Effects of Pharmacological Intervention on Recovery After Sevoflurane Anesthesia in Children: a Network Meta-analysis of Randomized Controlled Trials.

Sevoflurane, commonly administered to children as anesthesia, often leads to emergence delirium (ED). Currently, a consensus is lacking among clinicians regarding pharmacological interventions to improve recovery. To determine an effective approach, we compared the effects of several drugs in lowering the incidence of ED after sevoflurane anesthesia in children.We searched online databases for relevant randomized controlled trials (59 studies selected; 5199 NMA-eligible participants) and performed a frequentist network meta-analysis (NMA). This study was registered on PROSPERO (number CRD: 42022329939).All included studies had a low to moderate risk of overall bias. The incidence of ED after sevoflurane anesthesia in children differed according to other drugs administered, and were ranked from high to low according to the surface under the cumulative ranking curve (SUCRA).Sufentanil (91.2%) and dexmedetomidine (77.6%) were more likely to reduce the incidence (SUCRA value) of ED, whereas the placebo (6.5%), ramelteon (11.1%), and magnesium (18%) were less likely to reduce the incidence of ED. Remifentanil (89.3%) ranked first in shortening emergence time, followed by placebo (82.4%) and ketamine (69.7%). Placebo shortened extubation time, followed by remifentanil (66.5%) and alfentanil (61.4%).Sufentanil and remifentanil lowered sevoflurane-induced ED incidences among children and shortened the emergence time more effectively than other drugs. Most adjuvant drugs that are combined with sevoflurane either do not change or may even prolong extubation time. Further research and clinical trials are required to support and update these conclusions.

Syringe or mask? Loop electrosurgical excision procedure under local or general anesthesia: a randomized trial.

BACKGROUND: Loop electrosurgical excision procedure may be performed under local anesthesia or general anesthesia, and practice patterns differ worldwide. No randomized head-to-head comparison has been published to confirm or refute either practice. OBJECTIVE: This study aimed to compare loop electrosurgical excision procedure under local anesthesia vs general anesthesia regarding patient satisfaction and procedure-related outcomes such as rates of involved margins, complications, pain, and blood loss. STUDY DESIGN: Consecutive women referred to our colposcopy unit were recruited. Loop electrosurgical excision procedure was performed under local anesthesia with 4 intracervical injections of bupivacaine hydrochloride 0.5% or under general anesthesia with fentanyl, propofol, and a laryngeal mask with sevoflurane maintenance. The primary endpoint was patient satisfaction assessed on the day of surgery and 14 days thereafter using a Likert scale (score 0-100) and a questionnaire. Secondary endpoints included rates of involved margins, procedure-related complications, pain, blood loss, and surgeon preference. Results were compared using nonparametric and chi-square tests. RESULTS: Between July 2018 and February 2020, we randomized 208 women, 108 in the local anesthesia arm and 100 in the general anesthesia arm. In the intention-to-treat analysis, patient satisfaction did not differ between the study groups directly after surgery (Likert scale 100 [90-100] vs 100 [90-100]; P=.077) and 14 days thereafter (Likert scale 100 [80-100] vs 100 [90-100]; P=.079). In the per-protocol analysis, women in the local anesthesia arm had significantly smaller cone volumes (1.11 cm3 [0.70-1.83] vs 1.58 cm3 [1.08-2.69], respectively; P<.001), less intraoperative blood loss (Δhemoglobin, 0.2 g/dL [-0.1 to 0.4] vs 0.5 g/dL [0.2-0.9]; P<.001), and higher satisfaction after 14 days (100 [90-100] vs 100 [80-100]; P=.026), whereas surgeon preference favored general anesthesia (90 [79-100] vs 100 [90-100], respectively; P=.001). All other secondary outcomes did not differ between groups (resection margin status R1, 6.6% vs 2.1% [P=.26]; cone fragmentation, 12.1% vs 6.3% [P=.27]; procedure duration, 151.5 seconds [120-219.5] vs 180 seconds [117-241.5] [P=.34]; time to complete hemostasis, 60 seconds [34-97] vs 70 seconds [48.25-122.25] [P=.08]; complication rate, 3.3% vs 1.1% [P=.59]). In a multivariate analysis, parity (P=.03), type of transformation zone (P=.03), and cone volume (P=.02) and not study group assignment, age, body mass index, and degree of dysplasia independently influenced the primary endpoint. CONCLUSION: Loop electrosurgical excision procedure under local anesthesia is equally well tolerated and offers patient-reported and procedure-related benefits over general anesthesia, supporting the preferred practice in some institutions and refuting the preferred practice in others.

