Inhaled Corticosteroids for Treatment of Bronchopulmonary Dysplasia
Condition: Bronchopulmonary Dysplasia
MeSH terms: Bronchopulmonary Dysplasia
Study type: Interventional

Summary: 
      While many short-term morbidities associated with extreme prematurity have declined over the
      last two decades, the incidence of bronchopulmonary dysplasia (BPD) has increased to a rate
      of approximately 45% in neonates <28 weeks gestational age (GA) and birth weight (BW) <1,500
      g. Neonates with BPD are at increased risk for adverse short-and long-term neurodevelopmental
      and respiratory outcomes that often persist into adulthood.

      There is a growing body of pathological and biochemical evidence that implicates inflammation
      in its pathogenesis. This is further supported by randomized controlled trials (RCTs) that
      demonstrate the efficacy of systemic corticosteroids in facilitating extubation and reducing
      BPD. However, several short- and long-term adverse effects associated with the use of
      systemic corticosteroids have been described, the most concerning of which is their effect on
      neurodevelopment, specifically an increased rate of cerebral palsy (CP).

      Inhaled corticosteroids (ICS) are an attractive alternative to systemic steroids because of
      these concerns. Earlier systematic reviews had not found any benefit in using ICS for the
      prevention or treatment of BPD. However, a recent systematic review showed a significant
      reduction in death or BPD at 36 weeks' corrected GA (CGA) (risk ratio=0.86, 95% confidence
      interval 0.75, 0.99), BPD (RR=0.77, 95% CI 0.65, 0.91), and use of systemic steroids
      (RR=0.87, 95% CI 0.76, 0.98) in infants treated with ICS.

      Despite growing evidence of the effectiveness of ICS for BPD, uncertainty remains over
      treatment timing, effective dose, and long-term effects. There is also variation in the
      delivery systems used for delivery of ICS. These concerns continue to be echoed in a recent
      review by Nelin et al. Given that the long-term neurodevelopmental impact of ICS were unknown
      at the time of this study and many infants are able to wean from ventilation without
      steroids, the investigators conducted an escalating-dose ranging study of late ICS (i.e.
      administered after the first week of life) delivered by a metered dose inhaler (MDI)
      utilizing a specially designed valved delivery system to determine the minimum effective dose
      necessary to achieve extubation or reduction in oxygen requirements and the long-term
      neurodevelopmental impact of increasing doses of ICS.
    

Detailed description: 
      Research Question:

      What is the effective dose of inhaled steroids (HFA-BDP) in ventilated preterm infants?
      Material and Methods Objective: The primary purpose of this study is to determine the optimal
      dose of inhaled steroids (using HFA-BDP) in ventilated preterm infants. The result from this
      study will determine the dose of inhaled steroids to be used for a subsequent randomized
      placebo-controlled trial with sufficient power to determine if inhaled steroid is associated
      with reduction in CLD in ventilated preterm infants without any detrimental effect on long
      term neurodevelopmental outcome.

      Study Design: Escalating dose-ranging study Study Population: Babies with birth weights <
      1,250 grams and gestational age < 32 weeks admitted in the NICU at Sunnybrook and Women's
      College Health Sciences Centre and Mount Sinai Hospital Inclusion Criteria: Birth weight <
      1,250 grams and gestational age < 32 weeks, Need for assisted mechanical ventilation
      (ventilation rate > 15 breaths/min, and fractional oxygen concentration of inspired gas
      (Fio2) > 0.3 but < 0.6), Postnatal age 10-21 days, Stable ventilatory requirements over the
      48-72 hours prior to enrollment Exclusion Criteria: Actual or suspected sepsis, Congenital
      cardiorespiratory malformation, Patent ductus arteriosus, Presence of necrotizing
      enterocolitis, gastrointestinal hemorrhage or perforation, Treatment with systemic
      dexamethasone Duration of therapy: 7 days Drug Regimen: Groups of neonates will be treated
      with an escalating dose of HFA-BDP until either efficacy equal to that seen with
      dexamethasone or significant side-effects are observed. 10 neonates will be treated at each
      dosage level before moving up to the next dose. Each neonate will be treated with only one
      dose.

