Objective To observe the effects of two different intranasal dexmedetomidine doses as premedication on the ECof sevoflurane for successful laryngeal mask airway placement in children. Methods Children aged 3-6 years, of American Society of Anesthesiologists physical status 1, and scheduled for plastic surgery were enrolled in this study. Children were assigned to receive either spray administration of intranasal dexmedetomidine 1 μg/kg (group D1, n=21) or 2 μg/kg (group D2, n=20) approximately 30 minutes before anesthesia. Anesthesia was induced with sevoflurane up to 8% in 100% O, with fresh gas flow set to 6 L/min. After the pupil fixed to the middle position, sevoflurane dial setting was reduced to 5% and fresh gas flow reduced to 3 L/min. The endtidal sevofluran (ET) concentration for laryngeal mask airway insertion sustained for 10 minutes after vein intubation, which was determined according to the Dixon's up and down method. The initial endtidal sevoflurane concentration in each group was set at 2%. ETwas increased/decreased (1:1.2) in the next patient according to the response to laryngeal mask airway insertion. Bispectral index, mask acceptance, all response to laryngeal mask airway insertion, and ETof laryngeal mask airway insertion of children were recorded. Results The bispectral index value was 77.4±3.6 in group D2, which was significantly lower than that (87.4±1.9) in group D1 when children entered operation room (P<0.05). Mask acceptance was 76.2% in group D1 and 90.0% in group D2. The ECof sevoflurane for laryngeal mask airway insertion was 1.09% (95% CI=0.89%-1.28%) in group D2, which was lower than 1.59% (95% CI=1.41%-1.78%) in group D1 (P<0.05). Conclusion Compared with the dose of 1 μg/kg, spray administration of intranasal dexmedetomidine 2 μg/kg as premedication can reduce the sevoflurane ECfor successful laryngeal mask airway placement in children.
Administration, Intranasal ; Anesthesia ; Anesthetics, Inhalation ; administration & dosage ; Child ; Child, Preschool ; Dexmedetomidine ; administration & dosage ; Humans ; Laryngeal Masks ; Methyl Ethers ; administration & dosage

BACKGROUND: The Vital capacity technique is known to have some advantages over the tidal volume technique during inhalation induction of anesthesia.The aim of this study was to compare the incidence of withdrawal movement associated with the intravenous administration of rocuronium 0.3 mg/kg in children during inhalation induction with sevoflurane using the tidal volume and vital capacity techniques. METHODS: We randomly assigned 130 patients (aged 5-12 years) to either tidal volume (group T) or vital capacity (group V) groups for inhalation induction with sevoflurane.Rocuronium 0.3 mg/kg was administrated after loss of the eyelash reflex.The time to loss of the eyelash reflex was recorded and adverse events during induction were documented.The patient's response to rocuronium injection was graded using a four-point scale. RESULTS: No significant differences were observed between the groups with respect to age, weight, and gender.The time to loss of the eyelash reflex was more rapid in group V than in group T (P < 0.05).Excitatory movement developed more frequently in group T, and no significant differences were found in the incidence of other adverse events between the groups.The incidence of withdrawal movement associated with the injection of rocuronium was significantly lower in group V compared to group T (30 vs. 60%; P < 0.05). CONCLUSIONS: Inhalation induction with sevoflurane using the vital capacity technique decreased the incidence of withdrawal movement during the injection of rocuronium compared to the tidal volume technique.
Administration, Intravenous ; Androstanols ; Child ; Humans ; Incidence ; Inhalation ; Methyl Ethers ; Reflex ; Tidal Volume ; Vital Capacity

INTRODUCTIONDraw-over anaesthesia remains an attractive option for conduct of anaesthesia in austere conditions. The Diamedica Draw-over Vaporiser (DDV) is a modern draw-over vaporiser and has separate models for isoflurane/halothane and sevoflurane.

MATERIALS AND METHODSA laboratory study was done to measure sevoflurane output in an isoflurane/ halothane DDV. We did 3 series of experiments with the isoflurane/halothane DDV. We measured anaesthetic agent output in both push-over and draw-over setups, and at minute ventilation of 6 L/min and 3 L/min. Series 1 experiment was done with isoflurane in the DDV at ambient temperature of 20°C. Series 2 experiment was done with sevoflurane in the DDV at ambient temperature of 20°C. Series 3 experiment was done with sevoflurane in the DDV and with the DDV placed in a water bath of 40°C.

