Randomized controlled trials in pediatric critical care: a scoping review

Pediatric intensive care stress ulcer prevention (PIC-UP): a protocol for a pilot randomized trial

Background

Despite sparse pediatric data on effectiveness, the majority of critically ill children receive medications to prevent gastrointestinal (GI) bleeding. Stress ulcer prophylaxis may have unintended consequences—increasing the risk of nosocomial infections—which may be more serious and common than the bleeding which these drugs are prescribed to prevent. Randomized controlled trials (RCTs) in pediatric critical care are exceptionally challenging to complete, thus a rigorous pilot RCT is crucial. The objective of this pilot RCT is to assess the feasibility of a large multicentre RCT of stress ulcer prophylaxis with pantoprazole to prevent upper GI bleeding vs. placebo.

Methods

A multi-centre blinded pilot RCT of 120 children in six Canadian PICUs. Children expected to require mechanical ventilation for more than 48 h will be randomized to receive intravenous pantoprazole 1 mg/kg or identical placebo once daily until they no longer need mechanical ventilation. We have four feasibility outcomes and will consider the trial successful if we achieve:

Effective screening: If >80% of eligible patients are approached for consent.

Timely enrollment: if >80% of participants receive their first dose of the assigned study drug within 1 day of becoming eligible.

Participant accrual: If the average monthly enrolment is two or more participants per centre per month.

Protocol adherence: if >90% of doses are administered according to the protocol.

Discussion

There are many uncertainties about the risks and benefits of stress ulcer prophylaxis. In an era of widespread use—where clinicians prescribe prophylaxis to the more severely ill—a large, rigorous RCT is required. A trial to determine if a strategy of withholding stress ulcer prophylaxis is not inferior to a strategy of routine stress ulcer prophylaxis will be challenging. A carefully designed and implemented pilot trial is essential.

Trial registration

ClinicalTrials.gov:NCT02929563 (Registered October 3, 2016).

High-Quality Randomized Controlled Trials in Pediatric Critical Care: A Survey of Barriers and Facilitators

OBJECTIVES

High-quality, adequately powered, randomized controlled trials are needed to inform the care of critically ill children. Unfortunately, such evidence is not always available. Our objective was to identify barriers and facilitators of conducting high-quality randomized controlled trials in pediatric critical care, from the perspective of trialists in this field.

DESIGN

Self-administered online survey. Respondents rated the importance of barriers and effectiveness of facilitators on seven-point scales.

SETTING

Authors of 294 pediatric critical care randomized controlled trials (published 1986 to June 2015).

SUBJECTS

One hundred sixteen researchers from 25 countries participated.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Respondents reported a median (Q1, Q3) of 21 years (15, 26 yr) of experience and 41 (36%) had authored more than one randomized controlled trial. More survey respondents, compared with nonrespondents, had published more than one trial (35% vs 26%; p = 0.002) and their trials were more often cited (median citations/yr, 2.4 vs 1.5; p < 0.001). Of the barriers listed, the five most important were primarily related to lack of funding. The five facilitators perceived as most effective were protected time for research, ability to recruit participants 24 hours per day/7 days per week, conducting randomized controlled trials in collaboration with a research network, funding from government agencies specifically for randomized controlled trials in critically ill children, and academic department support for conducting randomized controlled trials. Respondent experience and country income level were associated with differences in importance ratings for eight of 41 barriers. There were fewer such differences for facilitators.

CONCLUSIONS

Lack of funding and time are major barriers to conducting pediatric critical care randomized controlled trials worldwide. Although barriers varied among country income levels, the facilitators of such trials were more consistent. In addition to increased funding, respondents identified other strategies such as research networks that are within the purview of the pediatric critical care research community, to facilitate the conduct of rigorous randomized controlled trials.

Primary Outcome Measures in Pediatric Septic Shock Trials: A Systematic Review

OBJECTIVE

To evaluate all published pediatric randomized controlled trials of patients with septic shock from any cause to examine the outcome measures used, the strengths and limitations of these measurements and whether the trial outcomes met feasibility criteria.

DATA SOURCES

We used a previously published database of pediatric critical care randomized controlled trials (PICUtrials.net) derived from searches of MEDLINE, EMBASE, LILACS, and CENTRAL.

