TY - JOUR
T1 - The effect of high dose sodium thiopental on brain stem auditory and median nerve somatosensory evoked responses in humans
AU - Drummond, J. C.
AU - Todd, M. M.
AU - U, H. S.
PY - 1985/1/1
Y1 - 1985/1/1
N2 - Median nerve somatosensory evoked potentials (MnSSEPs), brain stem auditory evoked responses (BAERs), and the cortical electroencephalogram (EEG) were recorded in six patients during a 62-min infusion of sodium thiopental (STP) at a rate of 1.25 mg·kg-1·min-1 (total dose, 77.5 mg/kg). The EEG became isoelectric after 22 ± 8 (SD) min of STP infusion. Dose-related changes in the latencies and amplitudes of various evoked response wave forms were observed. However, in no instance was any component of either the MnSSEP or the BAER rendered unobtainable by STP administration. For the MnSSEP, progressive increases in the central conduction time (5.33 ± 0.41 ms preinduction vs. 7.46 ± 1.2 ms at t = 60 min) and in the latency of the cortical primary specific complex were observed simultaneously with significant reductions in the amplitude of the latter (2.10 ± 0.85 μV preinduction vs. 0.85 ± 0.55 μV at t = 60 min). Changes in the latency and amplitude of the response recorded over the upper cervical spine (C2) were not statistically significant in this small population. For the BAER, progressive and significant increases in the latencies of Waves I, III, V (e.g., Wave V latency: 6.16 ± 0.24 vs. 6.87 ± 0.32 ms) and in the I-III, III-V, and the I-V interwave latencies were observed. The amplitudes of the BAER components were not significantly altered. The authors conclude that the administration of a dose of STP in excess of twice that required to produce EEG isoelectricity can be compatible with effective monitoring of MnSSEPs and BAERs. However, STP produces dose-related changes in both evoked response wave forms, which must be considered in the interpretation of responses elicited during STP anesthesia.
AB - Median nerve somatosensory evoked potentials (MnSSEPs), brain stem auditory evoked responses (BAERs), and the cortical electroencephalogram (EEG) were recorded in six patients during a 62-min infusion of sodium thiopental (STP) at a rate of 1.25 mg·kg-1·min-1 (total dose, 77.5 mg/kg). The EEG became isoelectric after 22 ± 8 (SD) min of STP infusion. Dose-related changes in the latencies and amplitudes of various evoked response wave forms were observed. However, in no instance was any component of either the MnSSEP or the BAER rendered unobtainable by STP administration. For the MnSSEP, progressive increases in the central conduction time (5.33 ± 0.41 ms preinduction vs. 7.46 ± 1.2 ms at t = 60 min) and in the latency of the cortical primary specific complex were observed simultaneously with significant reductions in the amplitude of the latter (2.10 ± 0.85 μV preinduction vs. 0.85 ± 0.55 μV at t = 60 min). Changes in the latency and amplitude of the response recorded over the upper cervical spine (C2) were not statistically significant in this small population. For the BAER, progressive and significant increases in the latencies of Waves I, III, V (e.g., Wave V latency: 6.16 ± 0.24 vs. 6.87 ± 0.32 ms) and in the I-III, III-V, and the I-V interwave latencies were observed. The amplitudes of the BAER components were not significantly altered. The authors conclude that the administration of a dose of STP in excess of twice that required to produce EEG isoelectricity can be compatible with effective monitoring of MnSSEPs and BAERs. However, STP produces dose-related changes in both evoked response wave forms, which must be considered in the interpretation of responses elicited during STP anesthesia.
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U2 - 10.1097/00000542-198509000-00002
DO - 10.1097/00000542-198509000-00002
M3 - Article
C2 - 4025886
AN - SCOPUS:0021930252
SN - 0003-3022
VL - 63
SP - 249
EP - 254
JO - Anesthesiology
JF - Anesthesiology
IS - 3
ER -