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

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.

Download Full-text

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

10.21203/rs.2.15936/v1 ◽

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.

Download Full-text

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

10.21203/rs.2.15936/v3 ◽

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.

Download Full-text

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

10.21203/rs.2.407/v1 ◽

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.

Download Full-text

Effect of N2O on Sevoflurane Vaporizer Settings during Minimal- and Low-flow Anesthesia

Anesthesiology ◽

10.1097/00000542-200208000-00017 ◽

2002 ◽

Vol 97 (2) ◽

pp. 400-404 ◽

Cited By ~ 8

Author(s):

Jan F. A. Hendrickx ◽

José Coddens ◽

Frederik Callebaut ◽

Hermes Artico ◽

Thierry Deloof ◽

...

Keyword(s):

Nitrous Oxide ◽

Gas Flow ◽

Low Flow ◽

Oxide Mixture ◽

Factors Affecting ◽

Carrier Gas ◽

Dial Setting ◽

Oxygen Nitrous Oxide ◽

Low Flow Anesthesia ◽

Almost All

Background Uptake of a second gas of a delivered gas mixture decreases the amount of carrier gas and potent inhaled anesthetic leaving the circle system through the pop-off valve. The authors hypothesized that the vaporizer settings required to maintain constant end-expired sevoflurane concentration (Etsevo) during minimal-flow anesthesia (MFA, fresh gas flow of 0.5 l/min) or low-flow anesthesia (LFA, fresh gas flow of 1 l/min) would be lower when sevoflurane is used in oxygen-nitrous oxide than in oxygen. Methods Fifty-six patients receiving general anesthesia were randomly assigned to one of four groups (n = 14 each), depending on the carrier gas and fresh gas flow used: group Ox.5 l (oxygen, MFA), group NOx.5 l (oxygen-nitrous oxide, MFA after 10 min high fresh gas flow), group Ox1 l (oxygen, LFA), and group NOx1 l (oxygen-nitrous oxide, LFA after 10 min high fresh gas flow). The vaporizer dial settings required to maintain Etsevo at 1.3% were compared between groups. Results Vaporizer settings were higher in group Ox.5 l than in groups NOx.5 l, Ox1 l, and NOx1 l; vaporizer settings were higher in group NOx.5 l than in group NOx1 l between 23 and 47 min, and vaporizer settings did not differ between groups Ox1 l and NOx1 l. Conclusions When using oxygen-nitrous oxide as the carrier gas, less gas and vapor are wasted through the pop-off valve than when 100% oxygen is used. During MFA with an oxygen-nitrous oxide mixture, when almost all of the delivered oxygen and nitrous oxide is taken up by the patient, the vaporizer dial setting required to maintain a constant Etsevo is lower than when 100% oxygen is used. With higher fresh gas flows (LFA), this effect of nitrous oxide becomes insignificant, presumably because the proportion of excess gas leaving the pop-off valve relative to the amount taken up by the patient increases. However, other unexplored factors affecting gas kinetics in a circle system may contribute to our observations.

Download Full-text

Change of inspired oxygen concentration in low flow anesthesia

Anesthesia and Pain Medicine ◽

10.17085/apm.20055 ◽

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.

Download Full-text

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

Journal of Applied Physiology ◽

10.1152/jappl.1984.57.3.711 ◽

1984 ◽

Vol 57 (3) ◽

pp. 711-719 ◽

Cited By ~ 55

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.

Download Full-text

The Cardiovascular Effects and Histamine-releasing Properties of 51W89 in Patients Receiving Nitrous Oxide/Opioid/Barbiturate Anesthesia

Anesthesiology ◽

10.1097/00000542-199505000-00007 ◽

1995 ◽

Vol 82 (5) ◽

pp. 1131-1138 ◽

Cited By ~ 83

Author(s):

Cynthia A. Lien ◽

Matthew R. Belmont ◽

Amy Abalos ◽

Larissa Eppich ◽

Steve Quessy ◽

...