      Bowser et al have performed an in vitro evaluation of drug deposition of HFA-BDP (QVAR*) and
      CPC-BDP MDI (Beclovent) via an aerosol delivery chamber (Aerochamber) and endotracheal tube
      (uncuffed Portex 3.5, 3.0 and 2.5) at low tidal volumes. The PARI Compas Breath Simulator was
      used to simulate neonatal and infant respiratory cycles. For both formulations and all
      endotracheal tubes, the output (*g) increased significantly at the tidal volume and
      inspiratory flow rates were increased. The 3.5 endotracheal tube side gave greater
      output/puff at all tidal volumes and for both formulations as compared to the smaller
      endotracheal tubes. Greater in vitro deposition was measured for QVAR than for beclovent,
      possibly leading to greater in vivo delivery to the lung of this new HFA-BDP MDI formulation
      to intubated infants

      Thus, for the purpose of this study Beclomethasone Dipropionate (HFA-BDP, QVAR*) in the
      following doses will be evaluated:

        1. 200 *g bid

        2. 400 *g bid

        3. 600 *g bid

        4. 800 *g bid Inhaled steroids will be administered using a specially designed neonatal
           aerosol delivery system manufactured by Trudell Canada (see diagram, Appendix I). The
           device will be connected directly to the endotracheal tube on one side with the
           ventilator circuit on the other. The ventilator settings will be temporarily adjusted to
           achieve an expiratory tidal volume of 7ml/kg (based on birth weight) and a rate of 30
           breaths/min and an inspiratory time of 0.5 seconds. There will be a one-minute interval
           between each actuation from the MDI. Continuous cardiac and oxygen saturation monitoring
           will be used throughout the treatment period. One-minute after the final puff has been
           administered, the delivery system will be removed and the baby returned to the
           ventilator settings previously used. The total daily dose will be administered in two
           divided doses.

      If the infant is extubated during the study period administration of inhaled medications will
      be stopped.

      Outcome Measures - Efficacy Primary Outcome: Reduction in Fio2 from the 2 days prior to
      treatment to the final 2 days of the study period or extubation during the study period.
      Extubation is considered to be successful if the infant does not require assisted ventilation
      in the next 48 hours. A reduction in additional Fio2 of 75% or greater will be considered a
      significant improvement (i.e. a baby with a baseline Fio2 of 0.51 who requires less than 0.28
      [0.21 + 0.25 (0.51-0.21)] at the end of the treatment period will be considered a treatment
      success).

      Secondary Outcome:

      Ventilatory status: Ventilator rate Mean airway pressure Peak inspiratory pressure
      Ventilatory parameters will be assessed at the same time intervals as Fio2 described above.

      Adverse Event Monitoring Each patient will be carefully monitored for adverse events by the
      investigators. The following events will be specifically monitored.

        1. Hypertension: Blood pressure (BP) will be noted every 12 hourly using an automatic
           sphygmomanometer (Dinamap, Criticon Inc.). Hypertension is defined as BP higher than 2
           SD above the mean for the infant's gestational and postnatal age.

        2. Hyperglycemia: Urine and blood glucose will be monitored as per nursing standard
           protocol for infants who are on steroids. Hyperglycemia will be defined as a blood
           glucose > 10 *mol/L.

        3. Growth: Weight and head circumference will be recorded prior to and after completion of
           the study period.

        4. Infection: Sepsis is defined as a need for antibiotic therapy because of a positive
           blood or cerebrospinal fluid culture or clinical diagnosis of pneumonia.

        5. Evidence of feeding intolerance, necrotizing enterocolitis or intestinal perforation
           will be noted.

        6. Candidiasis of the mouth and throat will be noted. Assessment will be made of the
           seriousness, intensity and relationship to the administration of the study medication.
           If, in the opinion of the investigator, the adverse event is not tolerated, the patient
           will be withdrawn from the study and monitored until resolution of the adverse event or
           until a conclusion is reached as to its irreversible nature.

