title: Effects of increased positive end-expiratory pressure on intracranial pressure in acute respiratory distress syndrome: a protocol of a prospective physiological study.
abstract: There are concerns that the use of positive end-expiratory pressure (PEEP) in patients with brain injury may potentially elevate intracranial pressure (ICP). However, the transmission of PEEP into the thoracic cavity depends on the properties of the lungs and the chest wall. When chest wall elastance is high, PEEP can significantly increase pleural pressure. In the present study, we investigate the different effects of PEEP on the pleural pressure and ICP in different respiratory mechanics.
  
  
  
  This study is a prospective, single-centre, physiological study in patients with severe brain injury. Patients with acute respiratory distress syndrome with ventricular drainage will be enrolled. An oesophageal balloon catheter will be inserted to measure oesophageal pressure. Patients will be sedated and paralysed; airway pressure and oesophageal pressure will be measured during end-inspiratory occlusion and end-expiratory occlusion. Elastance of the chest wall, the lungs and the respiratory system will be calculated at PEEP levels of 5, 10 and 15 cm H2O. We will classify each patient based on the maximal ΔICP/ΔPEEP being above or below the median for the study population. 2 groups will thus be compared.
  
  
  
  The study protocol and consent forms were approved by the Institutional Review Board of Fujian Provincial Hospital. Study findings will be disseminated through peer-reviewed publications and conference presentations.
  
  
  
  NCT02670733; pre-results.
authors.affiliation: Department of Critical Care Medicine, Beijing Tiantan Hospital, Capital Medical University, Beijing, China.|Surgical Intensive Care Unit, Fujian Provincial Clinical College Hospital, Fujian Medical University, Fuzhou, China.
authors.forename: Han
authors.initials: H
authors.lastname: Chen
authors.affiliation: Department of Critical Care Medicine, Beijing Tiantan Hospital, Capital Medical University, Beijing, China.
authors.forename: Ming
authors.initials: M
authors.lastname: Xu
authors.affiliation: Department of Critical Care Medicine, Beijing Tiantan Hospital, Capital Medical University, Beijing, China.|Intensive Care Unit, Beijing Electric Power Hospital, Capital Medical University, Beijing, China.
authors.forename: Yan-Lin
authors.initials: YL
authors.lastname: Yang
authors.affiliation: Surgical Intensive Care Unit, Fujian Provincial Clinical College Hospital, Fujian Medical University, Fuzhou, China.
authors.forename: Kai
authors.initials: K
authors.lastname: Chen
authors.affiliation: Surgical Intensive Care Unit, Fujian Provincial Clinical College Hospital, Fujian Medical University, Fuzhou, China.
authors.forename: Jing-Qing
authors.initials: JQ
authors.lastname: Xu
authors.affiliation: Surgical Intensive Care Unit, Fujian Provincial Clinical College Hospital, Fujian Medical University, Fuzhou, China.
authors.forename: Ying-Rui
authors.initials: YR
authors.lastname: Zhang
authors.affiliation: Surgical Intensive Care Unit, Fujian Provincial Clinical College Hospital, Fujian Medical University, Fuzhou, China.
authors.forename: Rong-Guo
authors.initials: RG
authors.lastname: Yu
authors.affiliation: Department of Critical Care Medicine, Beijing Tiantan Hospital, Capital Medical University, Beijing, China.
authors.forename: Jian-Xin
authors.identifier: 0000-0002-1559-7554
authors.initials: JX
authors.lastname: Zhou
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001930:Brain Injuries / Q000150:complications*; D002681:China; D002985:Clinical Protocols; D005260:Female; D006801:Humans; D007427:Intracranial Pressure; D008168:Lung / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D011175:Positive-Pressure Respiration / Q000009:adverse effects*; D011446:Prospective Studies; D012128:Respiratory Distress Syndrome / Q000628:therapy*; D015656:Respiratory Mechanics; D035441:Thoracic Wall; D055815:Young Adult
keywords: Acute respiratory distress syndrome; Intracranial pressure; Oesophageal pressure; Positive end-expiration pressure