Comparison of models for predicting intracranial pressure by optic nerve sheath diameter in combination with other indicators: A study based on ultrasound measurements

Abstract

Abstract Introduction: The optic nerve sheath diameter (ONSD) assessment of elevated intracranial pressure is increasingly emphasized as a noninvasive modality. Still, quantitative assessment is less common in current studies, and study criteria are variable. We constructed four prediction models related to ONSD and compared their accuracy in predicting intracranial pressure (ICP). Methods This study included 223 patients who completed lumbar puncture (LP) at the First Hospital of Shanxi Medical University with values of ICP and Mindray-M58 ultrasound-measured ONSD, optic nerve sheath (OND), and eyeball transverse diameter (ETD). The patients were randomly assigned 7:3 to model and test groups, and predictive models (ONSD model, ONSD combined OND model, ΔONSD model, and ONSD/ETD model) were established in the model group using linear regression analysis. The test group evaluated the agreement between the models' predicted and actual ICP values using Bland‒Altman analysis and the intragroup correlation coefficient (ICC). Results ICP values were strongly correlated with ΔONSD, ONSD, and ONSD/ETD. The ONSD combined OND model showed the highest predictive power for increased ICP (area under the receiver operating characteristic curve [AUC] = 0.933). The four mathematical equations established in the model group (n = 154) were as follows: 1. ONSD combined OND model: predicted ICP = 139.394×ONSD-112.428×OND-267.461; 2. ONSD model: predicted ICP = 108.227× ONSD-404.446; 3. ΔONSD model: predicted ICP = 140.216 × ΔONSD-196.335; 4. ONSD/ETD model: predicted ICP = 1624.283×ONSD/ETD-196.904. In the test group (n = 66), it was shown that ONSD combined OND (ICC = 0.88) prediction accuracy was the highest. Conclusion Bedside ultrasound measurement of ONSD combined OND is a practical method to assess ICP values. This study indicated that the efficacy of the ONSD combined with the OND model and the ΔONSD model in predicting ICP was better than that of ONSD alone, reflecting the fact that intracranial pressure changes mainly affect the optic nerve sheath rather than the optic nerve.