scholarly journals Change of inspired oxygen concentration in low flow anesthesia

2020 ◽  
Vol 15 (4) ◽  
pp. 434-440
Author(s):  
Jiwook Kim ◽  
Donghee Kang ◽  
Hochul Lee ◽  
Sungwon Ryu ◽  
Siejeong Ryu ◽  
...  
Keyword(s):  
Oxygen Concentration ◽  
Initial Phase ◽  
Gas Flow ◽  
Elective Surgery ◽  
Low Flow ◽  
Physical Status ◽  
Gas Concentration ◽  
Low Flow Anesthesia ◽  
American Society ◽  
Inspired Oxygen

Background: There are several advantages of low flow anesthesia including safety, economics, and eco-friendliness. However, oxygen concentration of fresh gas flow and inspired gas are large different in low flow anesthesia. This is a hurdle to access to low flow anesthesia. In this study, we aimed to investigate the change in inhaled oxygen concentration in low flow anesthesia using oxygen and medical air.Methods: A total of 60 patients scheduled for elective surgery with an American Society of Anesthesiologist physical status I or II were enrolled and randomly allocated into two groups. Group H: Fresh gas flow rate (FGF) 4 L/min (FiO₂ 0.5). Group L: FGF 1 L/min (FiO₂ 0.5). FGF was applied 4 L/min in initial phase (10 min) after intubation. After initial phase FGF was adjusted according to groups. FGF continued at the end of surgery. Oxygen and inhalation anesthetic gas concentration were recorded for 180 min at 15 min interval.Results: The inspired oxygen concentration decreased by 5.5% during the first 15 min in the group L. Inspired oxygen decreased by 1.5% during next 15 min. Inspired oxygen decreased by 1.4% for 30 to 60 min. The inspired oxygen of group L is 35.4 ± 4.0% in 180 min. The group H had little difference in inspired oxygen concentration over time and decreased by 1.8% for 180 min.Conclusions: The inspired oxygen concentration is maintained at 30% or more for 180 min in patients under 90 kg. Despite some technical difficulties, low flow anesthesia may be considered.

Effect of Fresh Gas Flow on Isoflurane Concentrations during Low-flow Anaesthesia

2005 ◽  
Vol 33 (5) ◽  
pp. 513-519 ◽  
Author(s):  
J-Y Park ◽  
J-H Kim ◽  
W-Y Kim ◽  
M-S Chang ◽  
J-Y Kim ◽  
...  
Keyword(s):  
Gas Flow ◽  
Low Flow ◽  
Physical Status ◽  
Closed Circle ◽  
Haemodynamic Changes ◽  
Low Flow Anaesthesia ◽  
Baseline Values ◽  
American Society ◽  
End Tidal ◽  
Closed Circle System

The effect of fresh gas flow (FGF) on isoflurane concentrations at given vaporizer settings during low-flow anaesthesia was investigated. Ninety patients (American Society of Anaesthesiologists physical status I or II) were randomly allocated to three groups (FGF 1 l/min, FGF 2 l/min and FGF 4 l/min). Anaesthesia was maintained for 10 min with vaporizer setting isoflurane 2 vol% and FGF 4 l/min for full-tissue anaesthetic uptake in a semi-closed circle system. Low-flow anaesthesia was maintained for 20 min with end-tidal isoflurane 1.5 vol% and FGF 2 l/min. FGF was then changed to FGF 1 l/min, FGF 2 l/min or FGF 4 l/min. Measurements during the 20-min period showed that inspired and end-tidal isoflurane concentrations decreased in the FGF 1-l/min group but increased in the FGF 4-l/min group compared with baseline values. No haemodynamic changes were observed. Monitoring of anaesthetic concentrations and appropriate control of vaporizer settings are necessary during low-flow anaesthesia.

scholarly journals In reply: Change of inspired oxygen concentration and temperature in low flow anesthesia

2021 ◽  
Vol 16 (1) ◽  
pp. 118
Author(s):  
Jiwook Kim ◽  
Hochul Lee ◽  
Sungwon Ryu ◽  
Donghee Kang ◽  
Siejeong Ryu ◽  
...  
Keyword(s):  
Oxygen Concentration ◽  
Low Flow ◽  
Low Flow Anesthesia ◽  
Inspired Oxygen

scholarly journals Change of inspired oxygen concentration and temperature in low flow anesthesia

