This study is a multi-center, double blind, randomized controlled trial of inhaled nitric oxide (iNO) in children and adults with cardiac arrest (CA). The purpose of this pilot study is to test the feasibility of rapidly randomizing patients to iNO or sham treatment during cardiopulmonary resuscitation (CPR) or shortly after return of circulation (ROC) and evaluate blood biomarkers associated with iNO compared to sham. Return of circulation may refer to return of spontaneous circulation (ROSC) or ROC through extracorporeal cardiopulmonary resuscitation (E-CPR).
Background: Sudden cardiac arrest is a leading cause of death and neurological handicaps but there is no neuroprotective drug which improves outcome. Recently we discovered a blood biomarker of response to a neuroprotective therapy in our pre-clinical model of cerebral ischemia-reperfusion injury. Biomarkers will likely be used, in the future, to assess response to specific neuroprotective drugs and to help titrate drug dose and duration in individual patients. Inhaled nitric oxide (iNO) has recently been shown to improve return of spontaneous circulation, survival, and neurological outcome in animal models of cardiac arrest. We have therefore started a pilot randomized controlled trial (RCT) and translational biology study of iNO in children and adults with cardiac arrest. This study will help us design future fully powered RCTs of iNO. We will use methods, from our pre-clinical model, to discover blood biomarkers of response to therapy. Objectives: In patients with cardiac arrest: (1) Test the safety and feasibility of rapidly randomizing patients to iNO or sham during chest compressions, or shortly after return of circulation (ROC), either spontaneous or by extracorporeal life support. (2) Maintain blinding and measure study outcomes for 6 months post-arrest. (3) Use immunoassays, mass spectrometry and fluorometric assays to determine the differences in serum protein, nitrite, and nitrate biomarker concentrations between the two intervention groups and discover blood biomarkers of therapeutic response to iNO. Patient population and sample size: Pediatric and adult (total N=40) patients with cardiac arrest admitted to 8 intensive care units (ICUs) at 4 hospitals: SickKids, University Health Network - Toronto General Hospital (TGH) and Toronto Western Hospital (TWH) and Unity Health - St. Michael's Hospital (SMH). Methods: All patients meeting eligibility criteria will be enrolled, during chest compressions or within 6 hours of ROC, using deferred consent. Patients will be randomized to iNO or sham procedures, using a Redcap screening and randomization tool. Registered respiratory therapists will rapidly start the study gas using our blinded study apparatus. Inhaled NO will be started at a dose of 80 ppm via the endotracheal or tracheostomy tube during chest compressions and reduced to, or started at, 20 ppm after ROC. The iNO or sham procedures will be continued for 72 hours, and weaned off over 12 hours, or stopped earlier if the patient is extubated or dies. Using the Utstein data template for cardiac arrest research, we will collect data into an electronic case report form and Oracle database. Survival, cerebral performance category scores and quality of life scores will be assessed at 1 and 6 months following cardiac arrest. Data and documentation will be reviewed intermittently to ensure that we are compliant with Health Canada guidelines for drug trials. Serum is being collected and banked at 4 time points following cardiac arrest. The concentrations of biomarkers will be measured and compared between the 2 intervention groups. Progress: This study is funded by the Heart and Stroke Foundation of Canada.
In patients randomized to the this arm, iNO will be delivered into the ventilator circuit through the endotracheal tube or tracheostomy. The dose will be 80 ppm during chest compressions and reduced to 20 ppm immediately following ROC. If the patient is enrolled following ROC, the dose will be 20 ppm. Dose modifications will occur if there is toxicity or if there is a clinical concern. The iNO or sham will be continued for 72 hours or until extubation.
In patients randomized to sham, the iNO delivery device will be connected to the ventilator circuit or manual ventilation bag but flow of iNO will not be turned on. For the purposes of patient safety and to maintain blinding, the respiratory therapists (RTs) will continue checks of gas flow, flow adjustments and change iNO gas tanks at rates like routine clinical procedures on patients treated with iNO or sham.
St. Michael's Hospital
Toronto, Ontario, Canada
NOT_YET_RECRUITINGToronto General Hospital
Toronto, Ontario, Canada
RECRUITINGToronto Western Hospital
Toronto, Ontario, Canada
NOT_YET_RECRUITINGDrug Procedural Feasibility
Number of successful initiations of iNO or sham among the 40 patients enrolled in the study. We will monitor and improve our rates of enrolment and study intervention by examining and improving upon factors related to protocol compliance.
Time frame: We will monitor screening numbers, rates of enrolment of eligible patients and delivery of study intervention according to CONSORT criteria over the 2 year timeframe of study enrolment.
Drug Procedural Feasibility
Number of successful continuations of iNO or sham for 72 hours followed by weaning and stopping the study intervention over the next 12 hours. Using real time monitoring of the study intervention we will optimize compliance to the full duration of the study intervention and improve upon any deviations to the study intervention over the full 72 + 12 hours of the study protocol.
Time frame: We will monitor compliance to the study intervention during the 72 hours of drug/sham delivery and 12 hours of weaning and stopping the study intervention on each enrolled patient over the 2 years of study enrolment.
Monitor recruitment rate
Recruitment rate is the rate of enrolment/randomization/consent divided by the number of eligible patients which meet all inclusion criteria and have no exclusion criteria.
Time frame: For study duration, approximately 2 years.
Monitor time to randomization of eligible patients
Timing of randomization. The time of randomization following onset of cardiac arrest will be recorded. We will attempt to speed up this time using simulations with study and clinical personnel and by debriefing each enrolled patient with the teams involved. We will attempt to enrol some patients who have a cardiac arrest in the ICU during chest compressions and for those patients enrolled following return of circulation, the timeframe is a maximum of 5 hours.
Time frame: At study enrollment during the 2 years of study recruitment.
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Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
TREATMENT
Masking
QUADRUPLE
Enrollment
40
The Hospital for Sick Children
Toronto, Ontario, Canada
RECRUITINGMonitor masking and unmasking events
Number of unblinding instances. The study apparatus (inhaled nitric oxide gas delivery device) has a secure cover that only the Respiratory Therapists are trained to open. The RTs will record any unblinding events which may include breaking/cutting of the cover ties and opening of the apparatus cover by clinical personnel other than RTs. The RTs will record and sign 'unblinding yes/no' into their masked RT study case report form on each RT clinical shift and study Research Coordinators will enter this data into the study electronic database. We will monitor unblinding events in real time and attempt to prevent these from happening.
Time frame: During the 2 year study duration and data analysis.
Study follow-up rates
We will measure outcomes at 1 and 6 months following cardiac arrest as outlined in more detail below. Number of completed study outcomes at 6 months following cardiac arrest will be followed in real time and we will attempt to maximize follow-up rates.
Time frame: For study follow-up, approximately 2.5 years.