Application Of The Ratio Of Optic Nerve Sheath Diameter To Eyeball Transverse Diameter Under Ultrasound In Accessing Intracranial Hypertension In Traumatic Injury Patients

Objectives:To explore the application of the ratio of optic nerve sheath diameter to eyeball transverse diameter under ultrasound in judging intracranial hypertension(>20 mmHg)in patients with craniocerebral injury.There are two contents in this study:(1)the accuracy and consistency of ONSD/ETD and ONSD in predicting intracranial hypertension in patients with traumatic injury were compared,and the related factors of ONSD/ETD were analyzed.(2)the accuracy and consistency of ONSD/ETD in patients with traumatic injury by ultrasound and CT measurements were compared.Methods:Study one:ICP,ONSD and ETD were monitored in 61 patients with traumatic injury in surgical intensive care unit(SICU)within 24 hours after intracranial pressure probe was placed into ventricle.ICP value,blood pressure,Glasgow coma score and intracranial temperature were recorded at the same time.General information on admission such as sex and age were collected.According to ICP value,patients were divided into ICP<20 mmHg group and ICP>20 mmHg group.(1)The relationship between ONSD/ETD and general information at admission and other information after admission like ICP,blood pressure,GCS and intracranial temperature were analyzed.(2)The independent factor of ONSD/ETD was identified.(3)Accuracy and threshold of predicting intracranial hypertension by ONSD/ETD and ONSD both under ultrasound were determined by ROC curves.(4)Consistency of diagnostic effect of both ONSD/ETD and ONSD under ultrasound and intraventricular manometry were compared.Study two:Forty-six patients with traumatic injury in SICU were selected.All of them underwent craniotomy and intraventricular pressure probes were placed into ventricle.Collect general information on admission.Ultrasound measurements of ONSD and ETD were completed in SICU within 24 hours after operation,and then repeated them in CT examination room.At the same time,ICP values were recorded.At last,ONSD and ETD measurements were completed on CT images.According to the ICP value after operation,the patients were divided into ICP<20 mmHg group and ICP>20 mmHg group.(1)The correlation between ONSD/ETD and invasive ICP both under ultrasound and CT was analyzed respectively.(2)Using ROC curve to determine the accuracy and threshold of ONSD/ETD for predicting intracranial hypertension under ultrasound and CT.(3)Comparing the 3 methods for predicting intracranial hypertension by intraventricular manometry and ratio of ONSD/ETD both under ultrasound and CT.Results:Study one:(1)There were significant differences in GCS,intracranial temperature and ICP between the two groups at the same time after admission(P<0.05).(2)ONSD/ETD and ONSD in ICP?20 mmHg group were both positively correlated with ICP(r=0.544,P<0.001;r=0.446,P<0.001),so were in ICP>20 mmHg group(r=0.688,P<0.001;r=0.608,P<0.001).Intracranial temperature was the independent influencing factor of ONSD/ETD,but it was not clear that GCS,SBP,DBP,MAP and ICP were the independent influencing factors of ONSD/ETD(P>0.05).(3)The area under the curve(AUC)of ROC curve about ultrasound-ONSD/ETD predicting intracranial hypertension was 0.920(95%CI:0.877-0.964),the corresponding threshold was 0.248(sensitivity of 90%,specificity of 82.3%).And the AUC of ROC curve about ultrasound-ONSD was 0.870(95%CI:0.798-0.910),the corresponding threshold was 5.53 mm(sensitivity of 80%,specificity of 79.3%).(4)The results of predicting intracranial hypertension by ultrasound-ONSD/ETD and ultrasound-ONSD were consistent with measurements by intraventricular manometry(Kappa=0.710,P<0.05;Kappa=0.602,P<0.05).Study two:(1)There was a positive correlation between ultrasound-ONSD/ETD and invasive ICP(r=0.758,P<0.001),so was between CT-ONSD/ETD and invasive ICP(r=0.751,P<0.001).(2)The AUC of ROC curve about ultrasound-ONSD/ETD was 0.900(95%CI:0.854-0.946),and the corresponding threshold was 0.248(sensitivity of 90.5%,specificity of 77.3%).The AUC of ROC about CT-ONSD/ETD was 0.886(95%CI:0.833-0.921),and the corresponding threshold was 0.245(sensitivity of 85.7%,specificity of 83.3%).(3)The effect of ultrasound-ONSD/ETD and CT-ONSD/ETD on predicting intracranial hypertension is consistent with intraventricular manometry(Kappa=0.732,P<0.05;Kappa=0.745,P<0.05).The diagnostic effect of ultrasound-ONSD/ETD and CT-ONSD/ETD were of good consistency(Kappa=0.764,P<0.001),and there was no statistical difference between the two methods(P>0.05).Conclusions:Ultrasound-ONSD/ETD is more accurate than ONSD in predicting intracranial hypertension in patients with traumatic injury,and it has good consistency with CT-ONSD/ETD and gold standard intraventricular manometry.It is a non-invasive and reliable means which has certain clinical value for diagnosis of intracranial hypertension.