Ultrasonographic Optic Nerve Sheath Diameter as a Surrogate Measure of Raised Intracranial Pressure in Severe Pregnancy-induced Hypertension Patients

Anesth Essays Res. Jan-Mar 2018;12(1):42-46. doi: 10.4103/aer.AER_218_17.


Context: It is a well-known fact that severe pregnancy-induced hypertension (PIH) can be disastrous at times as it can cause a lot of complications to both pregnant women and her baby. Hence, it is always desirable to know the extent of severity by a real-time and easily accessible modality like ultrasound.

Aims: The aim of the study was to evaluate the incidence of raised intracranial pressure (ICP) in severe preeclampsia and eclampsia patients using ocular ultrasonography with optic nerve sheath diameter (ONSD) measurement.

Settings and design: This study design was a prospective and clinically controlled blinded observational study.

Materials and methods: After taking necessary permissions from the Institution Ethical Committee, 75 patients were enrolled for the study. However, finally, 25 patients in severe preeclampsia and 24 in eclampsia group were compared with 25 normal term antenatal women. Demographic profiles, hemodynamic parameters, laboratory markers for severity of PIH, and ultrasonographic OSND were measured.

Statistical analysis used: They were statistically analyzed and compared using one-way ANOVA and Tukey's test. Value of P < 0.05 was considered statistically significant.

Results: All the three groups were comparable in terms of age, body weight, gestation age, gestity, and the number of primigravida in each group. There was a significant difference (P < 0.05) in mean levels of hepatic aminotransferase levels and platelet counts between groups. Aspartate transaminase and alanine transaminase levels were much higher in Group II and III as compared to Group I, while platelet levels were lower in study groups indicating increase in severity of PIH. There was also a significant difference for systolic blood pressure and diastolic blood pressure (P < 0.001) as both were significantly higher in study groups. Among severe PIH groups (Group II and III), the difference was comparable.

Conclusions: OSND is a surrogate marker for raised ICP in severe PIH patients. It is a rapid, bedside, noninvasive, and readily accessible tool and could be a part of a holistic approach for managing such patients.

Keywords: Eclampsia; optic nerve sheath diameter; severe preeclampsia; ultrasonography.