Measures to Lower the Stress Response in Pediatric Cardiac Surgery
Condition: Tetralogy of Fallot (TOF); Ventricular Septal Defects (VSD); Atrioventricular Septal Defects (AVSD)
MeSH terms: Heart Septal Defects; Tetralogy of Fallot; Heart Septal Defects, Ventricular; Endocardial Cushion Defects
Study type: Interventional
Phase: Phase 2

Summary: 
      Cardiac surgery induces a measurable stress response in patients which leads to increased
      morbidity and mortality post-operatively. Through clinical observation, anesthesiologists
      have determined that varying the combinations of anesthesia drugs used during surgery and
      just after reduces the stress response, and by extension, morbidity and mortality. However,
      only a few studies have explored this phenomenon scientifically.
    

Detailed description: 
      In this study, we aim to demonstrate comparatively that use of dexmedetomidine in addition to
      low dose narcotics reduces the stress response in cardiac surgical patients and results in
      less morbidity and mortality. Additionally, dexmedetomidine (Dex) should facilitate safe
      early extubation in pediatric cardiac patients, which results in decreased ventilator
      associated co-morbidities. Patients will be randomly assigned to three groups; one group will
      receive low dose fentanyl (LDF), one will receive low dose fentanyl with dexmedetomidine (LDF
      + Dex), and one will receive high dose fentanyl (HDF). Blood samples will be collected
      post-induction, post-sternotomy, after going on cardiopulmonary bypass, at the completion of
      surgery, and post-operatively to determine the patients' stress hormone levels. The patients
      will receive standard post-operative care, and clinical data collected as part of this care
      will be used to determine the incidence of morbidity and mortality. The results of the blood
      tests will be correlated with the incidence of morbidity and mortality to demonstrate the
      relative effectiveness of the different anesthesia methods.

      Blood samples will be analyzed for the presence of the stress hormones cortisol, epinephrine,
      norepinephrine, adrenocorticotropic hormone (ACTH), Interleukin 8 (IL-8), TNF-alpha (Tumor
      Necrosis Factor), and nitrated albumin. Arterial blood gas, glucose and lactate levels, heart
      rate, blood pressure, use of vasoactive support, length of ventilator use, post-operative
      mortality, post-operative morbidity, length of Intensive Care Unit (ICU) stay, and length of
      hospital stay will be recorded.

      Children previously enrolled in the surgery study will complete assessments of their
      cognitive ability, developmental status, and emotional and behavioral adjustment. For the
      neuro-developmental outcome follow up, Children's cognitive ability will be assessed using
      the Stanford-Binet Intelligence Scales, 5th Edition (SB5). The SB5 is a widely-used measure
      of intellectual functioning that is normed for ages 2 and up. The test takes 30-50 minutes to
      administer to young children, and provides an overall Intelligence Quotient (IQ) score, as
      well as scores for five primary factors of cognitive ability: Fluid Reasoning, Knowledge,
      Quantitative Reasoning, Visual-Spatial Processing; and Working Memory. The SB5 has
      demonstrated excellent reliability and validity.
    

Intervention name(s): Fentanyl (High Dose); Fentanyl (Low Dose); Fentanyl (Low Dose) + Dexmedetomidine
Intervention type(s): Drug; Drug; Drug
Intervention description(s): Fentanyl (High Dose) 25 mcg/kg in two divided doses. Half-dose will be given at induction and the second half-dose given prior to incision.; Fentanyl (Low Dose) 10 mcg/kg in two divided doses. Half-dose will be given at induction and the second half-dose given prior to incision.; Fentanyl (Low Dose) + Dexmedetomidine. Dexmedetomidine at 1mcg/kg loading dose over 10 minutes, followed by an infusion at a rate of 0.5mcg/kg/hr. In addition, this group will receive a total of 10 mcg/kg Fentanyl (Low Dose). Half the dose will be given at induction and the second half before incision.
Other intervention name(s): Fentanyl citrate; Fentanyl citrate; Fentanyl citrate + Precedex for dexmedetomidine
Intervention MeSH terms: Fentanyl; Dexmedetomidine; Citric Acid; Sodium Citrate
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Double (Participant, Investigator)
Primary purpose: Treatment
Keywords: pediatric cardiac surgery; stress response; early extubation; Dexmedetomidine; TOF; VSD; AVSD