Blood pressure in head-injured patients
- Patrick Mitchell1,
- Barbara A Gregson1,
- Ian Piper3,
- Giuseppe Citerio4,
- A David Mendelow1,
- Iain R Chambers2
- 1Department of Neurosurgery, Newcastle General Hospital, Newcastle upon Tyne, UK
- 2Regional Medical Physics Department, The James Cook University Hospital, Middlesborough, UK
- 3Department of Clinical Physics, Institute of Neurological Sciences, Southern General Hospital, Glasgow, UK
- 4Department of Perioperative and Intensive Care, Neuro Intensive Care Unit, Hospital San Gerado, Monza, Italy
- Correspondence to: Dr I R Chambers Regional Medical Physics Department, The James Cook University Hospital, Marton Road, Middlesbrough TS4 3BW, UK;
- Received 16 June 2006
- Accepted 17 November 2006
- Revised 2 October 2006
- Published Online First 30 November 2006
Objective: To determine the statistical characteristics of blood pressure (BP) readings from a large number of head-injured patients.
Methods: The BrainIT group has collected high time-resolution physiological and clinical data from head-injured patients who require intracranial pressure (ICP) monitoring. The statistical features of this dataset of BP measurements with time resolution of 1 min from 200 patients is examined. The distributions of BP measurements and their relationship with simultaneous ICP measurements are described.
Results: The distributions of mean, systolic and diastolic readings are close to normal with modest skewing towards higher values. There is a trend towards an increase in blood pressure with advancing age, but this is not significant. Simultaneous blood pressure and ICP values suggest a triphasic relationship with a BP rising at 0.28 mm Hg/mm Hg of ICP, for ICP up to 32 mm Hg, and 0.9 mm Hg/mm Hg of ICP for ICP from 33 to 55 mm Hg, and falling sharply with rising ICP for ICP >55 mm Hg.
Conclusions: Patients with head injury appear to have a near normal distribution of blood pressure readings that are skewed towards higher values. The relationship between BP and ICP may be triphasic.
Published Online First 11 December 2006
Competing interests: None declared.
Funding: This study was facilitated by a grant from the European Union (Contract number QLG3-CT-2002–01160). The funding source had no involvement in the design, data collection, analysis or interpretation of the data, in the writing of the report or in the decision to submit this work for publication.
Participating Centres and investigators: Barcelona, Spain, Professor J Sahuquillo; Cambridge, UK, Prof JD Pickard; Edinburgh, UK, Professor I Whittle; Glasgow, UK, Mr L Dunn; Gothenburg, Sweden, Dr B Rydenhag; Heidelberg, Germany, Dr K Kiening; Iasi Romania, Dr S Iencean; Kaunas, Lithuania, Professor D Pavalkis; Leipzig, Germany, Professor J Meixensberger; Leuven, Belgium, Professor J Goffin; Mannheim, Germany, Professor P Vajkoczy; Milano, Italy, Professor N Stocchetti; Monza, Italy, Dr G Citerio; Newcastle upon Tyne, UK, Dr IR Chambers; Novara, Italy, Professor F Della Corte; Southampton, UK, Dr J Hell; Uppsala, Sweden, Professor P Enblad; Torino, Italy, Dr L Mascia; Vilnius, Lithuania, Professor E Jarzemaskas; Zurich, Switzerland, Professor R Stocker.
BrainIT Steering Group members: IR Chambers, Newcastle upon Tyne, UK; G Citerio, Monza, Italy; P Enblad Uppsala, Sweden; BA Gregson, Newcastle upon Tyne, UK; T Howells, Uppsala, Sweden; Karl Kiening, Heidelberg, Germany; P Nilsson Uppsala, Sweden; I Piper, Glasgow, UK; A Ragauskas, Kaunas, Lithuiania; J Sahuquillo, Barcelona, Spain and YH Yau, Edinburgh, UK.
PM, BAG, ADM and IRC conceived the analysis. PM, BAG and IRC performed the analysis. PM, BAG, IP, GC, ADM and IRC helped draft the manuscript. IP, BAG, GC and IRC are on the Steering Committee of BrainIT. All authors have had access to all of the data in the study and they held final responsibility for the decision to submit for publication.