Effects of Etco 2 on the Minimum Alveolar Concentration of Sevoflurane that Blunts the Adrenergic Response to Surgical Incision: A Prospective, Randomized, Double-Blinded Trial

2021 ◽  
Vol Publish Ahead of Print ◽  
Author(s):  
Zhijie Wu ◽  
Junjie Yu ◽  
Tianhua Zhang ◽  
Hongying Tan ◽  
Huiting Li ◽  
...  
1999 ◽  
Vol 90 (2) ◽  
pp. 398-405 ◽  
Author(s):  
Takasumi Katoh ◽  
Syunji Kobayashi ◽  
Akira Suzuki ◽  
Tatsuaki Iwamoto ◽  
Hiromichi Bito ◽  
...  

Background Fentanyl produces a reduction in the minimum alveolar concentration (MAC) of isoflurane and desflurane needed to blockade adrenergic response (BAR) to surgical incision in 50% of patients (MAC-BAR). MAC-BAR of sevoflurane and the reduction in MAC-BAR of sevoflurane by fentanyl have not been described previously. The purpose of this study was to determine the MAC and MAC-BAR reduction of sevoflurane by fentanyl with and without nitrous oxide (N2O). Methods Two hundred twenty-six patients were randomly assigned to one of two groups: a sevoflurane group and a sevoflurane/N2O group. Patients in each group were randomly assigned to one of five different fentanyl concentration subgroups. Patients were anesthetized with sevoflurane and fentanyl in the sevoflurane group and with sevoflurane, fentanyl, and N2O (66 vol%) in the sevoflurane/N2O group. Somatic and sympathetic responses to surgical incision were observed for MAC and MAC-BAR assessment at predetermined concentrations of sevoflurane. Results Fentanyl produced an initial steep reduction in the MAC and MAC-BAR of sevoflurane, with 3 ng/ml resulting in a 61% reduction in MAC and an 83% reduction in MAC-BAR. A ceiling effect was observed for MAC and MAC-BAR, with 6 ng/ml fentanyl providing only an additional 13% and 9% reduction in MAC and MAC-BAR, respectively. In the presence of 66 vol% N2O, MAC and MAC-BAR of sevoflurane were reduced with increasing concentrations of fentanyL A ceiling effect was not observed for reduction in MAC and MAC-BAR in the presence of N2O. Conclusions MAC and MAC-BAR decreased similarly with increasing concentrations of fentanyl in plasma, showing an initial steep reduction followed by a ceiling effect. In the presence of N2O, MAC and MAC-BAR decreased similarly but did not exhibit a ceiling effect.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Ha Yeon Kim ◽  
Hyun Jeong Kwak ◽  
Dongchul Lee ◽  
Ji Hyea Lee ◽  
Sang Kee Min ◽  
...  

Abstract Background Preventing emergence cough after nasal surgery is critical. Emergence cough can provoke immediate postoperative bleeding, which leads to upper airway obstruction. In the present study, we compared the effect-site concentration (Ce) of remifentanil to prevent emergence cough after propofol anesthesia for nasal surgery when remifentanil was or was not combined with dexmedetomidine. Methods Forty-seven patients with propofol-remifentanil anesthesia for nasal surgery were randomly assigned to a dexmedetomidine group (Group D, n = 23) or a saline group (Group S, n = 24). Group D and Group S were infused with dexmedetomidine (0.5 μg/kg) and saline, respectively, for 10 min before the completion of surgery. A predetermined Ce of remifentanil was infused until extubation. Remifentanil Ce to prevent cough in 50 and 95% of patients (EC50 and EC95) was estimated using modified Dixon’s up-and-down method and isotonic regression. Hemodynamic and recovery parameters were recorded. Results The EC50 of remifentanil Ce was significantly lower in Group D than in Group S (2.15 ± 0.40 ng/mL vs. 2.66 ± 0.36 ng/mL, p = 0.023). The EC95 (95% CI) of remifentanil Ce was also significantly lower in Group D [2.75 (2.67–2.78) ng/mL] than in Group S [3.16 (3.06–3.18) ng/mL]. Emergence and recovery variables did not differ between the two groups. Conclusion The remifentanil EC50 to prevent cough after propofol-remifentanil anesthesia was significantly lower (approximately 19%) when a combination of remifentanil and 0.5 μg/kg dexmedetomidine was used than when remifentanil infusion alone was used in patients undergoing nasal surgery. Therefore, the Ce of remifentanil may be adjusted to prevent emergence cough when used in combination with dexmedetomidine. Trial registration ClinicalTrials.gov (NCT03622502, August 9, 2018).


2017 ◽  
Vol 79 (3) ◽  
pp. 502-508 ◽  
Author(s):  
Sho FUKUI ◽  
Norihiko OOYAMA ◽  
Jun TAMURA ◽  
Mohammed Ahmed UMAR ◽  
Tomohito ISHIZUKA ◽  
...  

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