2021 ◽  
Vol 16 (1) ◽  
pp. 116-118
Author(s):  
Hong Seuk Yang ◽  
Dong Ho Park ◽  
Chang Young Jeong
Keyword(s):  
Oxygen Concentration ◽  
Low Flow ◽  
Low Flow Anesthesia ◽  
Inspired Oxygen

scholarly journals 1-1-12 One-Step Wash-In Scheme for Desflurane-Nitrous Oxide Low-Flow Anesthesia: Rapid and Predictable Induction

2014 ◽  
Vol 2014 ◽  
pp. 1-5 ◽  
Author(s):  
Thepakorn Sathitkarnmanee ◽  
Sirirat Tribuddharat ◽  
Chakthip Suttinarakorn ◽  
Duangthida Nonlhaopol ◽  
Maneerat Thananun ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Nitrous Oxide ◽  
Gas Flow ◽  
Elective Surgery ◽  
Low Flow ◽  
One Step ◽  
Low Flow Anesthesia ◽  
Clinically Significant ◽  
Linear Manner

Background. We propose a 1-1-12 wash-in scheme for desflurane-nitrous oxide (N2O) low-flow anesthesia. The objective of our study was to determine the time to achieve alveolar concentration of desflurane (FAD) at 1, 2, 3, 4, 5, and 6%.Methods. We enrolled 106 patients scheduled for elective surgery under general anesthesia. After induction and intubation, wash-in was started with a fresh gas flow (FGF) of N2O : O21 : 1 L min−1and vaporizer concentration of desflurane (FD) of 12%. Ventilation was controlled to maintainPACO2at 30–35 mmHg.Results. TheFADrose rapidly from 0 to 4% in 2 min in a linear manner in 0.5 min increments. AnFADof 6% was achieved in 4 min in a linear fashion fromFADof 4% but in 1 min increments. AnFADof 1 to 6% occurred at 0.6, 1, 1.5, 2, 3, and 4 min. Heart rate during wash-in showed a statistically, albeit not clinically, significant pattern of increase. By contrast, blood pressure slightly decreased during this period.Conclusions. We developed a 1-1-12 wash-in scheme using a FGF of N2O : O21 : 1 L min−1and FD of 12% for desflurane-nitrous oxide low-flow anesthesia. A respectiveFADof 1, 2, 3, 4, 5, and 6% can be expected at 0.6, 1, 1.5, 2, 3, and 4 min.

scholarly journals Cost-effectiveness of Basal Flow Sevoflurane Anaesthesia Using the Komesaroff Vaporizer inside the Circle System

2005 ◽  
Vol 33 (5) ◽  
pp. 609-615 ◽  
Author(s):  
S. P. Nandalan ◽  
R. J. Eltringham ◽  
Q. W. Fan
Keyword(s):  
Gas Flow ◽  
Low Flow ◽  
Gas Flows ◽  
Physical Status ◽  
Mechanically Ventilated ◽  
Sevoflurane Anaesthesia ◽  
Inspiratory Limb ◽  
Low Flow Anaesthesia ◽  
Induction Of Anaesthesia ◽  
Basal Flow

After ethics committee approval, 51 consenting ASA physical status 1 or 2 adult patients were given basal flow sevoflurane anaesthesia using fresh gas flows of 150 to 300 ml.min-1 oxygen. A Komesaroff vaporizer was placed on the inspiratory limb of the circle system. Basal flows were introduced immediately following intravenous induction of anaesthesia. The vaporizer was set to deliver the maximum concentration until the inspired sevoflurane concentration (FSI) reached 3%. The dial was then adjusted to maintain the FSI at 3%. After every 60 minutes, the circuit was washed out with 100% oxygen at a flow rate of 10 l.min-1 for one minute. The FSI reached 3% after an average of 8.5 (3.8) [mean (SD)] minutes. The trends in FSI and the expired sevoflurane concentrations were significantly different (P<0.05) between the mechanically ventilated patients (n=21) and the spontaneously ventilating patients (n=30) and demonstrated a more gradual build-up in the former group. The consumption of sevoflurane was found to be 9.2 (2.8) ml.h-1. This represented a 52.5% cost saving over the clinical application of the Mapleson's ideal fresh gas flow sequence for low-flow anaesthesia.

scholarly journals Analysis of ease of insertions, its attempts and time taken to insert for i-gel and cLMA in paediatric cases.

