Haemodynamic and electroencephalograph responses to intubation during induction with propofol or propofol/fentanyl

Abstract

with propofol or propofol/fentanylPurpose: To observe the changes in EEG bispectral index (BIS), 95% spectral edge frequency (95% SEF) and median frequency (MF)with haemodynamic changes to intubation during induction with propofol or propofol and 2 ~ug.l,,g -I fentanyl/v. Methods: Twenty four ASA I-II patients were randomized to receive either propofol infusion preceded by normal saline (group P, n= 12) or propofol preceded by 2/./g.kg -I fentanyl (group PF, n= 12). Intubation was performed five minutes after maintenance of BIS within 45 ---S. EEG and haemodynamic variables were recorded at before induction, and before and after intubation. Results: l-laemodynamiC responses to intubation were greater in group P than in group PF (P < 0.05). Postintubation SBP, DBP and HR increased, compared with preinduction values, more in group P than in group PE Postintubation BIS values increased from 45.5 ___ 3.5 and 44.2 ___ 4. I to 51. I ___ 4. I and 50.9 +_ 5.3 in groups P and PF, respectively, compared with preintubation values. The BIS values were not different between treatment groups before and after intubation, and 95% SEF and MF values did not increase after intubation. Conclusion: Fentanyl, 2/dg.kg -~/v, blunted the haemodynamic responses to intubation, but failed to attenuate the arousal of cerebral cortical activity. The different haemodynamic responses postintubation but similar BIS and 95% SEF changes in the two groups suggest that BIS or 95% SEF cannot predict the haemodynamic responses to intubation during anaesthesia induction with propofol and fentanyl.Objectif : Observer les alt6rations de rindex I~EG bispectral (BIS), sur la fr~quence spectrale de marge (95% SEF) et la fr&luence moyenne (FM) caus~es par les changements h~modynamiques de l'intubation pendant l'induction au propofol ou au propofol associ~ au fentanyl 2/./g.kg -i iv.M&hodes : Vingt-quatre patients ASA I -I I ont re~u al~atoirement soit une perfusion de propofol pr&~d~e de sol. phys. (groupe P, n = 12) ou de propofol pr&~d,6 de fentanyl 2 jug'kg -I (groupe PF, n = 12). On intubait cinq minutes apr& la stabilisation du BIS entre 45 _+ S. I'EEg et les variables h~modynamiques ~taient enregistr~es avant l'induction, et avant et apr~s l'intubation. R~sultats : Les r~ponses h~modynamiques ~ l'intubation &aient plus importantes dans le groupe P que dans le groupe PF (P<0,05). Apt& l'intubation, la pression art&ielle systolique et diastolique et la Fc augmentaient comparativement aux valeurs de pr~induction, mais plus dans le groupe P que dans le groupe PE Apr~s l'intubation, les valeurs du BIS augmentaient de 45 ___ 3,5 ~ 51 +__ 4. I dans le groupe Pet de 44 _+ 4, I ~ 50,9 ---5,3 dans les groupes PF comparativement aux valeurs pr&~dant l'intubation ; les valeurs SEF 95% et MF n'augmentaient pas apt& l'extubation.Conclusion : Le fentanyl 2 pg.kg-% att~nue les r~ponses h~modynamiques ~ l'intubation mais ne parvient pas att~nuer l'~veil de l'activit~ corticale c&~brale. La diff&ence des r~ponses h~modynamiques postintubation mais la similarit~ des cha...

Les valeurs de l’index bispectral ne correspondent pas a la réponse hémodynamique à la suite de l’augmentation rapide de la concentration d’isoflurane

“…[11][12][13] However, to our knowledge, there have been no reports on the effects of abrupt increases in isoflurane and sevoflurane concentrations on BIS. Since BIS has been shown to be increased by stimuli to the airways, such as endotracheal 14 and mechanical stimulation of the nasal mucosa, 15 it is possible that the administration of a high concentration of isoflurane will increase BIS. The objective of the present study was to elucidate the changes in hemodynamics and BIS after rapid increases in isoflurane and sevoflurane concentrations.…”

“…7 It has been suggested that a reflex response to a noxious stimulus to the airway is mediated at the subcortical level 14,15 and thus may be unrelated to the state of consciousness. 11 Therefore, the BIS value, which reflects cerebral cortical activity, is not influenced by noxious stimuli.…”

La réponse de l’index bispectral à l’intubation endotrachéale est similaire chez les patients normotendus et hypertendus

“…due to tracheal intubation is mediated at the subcortical level, 4 peripheral stimuli reach the brain through the ascending reticular activating systems of the brain stem and may affect the state of consciousness. 9 Mi et al 4 reported that BIS was significantly increased by laryngoscopy and intubation during infusion of propofol with or without fentanyl pretreatment. Guignard et al 5 demonstrated that laryngoscopy and intubation were associated with an increase in BIS during target-controlled infusion of propofol.…”

“…[1][2][3] Previous studies have shown that tracheal intubation is associated with increases in BIS as well as heart rate (HR) and blood pressure. [4][5][6] Therefore, intubation is likely to affect both the hypnotic and antinociceptive components of anesthesia. Although the enhanced hemodynamic response to intubation in patients with hypertension is well documented, 7,8 the degree of the arousal response has not been studied.…”

Entropia: um novo método de mensuração da profundidade da anestesia. Estudo comparativo com o índice bispectral na avaliação clínica da intubação traqueal com sevoflurano

“…Randel et al 24 have reported that patients ventilated with isoflurane in nitrous oxide and oxygen have presented sympathetic activation represented by heart rate increase without changes in pressure response to intubation, and premedication with opioids may prevent plasma epinephrine, but not norepinephrine, concentration increase after laryngoscopy and intubation. Other authors have evaluated the influence of intravenous 2 µg.kg -1 fentanyl associated to propofol in attenuating hemodynamic and cortical responses (through BIS) to intubation and have concluded that this technique has been effective in blocking hemodynamic responses without attenuating brain cortical activity response 25 . Billar et al 26 have shown that 2 µg.kg -1 fentanyl associated to propofol have decreased blood pressure and heart rate in response to intubation.…”