Effect Of Bispectral Index During Nursing Sedation Assessment Procedure In Critically Brain Injury Patients

Objective:?1?To explore the Bispectral index?BIS?value range which is suitable for light sedation in critically brain injury patients.?2?A mixed study combining quantitative and qualitative study was used to evaluate the effectiveness and safety of BIS monitoring in critically brain injury patients.Methods:The research included 3 stages.Stage 1:A total of 60 critically brain injury patients treated with light sedation were included in this study from December 2018 to March2019.Two trained research nurses independently scored the RASS or documented the BIS after the implement of light sedation for 24 hours.We intended to learn about the distribution of different sedation levels of critically brain injury patients according to the RASS score and explore the correlation of BIS value and RASS score.RASS score fluctuated between 0 to-2 were set as the golden standard of light sedation to draw Receiver Operating Characteristic Curves?ROC?of BIS with the Area under the curves?AUC?.The BIS cut-off values were set by the biggest Youden Index.Sensitivity and specificity were included accordingly.Stage 2:Convenient sampling was used to recruit 120 critically brain injury patients receiving early goal-directed sedation.Patients were randomised into two groups.Patients in intervention group?n=60?were monitored by BIS under the goal of 64⁸6;Patients in control group?n=60?were assessed by RASS scale under the goal of-2 to 0.Stage 3:Semi-structure interview was conducted,experience of 8 nurses who participated in the earlier research were analyzed by Colaizzi to learn about the experience of nurses using BIS monitoring the sedation level in critically brain injury patients.ResultStage 1:A total of 887 pairs of statistics in 900 times of assessment were included in our analysis.In the first 24 hours after light sedation imply,according to the RASS scores,the percentage of oversedation sedation,light and undersedation was 55.6%,31.9%and 12.5%respectively.BIS and RASS were strongly positively correlated?Spearman r=0.916,P?0.001?.The AUC of RASS?0 was 0.925?95%CI=0.893⁰.958?,the maxim Youden Index was 0.648 when the BIS cut-off value equaled to 86.5,with sensitivity of 83.9%and specificity of 84.5%.The AUC of RASS?-2 was 0.952?95%CI=0.936,0.968?,the maxim Youden Index is 0.832 when the BIS cut-off value equal to 64.5 with sensitivity of 84.8%and specificity 98.4%.Stage 2:Except a higher number of RASS score equal or more than 3 in intervention group,(^?2=5.048,P=0.025),there was no difference on demographic characteristics between two groups?P?0.05?.Patients in intervention group had shorter time interval on goal gaining?Median=12 min,U=755.0,P?0.001?,higher rate of goal gaining?Median=83.3%,U=1017.0,P?0.001?,received lower does of sedatives?Median=336ug,U=1066.5,P?0.001?and shorter mechanical ventilated days?Median=2 days,U=392.5,P=0.007?.There was no difference between the two groups in sedation-related adverse events,length of stay in NICU nor in hospital?P?0.05?.Stage 3:Four themes were abstracted:divergence on the accuracy of BIS monitoring on sedation;improving clinical procedure;existence of obstruct on further application;other usage in addition to sedation monitoring..Conclusion:The suitable BIS value range for light sedation in critically brain injury patients is64⁸6 with a relatively high sensitivity and specificity.Comparing wit RASS,BIS monitoring can reduce the interval of goal reaching,increase the rate of goal maintaining,reduce the amount of sedatives and the duration of mechanically ventilated days in critically brain injury patients.BIS monitoring can promote clinical procedure,which is an essential indicator for nurses to identify the patients current situation and can be considered as a part of multi-model monitoring in NICU.There still exists weakness of BIS monitoring including the divergence between patients behavior and BIS value,the short expiration time of 24h and the potential of damaging skin which need further improvement.In addition,researches with larger number of sample are needed to explore the effects on reducing adverse events associated with unproper sedation and on shortening the length of stay in NICU or in hospital.