The Effect of the Interaction of Propofol and Alfentanil on Recall, Loss of Consciousness, and the Bispectral Index

Purpose:A study was undertaken to compare the influence of midazolam, isoflurane, and aminophylline (which may antagonize anesthetic action) on bispectral index (BIS) and regional cerebral oxygen saturation (rSO 2 ) during propofol/N 2 O anesthesia, and to test the hypothesis that the drug-induced changes in BIS values are accompanied by a change in rSO 2 .Methods: General anesthesia was administered to 36 patients with a continuous infusion of propofol to maintain a BIS value of 40 ± 5. After baseline recordings, patients were randomly assigned to receive either midazolam, isoflurane, or aminophylline. Bispectral index values, rSO 2 using near-infrared spectroscopy, and hemodynamic parameters were recorded for 60 min.Results: Midazolam (0.05 mg·kg -1 ) significantly decreased the BIS from 47.8 ± 5.4 to 35.0 ± 4.5 at five minutes after injection (P < 0.001 vs control) during propofol anesthesia, whereas the rSO 2 was unchanged. Similarly, isoflurane (1.1% end-tidal) decreased the BIS from 42.5 ± 7.5 to 27.8 ± 6.9 (P < 0.001) without affecting rSO 2 . In contrast, aminophylline (3 mg·kg -1 ) was associated with an increase in BIS from 41.6 ± 2.1 to 48.3 ± 9.2 at five minutes after injection (P < 0.05) without affecting rSO 2 .Conclusions: Midazolam or isoflurane-induced decreases in the BIS during propofol anesthesia were not accompanied by a decrease in rSO 2 . Aminophylline significantly increased the BIS score during propofol anesthesia, suggesting that aminophylline can antagonize, at least in part, the sedative actions of propofol. 47,8 ± 5,4 à 35,0 ± 4,5 cinq minutes après l'injection (P < 0,001 vs témoin) pendant l'anesthésie au propofol, tandis que la rSO 2 n'a pas changé. De même,1,1 %) a diminué le BIS de 42,5 ± 7,5 à 27,8 ± 6,9 (P < 0,001) Objectif : Comparer l'influence du midazolam, de l'isoflurane et de l'aminophylline (qui peut contrer l'action anesthésique) sur l'index bispectral (BIS) et

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confidence: 99%

Ľindex bispectral et la saturation en oxygène du sang cérébral régional pendant ľanesthésie au propofol/N2O

Kanemaru

Nishikawa

Goto

2006

“…8 The bispectral index (BIS), obtained from bispectral analysis of the electroencephalogram, has been shown to reflect the hypnotic component of anesthesia. 9,10 It has been reported that BIS decreases with increasing concentrations of anesthetics. [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.…”

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confidence: 99%

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

Nakayama

Hayashi

Ichinose

et al. 2001

P Pu ur rp po os se e: : To investigate the changes in hemodynamic variables and bispectral index (BIS) in response to a rapid increase in isoflurane or sevoflurane concentration.M Me et th ho od d: : Thirty adult patients were anesthetized with either isoflurane (isoflurane group) or sevoflurane (sevoflurane group). Two minutes after induction of anesthesia with thiamylal, the inspired concentrations of isoflurane and sevoflurane were rapidly increased from 0.5 minimum alveolar anaesthetic concentration (MAC) to 3 MAC and maintained for five minutes. Heart rate (HR), mean arterial pressure (MAP), and BIS were measured every minute.R Re es su ul lt ts s: : An increase in the anesthetic concentration caused increases in HR and MAP in the isoflurane group and a decrease in MAP in the sevoflurane group. Consequently, HR and MAP in the isoflurane group were significantly higher than those in the sevoflurane group. After inhalation of high concentrations, BIS significantly and progressively decreased in both groups.

“…3 The impact of alfentanil on propofol requirements for loss of consciousness and lack of recall was also assessed using the BIS monitoring. 4 The propofol (3 mg.kg 1)/BIS ratio and, thus, the hypnotic effect obtained after the predetermined bolus dose did not differ between groups. The cumulative infusion doses required to maintain a BIS 40% normalized by the corresponding BIS values did not differ between the two groups as well.…”

Section: Discussionmentioning

confidence: 84%

Hypnotic and cardiovascular effects of proprietary and generic propofol formulations do not differ

Fassoulaki

Paraskeva

Papilas

et al. 2001

Purpose: The aim of the study was to compare the potency of two different propofol formulations: proprietary and generic propofol using the bispectral index (DIS) monitoring.Methods: Forty female patients undergoing breast surgery received propofol 3 mgkg i followed by propofol infusion adjusted to maintain a 40% DIS value, supplemented by 50% nitrous oxide. Proprietary or generic propofol was administered in a randomized double-blind manner.Results: The propofol mg/BIS% ratio obtained after the bolus dose, the cumulative infused propofol mg/DIS% ratio at the end of each five-minute interval and the total dose of propofol administered as bolus + infusion were similar between the two groups. The two groups did not differ with regard to systolic and diastolic blood pressure, heart rate, end-tidal carbon dioxide and arterial oxygen saturation.Conclusion: The two propofol formulations are equipotent when hypnotic effect is assessed by DIS monitoring.