Keyword(s):

Blood Pressure ◽

Heart Rate ◽

Nitrous Oxide ◽

Surgical Procedures ◽

Muscle Relaxant ◽

Venous Blood ◽

Cardiovascular Effects ◽

Plasma Histamine ◽

Elective Surgical Procedures ◽

Rapid Injection

Background Atracurium consists of a mixture of ten stereoisomers. One of these isomers, 51W89, is a potent intermediate-acting nondepolarizing neuromuscular blocking agent. Its ED95 is 0.05 mg.kg-1 in patients receiving nitrous oxide/opioid anesthesia. In preclinical trials, 51W89 did not show evidence of histamine release in cats at doses up to 80 times the human ED95. This study was undertaken to determine the cardiovascular effects and histamine-releasing properties of 51W89 in patients undergoing elective surgical procedures. Methods Sixty patients, ASA physical status 1 or 2, anesthetized with nitrous oxide/fentanyl/thiopental were studied. Patients received either 2 times the ED95 of atracurium or 51W89 or 4 or 8 times the ED95 of 51W89 as a rapid intravenous bolus under stable anesthesia, before surgical stimulation. Blood pressure and heart rate were measured by oscillometry and the electrocardiogram in patients receiving 2 times the ED95 of 51W89 or atracurium and by an intraarterial catheter and a tachograph triggered by the arterial pulse waveform in patients receiving 4 or 8 times the ED95 of 51W89. Maximal blood pressure and heart rate changes during the 5 min after administration of the muscle relaxant were recorded. Venous blood samples were obtained before the administration of relaxant and at 2 and 5 min after the administration of relaxant for determination of plasma histamine concentrations by radioenzymatic assay. Results Maximal blood pressure and heart rate changes in all groups of patients receiving 51W89 were small and similar to those observed in patients receiving 2 times the ED95 of atracurium. The mean maximum percent changes (+/- SE) in heart rate and mean arterial pressure were -0.6 +/- 1.5 and 0.4 +/- 2.5, respectively, in the group receiving 2 times the ED95 atracurium; -1.3 +/- 3.3 and 2.3 +/- 4.4, respectively, in the group receiving 2 times the ED95 51W89; -2.6 +/- 1.0 and 2.6 +/- 1.5, respectively, in the group receiving 4 times the ED95 51W89; and -2.4 +/- 1.5 and -1.0 +/- 1.3, respectively, in the group receiving 8 times the ED95 51W89. No patient developed a decrease in blood pressure > or = 20% or an increase in heart rate > or = 20% that was attributable to muscle relaxant administration. There was no dose-related change in plasma histamine concentration associated with the administration of 51W89. One patient in the study developed transient facial flushing after the administration of atracurium. Conclusions 51W89 is a benzylisoquinolinium-type, nondepolarizing muscle relaxant that does not affect plasma histamine concentrations. No cutaneous flushing or clinically important cardiovascular effects were noted after rapid injection of doses up to and including 8 times its ED95 (0.4 mg.kg-1) in healthy patients undergoing elective surgical procedures.

Download Full-text

Comparison of non-invasive haemodynamic monitors of stress response to endo-tracheal intubation with perfusion index in patients undergoing elective surgery

Journal of Society of Surgeons of Nepal ◽

10.3126/jssn.v23i2.35797 ◽

2020 ◽

Vol 23 (2) ◽

pp. 9-13

Author(s):

Sushila Lama Moktan ◽

Manan Karki

Keyword(s):

Blood Pressure ◽

Heart Rate ◽

Stress Response ◽

Tracheal Intubation ◽

Endotracheal Tube ◽

Diastolic Blood Pressure ◽

Endotracheal Intubation ◽

Elective Surgery ◽

Perfusion Index ◽

Non Invasive

Introduction: Laryngoscopy and intubation is always associated with a short term reflex sympathetic pressor response. The perfusion index is an indirect, non-invasive, and continuous measure of peripheral perfusion by pulse oximeter which can detect the stress response to intubation similar to heart rate, systolic blood pressure and diastolic blood pressure. Methods: This prospective observational study enrolled sixty-five normotensive patients of American society of anesthesiologists physical status grade I and II scheduled for elective surgery under general anaesthesia. Tracheal intubation was performed after induction with intravenous fentanyl, propofol and vecuronium. Heart rate, Systolic and Diastolic Blood Pressure and Perfusion Index were measured before induction of anesthesia, before intubation and one minute, three minutes, five minutes after the insertion of the endotracheal tube. Increase in heart rate by ?10 beats per minute, systolic and diastolic blood pressure by ?15 millimeters of mercury and decrease in Perfusion index ?10% after endotracheal intubation as compared to preintubationvalue were considered positive haemodynamic changes. Results: Endotracheal intubation produced a significant increase in heart rate and blood pressure whereas perfusion index decreased significantly. Our study showed that perfusion index response criterion achieved 97.7% (Confidence interval 97.58-97.86) sensitivity in detecting the stress response to insertion of endotracheal tube whereas systolic and diastolic blood pressure achieved sensitivity of 90% and 92% respectively. Conclusion: Perfusion Index is easier, reliable and non-invasive alternative to conventional haemodynamic criteria for detection of stress response to endotracheal intubation.

