Bart Depreitere1, Geert Meyfroidt2, Fabian Güiza2. 1. Department of Neurosurgery, University Hospitals Leuven, Leuven, Belgium. bart.depreitere@uzleuven.be. 2. Department of Intensive Care Medicine, University Hospitals Leuven, Leuven, Belgium.
Abstract
INTRODUCTION: No consensus exists on the exact method for measuring mean arterial blood pressure (MAP) in the definition of cerebral perfusion pressure (CPP). The aim of the current study is to investigate how different MAP measurement methods have influenced the CPP recommendations in the Brain Trauma Foundation (BTF) guidelines. METHODS: All papers on which the chapter on CPP thresholds in the 2007 version of the BTF guidelines is based, were reviewed. If accurate descriptions of head of bed elevation and arterial pressure transducer height were lacking, the authors were emailed for clarification. Additionally, the effect of choosing the radial artery for MAP measurement and the potential effect of gravity were studied in the literature. RESULTS: Thresholds of CPP in the BTF guidelines are based on 11 studies. Head of bed elevation at 30° was part of the protocol in 5 studies, patients were nursed flat in 1 study, and this variable remained unknown for 5 studies. The arterial pressure transducer was at heart level in 5 studies, at ear level in 3 studies, and height was unknown in 3 studies. Measuring MAP in the radial artery underestimates carotid artery MAP by approximately 10 mmHg in the flat position, and in a nonflat position gravity influences MAP of the internal carotid artery. CONCLUSION: There is no uniform definition for CPP, which may affect conclusions on proposed CPP targets in severe traumatic brain injury by ±10 mmHg.
INTRODUCTION: No consensus exists on the exact method for measuring mean arterial blood pressure (MAP) in the definition of cerebral perfusion pressure (CPP). The aim of the current study is to investigate how different MAP measurement methods have influenced the CPP recommendations in the Brain Trauma Foundation (BTF) guidelines. METHODS: All papers on which the chapter on CPP thresholds in the 2007 version of the BTF guidelines is based, were reviewed. If accurate descriptions of head of bed elevation and arterial pressure transducer height were lacking, the authors were emailed for clarification. Additionally, the effect of choosing the radial artery for MAP measurement and the potential effect of gravity were studied in the literature. RESULTS: Thresholds of CPP in the BTF guidelines are based on 11 studies. Head of bed elevation at 30° was part of the protocol in 5 studies, patients were nursed flat in 1 study, and this variable remained unknown for 5 studies. The arterial pressure transducer was at heart level in 5 studies, at ear level in 3 studies, and height was unknown in 3 studies. Measuring MAP in the radial artery underestimates carotid artery MAP by approximately 10 mmHg in the flat position, and in a nonflat position gravity influences MAP of the internal carotid artery. CONCLUSION: There is no uniform definition for CPP, which may affect conclusions on proposed CPP targets in severe traumatic brain injury by ±10 mmHg.
Authors: Geert Meyfroidt; Pierre Bouzat; Michael P Casaer; Randall Chesnut; Sophie Rym Hamada; Raimund Helbok; Peter Hutchinson; Andrew I R Maas; Geoffrey Manley; David K Menon; Virginia F J Newcombe; Mauro Oddo; Chiara Robba; Lori Shutter; Martin Smith; Ewout W Steyerberg; Nino Stocchetti; Fabio Silvio Taccone; Lindsay Wilson; Elisa R Zanier; Giuseppe Citerio Journal: Intensive Care Med Date: 2022-05-20 Impact factor: 41.787
Authors: B Depreitere; G Citerio; M Smith; P David Adelson; M J Aries; T P Bleck; P Bouzat; R Chesnut; V De Sloovere; M Diringer; J Dureanteau; A Ercole; G Hawryluk; C Hawthorne; R Helbok; S P Klein; J O Neumann; C Robba; L Steiner; N Stocchetti; F S Taccone; A Valadka; S Wolf; F A Zeiler; G Meyfroidt Journal: Neurocrit Care Date: 2021-01-25 Impact factor: 3.210
Authors: Peter Reinstrup; Mårten Unnerbäck; Niklas Marklund; Wilhelm Schalen; Jesus Cabrera Arrocha; Eric L Bloomfield; Vahabi Sadegh; Karin Hesselgard Journal: Acta Neurochir (Wien) Date: 2019-03-08 Impact factor: 2.216