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.

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.

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

2020 ◽  
Author(s):  
Sirirat Tribuddharat ◽  
Thepakorn Sathitkarnmanee ◽  
Naruemon Vattanasiriporn ◽  
Maneerat Thananun ◽  
Duangthida Nonlhaopol ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
General Anesthesia ◽  
Gas Flow ◽  
Low Flow ◽  
Target Coverage ◽  
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.

scholarly journals 1-1-8 one-step sevoflurane-nitrous oxide 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):  
Nitrous Oxide ◽  
Gas Flow ◽  
Low Flow ◽  
Gas Analyzer ◽  
Controlled Ventilation ◽  
End Tidal Carbon Dioxide ◽  
One Step ◽  
Low Flow Anesthesia ◽  
Carbon Dioxide Co2 ◽  
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-nitrous oxide (N2O) LFA. The objective of our study was to identify times to achieve every alveolar concentration of sevoflurane (FAS) from 1% to 3.5%. Methods We recruited 102 adults requiring general anesthesia with endotracheal intubation and controlled ventilation. After induction and intubation, a wash-in was started using a fresh gas flow of oxygen (O2):N2O at 1:1 L·min-1 plus sevoflurane 8%. The ventilation was controlled to maintain end-tidal carbon dioxide (CO2) of 30-35 mmHg. Results The rising patterns of FAS and inspired concentration of sevoflurane (FIS) are similar and parallel. The FAS/FIS ratio increased from 0.46 to 0.72 within 260 sec. The respective times to achieve FAS of 1%, 1.5%, 2%, 2.5%, 3% and 3.5% were 1, 1.5, 2, 3, 3.5, and 4.5 min. The heart rate and blood pressure significantly increased initially then gradually decreased as FAS increased. Conclusions The 1-1-8 wash-in scheme for sevoflurane has many advantages, including simplicity, coverage, swiftness, safety, and economy. A respective FAS of 1%, 1.5%, 2%, 2.5%, 3%, and 3.5% can be expected at 1, 1.5, 2, 3, 3.5, and 4.5 min. This scheme may be applied for LFA in the situation where anesthetic gas analyzer is not available.

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.

Leukocyte kinetics in the human lung: role of exercise and catecholamines

1984 ◽  
Vol 57 (3) ◽  
pp. 711-719 ◽  
Author(s):  
A. L. Muir ◽  
M. Cruz ◽  
B. A. Martin ◽  
H. Thommasen ◽  
A. Belzberg ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Peripheral Blood ◽  
Human Lung ◽  
Work Load ◽  
Low Flow ◽  
Epinephrine Infusion ◽  
First Pass ◽  
Pass Through

In six normal supine subjects epinephrine infusion produced a greater leukocytosis with smaller changes in heart rate and blood pressure than did norepinephrine or isoproterenol. Upright exercise in those subjects produced a greater leukocytosis than supine exercise at the same work load. To determine the lung's participation in these events, indium-labeled neutrophils (PMN) were given to four of the subjects. We found that 20–25% were retained in the first pass through the lung when compared with technetium-labeled erythrocytes. The number of labeled PMN in the lung gradually decreased and the number in the spleen and the liver increased. Exercise and catecholamine infusion caused an acceleration in the release of labeled cells from the lung, an increase in both labeled and unlabeled cells in the peripheral blood, and an increase in the number of labeled cells in the liver and spleen. This suggests that increased perfusion of low-flow areas in the lung may contribute to the increased leukocytosis seen in association with both exercise and catecholamine infusion.

Effects of the Water Content of Soda Lime on Compound A Concentration in the Anesthesia Circuit in Sevoflurane Anesthesia 

1998 ◽  
Vol 88 (1) ◽  
pp. 66-71 ◽  
Author(s):  
Hiromichi Bito ◽  
Yukako Ikeuchi ◽  
Kazuyuki Ikeda
Keyword(s):  
Gas Flow ◽  
Soda Lime ◽  
Absorption Capacity ◽  
Low Flow ◽  
Co2 Absorption ◽  
Sevoflurane Anesthesia ◽  
Compound A ◽  
Carbon Dioxide Co2 ◽  
End Tidal ◽  
Co2 Elimination

