Incidence of Epileptiform EEG Activity in Children during Mask Induction of Anaesthesia with Brief Administration of 8% Sevoflurane

Abstract

BackgroundA high incidence of epileptiform activity in the electroencephalogram (EEG) was reported in children undergoing mask induction of anaesthesia with administration of high doses of sevoflurane for 5 minutes and longer. This study was performed to investigate whether reducing the time of exposure to a high inhaled sevoflurane concentration would affect the incidence of epileptiform EEG activity. It was hypothesized that no epileptiform activity would occur, when the inhaled sevoflurane concentration would be reduced from 8% to 4% immediately after the loss of consciousness.Methodology/Principal Findings70 children (age 7–96 months, ASA I–II, premedication with midazolam) were anaesthetized with 8% sevoflurane in 100% oxygen via face mask. Immediately after loss of consciousness, the sevoflurane concentration was reduced to 4%. EEGs were recorded continuously and were later analyzed visually with regard to epileptiform EEG patterns. Sevoflurane at a concentration of 8% was given for 1.2±0.4 min (mean ± SD). In 14 children (20%) epileptiform EEG patterns without motor manifestations were observed (delta with spikes (DSP), rhythmic polyspikes (PSR), epileptiform discharges (PED) in 10, 10, 4 children (14%, 14%, 6%)). 38 children (54%) had slow, rhythmic delta waves with high amplitudes (DS) appearing on average before DSP.Conclusions/SignificanceThe hypothesis that no epileptiform potentials would occur during induction of anaesthesia with a reduction of the inspired sevoflurane concentration from 8% to 4% directly after LOC was not proved. Even if 8% sevoflurane is administered only briefly for induction of anaesthesia, epileptiform EEG activity may be observed in children despite premedication with midazolam.

Variations in Values of State, Response Entropy and Haemodynamic Parameters Associated with Development of Different Epileptiform Patterns during Volatile Induction of General Anaesthesia with Two Different Anaesthetic Regimens Using Sevoflurane in Comparison with Intravenous Induct: A Comparative Study

“…In our study, induction of VIGA with sevoflurane resulted in the presence of EPs in patients' EEGs at a similar rate to previous studies concerning the presence of EPs during GA with sevoflurane [1][2][3][5][6][7]26,27]. We observed significantly higher HR values in patients induced with the VCRII technique when the EPs appeared; therefore, their appearance resulted in haemodynamic instability, since patients who were induced with the VCRII technique but did not show EPs showed lower haemodynamic parameters at the same stages (Table 3).…”

“…Both volatile induction of general anaesthesia (VIGA) with sevoflurane and intravenous induction of general anaesthesia with propofol may induce seizure-like movements or seizures accompanied by haemodynamic instability [1,2], which are defined as clinically manifest events with confirmatory electroencephalographic patterns. Seizures during VIGA with sevoflurane were observed with an incidence of 5% in children [2], whereas subclinical activity in children's electroencephalographic recordings (without clinically manifest events) during VIGA with sevoflurane have been reported to appear in 20% of cases [1,3], as compared to 47% in adults breathing spontaneously [4]. The appearance of these findings during VIGA with sevoflurane in children is known to increase to 88% with controlled hyperventilation and even up to 100% with hypocapnia [2].…”

Influence of the Sevoflurane Concentration on the Occurrence of Epileptiform EEG Patterns

“…In another study from the own department on EEG effects during induction of anaesthesia with sevoflurane in children, also no gender effect was found [13].…”

Epileptiform EEG discharges and sevoflurane in children

“…[1] Some studies had shown that lower sevoflurane concentration during induction and shorter induction time can reduce the occurrence of epileptic discharge. [4,14] Iijima et al reported that nitrous oxide may diminish epileptogenic effects of sevoflurane in patients with epilepsy. [5] And the addition of alfentanil in the induction process of sevoflurane may have a protective effect on sevoflurane induced epileptic discharges.…”