La anestesia causa obstrucción de las vías respiratorias superiores (VRS) debido a que genera una hipotonía responsable del desplazamiento posterior de las estructuras faríngeas. La obstrucción se produce a nivel de la nasofaringe y la epiglotis y, en menor grado, en la base de la lengua. La extensión de la cabeza, la protrusión mandibular y la elevación del mentón permiten hacerla desaparecer. La permeabilidad de las VRS se puede conseguir mediante dispositivos supralaríngeos o por intubación. Los adelantos relativos al material tienden hacia el uso único. Los dispositivos supralaríngeos provistos de un tubo de drenaje brindarían mayor seguridad. El problema principal de estos dispositivos es el riesgo de aspiración, que puede reducirse con una anestesia estable profunda y con presiones inspiratorias inferiores a la presión de fuga. Las reglas de buenas prácticas sobre la intubación estándar, la anestesia y la elección del material han sido elaboradas por una conferencia de consenso. La conferencia de expertos sobre la intubación difícil (ID) ha dado recomendaciones relativas al tratamiento de una dificultad potencial de intubación y de ventilación difícil con mascarilla (VDM) (preoxigenación, búsqueda sistemática de criterios predictivos de una ID y una VDM, conducta anestésica y selección del material) y ha elaborado una estrategia de tratamiento y algoritmos que tiene en cuenta una ID o una VDM previstas o no. Las complicaciones respiratorias de la extubación pueden prevenirse, en su mayoría, si se respetan los criterios de extubación y una estrategia de prevención en caso de extubación de riesgo. Las complicaciones vinculadas al uso de dispositivos supralaríngeos y a la intubación se deben a traumatismo directo o a compresión. Las manifestaciones más frecuentes son el dolor de garganta, la disfonía y los trastornos de la deglución. En la mayoría de los casos son pasajeros. Las complicaciones más graves son raras.

BACKGROUND:In this study, we sought to determine the level of inspiratory pressures allowing adequate and safe ventilation without any risk of gastric insufflation (GI) in children according to age. METHODS:One hundred children, aged 1 day to 16 years, ASA physical status I to II, scheduled for general anesthesia were studied prospectively. After induction of anesthesia, children's lungs were ventilated with pressure-controlled ventilation. The initial inspiratory pressure was 10 cm H(2)O and was increased by steps of 5 cm H(2)O, up to a maximum of 25 cm H(2)O. At each step, GI was detected by epigastric auscultation. The recorded data were age and weight. At each step, the inspiratory pressure, the respiratory rate, the expired tidal volume, the minute ventilation, and the occurrence of GI were also recorded. RESULTS:GI occurred in 78 children. GI occurred in 95% of children younger than 1 year, in 93% of children aged 1 to 5 years, and 56% of children older than 5 years (P = 0.001). The pressure threshold at which GI occurred increased with age: the younger the child, the lower the GI pressure threshold. Tidal volume increased with inspiratory pressure, but at >15 cm H(2)O, tidal volume did not change significantly. CONCLUSION:The inspiratory pressure threshold at which GI can occur depends on age. It is low in infants and increases with age. In most cases, proper ventilation without GI was obtained with an inspiratory pressure </=15 cm H(2)O. Increasing inspiratory pressure above this threshold results in an increase in GI and no change in tidal volume.

BACKGROUND:We studied 63 ASA I children (age 2-8 yr) to determine the sufentanil dose needed to facilitate intubation under excellent conditions after inhalation induction with various end-tidal concentrations of sevoflurane without neuromuscular block.METHODS:Subjects were allocated randomly to receive sevoflurane end-tidal concentrations (e'(sevo)) of 2.5%, 3%, or 3.5%. Anaesthesia was induced with sevoflurane 6% without nitrous oxide for 2 min, and then inspired sevoflurane concentration was adjusted to keep e'(sevo) at 2.5%, 3%, or 3.5% according to the group. Subjects received i.v. sufentanil according to an 'up and down' design. Tracheal intubation by direct laryngoscopy was performed 6 min after sufentanil injection. Intubation was considered successful, if intubation conditions were excellent as determined by the laryngoscopist.RESULTS:The ED(50) [effective dose for 50% of subjects; mean (sd)] of sufentanil required for excellent intubation conditions was 0.6 (0.12), 0.32 (0.10), or 0.11 (0.07) microg kg(-1) for e'(sevo) of 2.5%, 3%, or 3.5%, respectively. Using logistic analysis, the 95% effective dose (ED(95)) of sufentanil was 1.02 [95% confidence intervals (CI) 0.31-1.74] microg kg(-1), 0.58 (95% CI 0.17-0.99) microg kg(-1), or 0.28 (95% CI 0.04-0.52) microg kg(-1) for e'(sevo) of 2.5%, 3%, or 3.5%, respectively.CONCLUSIONS:Excellent intubation conditions could be obtained in children after inhalation induction with low sevoflurane concentrations and adjuvant sufentanil.