      Suppression of the hypothalamic-pituitary-adrenal axis (HPA):

      Adrenal suppression is an important adverse effect, which occurs during glucocorticoid
      therapy (particularly when administered systemically). Controversy exists regarding the
      variable effect of glucocorticoid therapy on the immature HPA axis. The dose and duration of
      therapy, methodology and timing of adrenal function assessment and inter-patient variablity
      influence the degree and duration of suppression. Also, there is no consensus regarding
      normal HPA function in extremely premature infant. Therefore, for the purpose of this pilot
      study where the drug is administered for a very short duration the HPA axis will not be
      investigated. Assessment of the HPA axis will be part of the larger randomized controlled
      trial.

      Laboratory test abnormalities considered by the Investigator to be clinically relevant will
      be reported on the Adverse Event Page of the CRF.

      Adverse events and laboratory test abnormalities fulfilling the definition of "serious" must,
      in addition, be reported in detail on the Serious Adverse Event Form.

      Signs and symptoms of each AE should be described in detail: start and stop dates, intensity,
      relationship it investigational product, action taken and outcome.

      Safety Assessment Adverse events will be tracked as described below. After each serious AE,
      the safety monitoring committee will be informed and will investigate the relationship
      between the AE and study drug administration. Any time a serious AE is felt to be "probably
      related" to the therapy, consideration will be given to stopping the study. If a series of
      serious AE events are felt to be "possibly related" or a series of minor events felt to be
      "probably related" to treatment with the study drug, the study may also be stopped. The REB,
      3M pharmaceuticals and HPB will be kept informed of all such deliberations. The members of
      the safety committee include Dr. Arne Ohlsson, Director Evidence Based Neonatal Care and
      Outcomes Research, MSH, Dr. Elizabeth Asztalos, Staff Neonatologist, SWCHSC and Joseph
      Beyene, Biostatistician, MSH. After enrollment of 10 neonates at a particular dosing level
      the safety committee will be requested to review the data for efficacy and safety. If no
      benefit or no significant adverse events are noted then the decision will be made to move to
      the next dosing level.

      Weaning Protocol Respiratory therapists will use set criteria for weaning from ventilation.
      For 48 hours prior to commencement of treatment, a record will be made of the baseline
      ventilator settings. A transcutaneous pCO2 monitor will be applied daily for the duration of
      the study. Blood gases (capillary or arterial) will be performed as clinically indicated: ie.
      in response to changes in clinical status, oxygen requirements (oxygen saturation) or
      transcutaneous pCO2. Supplemental oxygen and ventilation will be adjusted to maintain an
      oxygen saturation of 90-95%, carbon dioxide tension between 45-60mm Hg (5.8-7.8 KPA) and a
      blood pH of at least 7.25. If clinically indicated, the proximal airway pressure will be
      reduced in decrements of 2mm Hg until a mean airway pressure of 8mm Hg is reached, following
      which the ventilator rate will be reduced in decrements of 2-5 breaths/min until a rate of
      10-12 breaths/min is achieved. Neonates will be extubated from a rate of 10-12 breaths/min a
      mean airway pressure of 8mm Hg and Fio2 concentration of < 0.3. A record will be made of the
      need for nasal CPAP following extubation.

      Sample size estimation The study design is an escalating dose ranging study with an aim to
      identify both an effective and a safe dose of inhaled steroids. 10 babies will be enrolled in
      each dose category. The study will be stopped if the therapeutic efficacy is achieved in a
      given dosage group or if significant side effects are noted. Therapeutic efficacy will be
      considered to have occurred in a group of 6 or more babies out of 10 meet the primary outcome
      [based upon response expected with dexamethasone therapy - data from Ohlsson et al
      (Unpublished data from MSc thesis)].

      Statistical Analysis Analysis of variance for repeated measures will be used to assess the
      effect of therapy over time in each dosage group. This analysis will be applied to Fio2 and
      ventilatory parameters
    

Intervention name(s): Inhaled Beclomethasone Dipropionate Monohydrate
Intervention type(s): Drug
Intervention description(s): Beclomethasone Dipropionate (HFA-BDP, QVAR*) in the following doses will be evaluated:
200 mcg bid
400 mcg bid
600 mcg bid
800 mcg bid
Intervention MeSH terms: Beclomethasone
Intervention model: Single Group Assignment
Masking: None (Open Label)
Primary purpose: Treatment