax developed within 30 days of cardiac surgery. Patients with cavopulmonary anastomoses were excluded. The preintervention cohort consisted of 19 patients with a diagnosis of chylothorax between February 2014 and June 2015, and the postintervention cohort comprised 98 patients from July 2015 to December 2019. FMD duration was decreased from 6 weeks to 4 weeks in May 2016 and to 2 weeks in June 2018. Recurrence was defined as a return of a chylous effusion requiring chest tube placement or hospital readmission within 30 days of resuming a regular diet.
The median duration of FMD decreased from 42 days (interquartile range, 30, 43 days) in the preintervention cohort to 26 days (interquartile range, 14, 29 days) in the postintervention cohort, with no recurrence of chylothorax in any group. Compliance with the FMD duration instruction in the 6-week, 4-week, and 2-week groups was 100%, 84%, and 67% respectively. Compared with the first 6 months, compliance with the 2-week FMD instruction during the final 12 months increased from 40% (6/15) to 79% (26/33).
At the study center, FMD duration decreased from 6 weeks to 2 weeks without any recurrence of chylothorax.
OBJECTIVE:Our objective was to develop and validate a prognostic score for predicting mortality at the time of extracorporeal membrane oxygenation initiation for children with respiratory failure. ...Preextracorporeal membrane oxygenation mortality prediction is important for determining center-specific risk-adjusted outcomes and counseling families.
DESIGN:Multivariable logistic regression of a large international cohort of pediatric extracorporeal membrane oxygenation patients.
SETTING:Multi-institutional data.
PATIENTS:Prognostic score developmentA total of 4,352 children more than 7 days to less than 18 years old, with an initial extracorporeal membrane oxygenation run for respiratory failure reported to the Extracorporeal Life Support Organization’s data registry during 2001–2013 were used for derivation (70%) and validation (30%). Bidirectional stepwise logistic regression was used to identify factors associated with mortality. Retained variables were assigned a score based on the odds of mortality with higher scores indicating greater mortality. External validation was accomplished using 2,007 patients from the Pediatric Health Information System dataset.
INTERVENTIONS:None.
MEASUREMENTS AND MAIN RESULTS:The Pediatric Pulmonary Rescue with Extracorporeal Membrane Oxygenation Prediction score included mode of extracorporeal membrane oxygenation; preextracorporeal membrane oxygenation mechanical ventilation more than 14 days; preextracorporeal membrane oxygenation severity of hypoxia; primary pulmonary diagnostic categories including, asthma, aspiration, respiratory syncytial virus, sepsis-induced respiratory failure, pertussis, and “other”; and preextracorporeal membrane oxygenation comorbid conditions of cardiac arrest, cancer, renal and liver dysfunction. The area under the receiver operating characteristic curve for internal and external validation datasets were 0.69 (95% CI, 0.67–0.71) and 0.66 (95% CI, 0.63–0.69).
CONCLUSIONS:Pediatric Pulmonary Rescue with Extracorporeal Membrane Oxygenation Prediction is a validated tool for predicting in-hospital mortality among children with respiratory failure receiving extracorporeal membrane oxygenation support.
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