Download Full-text

EFEK PREMEDIKASI MIDAZOLAM 0,05 MG/KGBB IV TERHADAP TEKANAN DARAH dan LAJU NADI

Jurnal e-Biomedik ◽

10.35790/ebm.1.1.2013.4621 ◽

2013 ◽

Vol 1 (1) ◽

Author(s):

Marlin Matana ◽

Mordekhai Laihad ◽

Harold Tambajong

Keyword(s):

Blood Pressure ◽

Heart Rate ◽

Pulse Rate ◽

Analytical Study ◽

Elective Surgery ◽

Sample Selection ◽

Significant Drop ◽

Before And After ◽

Test Result ◽

Midazolam Premedication

Abstrak: Operasi merupakan tindakan yang banyak menimbulkan kecemasan. Hal tersebut menyebabkan timbulnya respons stres, dengan akibat dapat terjadinya peningkatan tekanan darah dan laju nadi. Midazolam merupakan obat premedikasi yang mampu menurunkan tingkat kecemasan. Peningkatan tekanan darah dan laju nadi akibat stres psikologi sebelum menghadapi tindakan operasi, dapat mempengaruhi kondisi yang tidak menguntungkan. Tujuan: Untuk mengetahui perubahan tekanan darah dan laju nadi pada pasien setelah premedikasi Midazolam 0,05 mg/kgbb IV. Metode penelitian: Penelitian ini merupakan penelitian analitik prospektif. Sampel ialah 25 pasien yang menjalani bedah elektif. Cara pemilihan sampel dilakukan dengan accidental sampling. Uji statitik menggunakan uji t berpasangan. Hasil penelitian: Tekanan darah sistolik, diastolik, pada pasien sebelum dan sesudah premedikasi Midazolam menit ke lima dan sepuluh terdapat perbedaan yang bermakna (p <0,05), sedangkan laju nadi pasien sebelum premedikasi dan sesudah premedikasi menit ke lima dan sepuluh terdapat perbedaan yang tidak bermakna (p > 0,05). Simpulan: Pemberian premedikasi Midazolam 0,05 mg/kgbb IV, dapat memperlihatkan penurunan tingkat ansietas pasien yang dapat dilihat dari penuruan tekanan darah yang bermakna namun penuruan laju nadi tidak bermakna. Kata kunci: Midazolam 0,05 mg/kgbb iv, kecemasan, tekanan darah, laju nadi. Abstract: Surgery is the treatment measurement thet generated a lot of anxiety. This causes the onset of the stress response, with the result can be an increase blood pressure and heart rate. Midazolam premedication is a drug that can reduce the level of anxiety. The change in pulse rate and blood pressure to be high due psychological stress, before facing surgery can affect unfavorable conditions. Purpose: To know the change of blood pressure and heart rate to patient who take premedication Midazolam 0,05 mg/kgbb IV. Methods: This research is a prospective analytical study. The sample is 25 patients who have elective surgery. Sample selection method is done by accidental sampling. Statistic test using a paired t test. Result: Systolic and diastolic blood pressure were measured in patients before and after midazolam premedication and ten minutes to five, there is a significicant difference (p < 0,05 ), whereas the patien’s heart rate before and after premedication at minute five and ten there were no significant differences (p < 0,05 ) Conclution: By providing premedication Midazolam 0.05 mg/kg, may show decreased levels of anxiety patients that can be seen from the significant drop in blood pressure and pulse rate were not significant. Keyword: Midazolam 0,05 mg/kgbb iv, anxiety, blood pressure, heart rate.

Download Full-text