Can we use short recordings for assessment of dynamic cerebral autoregulation? A sensitivity analysis study in acute ischaemic stroke and healthy subjects.
posted on 2019-08-14, 11:07authored byK Intharakham, RB Panerai, E Katsogridakis, MY Lam, O Llwyd, ASM Salinet, RC Nogueira, VJ Haunton, TG Robinson
Objective: It is unclear whether the duration of recordings influences estimates of dynamic cerebral autoregulation (dCA). Therefore, we performed a retrospective study of the effects of
reducing recording durations on dCA estimates; with the potential to inform recording
duration for reliable estimates in challenging clinical populations.
Approach: Seventy-eight healthy control subjects and 79 acute ischaemic stroke (AIS) patients were
included. Cerebral blood flow velocity was recorded with transcranial Doppler and continuous blood
pressure with the Finapres device. The autoregulation index (ARI), derived with transfer
function analysis, was calculated for recording durations at one-minute intervals between 1 and 5
minutes using the same starting point of each recording.
Main results: Though recording duration did not affect the overall ARI value, when compared to
control subjects, AIS patients had significantly lower ARI values for durations between 3 and 5
(p<0.0001), but not 1 and 2 minutes. The intraclass correlation coefficient of all participants,
for reproducibility of the five recording durations, was 0.69. AIS patients
classified as having impaired cerebral autoregulation (CA; ARI≤4) at 5 min, had a 7.1% rate
of false negatives for both 4 and 3 min recordings, reaching 42.9% for 1 min recording. The
percentage of false-positives also increased with reduced recording durations (from 0% at 5 to
16.2% at 1 minute).
Significance: Reducing recording durations from 5 to 3 min can still provide reliable estimates of
ARI, and may facilitate CA studies in potentially medically unstable AIS patients, as well as in
other patient groups.
Funding
Supported by EPSRC grant EP/K041207/1. The authors would like to thank the Ministry of Sciences and Technology of the Royal Thai Government and Thammasat University (Thailand) for supporting a PhD scholarship for the first author.
History
Citation
Physiological Measurement, 2019
Author affiliation
/Organisation/COLLEGE OF LIFE SCIENCES/School of Medicine/Department of Cardiovascular Sciences
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