Wake Up Estimation Algorithm
Wake up estimation algorithm estimates the propofol Cp at which the patient emerges from general anaesthesia (i.e. eye open to voice).
For detailed mathematical derivation of the algorithm, please click here.
Usage
(1) Enter the maintenance phase EleMarsh Cp (ensure steady state has been achieved).
(2) Enter the corresponding state entropy (SE) observed. BIS value may be used in place of SE without significant degradation in predictive accuracy.
(3) The algorithm will derive the Cp range for anaesthesia emergence based on the individual’s propofol sensitivity.
Limitations
(a) Wake up Cp estimate assumes minimal stimulus. Actual wake up Cp will depend on stimulus, pain, paralysis and adjuvants.
(b) Validated for surgeries longer than 60 minutes. May be inaccurate for shorter procedures.
References
Zhong G., Tung AMS, Xu X. Simple model for predicting the awakening propofol plasma concentration during target-controlled infusion with the Marsh model. British Journal of Anaesthesia. 2025, 134(4): 275 (doi)