2021 ◽  
Vol 9 (2) ◽  
pp. 95-101
Author(s):  
Dr. Nimish Jain ◽  
◽  
Dr. Susheela Taxak ◽  
Dr. Karampal Singh ◽  
◽  
...  
Keyword(s):  
General Anaesthesia ◽  
Elective Surgery ◽  
Airway Device ◽  
Blind Study ◽  
Supraglottic Airway ◽  
Supraglottic Airway Device ◽  
Physical Status ◽  
Aim Analysis ◽  
American Society ◽  
Single Blind

Aim: Analysis of ease of insertions, its attempts and time taken to insert for i-gel and cLMA inpaediatric cases. Methods: We did a prospective, randomised single-blind study on Eighty patientsof either sex belonging to American Society of Anaesthesiologists (ASA) physical status class I or II,between 6 months to 8 years of age, scheduled to undergo elective surgery for less than one andhalf hour duration under general anaesthesia. In this study we analysed the ease of insertion,attempts and time were taken to insert the supraglottic airway device. Results: The ease ofinsertion observed was easy in 39(97.5%) in the i-gel group and 35(87.5%) in cLMA group in ourstudy. The i-gel was placed successfully in 39 out of 40 (97.5%) patients in the first attempt, andachieved 100% insertion on the second attempt. Correct positioning of cLMA in the first attempt wasseen in 35 out of 40 (87.5%) patients. The remaining 5 patients (12.5%) required a secondattempt. The average insertion time of cLMA (12.88 ± 1.771 seconds) was longer than the averagetime of insertion of i-gel (9.48 ± 1.037 seconds), and these differences were highly significantstatistically (p= 0.000). Conclusion: To conclude, i-gel and cLMA is effective and safe devices foruse in children. Both are easy to insert and have insignificant morbidity, however, time taken andattempts of insertions for i-gel was lesser than cLMA. Also, the ease of insertion was relatively easyfor i-gel than cLMA in pediatric cases.

scholarly journals 1-1-8 one-step sevoflurane wash-in scheme for low-flow anesthesia: simple, rapid, and predictable induction

2019 ◽  
Author(s):  
Sirirat Tribuddharat ◽  
Thepakorn Sathitkarnmanee ◽  
Naruemon Vattanasiriporn ◽  
Maneerat Thananun ◽  
Duangthida Nonlhaopol ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Gas Flow ◽  
Low Flow ◽  
Target Coverage ◽  
Gas Analyzer ◽  
Controlled Ventilation ◽  
One Step ◽  
Low Flow Anesthesia ◽  
End Tidal

Abstract Background Sevoflurane is suitable for low-flow anesthesia (LFA). LFA needs a wash-in phase. The reported sevoflurane wash-in schemes lack simplicity, target coverage, and applicability. We proposed a one-step 1-1-8 wash-in scheme for sevoflurane LFA to be used with both N 2 O and Air. The objective of our study was to identify time for achieving each level of alveolar concentration of sevoflurane (F A S) from 1% to 3.5% in both contexts.Methods We recruited 199 adults requiring general anesthesia with endotracheal intubation and controlled ventilation—102 in group N 2 O and 97 in group Air. After induction and intubation, a wash-in was started using a fresh gas flow of O 2 :N 2 O or O 2 :Air at 1:1 L·min -1 plus sevoflurane 8%. The ventilation was controlled to maintain end-tidal CO 2 of 30-35 mmHg.Results The rising patterns of F A S and inspired concentration of sevoflurane (F I S) are similar, running parallel between the groups. The F A S/F I S ratio increased from 0.46 to 0.72 within 260 sec in group N 2 O and from 0.42 to 0.69 within 286 sec in group Air. The respective time to achieve an F A S of 1%, 1.5%, 2%, 2.5%, 3%, and 3.5% was 1, 1.5, 2, 3, 3.5, and 4.5 min in group N 2 O and 1, 1.5, 2, 3, 4, and 5 min in group Air. The heart rate and blood pressure of both groups significantly increased initially then gradually decreased as F A S increased.Conclusions The 1-1-8 wash-in scheme for sevoflurane LFA has many advantages, including simplicity, coverage, swiftness, safety, economy, and that it can be used with both N 2 O and Air. A respective F A S of 1%, 1.5%, 2%, 2.5%, 3%, and 3.5% when used with N 2 O and Air can be expected at 1, 1.5, 2, 3, 3.5, and 4.5 min and 1, 1.5, 2, 3, 4, and 5 min. This scheme may be applied for sevoflurane LFA in situations where an anesthetic gas analyzer is unavailable.

