title: The incidence of increased ICP in ICU patients with non-traumatic coma as diagnosed by ONSD and CT: a prospective cohort study.
abstract: Unexplained coma after critical illness can be multifactorial. We evaluated the diagnostic ability of bedside Optic Nerve Sheath Diameter [ONSD] as a screening test for non-traumatic radiographic cerebral edema.
  
  
  
  In a prospective study, mixed medical-surgical intensive care units [ICU] patients with non-traumatic coma [GCS < 9] underwent bedside ultrasonographic ONSD measurements. Non-traumatic radiographic cerebral edema [NTRCE] was defined as > 5 mm midline shift, cisternal, sulcal effacement, or hydrocephalus on CT.
  
  
  
  NTRCE was identified in 31 of 102 patients [30.4 %]. The area under the ROC curve for detecting radiographic edema by ONSD was 0.785 [95 % CI 0.695-0.874, p <0.001]. ONSD diameter of 0.57 cm was found to be the best cutoff threshold with a sensitivity 84 % and specificity 71 %, AUC 0.785 [95 % CI 0.695-0.874, p <0.001]. Using ONSD as a bedside test increased the post-test odds ratio [OR] for NTRCE by 2.89 times [positive likelihood ratio], whereas post-test OR for NTRCE decreased markedly given a negative ONSD test [ONSD measurement less than 0.57 cm]; negative likelihood ratio 0.22.
  
  
  
  The use of ONSD as a bedside test in patients with non-traumatic coma has diagnostic value in identifying patients with non-traumatic radiographic cerebral edema.
authors: Adult Critical Care Medicine, King Faisal Specialist Hospital & Research Centre, Riyadh, 11211, Saudi Arabia. nsalahuddin@kfsh.edu.sa.
authors: Nawal
authors: 0000-0002-4422-6699
authors: N
authors: Salahuddin
authors: Adult Critical Care Medicine, King Faisal Specialist Hospital & Research Centre, Riyadh, 11211, Saudi Arabia.
authors: Alaa
authors: A
authors: Mohamed
authors: Adult Critical Care Medicine, King Faisal Specialist Hospital & Research Centre, Riyadh, 11211, Saudi Arabia.
authors: Nadia
authors: N
authors: Alharbi
authors: Adult Critical Care Medicine, King Faisal Specialist Hospital & Research Centre, Riyadh, 11211, Saudi Arabia.
authors: Hamad
authors: H
authors: Ansari
authors: College of Medicine, Alfaisal University, P.O. Box 50927, Riyadh, 11533, Saudi Arabia.
authors: Khaled J
authors: KJ
authors: Zaza
authors: College of Medicine, Alfaisal University, P.O. Box 50927, Riyadh, 11533, Saudi Arabia.
authors: Qussay
authors: Q
authors: Marashly
authors: Adult Critical Care Medicine, King Faisal Specialist Hospital & Research Centre, Riyadh, 11211, Saudi Arabia.
authors: Iqbal
authors: I
authors: Hussain
authors: Adult Critical Care Medicine, King Faisal Specialist Hospital & Research Centre, Riyadh, 11211, Saudi Arabia.
authors: Othman
authors: O
authors: Solaiman
authors: Cleveland Clinic Abu Dhabi, P.O. Box 112412, Abu Dhabi, United Arab Emirates.
authors: Torbjorn V
authors: TV
authors: Wetterberg
authors: Adult Critical Care Medicine, King Faisal Specialist Hospital & Research Centre, Riyadh, 11211, Saudi Arabia.
authors: Khalid
authors: K
authors: Maghrabi
mesh_terms: D001929:Brain Edema / Q000150:complications / Q000453:epidemiology / Q000503:physiopathology*; D003128:Coma / Q000000981:diagnostic imaging* / Q000503:physiopathology; D005260:Female; D006801:Humans; D015994:Incidence; D007362:Intensive Care Units; D019586:Intracranial Hypertension / Q000150:complications / Q000000981:diagnostic imaging / Q000453:epidemiology*; D007427:Intracranial Pressure / Q000502:physiology*; D008297:Male; D008875:Middle Aged; D009900:Optic Nerve / Q000000981:diagnostic imaging*; D011446:Prospective Studies; D012529:Saudi Arabia / Q000453:epidemiology; D014057:Tomography, X-Ray Computed; D014463:Ultrasonography
keywords: Coma; Critical illness; Non-traumatic radiographic cerebral edema; Optic nerve sheath diameter