Background Sevoflurane anesthesia is usually performed with fresh gas flow rates greater than 2 l/min due to the toxicity of compound A in rats and limited clinical experience with sevoflurane in low-flow systems. However, to reduce costs, it would be useful to identify ways to reduce compound A concentrations in low-flow sevoflurane anesthesia. This goal of this study was to determine if compound A concentrations can be reduced by using soda lime with water added. Methods Low-flow sevoflurane anesthesia (fresh gas flow of 1 l/min) was performed in 37 patients using soda lime with water added (perhydrated soda lime) or standard soda lime as the carbon dioxide (CO2) absorbent. The soda lime was not changed between patients, but rather was used until CO2 rebreathing occurred. The perhydrated soda lime was prepared by spraying 100 ml distilled water onto 1 kg fresh soda lime, and water was added only when a new bag of soda lime was placed into the canister. Compound A concentrations in the circle system, soda lime temperatures, inspired and end-tidal CO2 and end-tidal sevoflurane concentrations, and CO2 elimination by the patient were measured during anesthesia. Results Compound A concentrations were significantly lower for the perhydrated soda lime (1.9 +/- 1.8 ppm; means +/- SD) than for the standard soda lime (13.9 +/- 8.2 ppm). No differences were seen between the two types of soda lime with regard to the temperature of the soda lime, end-tidal sevoflurane concentrations, or CO2 elimination. Compound A concentration decreased with the total time of soda lime use for both types of soda lime. The CO2 absorption capacity was significantly less for perhydrated soda lime than for standard soda lime. Conclusions Compound A concentrations in the circuit can be reduced by using soda lime with water added. The CO2 absorption capacity of the soda lime is reduced by adding water to it, but this should not be clinically significant.

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.

Pet CO2 inversely affects MSNA response to orthostatic stress

2001 ◽  
Vol 281 (3) ◽  
pp. H1040-H1046 ◽  
Author(s):  
J. Kevin Shoemaker ◽  
Debbie D. O'Leary ◽  
Richard L. Hughson
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Cardiac Output ◽  
Orthostatic Intolerance ◽  
Muscle Sympathetic Nerve Activity ◽  
Peripheral Resistance ◽  
Burst Frequency ◽  
Head Up Tilt ◽  
End Tidal ◽  
Combined Data

Arterial hypocapnia has been associated with orthostatic intolerance. Therefore, we tested the hypothesis that hypocapnia may be detrimental to increases in muscle sympathetic nerve activity (MSNA) and total peripheral resistance (TPR) during head-up tilt (HUT). Ventilation was increased ∼1.5 times above baseline for each of three conditions, whereas end-tidal Pco 2 (Pet CO2 ) was clamped at normocapnic (Normo), hypercapnic (Hyper; +5 mmHg relative to Normo), and hypocapnic (Hypo; −5 mmHg relative to Normo) conditions. MSNA (microneurography), heart rate, blood pressure (BP, Finapres), and cardiac output (Q, Doppler) were measured continuously during supine rest and 45° HUT. The increase in heart rate when changing from supine to HUT ( P < 0.001) was not different across Pet CO2 conditions. MSNA burst frequency increased similarly with HUT in all conditions ( P < 0.05). However, total MSNA and the increase in total amplitude relative to baseline (%ΔMSNA) increased more when changing to HUT during Hypo compared with Hyper ( P < 0.05). Both BP and Q were higher during Hyper than both Normo and Hypo (main effect; P < 0.05). Therefore, the MSNA response to HUT varied inversely with levels of Pet CO2 . The combined data suggest that augmented cardiac output with hypercapnia sustained blood pressure during HUT leading to a diminished sympathetic response.

Hypoxemia raises muscle sympathetic activity but not norepinephrine in resting humans

1989 ◽  
Vol 66 (4) ◽  
pp. 1736-1743 ◽  
Author(s):  
L. B. Rowell ◽  
D. G. Johnson ◽  
P. B. Chase ◽  
K. A. Comess ◽  
D. R. Seals
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Nervous Activity ◽  
Plasma Concentrations ◽  
Random Order ◽  
Sympathetic Nervous Activity ◽  
Severe Hypoxemia ◽  
Arterial Blood ◽  
End Tidal ◽  
Venous Plasma

The experimental objective was to determine whether moderate to severe hypoxemia increases skeletal muscle sympathetic nervous activity (MSNA) in resting humans without increasing venous plasma concentrations of norepinephrine (NE) and epinephrine (E). In nine healthy subjects (20–34 yr), we measured MSNA (peroneal nerve), venous plasma levels of NE and E, arterial blood pressure, heart rate, and end-tidal O2 and CO2 before (control) and during breathing of 1) 12% O2 for 20 min, 2) 10% O2 for 20 min, and 3) 8% O2 for 10 min--in random order. MSNA increased above control in five, six, and all nine subjects during 12, 10, and 8% O2, respectively (P less than 0.01), but only after delays of 12 (12% O2) and 4 min (8 and 10% O2). MSNA (total activity) rose 83 +/- 20, 260 +/- 146, and 298 +/- 109% (SE) above control by the final minute of breathing 12, 10, and 8% O2, respectively. NE did not rise above control at any level of hypoxemia; E rose slightly (P less than 0.05) at one time only with both 10 and 8% O2. Individual changes in MSNA during hypoxemia were unrelated to elevations in heart rate or decrements in blood pressure and end-tidal CO2--neither of which always fell. We conclude that in contrast to some other sympathoexcitatory stimuli such as exercise or cold stress, moderate to severe hypoxemia increases leg MSNA without raising plasma NE in resting humans.

Sign in / Sign up

Export Citation Format

Share Document