Prediction of movement at laryngeal mask airway insertion: comparison of auditory evoked potential index, bispectral index, spectral edge frequency and median frequency
M. Doi et al., Prediction of movement at laryngeal mask airway insertion: comparison of auditory evoked potential index, bispectral index, spectral edge frequency and median frequency, BR J ANAEST, 82(2), 1999, pp. 203-207
Citations number
22
Categorie Soggetti
Aneshtesia & Intensive Care","Medical Research Diagnosis & Treatment
We have studied 46 patients to compare the efficacy of the auditory evoked
potential (AEP) index, bispectral index (BIS), 95% spectral edge frequency
(SEF) and median frequency (MF) in predicting movement in response to inser
tion of the laryngeal mask airway (LMA). Anaesthesia was induced with targe
t-controlled infusions of propofol and alfentanil. After loss of eyelash re
flex and adequate jaw relaxation, the LMA was inserted without the assistan
ce of a laryngoscope or neuromuscular blocker. Patients who showed any visi
ble spontaneous muscle movement within 1 min of LMA insertion were defined
as movers. Values in movers and nonmovers at 30 s before LMA insertion were
analysed. Only AEP index discriminated between movers and non-movers with
a prediction probability of 0.872. BIS, SEF and MF could not predict moveme
nt at LMA insertion. AEP index was the most reliable predictor of movement
in response to LMA insertion.