ORIGINAL ARTICLES  CARDIAC PAPERS 

The Journal of Cardiovascular Surgery 2000 February;41(1):1-6

Copyright © 2009 EDIZIONI MINERVA MEDICA

lingua: Inglese

Effects of temperature strategy during cardiopulmonary bypass on cerebral oxygen balance

Ip-Yam P. C., Thomas S. D., Jackson M., Rashid A., Behl S.

From the Department of Anaesthesia Royal Liverpool University Hospital, Liverpool, UK *Cardiothoracic Centre, Liverpool, UK

Background. Cerebral inju­ry is the ­most seri­ous com­pli­ca­tion of car­di­o­pul­mo­nary per­fu­sion (CPB). With the ­advent of ­warm ­heart sur­gery, the ­effect of tem­per­a­ture strat­e­gy dur­ing per­fu­sion and its ­effect on cere­bral oxy­gen bal­ance ­needs fur­ther ­study.
Methods. Three ­groups of ­patients (n=8, ­each) under­go­ing cor­o­nary ­artery ­bypass ­graft (­CABG) sur­gery ­were stud­ied. Group H, M and N under­went CPB at 28°C, 32°C and nor­mo­ther­mia (>36°C), respec­tive­ly. The extra­cor­po­real cir­cuit was ­primed ­with Hartmann’s solu­tion 2.5 l and ­flow of 1.8 l min-1 m-2 at 28°C, and 2.4 l min-1 m-2 at 32°C and nor­mo­ther­mia. All ­patients had a 4F oxim­e­try cath­e­ter (Opticath, Oximetrix, Abbott Laboratories) insert­ed in the ­right jug­u­lar ­bulb for con­tin­u­ous meas­ure­ment of jug­u­lar ­venous oxy­gen sat­u­ra­tion (sjvO2). Data was col­lect­ed at six spe­cif­ic ­times: T1- with­in 5 min ­before initi­a­tion of CPB, T2 - with­in the ­first min­ute ­after CPB, T3 - dur­ing ­stable tem­per­a­ture on CPB (28°C, 32°C, >36°C), T4 - dur­ing rewarm­ing at 34°C in ­groups H and M, 15 min ­before com­ing off CPB in ­group N, T5 - 15 min ­after CPB, T6 - ­skin clo­sure. At ­each ­time ­mean arte­ri­al pres­sure (MAP) and sjvO2 ­were record­ed. Arterial ­blood and jug­u­lar ­venous ­blood ­were sam­pled for meas­ure­ment of arte­ri­al oxy­gen sat­u­ra­tion (saO2) and jug­u­lar ­venous lac­tate (sjvlac­tate), respec­tive­ly.
Results. SjvO2 val­ues ­decreased at ­times T2, T3 and T4 ­when com­pared to base­line (p<0.05) but ­there ­were no sig­nif­i­cant ­group dif­fer­enc­es at any ­time. Cerebral arter­i­ov­e­nous oxy­gen sat­u­ra­tion (a-jvO2) dif­fer­enc­es mir­rored sjvO2 chang­es. Sjvlac­tate val­ues ­increased ­from base­line fol­low­ing CPB but ­fell con­sis­tent­ly ­with ­time - ­there ­were no sig­nif­i­cant ­group dif­fer­enc­es at ­each ­time ­point. SjvO2 and a-jvO2 val­ues ­were not sig­nif­i­cant­ly cor­re­lat­ed ­with sjvlac­tate.
Conclusion. During ­pump ­flows ­employed in ­this ­study, cere­bral oxy­gen bal­ance and per­fu­sion ­appear unaf­fect­ed by tem­per­a­ture.