Severe hyperhomocysteinemia and peripheral neuropathy as side effects of nitrous oxide in two patients with sickle cell disease.

Nitrous oxide (N2O) is a widely used anesthetic agent. We report two patients with sickle cell disease (SCD) who presented with complications following the use of N2O. Patient 1, a 15-year-old girl, presented severe hyperhomocysteinemia, pancytopenia, vitamin B12 deficiency, and peripheral polyneuropathy after massive use of N2O for pain management. At the 1-year follow-up, hyperhomocysteinemia and B12 deficiency had resolved, but she had persisting mild symptoms of polyneuropathy. Patient 2, a 17-year-old boy, presented only severe hyperhomocysteinemia, only partially corrected by initial B12 supplementation. Careful monitoring of N2O use, especially in patients with SCD, is mandatory to prevent complications.

An unusual cause of falls in a young woman.

Nitrous oxide is commonly used as an analgesic and anaesthetic agent. Nitrous oxide is also in use in industry as an aerosol propellant and is now recognised as a recreational drug whose use is growing, especially among the young. Nitrous oxide from whipped cream canisters is inhaled to produce a dissociative, intoxicated state. Nitrous oxide is known to inactivate vitamin B12 via oxidation, which can precipitate a demyelinating myelopathy akin to the classical B12 deficiency syndrome, subacute combined degeneration of the spinal cord. This case describes a young woman with chronic pain and a poor nutritional state who took regular nitrous oxide as an opiate-sparing agent. She developed a progressive subacute myelopathy with a sensory level, profoundly impaired joint position sense, extensor plantars and required a wheelchair. Once diagnosed, she responded well to a regime of nitrous oxide withdrawal, high-dose B12 replacement and physiotherapy. The case illustrates the need for clinical teams to be able to dentify a nitrous oxide-precipitated myelopathy as its use as a drug of abuse increases; particularly in the case of malnourished patients who receive nitrous oxide surgically or obstetrically.

Fall in inspired oxygen and anaesthetic agent concentrations during change of soda lime absorber.

Following an episode of reduction in inspired oxygen concentration (FiO(2)) and inhalational agent concentration (Fi agent) during the changing of a soda lime absorber, We conducted an in vitro experiment to understand the impact of disconnection of the absorber on inspired gas dilution at different fresh gas flows. We found that both in Dräger Fabius GS and Primus anaesthesia work stations, disconnection of the absorber caused progressive reduction in FiO(2) and Fi agent as the FGF was decreased. The operating principle of fresh gas decoupling (FGD) valve is a potential source of this complication, which must be kept in mind while changing the soda lime during the course of surgery where an anaesthetic work stations utilizing FGD valves are used.

Early treatment with xenon protects against the cold ischemia associated with chronic allograft nephropathy in rats.

Chronic allograft nephropathy (CAN) is a common finding in kidney grafts with functional impairment. Prolonged hypothermic storage-induced ischemia-reperfusion injury is associated with the early onset of CAN. As the noble gas xenon is clinically used as an anesthetic and has renoprotective properties in a rodent model of ischemia-reperfusion injury, we studied whether early treatment with xenon could attenuate CAN associated with prolonged hypothermic storage. Exposure to xenon enhanced the expression of insulin growth factor-1 (IGF-1) and its receptor in human proximal tubular (HK-2) cells, which, in turn, increased cell proliferation. Xenon treatment before or after hypothermia-hypoxia decreased cell apoptosis and cell inflammation after reoxygenation. The xenon-induced HK-2 cell proliferation was abolished by blocking the IGF-1 receptor, mTOR, and HIF-1α individually. In the Fischer-to-Lewis rat allogeneic renal transplantation model, xenon exposure of donors before graft retrieval or recipients after engraftment enhanced tubular cell proliferation and decreased tubular cell death and cell inflammation associated with ischemia-reperfusion injury. Compared with control allografts, xenon treatment significantly suppressed T-cell infiltration and fibrosis, prevented the development of CAN, and improved renal function. Thus, xenon treatment promoted recovery from ischemia-reperfusion injury and reduced susceptibility to the subsequent development of CAN in allografts.

The effect of preoperative consumption of potatoes on succinylcholine-induced block and recovery from anesthesia.

