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The correlation of the Narcotrend ® Index and classical electroencephalographic parameters with endtidal desflurane concentrations and hemodynamic parameters in different age groups
Author(s) -
WEBER FRANK,
GRUBER MICHAEL,
TAEGER KAI
Publication year - 2005
Publication title -
pediatric anesthesia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.704
H-Index - 82
eISSN - 1460-9592
pISSN - 1155-5645
DOI - 10.1111/j.1460-9592.2005.01465.x
Subject(s) - medicine , anesthesia , desflurane , pharmacodynamics , unconsciousness , heart rate , hemodynamics , electroencephalography , mean arterial pressure , propofol , blood pressure , pharmacokinetics , psychiatry
Summary Background : The Narcotrend ® Index (NI) for assessment of depth of anesthesia by analysis of the electroencephalogram (EEG), is potentially a pharmacodynamic measure of the effects of desflurane on the brain. Methods : In this prospective study of 30 pediatric and adult patients (group 1: 3–6 years, n = 10; group 2: > 6 < 12 years; group 3: 12–40 years), undergoing ophthalmological surgery, we investigated the pharmacodynamic relationship between nonsteady state endtidal desflurane concentrations (eT Des ), NI, classical EEG parameters (cEEG), heart rate (HR) and mean arterial pressure (MAP). The performance of the Narcotrend for differentiation between consciousness and unconsciousness was evaluated using prediction probability ( P K ). Results : Spearman correlation analysis showed significant negative correlations ( P < 0.001) between eT Des and NI (group 1: r = −0.93, group 2: r = −0.86, group 3: r = −0.66). Correlations between eT Des and MAP or HR were either only weak negative ( r < −0.5) or not significant. Desflurane EC 50 (eT Des with half maximal effect on NI) was 7.18% for group 1, 7.34% for group 2, and 4.15% for group 3 ( P < 0.001 Vs groups 1 and 2). Overall awake NI values (96.7 ± 1.4) were significantly higher ( P < 0.001) than at the moment of loss of consciousness (58.3 ± 17.5), with no overlap ( P K 1.0), whereas P K values for cEEG, MAP and HR were all <0.85. Conclusions : The pharmacodynamic relationship between eT Des and NI is age dependent with a significantly higher EC 50 in children than in adolescents and adults. The NI appears to be superior to cEEG, MAP and HR in differentiating consciousness from unconsciousness.