Related Experiment Video
Updated: Aug 8, 2026

Assessing Changes in Volatile General Anesthetic Sensitivity of Mice after Local or Systemic Pharmacological Intervention
Published on: October 16, 2013
Using the Perfusion Index to predict changes in the depth of anesthesia in children compared with the A-line
Hala Saad Abdel-Ghaffar1, Amani Hassan Abdel-Wahab1, Mohammed Mahmoud Roushdy1
1Assiut University, Faculty of Medicine, Anesthesia and Intensive Care Department, Assiut, Egypt.
Background:
We investigated the performance of the Perfusion Index (PI) derived from pulse oximetry waveform as a tool for assessment of anesthetic depth in comparison with A-line Autoregression Index (AAI) derived from analysis of Middle-Latency Auditory Evoked Potentials (MLAEP) waveform integrated by aepEXplus monitor in children receiving sevoflurane anesthesia for tonsillectomy.
Methods:
Forty-one patients (4...12 years old) were included in this study. The PI and AAI were recorded simultaneously every minute during different stages of anesthesia delivery. The statistical tests included descriptive analysis, significance tests, correlation tests, and Receiver Operating Characteristic (ROC) curve. The AAI served as a reference.
Results:
The PI significantly decreased during light anesthesia and recovery, and significantly increased during deeper planes of anesthesia, with an inverse mirror-image relationship with the AAI. A negative correlation of low to moderate degree was detected between PI and AAI during the study (p.ß>.ß0.05), that reached a statistical significance at the 5th minute during sevoflurane mask induction (r.ß=.ß...0.457, p.ß=.ß0.008). ROC analysis at an AAI < 25 extracted the best cut-off value for PI before intubation as 1.48 (AUC.ß=.ß0.698 [0.537...0.859], 94.4% sensitivity, 44.5% specificity) and at 10-minute intraoperatively as 2.4 (AUC.ß=.ß0.537 [0.354...0.721], 91.7% sensitivity, 31% specificity). During recovery, at an AAI.ß....ß50, the best cutoff was 1.82 (AUC.ß=.ß0.661 [0.46...0.863], 100% sensitivity and 50% specificity) 2 minutes before spontaneous eye opening.
Conclusions:
Compared with the AAI, the PI can track changes in depth of anesthesia in pediatric patients undergoing tonsillectomy under sevoflurane anesthesia.
Trial Registration:
Clinical Trials. Gov. Identifier: NCT03412214.
Related Concept Videos
Assessment of Diffusion and Perfusion
The Role of Diffusion in Respiration
Diffusion is the process by which molecules move from an area of higher concentration to an area of lower concentration. In the respiratory system, this principle...
Stages of General Anesthesia
Methods for Studying Drug Absorption: In situ
The Doluisio method involves perfusing a prepared segment of a rat's small intestine with a solution of radiolabeled drug and a non-absorbable marker. This helps to differentiate between absorbed and non-absorbed drug concentrations. The intestinal segment is connected at both ends using tubing and syringes,...