STUDY SELECTION

We included randomized controlled trials of interventions to children admitted to a PICU with septic or dengue hemorrhagic shock which were published in English.

DATA EXTRACTION

Study characteristics and outcomes were retrieved by two independent reviewers with disagreement being resolved by a third reviewer. We defined feasibility as 1) recruitment of at least 90% of the targeted sample size and agreement of the observed outcome rate in the control group with the rate used for the sample size calculation to within 10% or 2) finding of a statistically significant difference in an interim or final analysis.

DATA SYNTHESIS

Nineteen of 321 identified articles were selected for review. Fourteen of 19 studies (74%) provided an a priori definition of their primary outcome measure in their "Methods section." Mortality rate was the most commonly reported primary outcome (8/14; 57%), followed by duration of shock (4/14; 29%) followed by organ failure (1/14; 7%). Only three of 19 included trials met feasibility criteria.

CONCLUSIONS

Our review found that use of mortality alone as a primary outcome in pediatric septic shock trials was associated with significant limitations and that long-term patient-centered outcomes were not used in this setting. Composite outcomes incorporating mortality and long-term outcomes should be explored for use in future pediatric septic shock trials.

The Impact of Clinical Trials Conducted by Research Networks in Pediatric Critical Care

OBJECTIVES

Research networks in adult and neonatal critical care have demonstrated collaborative and successful execution of clinical trials. Such networks appear to have been relatively recently established in the field of pediatric critical care. The objective of this study was to evaluate the productivity and impact of randomized controlled trials conducted by pediatric critical care research networks, compared with nonnetwork trials.

DATA SOURCES, STUDY SELECTION, AND DATA ABSTRACTION

We searched multiple online databases including MEDLINE, reference lists of randomized controlled trials, and relevant systematic reviews. Independent pairs of reviewers identified published randomized controlled trials administering any intervention to children in a PICU and abstracted data. A research network was defined as a formal consortium or collaborative research group established for the purpose of conducting clinical research. Data were independently abstracted in duplicate.

MAIN RESULTS

There were 288 pediatric critical care randomized controlled trials published in English between 1986 and July 2015, of which 15 randomized controlled trials (5.2%) were conducted by a total of five research networks. Network randomized controlled trials were more often multicentered, multinational, and larger in size (p < 0.001), compared with nonnetwork randomized controlled trials. Accordingly, their trials took longer to complete (median, 36 vs 21 mo; p < 0.001). Early stopping occurred in 46.7% of network randomized controlled trials (46.7%) and 27% of nonnetwork randomized controlled trials (p = 0.14), most commonly for futility. None of the network, but 45% of the nonnetwork trials found a significant difference in their primary outcome (p < 0.001). Network trials were more frequently cited (median, 6 vs 2 citations per year) and published in higher impact journals (median impact factor, 21.8 vs 3; p < 0.001).

CONCLUSIONS

Research networks have conducted a minority of randomized controlled trials in pediatric critical care. They infrequently demonstrate significant differences in their primary outcomes. Despite this, network trials are cited more frequently and appear to have greater impact. There are important lessons to learn from both individual researchers as well as research networks that may guide the successful conduct of collaborative, high-quality randomized controlled trials in critically ill children.

Latent AKI is… still AKI: the quantification of the burden of renal dysfunction

The association between pediatric cardiac surgery, acute kidney injury (AKI), and clinical outcomes has been studied several times in the recent literature. In this issue of Critical Care an interesting and original study analyzed the path from causal AKI entities to clinical AKI consequences through the application of structural equation modeling. The authors described the complex connections linking duration of cardiopulmonary bypass, cross clamp-time, and descriptors of low cardiac output syndrome to AKI modeled as a complex variable composed of post-operative serum creatinine increase of 50 % over baseline, urine output <0.5 ml/kg/h, and urine creatinine-normalized neutrophil gelatinase lipocalin within 12 h of surgery. Similarly, the causal relationships between AKI and hard outcomes in the analyzed population were verified and quantified. The authors, for the first time, produce a repeatable coefficient (0.741) that may become a useful quality benchmark and could be applied to test future interventions aiming to reduce the burden of AKI on children’s clinical course.

