The correlation between the frontal electromyography parameter in patient state index (PSİ) monitor and Train Of Four at the extubation phase of general anesthesia

Aim: PSI (Patient State Index) and TOF (Train Of Four) monitors are recommended for routine use however, these monitors have low routine usage rates and this situation endangers patient safety. Measuring these two parameters with a single monitoring technique will provide advantages in terms of both cost and time. The aim of our study is evaluating the correlation between the frontal EMG (Electromyography) parameter in PSI monitor and muscle strength monitor (TOF) under general anesthesia. Materials and Methods: Our study was approved by Medical Ethics Committee of Erzincan Binali Yildirim University. 100 patients aged between 18-65 years in ASA I, II and III risk groups who underwent surgeries for at least one hour under general anesthesia were included in the study. We applied routine general anesthesia prosedure. We applied TOF and Sedline (Masimo EMG and PSI) monitors in addition to standard ASA monitoring. After the end of the surgery we passed to the extubation phase. PSI and EMG values were recorded when TOF is %0, %25, %50, %75, %90. We extubated the patients after TOF was %90. After that we recorded TOF, PSI and EMG values 5 minutes after the extubation. The Aldrete scores were recorded 5, 10, 30 minutes after the extubation and the patient who had higher then 9 points were transfered to the service. Results: We determined strongly positive correlation (r=0,74 p<0,001) between TOF and PSI. And we determined strongly positive correlation (r=0,76 p<0,001) between TOF and EMG either. We accepted TOF=%90 as extubation limit. According to ROC analyze of EMG variables, we determined the point of 24,5 as cut-off point (AUC:0.852, p<0.001, sensitivity: %90, specificity: %68). We also determined the point of 60,5 as cut-off point (AUC:0,834, p<0.001, sensitivity: %96, specificity: %56) for PSI variables. As a result of the ROC analyze, we determined that the area under the curve is close to one and statistically significant. PSI>60 and EMG>24,5 values are determined as cut off points for extubation. Conclusion: In our study we found strongly positive correlation between TOF and Frontal EMG parameter in PSI monitor which is recommended for routine anesthetic depth monitoring. We also determined that we can extubate the patients whose EMG values are higher than 24,5.