Potatoes contain solanaceous glycoalkaloids (SGAs), which inhibit both butyrylcholinesterase (BuChE) and acetylcholinesterase (AChE). The present study investigated the effect of preoperative consumption of potatoes on succinylcholine-induced block and recovery from anesthesia. ASA I-II, adult patients, scheduled for elective surgery, were included in a randomized, blind and controlled study. Patients were randomly divided into two groups. Patients in Group P (n = 21) ate a standard portion of potatoes in their last meal prior to pre-operative fasting, while patients in Group C (n = 23) ate food not containing SGAs. Patients were premedicated with midazolam. Anesthesia was induced with thiopental and fentanyl, and maintained with sevoflurane in 50 % O2/air and fentanyl, as needed. Succinylcholine 1 mg kg(-1) was administered to facilitate endotracheal intubation. Duration of succinylcholine blockade, awakening and recovery times from anesthesia were measured. Serum BuChE levels were also measured at baseline and 4 time-points within 24 h post-consumption. Duration of succinylcholine-induced neuromuscular block, awakening and recovery time from anesthesia was significantly longer in Group P than in Group C (p < 0.05). Serum BuChE levels decreased at 6 h after consumption start in Group P. In addition, in both groups, BuChE levels markedly decreased after succinylcholine blockade, increased thereafter, but did not return to baseline within 24 h of consumption start. None of these differences observed in BuChE levels was statistically significant. This study suggests that potatoes eaten before anesthesia can prolong the duration of succinylcholine-induced neuromuscular block and delay recovery from anesthesia.

The effects of anesthetic regimen in 90% hepatectomy in rats.

PURPOSE: To evaluate the influence of the anesthetic regimen on anesthetic recovery, survival, and blood glucose levels following a 90% partial hepatectomy in rats. METHODS: Thirty adult male Wistar rats were divided into two groups according to their anesthetic regimens: intraperitoneal ketamine and xylazine or inhaled isoflurane. In order to prevent hypoglycemia, glucose was administered intraperitoneally and glucose (20%) was added to the drinking water. RESULTS: Anesthetic recovery time was longer in the ketamine and xylazine group. The survival rate after 72 hours was lower (log rank=0.0001) in the ketamine and xylazine group (0.0%) than in the isoflurane group (26.7%). The blood glucose after six hours was lower (p=0.017) in the ketamine and xylazine group (63 ± 31.7 mg/dL) than in the isoflurane group (98 ± 21.2 mg/dL). The prolonged anesthesia recovery time associated with ketamine and xylazine decreased the survival rate and blood glucose levels after 90% hepatectomy. CONCLUSION: Isoflurane anesthesia reduced the recovery time and incidence of hypoglycemia and increased the survival rate in the early hours, providing a therapeutic window that is suitable for experimental studies.

The effects of anesthetic regimen in 90% hepatectomy in rats / Os efeitos do regime anestésico na hepatectomia de 90% em ratos

PURPOSE: To evaluate the influence of the anesthetic regimen on anesthetic recovery, survival, and blood glucose levels following a 90% partial hepatectomy in rats. METHODS: Thirty adult male Wistar rats were divided into two groups according to their anesthetic regimens: intraperitoneal ketamine and xylazine or inhaled isoflurane. In order to prevent hypoglycemia, glucose was administered intraperitoneally and glucose (20%) was added to the drinking water. RESULTS: Anesthetic recovery time was longer in the ketamine and xylazine group. The survival rate after 72 hours was lower (log rank=0.0001) in the ketamine and xylazine group (0.0%) than in the isoflurane group (26.7%). The blood glucose after six hours was lower (p=0.017) in the ketamine and xylazine group (63±31.7 mg/dL) than in the isoflurane group (98±21.2 mg/dL). The prolonged anesthesia recovery time associated with ketamine and xylazine decreased the survival rate and blood glucose levels after 90% hepatectomy. CONCLUSION: Isoflurane anesthesia reduced the recovery time and incidence of hypoglycemia and increased the survival rate in the early hours, providing a therapeutic window that is suitable for experimental studies.