RESULTSThe sevoflurane output was found to be two-thirds of the isoflurane/ halothane DDV dial setting at ambient temperature of 20°C. With the DDV in a 40°C water bath, the sevoflurane output was found to be about the isoflurane/ halothane DDV dial settings.

CONCLUSIONIn our experiment, we show that it is possible to use sevoflurane in an isoflurane/halothane DDV.

Anesthesia, Inhalation ; instrumentation ; methods ; Anesthetics, Inhalation ; administration & dosage ; Halothane ; Humans ; Isoflurane ; Methyl Ethers ; administration & dosage ; Nebulizers and Vaporizers ; Temperature

BACKGROUNDMyocardial infarction is an important cause of mortality after carotid endarterectomy (CEA). Sevoflurane provides myocardial protection to patients undergoing coronary surgery, but whether it also reduces the incidence of myocardial injury in CEA patients is unclear. In this study, we evaluated the cardioprotective effect of low-dose sevoflurane with propofol in patients undergoing CEA.

METHODSThis was a single-center, prospective, randomized study conducted between November 2011 and December 2013. The study population of 122 patients who underwent CEA were randomly assigned to two groups. Group A (n = 62) received propofol for anesthetic maintenance, and Group B (n = 60) additionally received 0.8% end-tidal sevoflurane. The bispectral index was kept at 40-60. Myocardial injury, defined as cardiac troponin I (cTnI) levels >0.04 ng/ml, was the primary end-point. Levels of cTnI were measured before anesthesia, and at 4, 24, and 72 h after surgery. Perioperative hemodynamic parameters and adverse cardiovascular events after surgery were also recorded.

RESULTSMyocardial injury was detected in 18 patients in Group A and 7 in Group B. The difference was statistically significant (29.0% vs. 11.7%, P = 0.018). The hemodynamic parameters were comparable between the groups, as were adverse cardiovascular events (P = 0.619).

CONCLUSIONSLow-dose sevoflurane inhalation along with propofol reduces the incidence of myocardial injury in symptomatic patients after CEA.

Aged ; Drug Administration Schedule ; Endarterectomy, Carotid ; methods ; Female ; Humans ; Male ; Methyl Ethers ; administration & dosage ; therapeutic use ; Middle Aged ; Myocardium ; metabolism ; Propofol ; administration & dosage ; therapeutic use ; Troponin I ; metabolism

OBJECTIVETo study the feasibility of using Narcotrend (NCT) in monitoring the anesthetic depth during endotracheal intubation in sevoflurane anesthesia.

METHODSThirty ASA I-II patients (aged 20-49 years) undergoing gynecologic surgery under general anesthesia with tracheal intubation were randomized into sevoflurane group (n=15) and sevoflurane plus rocuronium group (n=15). In the former group, anesthesia was induced with sevoflurane at the primary concentration of 8% till the final end expiratory concentration reaching 2 MAC(minimum alveolar concentration) for 3 min, followed then by tracheal intubation and further observation of the indicators for another 3 min. The patients in sevoflurane plus rocuronium group received identical anesthesia procedures except for the administration of intravenous injection of rocuronium (0.6 mg/kg) after the loss of eyelash reflex. The NCT, BIS and hemodynamics were recorded during the process.

RESULTSNo significant differences were noted in NCT, bispectral index (BIS), MAP and heart rate before tracheal intubation between the two groups (P>0.05). The NCT and BIS increased significantly after tracheal intubation in sevoflurane group (P<0.05), but remained below 60. No significant changes in NCT and BIS occurred during intubation in sevoflurane plus rocuronium group (P>0.05). The mean arterial pressure (MAP) and heart rate were significantly increased in both groups after tracheal intubation in comparison with those before tracheal intubation (P<0.05), but the increment in sevoflurane group was significantly greater (P<0.05).

CONCLUSIONNCT may reflect the changes of the anesthetic depth resulting from the nociceptive stimulus of tracheal intubation in sevoflurane- induced anesthesia. NCT and BIS can not serve such a purpose in combined anesthesia with sevoflurane and rocuronium.

Adult ; Androstanols ; administration & dosage ; Anesthesia ; Anesthetics, Intravenous ; administration & dosage ; Hemodynamics ; Humans ; Intubation, Intratracheal ; methods ; Methyl Ethers ; administration & dosage ; Middle Aged ; Monitoring, Intraoperative ; methods ; Young Adult

OBJECTIVETo determine the minimum alveolar concentration (EC(50) and EC(95)) of sevoflurane in body movement response to surgical incision during combined anesthesia with dexmedetomidine, sevoflurane and fentanyl.

