Intraaortic Balloon Pump Counterpulsation and Cerebral Autoregulation: an observational study

BMC Anesthesiology

Research Article

Shureng Geng¹  John F Fraser¹  Daniel Timms¹  Kimble Dunster¹  Rob Boots²  Judith Bellapart²  Adrian G Barnett³ 

[1] Critical Care Research Group and Department of Intensive Care Medicine, The Prince Charles Hospital and University of Queensland, (Rode road), (4032), Brisbane, Australia;Department of Intensive Care, Royal Brisbane and Women's Hospital, (Butterfield Street), (4029), Herston, Australia;Institute of Health and Biomedical Innovation & School of Public Health, Queensland University of Technology, (George Street), (4000), Brisbane, Australia;

关键词: Cerebral Blood Flow;    Mean Arterial Pressure;    Cerebral Perfusion Pressure;    Cerebral Autoregulation;    Pulse Pressure Variation;   

DOI  :  10.1186/1471-2253-10-3

 received in 2009-10-13, accepted in 2010-03-12,  发布年份 2010

来源: Springer

【 摘 要 】

BackgroundThe use of Intra-aortic counterpulsation is a well established supportive therapy for patients in cardiac failure or after cardiac surgery. Blood pressure variations induced by counterpulsation are transmitted to the cerebral arteries, challenging cerebral autoregulatory mechanisms in order to maintain a stable cerebral blood flow. This study aims to assess the effects on cerebral autoregulation and variability of cerebral blood flow due to intra-aortic balloon pump and inflation ratio weaning.MethodsCerebral blood flow was measured using transcranial Doppler, in a convenience sample of twenty patients requiring balloon counterpulsation for refractory cardiogenic shock (N = 7) or a single inotrope to maintain mean arterial pressure following an elective placement of an intra-aortic balloon pump for cardiac surgery (N = 13). Simultaneous blood pressure at the aortic root was recorded via the intra-aortic balloon pump. Cerebral blood flow velocities were recorded for six minute intervals at a 1:1 balloon inflation-ratio (augmentation of all cardiac beats) and during progressive reductions of the inflation-ratio to 1:3 (augmentation of one every third cardiac beat). Real time comparisons of peak cerebral blood flow velocities with systolic blood pressure were performed using cross-correlation analysis. The primary endpoint was assessment of cerebral autoregulation using the time delay between the peak signals for cerebral blood flow velocity and systolic blood pressure, according to established criteria. The variability of cerebral blood flow was also assessed using non-linear statistics.ResultsDuring the 1:1 inflation-ratio, the mean time delay between aortic blood pressure and cerebral blood flow was -0.016 seconds (95% CI: -0.023,-0.011); during 1:3 inflation-ratio mean time delay was significantly longer at -0.010 seconds (95% CI: -0.016, -0.004, P < 0.0001). Finally, upon return to a 1:1 inflation-ratio, time delays recovered to those measured at baseline. During inflation-ratio reduction, cerebral blood flow irregularities reduced over time, whilst cerebral blood flow variability at end-diastole decreased in patients with cardiogenic shock.ConclusionsWeaning counterpulsation from 1:1 to 1:3 inflation ratio leads to a progressive reduction in time delays between systolic blood pressure and peak cerebral blood flow velocities suggesting that although preserved, there is a significant delay in the establishment of cerebral autoregulatory mechanisms. In addition, cerebral blood flow irregularities (i.e. surrogate of flow adaptability) decrease and a loss of cerebral blood flow chaotic pattern occurs during the end-diastolic phase of each beat in patients with cardiogenic shock.

【 授权许可】

CC BY   
© Bellapart et al; licensee BioMed Central Ltd. 2010