Comparative Hemodynamic Depression of Sevoflurane versus Halothane in Infants 

1997 ◽  
Vol 87 (4) ◽  
pp. 795-800 ◽  
Author(s):  
Eric Wodey ◽  
Patrick Pladys ◽  
Catherine Copin ◽  
Marie Madeleine Lucas ◽  
Andre Chaumont ◽  
...  
Keyword(s):  
Heart Rate ◽  
Cardiac Index ◽  
Elective Surgery ◽  
Physical Status ◽  
Inhalation Induction ◽  
Cardiovascular Side Effects ◽  
American Society ◽  
End Tidal ◽  
American Society Of Anesthesiologists ◽  
To Receive

Background The cardiovascular side effects of volatile anesthetics are one of the chief causes of postoperative complications in children, and infants seem to be at the greatest risk for this. This study compared cardiovascular changes at equipotent concentrations of sevoflurane and halothane in infants. Methods Thirty infants classified as American Society of Anesthesiologists physical status I or II who required elective surgery were randomized to receive either halothane or sevoflurane for inhalation induction. Cardiovascular and echocardiographic data were recorded in both groups at baseline and at end-tidal concentrations of 1 and 1.5 minimum alveolar concentration (MAC). Results Sevoflurane did not alter heart rate or cardiac index at all concentrations compared with awake values. Sevoflurane significantly decreased blood pressure and systemic vascular resistance compared with awake values at all concentrations. Shortening fraction and rate-corrected velocity of circumferential fiber shortening decreased at 1.5 but not at 1 MAC. Myocardial contractility assessed by stress-velocity index and stress-shortening index decreased significantly at all concentrations, but did not fall into the abnormal range at any concentration. Halothane caused a greater decrease in heart rate, shortening fraction, stress-shortening index, velocity of circumferential fiber shortening, stress-velocity index, and cardiac index at all concentrations than did sevoflurane. Conclusion Sevoflurane causes a lesser decrease in cardiac output than does halothane in infants.

scholarly journals 1-1-8 one-step sevoflurane wash-in scheme for low-flow anesthesia: simple, rapid, and predictable induction

2019 ◽  
Author(s):  
Sirirat Tribuddharat ◽  
Thepakorn Sathitkarnmanee ◽  
Naruemon Vattanasiriporn ◽  
Maneerat Thananun ◽  
Duangthida Nonlhaopol ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Gas Flow ◽  
Low Flow ◽  
Target Coverage ◽  
Gas Analyzer ◽  
Controlled Ventilation ◽  
One Step ◽  
Low Flow Anesthesia ◽  
End Tidal

Abstract Background Sevoflurane is suitable for low-flow anesthesia (LFA). LFA needs a wash-in phase. The reported sevoflurane wash-in schemes lack simplicity, target coverage, and applicability. We proposed a one-step 1-1-8 wash-in scheme for sevoflurane LFA to be used with both N 2 O and Air. The objective of our study was to identify time for achieving each level of alveolar concentration of sevoflurane (F A S) from 1% to 3.5% in both contexts.Methods We recruited 199 adults requiring general anesthesia with endotracheal intubation and controlled ventilation—102 in group N 2 O and 97 in group Air. After induction and intubation, a wash-in was started using a fresh gas flow of O 2 :N 2 O or O 2 :Air at 1:1 L·min -1 plus sevoflurane 8%. The ventilation was controlled to maintain end-tidal CO 2 of 30-35 mmHg.Results The rising patterns of F A S and inspired concentration of sevoflurane (F I S) are similar, running parallel between the groups. The F A S/F I S ratio increased from 0.46 to 0.72 within 260 sec in group N 2 O and from 0.42 to 0.69 within 286 sec in group Air. The respective time to achieve an F A S of 1%, 1.5%, 2%, 2.5%, 3%, and 3.5% was 1, 1.5, 2, 3, 3.5, and 4.5 min in group N 2 O and 1, 1.5, 2, 3, 4, and 5 min in group Air. The heart rate and blood pressure of both groups significantly increased initially then gradually decreased as F A S increased.Conclusions The 1-1-8 wash-in scheme for sevoflurane LFA has many advantages, including simplicity, coverage, swiftness, safety, economy, and that it can be used with both N 2 O and Air. A respective F A S of 1%, 1.5%, 2%, 2.5%, 3%, and 3.5% when used with N 2 O and Air can be expected at 1, 1.5, 2, 3, 3.5, and 4.5 min and 1, 1.5, 2, 3, 4, and 5 min. This scheme may be applied for sevoflurane LFA in situations where an anesthetic gas analyzer is unavailable.

Sign in / Sign up

Export Citation Format

Share Document