OBJETIVO: Avaliar a influência do regime anestésico sobre a recuperação anestésica, a sobrevida em 72 horas e a glicemia após hepatectomia parcial de 90% em ratos. MÉTODOS: Trinta ratos Wistar machos adultos foram distribuídos em dois grupos conforme o regime anestésico: combinação de ketamina e xilazina intraperitoneal ou isoflurano inalatório. Para prevenção de hipoglicemia foi administrada glicose intraperitoneal e adicionado glicose (20%) na água de beber. RESULTADOS: A recuperação anestésica no grupo ketamina e xilazina foi mais prolongada. Durante primeira hora após hepatectomia, nenhum rato anestesiado com ketamina e xilazina despertou. Todos do grupo isoflurano estavam ativos minutos após final da cirurgia. A sobrevida em 72 horas foi menor (Log rank=0,0001) no grupo ketamina e xilazina (0,0%) que no grupo isoflurano (26,7%). Glicemia em 6 horas do grupo ketamina e xilazina (63±31,7 mg/dL) foi menor (p=0,017) que no grupo isoflurano (98 ±21,2 mg/dL). Prolongado tempo de recuperação anestésica com ketamina e xilazina diminuiu sobrevida e glicemia após hepatectomia 90%. CONCLUSÃO: Anestesia com isoflurano reduziu tempo de recuperação e hipoglicemia, além de aumentar a sobrevida nas primeiras horas, possibilitando uma janela terapêutica adequada para estudos experimentais.

Improved sedation for dental extraction by using video eyewear in conjunction with nitrous oxide: a randomized, controlled, cross-over clinical trial.

OBJECTIVE: The purpose of this study was to investigate the effect of a portable video eyewear entertainment system used in conjunction with nitrous oxide/oxygen sedation during the removal of impacted lower third molars. STUDY DESIGN: Thirty-eight patients had their bilateral third molars removed under local anesthesia and nitrous oxide/oxygen inhalation sedation in 2 visits. On one side, video eyewear was used (group NE). On the other side, the tooth was removed without the use of video eyewear (group N). Vital signs were monitored. Overall behavior and the outcome of treatment were assessed. RESULTS: All 38 patients completed the study. The mean scores on behavior rating in group NE were significantly higher than those in group N (P < .05). The majority of patients (92.1%) preferred nitrous oxide with video eyewear. CONCLUSIONS: The use of video eyewear appeared to augment the effectiveness of nitrous oxide sedation in dental extraction patients.

[Concept of mechanisms of anesthetic and therapeutic properties of xenon].

The molecular theory of L. Poling is a genius example of scientific prediction, made in the middle of 20th century, when the studies about clathrates and methods of roentgen structured analysis were doing their first steps. The views expressed in this message are some additions on the structure of xenon clathrates, function-free xenon water associates and the use of cameras in the liberated associates of the water molecules, for the process of supramolecular detoxification and attempts to develop this theory more widely, to better understand the mechanisms of xenon anesthesia and treatment for further justification of its therapeutic features as well as for the use of other inert gases (Ar, Kr) in modern medicine.

Synergy of isoflurane preconditioning and propofol postconditioning reduces myocardial reperfusion injury in patients.

Either isoflurane preconditioning or high-dose propofol treatment has been shown to attenuate myocardial IRI (ischaemia/reperfusion injury) in patients undergoing CABG (coronary artery bypass graft) surgery. It is unknown whether isoflurane and propofol may synergistically attenuate myocardial injury in patients. The present study investigated the efficacy of IsoPC (isoflurane preconditioning), propofol treatment (postconditioning) and their synergy in attenuating postischaemic myocardial injury in patients undergoing CABG surgery using CPB (cardiopulmonary bypass). Patients (n = 120) selected for CABG surgery were randomly assigned to one of four groups (n = 30 each). After induction, anaesthesia was maintained either with fentanyl and midazolam (control; group C); with propofol at 100 µg x kg(-1) of body weight x min(-1) before and during CPB followed by propofol at 60 µg x kg(-1) of body weight x min(-1) for 15 min after aortic declamping (group P); with isoflurane 1-1.5% end tidal throughout the surgery (group I) or with isoflurane 1-1.5% end tidal before CPB and switching to propofol at 100 µg x kg(-1) of body weight x min(-1) during CPB followed by propofol at 60 µg x kg(-1) of body weight x min(-1) for 15 min after aortic declamping (group IP, i.e. IsoPC plus propofol postconditioning). A joint isoflurane and propofol anaesthesia regimen synergistically reduced plasma levels of cTnI (cardiac troponin I) and CK-MB (creatine kinase MB) and f-FABP (heart-type fatty acid-binding protein) (all P < 0.05 compared with control, group P or group I) and facilitated postoperative myocardial functional recovery. During reperfusion, myocardial tissue eNOS (endothelial NO synthase) protein expression in group IP was significantly higher, whereas nitrotyrosine protein expression was lower than those in the control group. In conclusion, a joint isoflurane preconditioning and propofol anaesthesia regimen synergistically attenuated myocardial reperfusion injury in patients.