METHODSTwenty-six ASA class I or II patients (aged 18-60 years) underwent selective surgery for lumbar disc herniation under general anesthesia with the combination of with dexmedetomidine, sevoflurane and fentanyl. All the patients received infusion with 0.5 mg/kg dexmedetomidine for 10 min before anesthesia induction with intravenous injection of 3 µg/kg fentanyl 8% sevoflurane inhalation. Upon loss of consciousness, sevoflurane concentration was reduced to 5% with intravenous injection of 1-2 mg/kg succinylcholine, and intubation was started after muscles relaxation. Anesthesia was maintained by sevoflurane and dexmedetomidine (0.2 µg·kg(-1)·h(-1)). Before the surgery, a steady state end-tidal sevoflurane concentration was maintained for at least 10 min. The first patient of the series was tested with 1.5% sevoflurane, and the concentration was adjusted according to modified Dixons up-and-down method (with a step size of 0.2%). Probit analysis was used for calculating EC(50), EC(95) and the 95% confidence interval (CI).

RESULTSThe EC(50) of sevoflurane was 0.94% (95%CI of 0.76%-1.07% ) and EC(95) was 1.23% (95%CI 1.09%-2.05% ).

CONCLUSIONThe EC(50) and EC(95) of sevoflurane are 0.94% and 1.23%, respectively, for suppressing body movement in response to surgical incision during combined anesthesia with sevoflurane, dexmedetomidine and fentanyl.

Adolescent ; Adult ; Anesthesia ; methods ; Anesthetics ; administration & dosage ; Dexmedetomidine ; administration & dosage ; Female ; Fentanyl ; administration & dosage ; Humans ; Male ; Methyl Ethers ; pharmacokinetics ; Middle Aged ; Pulmonary Alveoli ; metabolism ; Reference Values ; Young Adult

OBJECTIVETo observe the clinical effectiveness of inductions and tracheal intubating conditions with 3% sevoflurane and different doses of remifentanil without muscle relaxant in children.

METHODSTotally 120 peadiatric patients (aged 4-10 years, American Society of Anesthesiologists grade I for inhalational induction) were randomly allocated into group I (remifentanil 1 microg/kg), group II (remifentanil 2 microg/kg), group III (remifentanil 3 microg/kg), and control group (vecuronium bromide 0.1 mg/kg). After inhalational induction with 3% sevoflurane and 60% nitrous oxide in 40% oxygen for 2 minutes, remifentanil 1 microg/kg, 2 microg/ kg, and 3 microg/kg were intravenously injected over 1 minute into patients in group I , group II, and group III, respectively. After remifentanil administration and manual ventilation for 1 minute, the trachea was intubated. In the control group, 2 minutes after intravenous administration of vecuronium bromide 0.1 mg/kg, tracheal intubation was attempted. Agitation, intubating satisfactoriness, and the circulation changes after tracheal intubation and anesthesia induction were observed.

RESULTSIn these four groups, agitation occurred in 37.5% of patients during sevoflurane induction. Satisfactory intubation rate was 70.0% in group I, 86.7% in group II, 90.0% in group III, and 93.3% in the control group. Compared with the control group, the impact of tracheal intubation on the circulatory system was smaller in group I , II , and III.

CONCLUSIONSInduction with 3% sevoflurane combined with remifentanil can be smoothly performed, followed by the successful tracheal intubation. The intubating conditions are more satisfactory with 3% sevoflurane combined with remifentanil 2 microg/kg or 3 microg/kg.

Anesthesia, Inhalation ; Anesthetics, Inhalation ; administration & dosage ; Child ; Child, Preschool ; Dose-Response Relationship, Drug ; Female ; Humans ; Intubation, Intratracheal ; adverse effects ; Male ; Methyl Ethers ; administration & dosage ; Piperidines ; administration & dosage

OBJECTIVE: To observe the effect of sevoflurane on the induction and maintenance of anaesthesia in children, and to evaluate its safety and effectiveness. METHODS: Forty child patients who conformed to the selection standard were operated under anaesthesia with intubation.Without premedicant, all the patients inhaled 100% oxygen(1L/min) and sevoflurane by mask, and escalated the concentration of sevoflurane (to the maximum concentration 7%) until the lash reflex disappeared, and the maintenance concentration was controlled under 4%. All the patients were intubated, together with vecuronium 0.1mg/kg. RESULTS: With little tract excretion, the achievement ratio of induction by sevoflurane was 100%, and the children tolerated well. With stable hemodynajmics,1% approximately 4.0% maintenance concentration of sevoflurane during the operation showed effective anaesthesia, no decreased heart rate or blood pressure appeared, and all the patients' body temperature was normal. CONCLUSION Sevoflurane for children induction can bring fewer stimuli in the respiratory tract,less cardiac vascular inhibition and palinesthesia time. Anaesthesia in children induced by sevoflurane is safe and effective.
Anesthesia ; methods ; Anesthesia, Inhalation ; Anesthetics, Inhalation ; administration & dosage ; Child ; Child, Preschool ; Female ; Humans ; Male ; Methyl Ethers ; administration & dosage ; Sevoflurane ; Treatment Outcome

