Evaluation of Ultrasonographic Optic Nerve Sheath Diameter as a Point-of-Care Tool for Assessing Intracranial Pressure in Pediatric Patients With Hydrocephalus Undergoing Neurosurgical Intervention

Background The optic nerve sheath diameter (ONSD) on ocular ultrasonography has recently emerged as a reliable and useful indirect tool for measuring raised intracranial pressure (ICP). However, findings of previous studies have been inconsistent or inconclusive, and not many studies have evaluated its utility in the pediatric population undergoing neurosurgical interventions. This observational study aimed to evaluate the efficacy of ultrasonographic ONSD as a point-of-care tool for predicting real-time ICP in children with hydrocephalus undergoing shunt surgery. Methodology This study included 52 children aged 2 months to 10 years with hydrocephalus undergoing ventriculoperitoneal shunt under general anesthesia. Ultrasonographic ONSD for each eye and invasive ICP were measured before surgery (after induction) and after surgery (before extubation). Statistical analyses were performed using SPSS version 21 (IBM Corp., Armonk, NY, USA). Results Preoperatively, the mean ONSD in the right and left eyes was 5.75 ± 1.6 mm and 5.68 ± 1.35 mm, respectively, which reduced significantly to 4.3 ± 0.89 mm and 4.48 ± 0.79 mm, respectively, postoperatively. The correlation between ONSD and raised ICP was significantly positive (p < 0.001, r = 0.879). Analysis of the receiver operating characteristic curve revealed that a cutoff ONSD value of 5.5 mm predicted an ICP ≥20 mmHg with a specificity of 75%, sensitivity of 100%, and a positive predictive value of 95%. These results confirm that elevated ONSD is suggestive of raised ICP. Conclusions Ultrasonographic ONSD is a useful non-invasive point-of-care tool for the assessment and monitoring of children with hydrocephalus suspected of having raised ICP.