The NeurOptics NPi pupillometer

An international study found the neurological pupil index (NPi) is an effective means to evaluate disease progression and predict outcomes for acute brain injury patients. 

The ‘Orange’ study recruited 514 patients admitted to hospital intensive care units with traumatic brain injury, aneurysmal subarachnoid haemorrhage or intracerebral haemorrhage. Patients' NPi scores were measured with NeurOptics' NPi pupillometer every four hours during the initial seven days of admission. 

The study team found tracking a patient's NPi score dynamically predicts their neurological outcome and mortality over a six-month period, said principal investigator Professor Giuseppe Citerio from the University of Milan. “Reduced NPi scores are a serious alarm and are associated with unfavourable outcomes.” However, when the NPi returns to the normal range, the risk of poor outcomes diminishes, he said. “The findings support the use of NPi as a standardised, quantitative measurement of pupil reactivity and global midbrain function.” 

The NeurOptics NPi pupillometer’s values range from 0 to 4.9, with scores below 3 indicating abnormalities. Using it minimises the subjectivity of manual pupillary evaluations of adult and paediatric patients across a broad spectrum of diagnoses, including traumatic brain injury, stroke, seizure, or other neurological events after cardiac arrest, said NeurOptics in a statement.