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Titolo:
Effect of CO2 on dynamic cerebral autoregulation measurement
Autore:
Panerai, RB; Deverson, ST; Mahony, P; Hayes, P; Evans, DH;
Indirizzi:
Univ Leicester, Fac Med, Div Med Phys, Leicester Royal Infirm, Leicester LE1 5WW, Leics, England Univ Leicester Leicester Leics England LE1 5WW er LE1 5WW, Leics, England Leicester Royal Infirm, Dept Surg, Leicester LE1 5WW, Leics, England Leicester Royal Infirm Leicester Leics England LE1 5WW WW, Leics, England
Titolo Testata:
PHYSIOLOGICAL MEASUREMENT
fascicolo: 3, volume: 20, anno: 1999,
pagine: 265 - 275
SICI:
0967-3334(199908)20:3<265:EOCODC>2.0.ZU;2-F
Fonte:
ISI
Lingua:
ENG
Soggetto:
ARTERIAL BLOOD-PRESSURE; FREQUENCY-DOMAIN ANALYSIS; CARBON-DIOXIDE; FLOW VELOCITY; SPONTANEOUS FLUCTUATIONS; INTRACRANIAL-PRESSURE; AUTO-REGULATION; HEAD-INJURY; HUMANS; OSCILLATIONS;
Keywords:
cerebral autoregulation; cerebral blood how; transcranial Doppler; end-tidal CO2; cerebral haemodynamics;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Clinical Medicine
Life Sciences
Citazioni:
40
Recensione:
Indirizzi per estratti:
Indirizzo: Panerai, RB Univ Leicester, Fac Med, Div Med Phys, Leicester Royal Infirm,Leicester LE1 5WW, Leics, England Univ Leicester Leicester Leics England LE1 5WW Leics, England
Citazione:
R.B. Panerai et al., "Effect of CO2 on dynamic cerebral autoregulation measurement", PHYSL MEAS, 20(3), 1999, pp. 265-275

Abstract

Arterial pCO(2) is known to influence cerebral autoregulation but its effect on the dynamic relationship between mean arterial blood pressure (ABP) and mean cerebral blood flow velocity (CBFV), obtained from spontaneous fluctuations in ABP, has not been established. In 16 normal subjects, ABP was measured non-invasively (Finapres), CBFV was estimated with Doppler ultrasound in the middle cerebral artery, and end-tidal CO2 (EtCO2) was measured with an infrared capnograph. Recordings were made before, during and after breathing a mixture of 5% CO2 in air. The coherence function, amplitude and phase frequency responses, and impulse and step responses For the effects ofABP on CBFV were calculated by spectral analysis of beat-to-beat changes in mean ABP and CBFV before (mean CO2 5.55 +/- 0.38 kPa), during (6.43 +/- 0.31 kPa) and after 5% CO2 (5.43 +/- 0.26 kPa). During 5% CO2, the coherencefunction and the amplitude frequency response were significantly increasedfor frequencies below 0.05 Hz and the phase was reduced for the frequency range 0.02-0.1 Hz. The impulse and step responses indicated that 5% COz reduces the efficiency of the autoregulatory mechanism. A 20.7% average increase in CBFV induced by a 14.4% increase in EtCO2 was found to be mediated bya 25.9% reduction in critical closing pressure, while the change in resistance-area product was non-significant.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 25/11/20 alle ore 15:46:12