SummaryBackground: Target‐controlled inhalation induction (TCII) with sevoflurane is becoming possible with new anesthesia platforms. Although TCII has already been performed in adults, it remains to be evaluated in children.Methods: In a prospective study, we compared TCII using the Felix AInOC™ anesthetic station (Taema, Anthony, France) to our standard protocol inhalation induction in children scheduled for elective surgery under general anesthesia. After preoxygenation, sevoflurane induction was performed in both groups without priming of the circuit. Sufentanil was administered after venous line placement.Results: In the TCII group, no overdosage or underdosage was observed except in two children where TCII failed owing to high agitation, and the number of adjustments was lower compared with our standard protocol inhalation induction (1(1–2.5[0–5]) vs 6(5–6[4–10]) respectively). Moreover, the delay to obtain target end‐tidal sevoflurane concentration was shorter in the TCII group (2(1.6–2.7[1.3–4]) min vs 3.4(2.5–3.8[2.3–6.5]) min respectively). No significant difference in the delay of loss of consciousness or in the conditions for intubation or laryngeal mask placement was observed between the groups.Conclusion: The Felix AInOC™ allows TCII to be performed satisfactorily in children. Manual inhalation induction induced a higher number of adjustments and overdosages.

Background: The I‐gel ® is a new single‐use supraglottic airway device with a non‐inflatable cuff. It is composed of a thermoplastic elastomer and a soft gel‐like cuff that adapts to the hypopharyngeal anatomy. Like the LMA‐ProSeal, it has an airway tube and a gastric drain tube. Little is known about its efficiency in pediatric anesthesia. Methods: Fifty children above 30 kg, ASA I–II, undergoing a short‐duration surgery were included in this prospective, observational study. We evaluated ease in inserting the I‐gel ® , seal pressure, gastric leak, complications during insertion and removal, ease in inserting the gastric tube and ventilatory parameters during positive pressure ventilation. Results: All devices were inserted at the first attempt. The mean seal pressure was 25 cmH 2 O. There was no gastric inflation and gastric tube insertion was achieved in all cases. The results appear similar to those in a previous study concerning laryngeal mask airway in terms of leak pressure and complication rates. Conclusion: Because the I‐gel ® has a very good insertion success rate and very few complications, it seems to be an efficient and safe device for pediatric airway management.

L'anestesia comporta un'ostruzione delle vie aeree superiori (VAS) legata allo spostamento posteriore delle strutture faringee a causa dell'ipotonia che induce. L'ostruzione è situata a livello del rinofaringe e dell'epiglottide e, a un grado minore, a livello della base della lingua. L'estensione della testa sul collo, la protrusione mandibolare e il sollevamento del mento consentono di eliminarla. La pervietà delle VAS può essere assicurata dai dispositivi sopralaringei oppure mediante l'intubazione. L'evoluzione del materiale va verso il monouso. I dispositivi sopralaringei muniti di un tubo di drenaggio sembrano assicurare una migliore sicurezza. Il maggior problema di questi dispositivi è il rischio di inalazione che può essere diminuito con un'anestesia stabile profonda e pressioni inspiratorie inferiori alla pressione di perdita. Alcune regole di buona pratica a proposito della realizzazione di un'intubazione standard, l'anestesia e la scelta del materiale sono state emesse da una consensus conference. La conferenza di esperti sull'intubazione difficile (ID) ha fornito raccomandazioni concernenti la gestione di una difficoltà potenziale di intubazione e di ventilazione con maschera (VMD) (preossigenazione, ricerca sistematica dei criteri predittivi di una ID e di una VMD, condotta dell'anestesia e scelta del materiale), e sono stati elaborati una strategia di gestione e alcuni algoritmi che prendono in considerazione una ID o una VMD, previste o meno. Le complicanze respiratorie dell'estubazione possono essere prevenute nella maggior parte dei casi con il rispetto dei criteri di estubazione e una strategia preventiva in caso di estubazione a rischio. Le complicanze legate all'uso di dispositivi sopralaringei e all'intubazione sono dovute o a un trauma diretto o a una compressione. I sintomi più frequenti sono il mal di gola, la disfonia e i disturbi della deglutizione. Sono passeggeri nella maggior parte dei casi. Le complicanze più gravi sono rare.

