Regional oxygenation and systemic inflammatory response during cardiopulmonary bypass: influence of temperature and blood flow variations.
OBJECTIVE
To evaluate the role of target temperature (28 degrees or 34 degrees C) in cardiac surgery on regional oxygenation during hypothermia and rewarming and systemic inflammatory response.


METHODS
Prospective, controlled, and randomized clinical study.


METHODS
University hospital.


METHODS
Elderly patients (mean age 70 +/- 2 years) with acquired heart disease with an anticipated bypass time exceeding 120 minutes (n = 30).


METHODS
The patients were cooled to either 28 degrees C (n = 15) or 34 degrees C (n = 15). At hypothermia, bypass blood flow was reduced twice from full flow (2.4 L/min/m(2) body surface area [BSA]) to 2.0 L/min/m(2).


RESULTS
Hepatic and jugular venous oxygen tension and saturation were higher at 28 degrees C than at 34 degrees C. In comparison with the preoperative values, at 28 degrees C hepatic venous values were higher; whereas at 34 degrees C, they were lower. The reduction of pump blood flow during hypothermia, from 2.4 to 2.0 L/min/m(2)was accompanied by reductions of central, jugular, and hepatic oxygenation at both target temperatures. During rewarming, central and regional venous oxygenation decreased irrespective of the preceding temperature. The decrease was most pronounced in hepatic venous blood, with the lowest individual values <10%. Serum concentrations of C3a and IL-6 increased during hypothermia and increased further during rewarming irrespective of the preceding temperature.


CONCLUSIONS
During cardiopulmonary bypass, hypothermia at 28 degrees C increases regional and central venous oxygenation better than at 34 degrees C. In contrast, venous oxygenation decreases during rewarming irrespective of the preceding temperature. No significant difference in the systemic inflammatory response associated with target temperature was detected.
Lindholm
Lena
L
Department of Cardiothoracic Surgery, Sahlgrenska University Hospital, Göteborg, Sweden. lena.lindholm@vll.se
Bengtsson
Anders
A
Hansdottir
Vigdis
V
Lundqvist
Magnus
M
Rosengren
Lars
L
Jeppsson
Anders
A
D000368:Aged; D002315:Cardiopulmonary Bypass; D015926:Complement C3a / Q000378:metabolism; D003326:Coronary Circulation / Q000502:physiology*; D005260:Female; D006331:Heart Diseases / Q000601:surgery*; D006439:Hemodynamics / Q000502:physiology; D006454:Hemoglobins / Q000378:metabolism; D006801:Humans; D007036:Hypothermia, Induced / Q000009:adverse effects*; D007249:Inflammation / Q000276:immunology*; D015850:Interleukin-6 / Q000097:blood; D008297:Male; D010100:Oxygen / Q000097:blood*; D011446:Prospective Studies; D012039:Regional Blood Flow / Q000502:physiology; D017694:Rewarming / Q000009:adverse effects*
D006454:Hemoglobins; D015850:Interleukin-6; D015926:Complement C3a; D010100:Oxygen