Functional comparison of anaesthetic agents during myocardial ischaemia-reperfusion using pressure-volume loops.

BACKGROUND: Left ventricular (LV) pressure-volume (PV) loops were used to compare the functional effects that accompany the cardioprotection seen with desflurane, sevoflurane, and propofol in a rabbit preparation of coronary ischaemia-reperfusion (IR). METHODS: Male New Zealand White rabbits (n=48) were anaesthetized with propofol (70 mg kg(-1) h(-1)), desflurane (8.9%), or sevoflurane (3.8%) and randomized to receive IR or non-ischaemic time-matched (TC) perfusion protocol. IR groups (desIR, propIR, and sevIR) underwent 30 min of left anterior descending coronary artery occlusion and then 120 min of reperfusion. TC groups (desTC, propTC, and sevTC) were anaesthetized for 150 min without ischaemia. Haemodynamic endpoints included mean arterial pressure, heart rate, cardiac index, systemic vascular resistance index, preload-recruitable stroke-work, time constant of relaxation (tau), and end-diastolic PV relationship (EDPVR). Ventricles in the IR groups were excised and stained with 2,3,5-triphenyl-tetrazolium chloride in order to measure infarct size. RESULTS: Myocardial infarction size was greater in the propIR group [35.74 (sd 11.32)%] compared with the desIR [13.44 (3.09)%] and sevIR [17.96 (6.63)%] groups (P<0.001). EDPVR deteriorated in the sevIR and propIR groups compared with their TC groups, sevTC (P=0.03) and propTC (P=0.044), respectively. There was no difference in any haemodynamic endpoints for the desIR group compared with its TC control (desTC). CONCLUSIONS: During ischaemia, all anaesthetics provide haemodynamic stability and preservation of LV contractility, whereas propofol and sevoflurane, but not desflurane, caused increased LV diastolic stiffness. Desflurane and sevoflurane provide superior cardioprotection compared with propofol.

Sevoflurane post-conditioning protects against myocardial reperfusion injury by activation of phosphatidylinositol-3-kinase signal transduction.

The mechanisms underlying myocardial protection by sevoflurane post-conditioning are unclear. In the present study, we tested two hypotheses: (i) that sevoflurane post-conditioning produces cardioprotection via a phosphatidylinositol-3-kinase (PI3-K)-dependent pathway; and (ii) combining sevoflurane and ischaemic post-conditioning offers an additional benefit against reperfusion injury. Rat isolated perfused hearts were exposed to 25 min ischaemia followed by 90 min reperfusion. Sevoflurane post-conditioning was induced by administration of sevoflurane (3.0 vol%) for 15 min from the onset of reperfusion. In some groups, 15 micromol/L LY294002, a selective PI3-K inhibitor, was coadministrated with sevoflurane. Other groups of hearts were exposed to ischaemic post-conditioning or combined sevoflurane plus ischaemic post-conditioning in the presence and absence of LY294002. After 15 min reperfusion, phosphorylation of Akt and glycogen synthase kinase 3beta (GSK3beta) was determined by Western blot analysis. Infarct size was determined by 2,3,5-triphenyltetrazolium chloride staining and subsarcolemmal mitochondrial lesions were assessed by electron microscopy after 90 min reperfusion. Sevoflurane post-conditioning significantly decreased infarct size compared with control hearts (31 +/- 2 vs 42 +/- 3%, respectively; P < 0.05), diminished mitochondrial lesions and increased phosphorylation of Akt and GSK3beta, as did ischaemic post-conditioning. However, combined sevoflurane plus ischaemic post-conditioning did not further improve the cardioprotective effects compared with either intervention alone. Sevoflurane-mediated cardioprotection was abolished or inhibited by 15 micromol/L LY294002. In conclusion, sevoflurane acts during early reperfusion after ischaemia to salvage the myocardium by activating PI3-K. The combination of sevoflurane plus ischaemic post-conditioning does not offer any additional benefit over either intervention alone.

Is nitrous oxide necessary for general anaesthesia?