Infants with Pierre Robin syndrome are known to be difficult to intubate. We evaluated the paraglossal approach combined with a gum elastic bougie for intubation of these infants. Whilst under general anaesthesia, a conventional laryngoscopy was performed; if it failed to obtain a laryngoscopic grade I or II view, intubation was attempted using a paraglossal approach and a gum elastic bougie. Six consecutive infants were studied. Conventional laryngoscopy failed in all infants whilst the paraglossal approach combined with a gum elastic bougie was successful in five of the cases. The paraglossal approach combined with a gum elastic bougie made intubation easy in most children with severe Pierre Robin syndrome and difficult laryngoscopy. Therefore we recommend this as the first line for airway management in such children. However, a fibreoptic bronchoscope and an anaesthetist trained in fibreoptic intubation must still be present when dealing with severe Pierre Robin syndrome infants.

F. Sztark *, D. Francon , X. Combes , Y. Hervé , B. Marciniak , A.-M. Cros f a Service d’anesthésie-réanimation 1, hôpital Pellegrin, CHU de Bordeaux, 33076 Bordeaux cedex, France b Département d’anesthésie-réanimation, institut Paoli-Calmettes, CRLCC, 13009 Marseille, France c Département d’anesthésie-réanimation chirurgicale et Samu-Smur 94, hôpital Henri-Mondor, 94000 Créteil, France d Département d’anesthésie-réanimation, hôpital d’instruction des armées Percy, 92141 Clamart, France e Clinique d’anesthésie-réanimation, hôpital Jeanne-de-Flandre, CHRU de Lille, 59037 Lille, France f Service d’anesthésie-réanimation 4, hôpital Pellegrin, CHU de Bordeaux, 33076 Bordeaux cedex, France

BACKGROUND: The i-gel is a new single-use supraglottic airway device with a noninflatable cuff and an esophageal vent.METHOD: In this prospective, observational study, we evaluated the i-gel in 71 women.RESULTS: Insertion success rate was 97%. Insertion was easy and performed at the first attempt in every patient. Mean seal pressure was 30 +/- 7 cm H2O, and average peak pressure was 11 +/- 3 cm H2O. The gastric tube was inserted in 100% of cases. Only one case of coughing and one mild sore throat occurred.CONCLUSION: The i-gel is a reliable, easily inserted airway device that provides an adequate seal with a low morbidity rate.

BACKGROUND:The aim of this prospective study was to determine the risk factors of epileptiform discharge during induction with sevoflurane in healthy adult patients.METHODS:Forty adult patients with American Society of Anesthesiologists physical status I were randomly allocated to one of four groups. Group A: Patients breathed 8% sevoflurane in oxygen (8 l/min) via a prefilled circuit. End-tidal sevoflurane was maintained at 4%. Tracheal intubation was performed at the third minute after cisatracurium injection. Group B: The anesthesia protocol was similar, but a vital capacity technique was performed. Group C: Patients were anesthetized as in group A but were hyperventilated. Group D: Patients were anesthetized as in group A, but end-tidal sevoflurane was maintained at 2%. An electroencephalogram was recorded before and during induction up to 11 min after the start of induction. Statistical analysis was performed with Statview 5.0 (SAS Institute Inc., Cary, NC) for multivariate analysis.RESULTS:Twelve patients experienced epileptiform discharges. Risk factors were female sex (odds ratio, 12.60; 95% confidence interval, 1.46-135), delay to the occurrence of beta waves (odds ratio, 0.92; 95% confidence interval, 0.86-0.99), and end-tidal sevoflurane (odds ratio, 8.78; 95% confidence interval, 1.12-69). Epileptiform discharges were not associated with significant hemodynamic or Bispectral Index variations.CONCLUSION:Induction with sevoflurane may result in epileptiform electroencephalographic activity. Only electroencephalographic monitoring allows the diagnosis. Risk factors are mainly female sex, short delay to onset of anesthesia, and high alveolar sevoflurane concentration. Induction with high sevoflurane concentration is controversial mainly in women.

Objectives. - To evaluate the impact of difficult intubation workshops on airway management knowledge and daily medical practice in anaesthesiology.Study design. - Prospective survey.Methods. - The participants to the workshops accredited by the French college of anaesthesiologists (Cfar) in 2003 were invited to answer to MCQ before, immediately and three months after the course. They also completed a questionnaire provided during the workshop and three months later, focusing on medical practice and their own organization in the area of difficult intubation before and after the workshop.Results. - One hundred (and) seven participants responded to the immediate evaluation (MCQ) and questionnaire) whereas 32 responded to the delayed evaluation performed three months later. A subjective scale was used to assess the level of knowledge in difficult intubation (0: lowest level, 10 highest level).The mean score for subjective knowledge considering difficult intubation was 4.7 +/- 2.3 before the course and 6.9 +/- 1.6 at 3 months (P < 0.00 1). The mean scores attributed to MCQ were not different before and after the workshops Participants expected complementary practical training (65%) and theoretical courses (40%). Delayed evaluation revealed that 25/32 participants had to deal with difficult intubation during their clinical practice.after the workshop, but 3 cases (12%). could not be managed with success. Defects could be observed in terms of organization: no difficult airway trolley (22%), no predefined difficult airway algorithm (66%), and information: no written information given to the difficult airway patient (44%), and no information given to the difficult airway patient's home doctor (91%).Discussion. - These results showed that difficult intubation remains a real problem for anesthesiologists. They also revealed differences between subjective and objective knowledge and pointed out defects in terms of organization and management which should be improved. (c) 2007 Elsevier Masson SAS. Tous droits reserves.

