가스 유량에 따른 각성 시간의 예측

Abstract

흡입마취제를 이용한 전신마취에서 비용절감과 환경보호를 위해 마취유지기 동안 신선가스유량을 줄이고자 하는 노력이 적극적으로 이루어지고 있다. 하지만 빠른 의식 회복이 필요한 각성기에는 이러한 노력이 미미하다. 본 연구는 각성기에 신선가스유량에 따른 각성 시간을 측정함으로써 유량에 따른 각성 시기를 예측할 수 있는지 알아보고자 하여 진행되었다.

총 105명의 환자를 각성기에 신선가스 유량에 따라 무작위로 D2 군(2 L/min 산소 투여 군, n = 35), D4 군(4 L/min 산소 투여 군, n = 35), D6 군(6 L/min 산소 투여 군, n = 35 )의 3군으로 분배하였다. Desflurane 투여를 종료하는 시점부터 구두명령에 따라 처음 눈을 뜰 때까지의 시간과 처음으로 자발움직임을 보인 시간, 기관내튜브를 발관한 시간을 측정하였으며 각각 그 시간의 호기말 desflurane 농도, BIS를 기록하였다. 결과분석을 위해 One-way ANOVA, Dunnett test, Pearson correlation analysis를 사용하였다.

Desflurane 투여 종료 시점부터 기관튜브를 발관하기까지의 시간은 D2 군에서 17.56 ± 5.58 min, D4 군에서 9.89 ± 2.75 min, D6 군에서 9.06 ± 3.23 min이었다. D2 군과 D4 군, D2 군과 D6 군은 통계적으로 유의한 차이를 보였으나 D4 군과 D6 군 사이에는 차이가 없었다.

신선가스유량에 따른 평균 발관 시간을 알 수 있었으며 이에 맞춰 미리 흡입마취제의 투여를 중단한다면 각성 시간의 지연 없이 흡입마취제의 사용량을 줄일 수 있을 것으로 생각된다. 또한 빠른 각성을 위해 고유량의 신선가스 사용이 필요할 때에는 4 L/min의 신선가스유량 사용을 통해 6 L/min에 비해 각성시간은 지연시키지 않으면서 상대적인 저유량을 통한 이득을 기대할 수 있을 것으로 생각된다.

|Background : A number of efforts are being made to reduce fresh gas flow during anesthesia maintenance phase to cut costs and protect the environment. However, in case of an emergence phase requiring fast recovery, such efforts are relatively insufficient. This study was performed to understand whether it would be possible to predict emergence time according to the fresh gas flow, by measuring emergence time according to the fresh gas flow during an emergence period.

Methods : 105 patients were randomly assigned into three groups, such as D2 group (2 L/min oxygen administration group, n = 35), D4 group (4 L/min oxygen administration group, n = 35), and D6 group (6 L/min oxygen administration group, n = 35), according to the fresh gas flow during an emergence period. Every subject used desflurane as an inhalation anesthetic. Intervals between the end of administration of desflurane and time when the subjects opened their eyes according to verbal commands(eye opening time), time when the subjects showed a spontaneous movement for the first time(spontaneous movement time), and time when the endotracheal tube was extubated(extubation time) were measured. And, end tidal concentration of desflurane and BIS at each time was recorded respectively. Mean arterial pressure and heart rate were recorded every 3 minutes from the end of desflurane administration to extubation, and they were also recorded one minute after extubation. One-way ANOVA, Dunnett test, and Pearson correlation analysis were used to analyze results.

Results : Extubation time were 17.56 ± 5.58 min for D2 group, 9.89 ± 2.75 min for D4 group, and 9.06 ± 3.23 min for D6 group. As for extubation time, eye opening time, spontaneous movement time, there were statistically significant difference between D2 and D4, and between D2 and D6, but statistically significant difference was not observed between D4 and D6. And, among three groups, BIS, mean arterial pressure, and heart rate did not show any statistically significant difference relating to the extubation time, eye opening time, spontaneous movement time.

Dicussion : In this study, we were able to predict mean extubation time according to the fresh gas flow. The use of desflurane can be reduced during emergence period without delaying recovery time if desflurane stopped as predicted. And when fast recovery is necessary, 4 L/min fresh gas flow can substitute 6 L/min fresh gas flow, because 4 L/min is as fast as 6 L/min in emergence time, but also have advantage of cost reduction and environmental protection.; Background : A number of efforts are being made to reduce fresh gas flow during anesthesia maintenance phase to cut costs and protect the environment. However, in case of an emergence phase requiring fast recovery, such efforts are relatively insufficient. This study was performed to understand whether it would be possible to predict emergence time according to the fresh gas flow, by measuring emergence time according to the fresh gas flow during an emergence period.

Methods : 105 patients were randomly assigned into three groups, such as D2 group (2 L/min oxygen administration group, n = 35), D4 group (4 L/min oxygen administration group, n = 35), and D6 group (6 L/min oxygen administration group, n = 35), according to the fresh gas flow during an emergence period. Every subject used desflurane as an inhalation anesthetic. Intervals between the end of administration of desflurane and time when the subjects opened their eyes according to verbal commands(eye opening time), time when the subjects showed a spontaneous movement for the first time(spontaneous movement time), and time when the endotracheal tube was extubated(extubation time) were measured. And, end tidal concentration of desflurane and BIS at each time was recorded respectively. Mean arterial pressure and heart rate were recorded every 3 minutes from the end of desflurane administration to extubation, and they were also recorded one minute after extubation. One-way ANOVA, Dunnett test, and Pearson correlation analysis were used to analyze results.

Results : Extubation time were 17.56 ± 5.58 min for D2 group, 9.89 ± 2.75 min for D4 group, and 9.06 ± 3.23 min for D6 group. As for extubation time, eye opening time, spontaneous movement time, there were statistically significant difference between D2 and D4, and between D2 and D6, but statistically significant difference was not observed between D4 and D6. And, among three groups, BIS, mean arterial pressure, and heart rate did not show any statistically significant difference relating to the extubation time, eye opening time, spontaneous movement time.

Dicussion : In this study, we were able to predict mean extubation time according to the fresh gas flow. The use of desflurane can be reduced during emergence period without delaying recovery time if desflurane stopped as predicted. And when fast recovery is necessary, 4 L/min fresh gas flow can substitute 6 L/min fresh gas flow, because 4 L/min is as fast as 6 L/min in emergence time, but also have advantage of cost reduction and environmental protection.