title: Cardiopulmonary bypass and serum thyroid hormone profile in pediatric patients with congenital heart disease.
abstract: OBJECTIVE
  To study the effect of cardiopulmonary bypass (CPB) on serum thyroid hormone profile in children undergoing open-heart surgery.
  
  
  METHODS
  Prospective cross-sectional study.
  
  
  METHODS
  Multispecialty tertiary level referral center.
  
  
  METHODS
  One hundred consecutive patients (age 15.9 ± 14.6 months, weight 6.7 ± 2.5 kg) undergoing open-heart surgery under CPB.
  
  
  METHODS
  None.
  
  
  METHODS
  Levels and trends of serum total thyroxine (TT4), free thyroxine (FT4), total tri-iodothyronine (TT3), free tri-iodothyronine (FT3) and thyroid stimulating hormone (TSH), survival, inotropic score, duration of mechanical ventilation, postoperative complications.
  
  
  RESULTS
  TT4 levels were 9.08 ± 3.6, 6.4 ± 2.5, 6.24 ± 2.1, 6.43 ± 2.4, 7.20 ± 3.0 µg/dL at baseline and at 1, 24, 48 and 72 hours; FT4 levels were 1.82 ± 0.5, 1.49 ± 0.3, 1.29 ± 0.3, 1.32 ± 0.4, and 1.43 ± 0.5 ng/dL; TT3 levels were 1.81 ± 0.4, 1.31 ± 0.3, 0.99 ± 0.2, 1.0 ± 0.37, and 1.17 ± 0.48 ng/ml; FT3 levels were 4.09 ± 1.0, 3.02 ± 0.8, 2.21 ± 0.6, 2.22 ± 0.7, and 2.66 ± 1.05 pg/ml; TSH levels were 5.40 ± 3.8, 2.0 ± 3.1, 1.24 ± 1.1, 2.90 ± 3.3, and 4.03 ± 3.4 mIU/L. There was significant fall (29.1% for FT4, 32.1% for TT4, 77% for TSH, 46% for FT3 and 45% for TT3, p < 0.0001). When area under curve (AUC) TT4 was compared between survivors (n = 87) and nonsurvivors (n = 12), significantly larger AUC was seen in survivors (492.81 ± 158.6) than nonsurvivors (360.75 ± 179.6 p = 0.0125). In survivors >72 hours, AUC TT4 was larger in patients with uneventful postoperative course versus those with postoperative complications (516.48 ± 18.6 vs. 394.78 ± 29.9, p = 0.001). AUC TT4 showed significant inverse correlation with inotropic score and borderline inverse correlation with duration of mechanical ventilation.
  
  
  CONCLUSIONS
  Children undergoing surgery under CPB showed significant fall in thyroid hormones. Because TT4 level is modifiable, prophylactic administration of TT4 for improving outcomes needs to be studied further.
authors.affiliation: Departments of Cardiothoracic and Vascular Surgery, All India Institute of Medical Sciences, New Delhi, India. sachintalwar@hotmail.com
authors.forename: Sachin
authors.initials: S
authors.lastname: Talwar
authors.forename: Rajesh
authors.initials: R
authors.lastname: Khadgawat
authors.forename: Jandardhan Alamanda
authors.initials: JA
authors.lastname: Sandeep
authors.forename: Vishnubhatla
authors.initials: V
authors.lastname: Sreenivas
authors.forename: Shiv Kumar
authors.initials: SK
authors.lastname: Choudhary
authors.forename: Nandita
authors.initials: N
authors.lastname: Gupta
authors.forename: Balram
authors.initials: B
authors.lastname: Airan
mesh_terms: D019540:Area Under Curve; D015415:Biomarkers / Q000097:blood; D006348:Cardiac Surgical Procedures / Q000009:adverse effects / Q000401:mortality; D002315:Cardiopulmonary Bypass / Q000009:adverse effects / Q000401:mortality; D002316:Cardiotonic Agents / Q000627:therapeutic use; D002648:Child; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D015536:Down-Regulation; D005260:Female; D006330:Heart Defects, Congenital / Q000097:blood / Q000401:mortality / Q000601:surgery*; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D016014:Linear Models; D008297:Male; D011183:Postoperative Complications / Q000097:blood / Q000209:etiology / Q000628:therapy; D011446:Prospective Studies; D012121:Respiration, Artificial; D062606:Tertiary Care Centers; D013963:Thyroid Hormones / Q000097:blood*; D013972:Thyrotropin / Q000097:blood; D013974:Thyroxine / Q000097:blood; D013997:Time Factors; D016896:Treatment Outcome; D014284:Triiodothyronine / Q000097:blood
chemical_list: D015415:Biomarkers; D002316:Cardiotonic Agents; D013963:Thyroid Hormones; D014284:Triiodothyronine; D013972:Thyrotropin; D013974:Thyroxine