Elevated Intracranial Pressure Level Is a Risk Factor for Sepsis-associated Encephalopathy: A Prospective Cohort Study

Abstract

Background/Aim: Cerebral edema is common in patients with sepsis-associated encephalopathy (SAE) and is a major cause of elevated intracranial pressure (ICP); however, the relationship between elevated ICP and SAE is unclear. The aim of this study was to investigate the association between optic nerve sheath diameter (ONSD), a surrogate of ICP, and the incidence of SAE. Patients and Methods: A prospective observational study was performed in a medical–surgical adult intensive care unit (ICU). All patients in the ICU who were consecutively diagnosed with sepsis during the study period were evaluated for eligibility. Ultrasound measurements of ONSD were performed within 6 h of enrollment and every two days thereafter until the patient developed SAE. Clinical and blood test data were collected throughout this period. Patients underwent a daily conscious and cognitive assessment. SAE was diagnosed as delirium or Glasgow Coma Scale (GCS) <15 points. Multivariate modified Poisson regression analysis was performed to identify risk factors for SAE. Results: A total of 123 patients with sepsis were included in the analysis. 58 patients (47.2%) developed SAE. The levels of ONSD0 (the first measured value) and ONSDmax (the maximum measured value) in the SAE group were significantly higher than those in the non-SAE group (5.23±0.52 mm vs. 5.85±0.54 mm for ONSD0 and 5.41±0.46 mm vs. 6.09±0.58 mm for ONSDmax, respectively; all p-values <0.001). The area under the curves (AUCs) for the ONSD0 and ONSDmax values in predicting SAE were 0.801 (95%CI=0.723-0.880, p<0.001) and 0.829 (95%CI=0.754-0.903, p<0.001), respectively. A higher ONSD0 level was significantly associated with an increased risk of SAE (adjusted risk ratio 3.241; 95%CI=1.686-6.230, p<0.001). Conclusion: The levels of ONSD correlate with risk of SAE, indicating that increased ICP level is an independent risk factor for the development of SAE. Dynamic monitoring of ONSD/ICP has a high predictive value for SAE. Measures to prevent increases in ICP are helpful to reduce the incidence of SAE in sepsis patients.