While there is no standard anaesthetic protocol in France for children undergoing MRI, only specialist teams undertake such procedures.

OBJECTIVES:To evaluate the impact of difficult intubation workshops on airway management knowledge and daily medical practice in anaesthesiology.STUDY DESIGN:Prospective survey.METHODS:The participants to the workshops accredited by the French college of anaesthesiologists (Cfar) in 2003 were invited to answer to MCQ before, immediately and three months after the course. They also completed a questionnaire provided during the workshop and three months later, focusing on medical practice and their own organization in the area of difficult intubation before and after the workshop.RESULTS:One hundred seven participants responded to the immediate evaluation (MCQ and questionnaire) whereas 32 responded to the delayed evaluation performed three months later. A subjective scale was used to assess the level of knowledge in difficult intubation (0: lowest level, 10 highest level). The mean score for subjective knowledge considering difficult intubation was 4.7+/-2.3 before the course and 6.9+/-1.6 at 3 months (P<0.001). The mean scores attributed to MCQ were not different before and after the workshops. Participants expected complementary practical training (65%) and theoretical courses (40%). Delayed evaluation revealed that 25/32 participants had to deal with difficult intubation during their clinical practice after the workshop, but 3 cases (12%) could not be managed with success. Defects could be observed in terms of organization: no difficult airway trolley (22%), no predefined difficult airway algorithm (66%), and information: no written information given to the difficult airway patient (44%), and no information given to the difficult airway patient's home doctor (91%).DISCUSSION:These results showed that difficult intubation remains a real problem for anaesthesiologists. They also revealed differences between subjective and objective knowledge and pointed out defects in terms of organization and management which should be improved.

Objective. - To investigate the procedures used by French anaesthesiologists in children undergoing MRI.Methods. - A questionnaire was sent by Internet to every university hospital in France. Information concerning the specialty of the doctor in charge of the child, the age of the children, premedication,,airway control,. the agents used, presence of a specific recovery room, length of hospitalization and number of children undergoing MRI was obtained.Results. - Out of the 28, hospitals contacted, one. did not reply and two did not perform anaesthesia for MRI. In 80% of cases, paediatric anaesthesiologists were. in charge of the children. Only one team applied an age limit and performed sedation only in children over 10 kg. Specific. monitoring for MRI was used by all teams. Premedication was given in. 52% of cases. Parents were present: during induction in 52% of cases. Sevoflurane was used in 52%,, propofol in 40% and propofol with sufentanil in 8%. Presence, of a venous,line is systematic in 92% of cases., Intubation is systematic in 36% of cases, laryngeal mask in 20%, one or the other in 24%, and face mask and/or oral canula in 20%. The most widely used ventilation mode is spontaneous breathing (52%). All children go to the recovery room, which was close to the MRI unit in only 48% of cases and was less than 1 hour away in 72%. In 83% of cases, MRI is performed on a day-case basis and the number of procedures varies from 4 to 30 per week.Conclusion. - While there is no standard anaesthetic protocol. in France for children undergoing MRI, only specialist teams undertake such procedures. (c) 2007 Elsevier Masson SAS. Tous droits reserves.

The delay for loss of consciousness can be shortened by using high concentration sevoflurane > 6% and by adding N2O during inhalation induction with sevoflurane in paediatrics. Mean time for tracheal tube insertion is lower than 5 min in the majority of studies. This shorter delay is not associated with any significant increase in clinical side effects. However, recent studies have demonstrated the epileptogenic effect of high effect site sevoflurane concentration (occurrence of spike wave on the EEG). Inhalation induction with high alveolar sevoflurane concentration is questionable mainly when it is associated with hyperventilation. Positive pressure ventilation or pressure support ventilation make it possible to maintain normocapnia and to monitor FeSevo. Adding a narcotic decreases the target cerebral concentration required to perform tracheal intubation and consequently the risk of spike wave occurrence.