A systematic review of pediatric clinical trials of high dose vitamin D

Background. Due to inadequate UV exposure, intake of small quantities of vitamin D is recommended to prevent musculoskeletal disease. Both basic science and observational literature strongly suggest that higher doses may benefit specific populations and have non-musculoskeletal roles. Evaluating the evidence surrounding high dose supplementation can be challenging given a relatively large and growing body of clinical trial evidence spanning time, geography, populations and dosing regimens. Study objectives were to identify and summarize the clinical trial literature, recognize areas with high quality evidence, and develop a resource database that makes the literature more immediately accessible to end users. Methods. Medline (1946 to January 2015), Embase (1974 to January 2015), and Cochrane databases (January 2015), were searched for trials. All pediatric (0-18 years) trials administering doses higher than 400 IU (<1 year) or 600 IU (≥1 year) were included. Data was extracted independently by two of the authors. An online searchable database of trials was developed containing relevant extracted information (http://www.cheori.org/en/pedvitaminddatabaseOverview). Sensitivity and utility were assessed by comparing the trials in the database with those from systematic reviews of vitamin D supplementation including children. Results. A total of 2,579 candidate papers were identified, yielding 169 trials having one or more arms meeting eligibility criteria. The publication rate has increased significantly from 1 per year (1970-1979) to 14 per year (2010-2015). Although 84% of the total trials focused on healthy children or known high risk populations (e.g., renal, prematurity), this proportion has declined in recent years due to the rise in trials evaluating populations and outcomes not directly related to the musculoskeletal actions of vitamin D (27% in 2010s). Beyond healthy children, the only pediatric populations with more than 50 participants from low risk of bias trials evaluating a clinically relevant outcome were prematurity and respiratory illness. Finally, we created and validated the online searchable database using 13 recent systematic reviews. Of the 38 high dose trials identified by the systematic review, 36 (94.7%) could be found within the database. When compared with the search strategy reported in each systematic review, use of the database reduced the number of full papers to assess for eligibility by 85.2% (±13.4%). Conclusion. The pediatric vitamin D field is highly active, with a significant increase in trials evaluating non-classical diseases and outcomes. Despite the large overall number there are few high quality trials of sufficient size to provide answers on clinical efficacy of high-dose vitamin D. An open access online searchable data should assist end users in the rapid and comprehensive identification and evaluation of trials relevant to their population or question of interest.

Research as a Standard of Care in the PICU

OBJECTIVES

Excellence in clinical care coupled with basic and applied research reflects the maturation of a medical subspecialty, advances that field, and provides objective data for identifying best practices. PICUs are uniquely suited for conducting translational and clinical research. In addition, multiple investigations have reported that a majority of parents are interested in their children's participation in clinical research, even when the research offers no direct benefit to their child. However, such activity may generate ethical conflict with bedside care providers trying to acutely identify the best approach for an individual critically ill child. Ultimately, this conflict may diminish enthusiasm for the generation of scientific evidence that supports the application of evidence-based medicine into PICU clinical standard work. Accordingly this review endeavors to provide an overview of current state PICU clinical research strengths, liabilities, opportunities, and barriers and contrast this with an established pediatric hematology-oncology iterative research model that constitutes a learning healthcare system.

DATA SOURCES, DATA EXTRACTION, AND DATA SYNTHESIS

Narrative review of medical literature published in English.

CONCLUSIONS

Currently, most PICU therapy is not evidence based. Developing a learning healthcare system in the PICU integrates clinical research into usual practice and fosters a culture of evidence-based learning and continual care improvement. As PICU mortality has significantly decreased, identification and validation of patient-centered, clinically relevant research outcome measures other than mortality is essential for future clinical trial design. Because most pediatric critical illness may be classified as rare diseases, participation in research networks will facilitate iterative, collaborative, multiinstitutional investigations that over time identify the best practices to improve PICU outcomes. Despite real ethical challenges, critically ill children and their families should have the opportunity to participate in translational/clinical research whenever feasible.

