title: Moderate hypothermia during aortic arch surgery is associated with reduced risk of early mortality.
abstract: OBJECTIVE
  Selective antegrade cerebral perfusion (ACP) during hypothermic circulatory arrest (HCA) provides cerebral protection during aortic arch surgery. However, the ideal temperature for HCA during ACP remains unknown. Clinical outcomes were compared in patients who underwent moderate (nasopharyngeal temperature, ≥ 20 °C) versus deep (nasopharyngeal temperature, <20 °C) HCA with ACP during aortic arch repair.
  
  
  METHODS
  By using a prospectively maintained clinical database, we analyzed data from 221 consecutive patients who underwent aortic arch replacement with HCA and ACP between December 2006 and May 2009. Seventy-eight patients underwent deep hypothermia (mean lowest temperature, 16.8 °C ± 1.7 °C) and 143 patients underwent moderate hypothermia (mean, 22.9 °C ± 1.4 °C) before systemic circulatory arrest was initiated. Multivariate stepwise logistic and linear regressions were performed to determine whether depth of hypothermia independently predicted postoperative outcomes and blood-product use.
  
  
  RESULTS
  Compared with moderate hypothermia, deep hypothermia was associated independently with a greater risk of in-hospital death (7.7% vs 0.7%; odds ratio [OR], 9.3; 95% confidence interval [CI], 1.1-81.6; P = .005) and 30-day all-cause mortality (9.0% vs 2.1%; OR, 4.7; 95% CI, 1.2-18.6; P = .02), and with longer cardiopulmonary bypass time (154 ± 62 vs 140 ± 46 min; P = .008). Deep hypothermia also was associated with a higher incidence of stroke, although this association was not statistically significant (7.6% vs 2.8%; P = .073; OR, 4.3; 95% CI, 0.9-12.5). No difference was seen in acute kidney injury, blood product transfusion, or need for surgical re-exploration.
  
  
  CONCLUSIONS
  Moderate hypothermia with ACP is associated with lower in-hospital and 30-day mortality, shorter cardiopulmonary bypass time, and fewer neurologic sequelae than deep hypothermia in patients who undergo aortic arch surgery with ACP.
authors.affiliation: Department of Anesthesiology, Baylor College of Medicine, Houston, Tex, USA.
authors.forename: January Y
authors.initials: JY
authors.lastname: Tsai
authors.forename: Wei
authors.initials: W
authors.lastname: Pan
authors.forename: Scott A
authors.initials: SA
authors.lastname: Lemaire
authors.forename: Paul
authors.initials: P
authors.lastname: Pisklak
authors.forename: Vei-Vei
authors.initials: VV
authors.lastname: Lee
authors.forename: Arthur W
authors.initials: AW
authors.lastname: Bracey
authors.forename: MacArthur A
authors.initials: MA
authors.lastname: Elayda
authors.forename: Ourania
authors.initials: O
authors.lastname: Preventza
authors.forename: Matt D
authors.initials: MD
authors.lastname: Price
authors.forename: Charles D
authors.initials: CD
authors.lastname: Collard
authors.forename: Joseph S
authors.initials: JS
authors.lastname: Coselli
mesh_terms: D000368:Aged; D001013:Aorta, Thoracic / Q000601:surgery*; D001803:Blood Transfusion; D002315:Cardiopulmonary Bypass; D002560:Cerebrovascular Circulation; D002561:Cerebrovascular Disorders / Q000209:etiology / Q000401:mortality / Q000503:physiopathology / Q000517:prevention & control*; D016009:Chi-Square Distribution; D050792:Circulatory Arrest, Deep Hypothermia Induced / Q000009:adverse effects / Q000401:mortality; D005260:Female; D017052:Hospital Mortality; D006801:Humans; D007036:Hypothermia, Induced / Q000009:adverse effects / Q000401:mortality; D016014:Linear Models; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D010477:Perfusion / Q000009:adverse effects / Q000401:mortality; D012086:Reoperation; D012189:Retrospective Studies; D012307:Risk Factors; D013997:Time Factors; D016896:Treatment Outcome; D014656:Vascular Surgical Procedures / Q000009:adverse effects / Q000401:mortality
keywords: 19; 26.1.1; 26.1.3; ACP; AKI; AKIN; Acute Kidney Injury Network; CI; CPB; DHCA; HCA; LOS; MHCA; MI; OR; acute kidney injury; antegrade cerebral perfusion; cardiopulmonary bypass; confidence interval; deep hypothermic circulatory arrest; hypothermic circulatory arrest; length of stay; moderate hypothermic circulatory arrest; myocardial infarction; odds ratio