title: Pupillary reactivity as an early indicator of increased intracranial pressure: The introduction of the Neurological Pupil index.
abstract: BACKGROUND
  This paper introduces the 7/5/2011al Pupil index (NPi), a sensitive measure of pupil reactivity and an early indicator of increasing intracranial pressure (ICP). This may occur in patients with severe traumatic brain injury (TBI), aneurysmal subarachnoid hemorrhage, or intracerebral hemorrhage (ICH).
  
  
  METHODS
  134 patients (mean age 46 years, range 18-87 years, 54 women and 80 men) in the intensive care units at eight different clinical sites were enrolled in the study. Pupillary examination was performed using a portable hand-held pupillometer.
  
  
  RESULTS
  Patients with abnormal pupillary light reactivity had an average peak ICP of 30.5 mmHg versus 19.6 mmHg for the normal pupil reactivity population (P = 0.0014). Patients with "nonreactive pupils" had the highest peaks of ICP (mean = 33.8 mmHg, P = 0.0046). In the group of patients with abnormal pupillary reactivity, we found that the first evidence of pupil abnormality occurred, on average, 15.9 hours prior to the time of the peak of ICP.
  
  
  CONCLUSIONS
  Automated pupillary assessment was used in patients with possible increased ICP. Using NPi, we were able to identify a trend of inverse relationship between decreasing pupil reactivity and increasing ICP. Quantitative measurement and classification of pupillary reactivity using NPi may be a useful tool in the early management of patients with causes of increased ICP.
authors: Department of Neurological Surgery, Legacy Emanuel Hospital, Gantenbein, Portland, OR 97227.
authors: Jeff W
authors: JW
authors: Chen
authors: Zoe J
authors: ZJ
authors: Gombart
authors: Shana
authors: S
authors: Rogers
authors: Stuart K
authors: SK
authors: Gardiner
authors: Sandy
authors: S
authors: Cecil
authors: Ross M
authors: RM
authors: Bullock