Cerebral blood flow sensitivities to CO2 measured with steady-state and modified rebreathing methods

被引:24
作者
Pandit, Jaideep J. [1 ]
Mohan, Ravi M.
Paterson, Nicole D.
Poulin, Marc J.
机构
[1] John Radcliffe Hosp, Nuffield Dept Anaesthet, Oxford OX3 9DU, England
[2] Univ Lab Physiol, Oxford OX1 39T, England
[3] Univ Calgary, Fac Med & Kinesiol, Hotchkiss Brain Inst & Libin Cardiovasc Inst, Dept Physiol & Biophys & Clin Neurosci, Calgary, AB T2N 4N1, Canada
基金
英国惠康基金;
关键词
blood flow; cerebral; CO2; carbon dioxide; ventilatory response; cerebral blood flow; control of breathing; ventilatory response to CO2; mammals; humans; methods; rebreathing; steady-state CO2 response;
D O I
10.1016/j.resp.2007.05.007
中图分类号
Q4 [生理学];
学科分类号
071003 ;
摘要
It is well established that the ventilatory response to carbon dioxide (CO2) measured by modified rebreathing (Sr-VE) is closer to that measured by the steady-state method (Ss(VE)) than is the response measured by Read's rebreathing method. It is also known that the value estimated by the steady-state method depends upon the combination of data points used to measure it. The aim of this study was to investigate if these observations were also true for cerebral blood flow (CBF), as measured by steady-state (Ss(CBF)) and modified rebreathing (Sr-CBF) tests- Six subjects undertook two protocols: (a) steady state: PETCO2, was held at 1.5 mmHg above normal (isocapnia) for 10 min, then raised to three levels of hypercapnia, (8 min each; 6.5,11.5 and 16.5 mmHg above normal, separated by 4 min isocapnia). End-tidal P-O2, was held at 300 mmHg; (b) modified rebreathing: subjects underwent 6 min of voluntary hyperventilation to PETCO2 similar to 20 mmHg, and then rebreathed via a 61 bag filled with 6.5% CO2 in O-2. We confirmed that the value for Ss(VE) depended upon the combination of data points used to calculate it, and also confirmed that Ss(VE) and SrVE were similar. However, this was not the case with CBF. Estimates Of Ss(CBF) were the same, regardless of the data points used in calculation, and Ss(CBF) was 89% greater than SrCBF (P < 0.05). We interpret these findings as consistent with the notion that the Specific CO2 stimulus differs for CBF and ventilatory control. The data also indicate that prior hypocapnia in the modified rebreathing protocol may have a persistent effect on both cerebral vessels and central ventilatory control. (c) 2007 Elsevier B.V. All rights reserved.
引用
收藏
页码:34 / 44
页数:11
相关论文
共 47 条
[1]   Effect of different levels of hyperoxia on breathing in healthy subjects [J].
Becker, HF ;
Polo, O ;
McNamara, SG ;
BerthonJones, M ;
Sullivan, CE .
JOURNAL OF APPLIED PHYSIOLOGY, 1996, 81 (04) :1683-1690
[2]   THE VENTILATORY CO2 SENSITIVITIES FROM READ REBREATHING METHOD AND THE STEADY-STATE METHOD ARE NOT EQUAL IN MAN [J].
BERKENBOSCH, A ;
BOVILL, JG ;
DAHAN, A ;
DEGOEDE, J ;
OLIEVIER, ICW .
JOURNAL OF PHYSIOLOGY-LONDON, 1989, 411 :367-377
[3]   A PSEUDO-REBREATHING TECHNIQUE FOR ASSESSING THE VENTILATORY RESPONSE TO CARBON-DIOXIDE IN CATS [J].
BERKENBOSCH, A ;
DEGOEDE, J ;
OLIEVIER, CN ;
SCHUITMAKER, JJ .
JOURNAL OF PHYSIOLOGY-LONDON, 1986, 381 :483-495
[4]   INFLUENCE OF CSF BICARBONATE CONCENTRATION ON VENTILATORY RESPONSE TO CO2 IN RELATION TO LOCATION OF CENTRAL CHEMORECEPTORS [J].
BERKENBOSCH, A ;
GOEDE, JD ;
OLIEVIER, CN ;
QUANJER, PH .
RESPIRATION PHYSIOLOGY, 1978, 35 (02) :215-236
[5]   THE VENTILATORY RESPONSE TO CO2 OF THE PERIPHERAL AND CENTRAL CHEMOREFLEX LOOP BEFORE AND AFTER SUSTAINED HYPOXIA IN MAN [J].
BERKENBOSCH, A ;
DAHAN, A ;
DEGOEDE, J ;
OLIEVIER, ICW .
JOURNAL OF PHYSIOLOGY-LONDON, 1992, 456 :71-83
[6]   DYNAMICS OF VENTILATORY RESPONSE TO STEP CHANGES IN PCO2 OF BLOOD PERFUSING THE BRAIN-STEM [J].
BERKENBOSCH, A ;
WARD, DS ;
OLIEVIER, CN ;
DEGOEDE, J ;
VANHARTEVELT, J .
JOURNAL OF APPLIED PHYSIOLOGY, 1989, 66 (05) :2168-2173
[7]   THE EFFECT OF HIGH-CONCENTRATIONS OF INSPIRED OXYGEN ON MIDDLE CEREBRAL-ARTERY BLOOD VELOCITY MEASURED BY TRANSCRANIAL DOPPLER [J].
BEW, SA ;
FIELD, LM ;
DROSTE, DW ;
RAZIS, P .
EXPERIMENTAL PHYSIOLOGY, 1994, 79 (04) :593-596
[8]   TRANSCRANIAL DOPPLER MEASUREMENT OF MIDDLE CEREBRAL-ARTERY BLOOD-FLOW VELOCITY - A VALIDATION-STUDY [J].
BISHOP, CCR ;
POWELL, S ;
RUTT, D ;
BROWSE, NL .
STROKE, 1986, 17 (05) :913-915
[9]   THE STEADY-STATE AND REBREATHING METHODS COMPARED DURING MORPHINE ADMINISTRATION IN HUMANS [J].
BOURKE, DL ;
WARLEY, A .
JOURNAL OF PHYSIOLOGY-LONDON, 1989, 419 :509-517
[10]  
CASEY K, 1987, J PHYSIOL-LONDON, V383, P9