The Influence of Fluid Overload on the Length of Mechanical Ventilation in Pediatric Congenital Heart Surgery

Fluid overload and prolonged mechanical ventilation lead to worse outcomes in critically ill children. However, the association between these variables in children following congenital heart surgery is unknown. The objectives of this study were to describe the association between fluid overload and duration of mechanical ventilation, oxygen requirement and radiologic findings of pulmonary and chest wall edema. This study is a retrospective chart review of patients who underwent congenital heart surgery between June 2010 and December 2013. Univariate and multivariate associations between maximum cumulative fluid balance and length of mechanical ventilation and OI were tested using the Spearman correlation test and multiple linear regression models, respectively. There were 85 eligible patients. Maximum cumulative fluid balance was associated with duration of mechanical ventilation (adjusted analysis beta coefficient = 0.53, CI 0.38-0.66, P < 0.001), length of stay in the pediatric intensive care unit (Spearman's correlation = 0.45, P < 0.001), and presence of chest wall edema and pleural effusions on chest radiograph (Mann-Whitney test, P = 0.003). Amount of red blood cells transfused and use of nitric oxide were independently associated with increased duration of mechanical ventilation (P = 0.012 and 0.014, respectively). Fluid overload is associated with prolonged duration of mechanical ventilation and PICU length of stay after congenital heart surgery. Fluid overload was also associated with physiological markers of respiratory restriction. A randomized controlled trial of a restrictive versus liberal fluid replacement strategy is necessary in this patient population, but in the meantime, accumulating observational evidence suggests that cautious use of fluid in the postoperative care may be warranted.

Pilot Randomized Trials in Pediatric Critical Care: A Systematic Review

OBJECTIVES

Pilot trials are smaller randomized controlled trials conducted to inform the design and assess the feasibility of a large-scale trials. The objectives of this systematic review were to describe pilot trials in pediatric critical care, their conclusions about the clinical implications of the results, and the need for future research and to determine the frequency of large follow-up trials.

DATA SOURCES

The Evidence in Pediatric Intensive Care database (http://epicc.mcmaster.ca), a comprehensive repository of published pediatric critical care randomized controlled trials and the World Health Organization's Clinical Trials Registry Platform.

STUDY SELECTION

Randomized controlled trials described in the publication as "pilot," "feasibility," "proof-of-concept," "exploratory," "phase 2," "vanguard," or "preliminary."

DATA EXTRACTION

Pairs of reviewers screened studies for eligibility and abstracted data independently.

DATA SYNTHESIS

We found 32 pilot trials (12.2% of all pediatric critical care randomized controlled trials) published before July 2014, varying in size from 6 to 165 children. Pilot trials were significantly smaller than those not described as pilots, but other key characteristics were not significantly different. The authors of 16 publications (48.4%) included explicit and specific conclusions about the design or feasibility of larger trials based on the results of the pilot trial. In 20 publications (64.5%), the authors made conclusions about clinical efficacy based on results of the pilot trial. Four of the 32 pilot trials (12.9%) led to larger trials, two of which have been published.

CONCLUSIONS

Published pilot trials in pediatric critical care often focus on clinical outcomes. They uncommonly report explicit feasibility outcomes, criteria for success, or rationale for the pilot sample size. These pilot trials infrequently lead to larger trials. Understanding and addressing the reasons for this are key to the success of pediatric critical care research.

Ethics of drug research in the pediatric intensive care unit

Critical illness and treatment modalities change pharmacokinetics and pharmacodynamics of medications used in critically ill children, in addition to age-related changes in drug disposition and effect. Hence, to ensure effective and safe drug therapy, research in this population is urgently needed. However, conducting research in the vulnerable population of the pediatric intensive care unit (PICU) presents with ethical challenges. This article addresses the main ethical issues specific to drug research in these critically ill children and proposes several solutions. The extraordinary environment of the PICU raises specific challenges to the design and conduct of research. The need for proxy consent of parents (or legal guardians) and the stress-inducing physical environment may threaten informed consent. The informed consent process is challenging because emergency research reduces or even eliminates the time to seek consent. Moreover, parental anxiety may impede adequate understanding and generate misconceptions. Alternative forms of consent have been developed taking into account the unpredictable reality of the acute critical care environment. As with any research in children, the burden and risk should be minimized. Recent developments in sample collection and analysis as well as pharmacokinetic analysis should be considered in the design of studies. Despite the difficulties inherent to drug research in critically ill children, methods are available to conduct ethically sound research resulting in relevant and generalizable data. This should motivate the PICU community to commit to drug research to ultimately provide the right drug at the right dose for every individual child.

