Article Text

Download PDFPDF

Feasibility of Improving Cerebral Autoregulation in Acute Intracerebral Haemorrhage (BREATHE-ICH) study: a protocol for an experimental interventional study
  1. Jatinder S Minhas1,
  2. Ronney B Panerai1,2,
  3. Thompson G Robinson1,2
  1. 1 Cerebral Haemodynamics in Ageing and Stroke Medicine (CHiASM) Research Group, Department of Cardiovascular Sciences, University of Leicester, Leicester, UK
  2. 2 National Institute for Health Research Leicester Biomedical Research Centre, University of Leicester, Leicester, UK
  1. Correspondence to Dr Jatinder S Minhas; jm591{at}


Introduction Cerebral autoregulation (CA) is impaired in a multitude of neurological conditions. Increasingly, clinical studies are correlating the nature of this impairment with prognostic markers. In acute intracerebral haemorrhage (ICH), impairment of CA has been associated with worsening clinical outcomes including poorer Glasgow Coma Score and larger haematoma volume. Hypocapnia has been shown to improve CA despite concerns over hypoperfusion and consequent ischaemic risks, and it is therefore hypothesised that hypocapnia (via hyperventilation) in acute ICH may improve CA and consequently clinical outcome. BREATHE-ICH is a CA-targeted interventional study in acute ICH utilising a simple bedside hyperventilatory manoeuvre.

Methods and analysis Patients with acute ICH within 48 hours of onset will be included. The experimental set-up measures cerebral blood flow (cerebral blood velocity, transcranial Doppler), blood pressure (Finometer) and end tidal carbon dioxide (capnography) at baseline, and in response to hypocapnia (−5 mm and −10 mm Hg below baseline) achieved via a 90 s hyperventilatory manoeuvre. Autoregulation is evaluated with transfer function analysis and autoregulatory index calculations. Important classical endpoints associated with this before and after interventional study include death and disability at 14 days and the proportion of recruited individuals able to comply with the full measurement protocol.

Ethics and dissemination A favourable opinion was granted by the East Midlands-Nottingham 1 Research Ethics Committee (17/EM/0283). It is anticipated that the results of this study will be presented at national and international meetings, with reports being published in journals during late 2018.

Trial registration number NCT03324321.

  • physiology
  • hypertension
  • neuroradiology
  • stroke
  • neurological injury

This is an Open Access article distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See:

Statistics from


  • Contributors JSM, RBP and TGR participated in the developing and testing of the study set-up, conception of the study, designing the statistical and mathematical analysis, and drafted the manuscript.

  • Funding The BREATHE-ICH study is funded by a Dunhill Medical Trust Research Training Fellowship (RTF97/0117).

  • Competing interests None declared.

  • Patient consent Not required.

  • Ethics approval The East Midlands-Nottingham 1 Research Ethics Committee (17/EM/0283).

  • Provenance and peer review Not commissioned; externally peer reviewed.

Request Permissions

If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.