Ultrasonographic optic nerve sheath diameter to detect increased intracranial pressure in adults: a meta-analysis.

Background: The optimal optic nerve sheath diameter (ONSD) cut-off for identifying increased intracranial pressure (IICP) remains unclear in adult patients.

Objective: To validate the diagnostic accuracy of ultrasonographic (US) ONSD > 5.0 mm as a cut-off for detecting IICP by computed tomographic (CT) through a meta-analysis.

Methods: A systemic literature review was performed of online databases from January 1990 to September 2017. A bivariate random-effects model was used to estimate pooled sensitivity, specificity, and diagnostic odds ratio (DOR) with 95% confidence intervals (CIs). A summary receiver operating characteristic (SROC) graph was used to provide summary points for sensitivity and specificity. Meta-regression tests were performed to estimate the influence of the study characteristics on DOR. Publication bias was assessed using Deeks' funnel plot asymmetry test.

Results: Six studies with 352 patients were included in the meta-analysis. US ONSD > 5.0 mm revealed pooled sensitivity of 99% (95% CI = 96-100) and specificity of 73% (95% CI = 65-80) for IICP detection. DOR was 178. The area under the SROC curve was 0.981, indicating a good level of accuracy. Meta-regression studies showed no significant associations between DOR and study characteristics such as probe mode (relative DOR [RDOR] = 0.60; P = 0.78), study quality (RDOR = 0.52; P = 0.67), IICP prevalence (RDOR = 0.04; P = 0.17), or pathology at admission (RDOR = 1.30; P = 0.87).

Conclusions: US ONSD > 5.0 mm can be used to rapidly detect IICP in adults in emergency departments and intensive care units. Further meta-analysis based on individual patient-level databases is needed to confirm these results.