Steroid Use in Pediatric Fluid and Vasoactive Infusion Dependent Shock - Pilot Study

This study is a multi-centre pilot RCT to determine the feasibility of doing a full trial on the effect of steroids versus placebo in children with fluid and vasoactive infusion dependent shock. The principal investigator and colleagues recently published two articles on this topic which were selected as the Feature Article and Feature Review in the June edition of Pediatric Critical Care Medicine. Both of these publications strongly support the interest in this area and the accompanying editorial strongly supported the need for a well-designed RCT.

RATIONALE: Approximately 20,000 children per year present to emergency departments, pediatric wards and intensive care units in North America with fluid and vasoactive infusion dependent shock. This severe type of shock results in significant morbidity and carries a 2-10% mortality rate depending on the setting in which it occurs. This form of shock is thought to arise from dysfunction of the hypothalamic-pituitary-adrenal axis through a variety of mechanisms and has been referred to as relative adrenal insufficiency or critical illness related adrenal insufficiency. Many clinicians believe that corticosteroids improve outcomes in such patients and therefore use them when confronted with a critically ill child with fluid and vasoactive infusion dependent shock. However, the effectiveness and safety of steroid replacement therapy in pediatric shock remain to be demonstrated.

OBJECTIVES - PILOT STUDY: Before embarking on a multi-centre definitive trial to address the questions listed above, the STRIPES Pilot Study has 3 specific feasibility objectives: 1) To estimate the rate of patient recruitment and understand barriers to recruitment; 2) To assess adherence to our specific treatment protocol; and 3) To document the frequency of and understand the reasons for open label steroid use.

OBJECTIVES - FULL RCT: Following successful completion of the STRIPES Pilot Study, the next phase will be a large, multi centre RCT to answer the following questions: 1) What is the effect of hydrocortisone versus placebo on the time to discontinuation of vasoactive agents among pediatric patients with fluid and vasoactive infusion dependent shock?; and 2) In patients with fluid and vasoactive infusion dependent shock, what is the effect of hydrocortisone versus placebo on i) pediatric intensive care unit (PICU) mortality; ii) duration of mechanical ventilation; iii) new onset of organ dysfunction; iv) PICU length of stay; and v) incidence of adverse events?

RESEARCH PLAN: The STRIPES Pilot Study is designed as a pragmatic, multi-centre, double blind, RCT of intravenous hydrocortisone versus intravenous placebo in fluid and vasoactive infusion dependent shock. This study aims to enroll 72 patients from 7 pediatric centres across Canada over a one year period. Patients will be recruited from the Emergency Department and the PICU within 6 hours of being stared on a vasoactive agent. Research ethics board approval will be obtained from all participating centres and application for deferred consent will be made at 5 sites. Health Canada approval is not required as hydrocortisone is approved for use in children at the doses and for the indication for which it is being used in this study.

As part of the pragmatic design, the prescriptive component of the protocol will be limited to the administration and weaning of the study drug. The requirement for intubation, mechanical ventilation, sedation and analgesia, use of hemodynamic triggers and endpoints, red cell transfusions, antibiotics and fluid boluses will be left to the discretion of the treating physician. The Surviving Sepsis Guidelines Flowchart will be attached to the study protocol for easy reference by the treating physician but its use will not be mandated; however, the use of vasoactive infusions and other therapies will be recorded. The proposed duration of treatment will range from a minimum of 20 hours to a maximum of 7 days of study drug. Outcome data, including survival status and frequency of adverse events, will be collected daily until discharge from hospital.

Although the primary focus of this pilot study is to determine the feasibility of conducting a clinical outcome based RCT of steroids versus placebo in shock, this pilot also provides an excellent opportunity to perform some exploratory mechanistic studies. These will include 1) comparison of total and free cortisol levels of patients with shock; 2) measurement of stratification biomarkers; and 3) determination of 25 hydroxyvitamin D and 1,25 hydroxyvitamin D levels on admission. Patients with access for blood sampling and for whom consent has been obtained will have blood samples sent for these mechanistic studies.

Patients will be randomized to the hydrocortisone or placebo arm using web-based, centralized permuted block randomization, stratified by centre. All study personnel (the overall study research coordinator, research assistants, site investigators, principal investigator, co-investigators, data management personnel, and statisticians), members of the health care team (treating physicians, bedside nurses, and clinical pharmacists) and patients/families will be blinded to the study group assignment.

SIGNIFICANCE: Results of the STRIPES Pilot Study will provide essential feasibility data for planning and conducting a larger, multi-centre trial that will help to establish the role of steroids in children with fluid and vasoactive infusion dependent shock. There are special challenges to patient recruitment in critically ill pediatric populations, adherence to treatment protocols and to the limitation of open label use of steroids, all of which the STRIPES Pilot study will help to address. Success of the STRIPES Pilot Study will be based on the ability to achieve each of the three feasibility objectives listed above. If the pilot study demonstrates feasibility, no major protocol changes are needed, and no safety concerns are raised by the Data Safety Monitoring Board, then the results of the pilot study will be rolled into the full trial. However, if any of the above criteria are not met, then the protocol will be re-evaluated and the feasibility results of the pilot study published independently.