BACKGROUND: The chemical reaction of carbon dioxide absorbent and sevoflurane is known to produce compound A. However, carbon dioxide absorbents are not controlled by the Food and Drug Administration, but are treated as industrial products in some nations. Moreover, carbon dioxide absorbents differ in their capacities to produce compound A, because their chemical compositions differ. In this study, we compared the renal safety between carbon dioxide absorbent products in patients under sevoflurane anesthesia. METHODS: Eighty patients with no preexisting renal disease undergoing elective gynecologic surgery were randomly assigned to receive sevoflurane or isoflurane anesthesia with one of four carbon dioxide absorbent products (Sodasorblime(R), Sodalyme(R), Sodasorb(R), Spherasorb(R)) at the same fresh gas flow of 2 L/min. The renal safety was evaluated by changes of blood urea nitrogen (BUN), creatinine and urine N-acetyl-b-glucoseaminidase (NAG)-creatinine ratio at 24 hours and 72 hours after surgery from preoperative level. RESULTS: There was no significant difference in the renal safety indicators between carbon dioxide absorbents during sevoflurane anesthesia (P > 0.05). However, the BUN and urine NAG-creatinine ratios at 72 hours after surgery were higher in isoflurane anesthesia in some carbon dioxide absorbent groups (P = 0.03 and 0.04, respectively). CONCLUSIONS: We could not find significant differences of renal safety indicators with carbon dioxide absorbents. Although the adverse effect of carbon dioxide absorbents on renal function was not proved, consideration should be given to their contol by the regulation on their efficacy and safety because carbon dioxide absorbents can produce compound A.
Anesthesia ; Anesthetics ; Blood Urea Nitrogen ; Carbon ; Carbon Dioxide ; Creatinine ; Female ; Gynecologic Surgical Procedures ; Humans ; Inhalation ; Isoflurane ; Kidney ; Methyl Ethers ; Pilot Projects ; United States Food and Drug Administration

Background:Patients with potential difficult mask ventilation (DV) and difficult intubation (DI) are often managed with awake intubation, which can be stressful for patients and anesthesiologists. This prospective randomized study evaluated a new approach, fast difficult airway evaluation (FDAE). We hypothesized that the FDAE approach would reduce the need for awake intubation.

Methods:After obtaining informed consent, 302 patients with potential DV/DI undergoing elective surgeries were randomly assigned to the FDAE group (Group E) and the control group (Group C). In Group E, patients were gradually sedated, and adequacy of manual mask ventilation during spontaneous breathing was assessed at various sedation levels. Awake intubation was applied in those with inadequate mask ventilation. In Group C, DI was evaluated under local anesthesia. However, the care team could intubate under general anesthesia if the vocal cords were visible. The primary outcome was the rate of awake intubations in both groups and the induction efficiency assessed by the induction time. The secondary outcome was the incidence of serious complications.

ResultsThe rate of awake intubation was significantly lower in Group E than that in Group C (5.81% vs. 36.05%, χ = 42.3, P < 0.001). The induction time was much shorter in Group E than in Group C (11.85 ± 4.82 min vs. 18.71 ± 7.85 min, t = 5.39, P < 0.001). There was no significant difference in the incidence of intubation related complications between the two groups. Patients in Group E had a much lower incidence of recall (9.68% vs. 44.90%, χ = 47.68, P < 0.001) of the induction process and higher satisfaction levels than patients in Group C (t = 15.36, P < 0.001).

ConclusionsThe FDAE significantly reduces the need for awake intubation and improves the efficiency of the intubation process without comprising safety in patients with potential difficult mask ventilation and DI.

Trial Registration:No. ChiCTR-TRC-11001418; http://www.gctr.org/cn/proj/show.aspx?proj=1562.

Adult ; Airway Management ; Female ; Humans ; Intubation, Intratracheal ; methods ; Laryngeal Masks ; Male ; Methyl Ethers ; administration & dosage ; Middle Aged ; Prospective Studies ; Sevoflurane ; Wakefulness