Correlating optic nerve sheath diameter with opening intracranial pressure in pediatric traumatic brain injury

Introduction: The use of clinical markers to predict intracranial pressure (ICP) is desirable as a first-line measure to assist in decision making as to whether invasive monitoring is required. Correlations between ICP and optic nerve sheath diameter (ONSD) using CT and MRI have been observed in adult populations. However, data on this modality in children is less well documented. Methods: ONSD was measured by independent observers and correlated with opening ICP at insertion of invasive monitoring probes in pediatric traumatic brain injury patients admitted to Addenbrookes Hospital between January 2009 and December 2013. Results: Thirty-six patients with a mean age of 8.2 y were admitted to the Pediatric Intensive Care Unit (PICU) with a traumatic head injury and required invasive neurosurgical monitoring. The median ICP was 18 ± 10 mmHg (median ± IQR), the median right ONSD was 5.6 ± 2.5 mm and the left was 5.9 ± 3.2 mm. The Intraclass correlation between observers was 0.91 ( P < 0.0001). The correlation of mean ONSD and max ONSD with ICP was 0.712 ( P < 0.0001) and 0.713 ( P < 0.0001), respectively. Area under ROC curve for both mean and max ONSD is 0.85 (95% CI: 0.73–0.98). Conclusion: Where pediatric patients present with an ONSD of over 6.1 mm following a traumatic brain injury (TBI), ICP monitoring should be implemented.