Making decisions about medications in critically ill children: a survey of Canadian pediatric critical care clinicians

OBJECTIVE

Changing clinician practice in pediatric critical care is often difficult. Tailored knowledge translation interventions may be more effective than other types of interventions. To inform the design of tailored interventions, the primary objective of this survey was to describe the importance of specific factors that influence physicians and pharmacists when they make decisions about medications in critically ill children.

DESIGN

In this postal survey, respondents used 7-point scales to rate the importance of specific factors that influence their decisions in the following scenarios: corticosteroids for shock, intensive insulin therapy, stress ulcer prophylaxis, surfactant for acute respiratory distress syndrome, and sedation interruption. We used generalized estimating equations to examine the association between the importance of specific factors influencing decision making and the scenario and respondents' practice, views, and demographics.

SETTING

Canadian PICUs.

PARTICIPANTS

One hundred and seventeen physicians and pharmacists practicing in 18 PICUs.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

The response rate was 61%. The three factors reported to most strongly influence clinician decision making overall were: severity of illness (mean [SD] 5.8 [1.8]), physiologic rationale (5.2 [1.3]), and adverse effects (5.1 [1.9]). Factors least likely to influence decision making were drug costs (2.0 [1.5]), unit policies (2.9 [1.9]), and non-critical care randomized controlled trials (3.1 [1.9]). The relative importance of 8 of the 10 factors varied significantly among the five scenarios: only randomized controlled trials in critically ill children and other clinical research did not vary. Clinician characteristics associated with the greatest difference in importance ratings were: frequent use of the intervention in that scenario (seven factors), profession (five factors), and respondents' assessment of the quality of evidence (five factors).

CONCLUSIONS

The relative importance of many factors that clinicians consider when making decisions about medications varies by demographics, and depends on the clinical problem. This variability should be considered in quality improvement and knowledge translation interventions in this setting.

Dilemmas in undertaking research in paediatric intensive care

Providing evidence-based interventions for infants and children is important in paediatric intensive care, where decision making impacts most acutely on morbidity and mortality. However, despite the major progress of medicine in the 21st century, we still lack this evidence for majority of the decisions we make. In this article, we explore and suggest possible solutions for several dilemmas faced by paediatric intensive care researchers. These include ethical dilemmas such as validity of informed consent, use of deferred consent, balancing risk versus benefit and methodological dilemmas such as how to generate high-quality evidence with low-patient volume, choice of valid outcome measures and how best to use research and researchers' networks.

Update on pediatric neurocritical care

Paralytic poliomyelitis, Reye syndrome, Hemophilus Influenzae type B epiglottitis, bacterial meningitis, and meningococcal septic shock are catastrophic illnesses that in the last 60 years have shaped the development of pediatric intensive care. Neurocritical care has been at the forefront of our thinking and, more latterly, as a specialty we have had the technology and means to develop this focus, educate the next generation and show that outcomes can be improved-first in adult critical care and now the task is to translate these benefits to critically ill children. In our future we will need to advance interventions in patient care with clinical trials. MeSH terms: Neurocritical care; child; traumatic brain injury; status epilepticus; cerebrovascular.

Rigorous scoping review of randomized trials in pediatric critical care highlights need for a rigorous rethink

The randomized controlled trial (RCT) remains the highest-ranked study design when grading recommendations for clinical practice. In the previous issue of Critical Care, Duffett and colleagues published a scoping review of RCTs in pediatric critical care medicine and identified some serious gaps in the body of research underlying the field. Relatively few published RCTs were identified, and they were mostly small and potentially susceptible to bias. High patient heterogeneity, relatively low prevalence of specific disorders such as acute respiratory distress syndrome or septic shock, along with relatively low mortality rates, all make it difficult to improve this situation without the collaboration of pediatric critical care research networks internationally. Designing a robust RCT that can impact clinical practice has always been challenging. First, one must assess current clinical practice and disease prevalence, refine definitions and measurements, and pilot-test the intervention to be studied. The first step, however, is to rigorously assess what has already been done. This step will be facilitated by the now available, innovative, online, searchable repository of RCTs in pediatric critical care on the Evidence in Pediatric Critical Care website.