title: Bedside sonographic measurement of optic nerve sheath diameter as a predictor of intracranial pressure in ED.
abstract: BACKGROUND
  Ocular ultrasonography of optic nerve sheath diameter (ONSD) to determine intracranial pressure (ICP) has become favorable in recent years.
  
  
  OBJECTIVE
  To demonstrate the efficacy of ONSD measurement in determining the ICP increase due to nontraumatic events in the emergency department.
  
  
  METHODS
  A total of 100 patients with suspected nontraumatic intracranial event were enrolled in this prospective study. Patients were divided equally into 2 groups including 50 patients as group I with pathology on cranial computed tomography (CT) and group II with normal cranial CT. Prior to CT scans, patients underwent ONSD measurement by a radiologist using 11- and 14-MHz transducers.
  
  
  RESULTS
  The ONSD values of groups I and II were 5.4±1.1and 4.1±0.5mm, respectively. Optic nerve sheath diameter was found to be larger on the side of lesion in patients with a lesion (P<.05). The cutoff value of the difference between ONSD values of both eyes in the presence of pathology was determined as 0.45 (sensitivity, 80%; specificity, 60%; the area under the curve, 0.794; 95% confidence interval, 0.705-0.883). The between-ONSD and midline shift size was statistically significant (r=0.366, P=.009). The cutoff value of ONSD for the detection of midline shift was determined as 5.3mm (sensitivity, 70%; specificity, 74%; the area under the curve, 0.728; 95% confidence interval, 0.585-0.871).
  
  
  CONCLUSIONS
  Optic nerve sheath diameter measurement via bedside ocular ultrasonography in patients with suspected intracranial event in the emergency department is a useful method to determine ICP increase and its severity.
authors.affiliation: Department of Radiology, Kazan Hamdi Eriş Hospital, Ankara, Turkey. Electronic address: erdalkomut@hotmail.com.
authors.forename: Erdal
authors.initials: E
authors.lastname: Komut
authors.affiliation: Department of Emergency Medicine, Antalya Education and Research Hospital, Antalya, Turkey. Electronic address: nalankozaci@gmail.com.
authors.forename: Nalan
authors.initials: N
authors.lastname: Kozacı
authors.affiliation: Department of Emergency Medicine, Ankara Numune Education and Research Hospital, Ankara, Turkey. Electronic address: mugesonmez06@yahoo.com.
authors.forename: Bedriye Müge
authors.initials: BM
authors.lastname: Sönmez
authors.affiliation: Department of Emergency Medicine, Antalya Education and Research Hospital, Antalya, Turkey. Electronic address: fevzi_yilmaz2002@yahoo.com.
authors.forename: Fevzi
authors.initials: F
authors.lastname: Yılmaz
authors.affiliation: Department of Emergency Medicine, Ankara Numune Training and Research Hospital, Ankara, Turkey. Electronic address: drsevalkomut@hotmail.com.
authors.forename: Seval
authors.initials: S
authors.lastname: Komut
authors.affiliation: Department of Radiology, Ankara Numune Training and Research Hospital, Antalya, Turkey. Electronic address: yildirimnilgun@yahoo.com.
authors.forename: Zeliha Nilgün
authors.initials: ZN
authors.lastname: Yıldırım
authors.affiliation: Department of Emergency Medicine, Antalya Education and Research Hospital, Antalya, Turkey. Electronic address: inan_beydilli@hotmail.com.
authors.forename: İnan
authors.initials: İ
authors.lastname: Beydilli
authors.affiliation: Department of Emergency Medicine, Antakya State Hospital, Antakya, Turkey. Electronic address: cihatyel@hotmail.com.
authors.forename: Cihat
authors.initials: C
authors.lastname: Yel
mesh_terms: D000328:Adult; D004636:Emergency Service, Hospital; D005260:Female; D006801:Humans; D019586:Intracranial Hypertension / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D009900:Optic Nerve / Q000000981:diagnostic imaging*; D000067716:Point-of-Care Testing; D011446:Prospective Studies; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed; D014463:Ultrasonography