title: Cardiac condition during cooling and rewarming periods of therapeutic hypothermia after cardiopulmonary resuscitation.
abstract: BACKGROUND
  Hypothermia has been used in cardiac surgery for many years for neuroprotection. Mild hypothermia (MH) [body temperature (BT) kept at 32-35°C] has been shown to reduce both mortality and poor neurological outcome in patients after cardiopulmonary resuscitation (CPR). This study investigated whether patients who were expected to benefit neurologically from therapeutic hypothermia (TH) also had improved cardiac function.
  
  
  METHODS
  The study included 30 patients who developed in-hospital cardiac arrest between September 17, 2012, and September 20, 2013, and had return of spontaneous circulation (ROSC) following successful CPR. Patient BTs were cooled to 33°C using intravascular heat change. Basal BT, systolic artery pressure (SAP), diastolic artery pressure (DAP), mean arterial pressure (MAP), heart rate, central venous pressure, cardiac output (CO), cardiac index (CI), global end-diastolic volume index (GEDI), extravascular lung water index (ELWI), and systemic vascular resistance index (SVRI) were measured at 36°C, 35°C, 34°C and 33°C during cooling. BT was held at 33°C for 24 hours prior to rewarming. Rewarming was conducted 0.25°C/h. During rewarming, measurements were repeated at 33°C, 34°C, 35°C and 36°C. A final measurement was performed once patients spontaneously returned to basal BT. We compared cooling and rewarming cardiac measurements at the same BTs.
  
  
  RESULTS
  SAP values during rewarming (34°C, 35°C and 36°C) were lower than during cooling (P < 0.05). DAP values during rewarming (basal temperature, 34°C, 35°C and 36°C) were lower than during cooling. MAP values during rewarming (34°C, 35°C and 36°C) were lower than during cooling (P < 0.05). CO and CI values were higher during rewarming than during cooling. GEDI and ELWI did not differ during cooling and rewarming. SVRI values during rewarming (34°C, 35°C, 36°C and basal temperature) were lower than during cooling (P < 0.05).
  
  
  CONCLUSIONS
  To our knowledge, this is the first study comparing cardiac function at the same BTs during cooling and rewarming. In patients experiencing ROSC following CPR, TH may improve cardiac function and promote favorable neurological outcomes.
authors.affiliation: Department of Anesthesiology and Reanimation, Bagcilar Educational and Training Hospital, Şenlikköy Mah, İncir Sokak, No:1/3, Sarı Konaklar Sitesi, B-Blok, Daire:6, Florya/ Bakırköy, Istanbul, Turkey.
authors.forename: Serdar
authors.initials: S
authors.lastname: Demirgan
authors.affiliation: Department of Anesthesiology and Reanimation, Bagcilar Educational and Training Hospital, Şenlikköy Mah, İncir Sokak, No:1/3, Sarı Konaklar Sitesi, B-Blok, Daire:6, Florya/ Bakırköy, Istanbul, Turkey.
authors.forename: Kerem
authors.initials: K
authors.lastname: Erkalp
authors.affiliation: Department of Anesthesiology and Reanimation, Bagcilar Educational and Training Hospital, Şenlikköy Mah, İncir Sokak, No:1/3, Sarı Konaklar Sitesi, B-Blok, Daire:6, Florya/ Bakırköy, Istanbul, Turkey.
authors.forename: M Salih
authors.initials: MS
authors.lastname: Sevdi
authors.affiliation: Department of Anesthesiology and Reanimation, Bagcilar Educational and Training Hospital, Şenlikköy Mah, İncir Sokak, No:1/3, Sarı Konaklar Sitesi, B-Blok, Daire:6, Florya/ Bakırköy, Istanbul, Turkey.
authors.forename: Meltem Turkay
authors.initials: MT
authors.lastname: Aydogmus
authors.affiliation: Department of Anesthesiology and Reanimation, Bagcilar Educational and Training Hospital, Şenlikköy Mah, İncir Sokak, No:1/3, Sarı Konaklar Sitesi, B-Blok, Daire:6, Florya/ Bakırköy, Istanbul, Turkey.
authors.forename: Numan
authors.initials: N
authors.lastname: Kutbay
authors.affiliation: Department of Anesthesiology and Reanimation, Bagcilar Educational and Training Hospital, Şenlikköy Mah, İncir Sokak, No:1/3, Sarı Konaklar Sitesi, B-Blok, Daire:6, Florya/ Bakırköy, Istanbul, Turkey.
authors.forename: Aydin
authors.initials: A
authors.lastname: Firincioglu
authors.affiliation: Department of Anesthesiology and Reanimation, Bagcilar Educational and Training Hospital, Şenlikköy Mah, İncir Sokak, No:1/3, Sarı Konaklar Sitesi, B-Blok, Daire:6, Florya/ Bakırköy, Istanbul, Turkey.
authors.forename: Ali
authors.initials: A
authors.lastname: Ozalp
authors.affiliation: Department of Anesthesiology and Reanimation, Bagcilar Educational and Training Hospital, Şenlikköy Mah, İncir Sokak, No:1/3, Sarı Konaklar Sitesi, B-Blok, Daire:6, Florya/ Bakırköy, Istanbul, Turkey.
authors.forename: Aysin
authors.initials: A
authors.lastname: Alagol
mesh_terms: D000328:Adult; D000368:Aged; D001831:Body Temperature; D016887:Cardiopulmonary Resuscitation; D005260:Female; D006321:Heart / Q000503:physiopathology*; D006323:Heart Arrest / Q000628:therapy; D006334:Heart Function Tests; D006439:Hemodynamics / Q000502:physiology; D006801:Humans; D007036:Hypothermia, Induced / Q000379:methods*; D008297:Male; D008875:Middle Aged; D017694:Rewarming; D013815:Thermodilution
keywords: Cardiac arrest; Cardiac function; Cardiac measurement; Cardioprotection; Therapeutic hypothermia