BACKGROUND: Nitrous oxide (N2O) has been used for about 150 years in clinical anaesthesia. Several recent reviews of the effect of nitrous oxide have concluded that there are certain contraindications to the use of this gas for general anaesthesia and its ecological effects, ozone depleting potential, immune depression and the proven factor of PONV have questioned the routine use of nitrous oxide in patients undergoing surgical procedures in general anaesthesia. METHODS: This study comprised of 200 adult patients undergoing general anaesthesia with 40% O2 and Sevoflurane with and without N2O. All patients had standard anaesthetic care and monitoring with BIS monitoring in 120 patients. The effect of avoiding N2O was observed on anaesthetic perioperative management and haemodynamics, PONV and pain in PACU. RESULTS: Demographic and perioperative characteristics were similar to both groups. Nitrous oxide free group needed only 0.233% (mean) more Sevoflurane. There was a marked reduction in incidence of PONV (11% to 5%) in N2O free group. Duration of surgery (97.72 +/- 52.393 in N2O group, 103.75 +/- 48.671 in N2O free group) and induction dose of propofol (155.30 +/-38.572 in N2O group and 158.50 +/- 36.164 in N2O free group) did not differ significantly in the two groups. CONCLUSION: The omitting of N2O from anaesthetic regimen has a substantial impact on patient comfort after surgery by reducing incidence of PONV and it does not have any justifiable indication of its use in General anaesthesia.

Balanced conscious sedation with intravenous induction and inhalational maintenance for patients requiring endoscopic and/or surgical procedures.

BACKGROUND AND OBJECTIVE: The use of inhalation sedation with sub-anaesthetic concentrations of sevoflurane and nitrous oxide mixture is expected to reduce amounts of intravenous sedative drugs needed to produce a balanced sedation with the benefits of having reduced side-effects. METHODS: Eighty-two patients requiring endoscopic and/or surgical procedures under conscious sedation and local anaesthesia were recruited for this pilot study. Conscious sedation was induced with a titrated dose of midazolam and propofol given intravenously until the clinical end-point of conscious sedation was achieved. Subsequently, during the procedure, the patient was asked to breathe sevoflurane 0.1-0.3% and a fixed ratio of 40% nitrous oxide in oxygen given through a face mask. RESULTS: In 78 patients (95.1%), the treatment was completed successfully. Patients were discharged back to the wards within 4-16 min (10.1) without significant side-effects. Treatment was satisfactorily accepted by 38 patients (48.7%) and considered excellent by 40 patients (51.3%). CONCLUSIONS: The use of titrated doses of intravenous sedative drugs for induction of conscious sedation followed by the use of low concentrations (0.1-0.3%) of sevoflurane combined with 40% nitrous oxide for maintenance of conscious sedation in patients requiring endoscopic and/or surgical procedures under local anaesthesia, has the potential advantages of reducing amounts of intravenous sedative drugs, less likelihood of problems from drug side-effects and fast recovery and discharge time. Further investigations to establish the technique are currently in progress.

Clinical management of dental anxiety: what works for whom?

This paper aims to provide an overview of the current knowledge regarding the management of adult dentally anxious patients. Furthermore, an attempt is made to formulate a number of preliminary clinical guidelines, based on the available literature. The findings are discussed in the light of the following four problem areas or types of patients, those with: 1) a mild form of fear or anxiety, 2) a phobia of specific dental procedures or situations, 3) interfering psychiatric symptoms and/or 4) a high treatment need. The literature suggests that particularly the implementation of a high level of predictability during treatment, the training of patients in the use of coping skills, and the application of in vivo exposure to anxiety provoking stimuli are the most appropriate options for the management of anxious dental patients and the reduction of their anxiety level.

Distorted perception of smell by volatile agents facilitated inhalational induction of anesthesia.

BACKGROUND: Unpleasant smell of halogenated volatile agents is one of the frustrating factors for inhalational induction. We developed a new modification that might enable children to enjoy the smell itself while incrementally elevating sevoflurane concentration. Troposmia is usually a pathological quality change of smell perception and an olfactory stimulus is distortedly perceived in this state, which we applied to inhalational induction. METHODS: At the preoperative visit an anesthetist told the children that the smell of a facemask could be magically changed from strawberry into anything and promised to change the smell as they requested. In the operating room, a strawberry scented facemask was fitted to the face and the anesthetist announced to them that the magical change of the smell would begin when sevoflurane was added. Whether children perceived the change of the smell as they requested was investigated in the troposmia group, and resistance to fit a facemask was compared between the troposmia group and a control group. RESULTS: Significantly fewer children resisted the facemask in the troposmia group (1 of 32 vs 9 of 32; P = 0.0059). In the troposmia group 18, 22 and 25 of the 32 children said the smell of the facemask changed as they requested before they fell asleep, at the postoperative visit or both, respectively. CONCLUSIONS: Troposmia can be intentionally induced to perceive the smell of sevoflurane on request. Troposmia might contribute to promote children's participation in anesthesia induction and facilitate inhalational induction.