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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

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.

Background: 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.

Aim of the Study: While several techniques are used for the management of difficult intubation (DI) in planned conditions in the operating theatre, they are not always suitable or usable in pre-hospital emergencies. We decided to assess the intubating laryngeal mask airway (ILMA) after failure of tracheal intubation (TI) under direct laryngoscopy., Material and Methods: After emergency physicians of the mobile intensive care unit were trained (theory and training on manikin) in using the ILMA (Fastrach), prospective data were collected after each use from March 2002 to December 2005. Data included patient's age, clinical status, number of direct laryngoscopies before using ILMA, Cormack and Lehane grade, subjective and objective evaluation of ease of ILMA insertion and TI (analogue scale from 1 to 10, attempts required, failure rate)., Results: Over 46 months, the ILMA was used 45 times (24: cardio-respiratory arrest, 21: anaesthesia with rapid sequence induction). Median age was 59 years [range 20-86]. The number of direct laryngoscopy attempts was 3 [0-4] (76% Cormack 4). The success of ILMA insertion and TI were 96 and 91%, respectively., Conclusion: Emergency physicians were satisfied with using the ILMA. It allowed TI in 91% of cases of DI. The ILMA can be recommended to be included in the algorithm of DI in pre-hospital emergencies after initial training.

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 H(2)O, and average peak pressure was 11 +/- 3 cm H(2)O. 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.

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.

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.

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.

Background: This prospective, randomized, crossover study had two purposes: first, to determine whether pressure-controlled ventilation (PCV) is safer than volume-controlled ventilation (VCV) by preventing gastric insufflation in children ventilated through an laryngeal mask airway (LMA); second, to assess whether the measurement of LMA leak pressure (P(leak)) is useful for preventing leakage during positive pressure ventilation (PPV)., Methods: Forty-one, 2 to 15-year-old children underwent general anesthesia with an LMA. The expiratory valve was set at 30 cmH(2)O and P(leak) was measured using constant gas flow. Children were randomly ventilated using PCV or VCV for 5 min in order to reach a P(ET)CO(2) not exceeding 45 mm Hg, and then they were ventilated with the alternative mode. If the target P(ET)CO(2) could not be obtained in one mode, we switched to the other. If both modes failed, children were intubated. Tidal volumes, P(ET)CO(2) and airway pressures were noted and compared between modes. Gastric insufflation was checked by epigastric auscultation., Results: PCV provided more efficient ventilation than VCV, as targeted P(ET)CO(2) was obtained without gastric insufflation using PCV in all cases except one, whereas VCV failed in three cases. No gastric insufflation occurred when ventilating below peak., Conclusions: These findings suggest that in the age group studied, PCV is more efficient than VCV for controlled ventilation with a laryngeal mask. Gastric insufflation did not occur with this mode.

Goal of the Study: To assess the benefit of pressure support ventilation during fibreoptic intubation performed under propofol anaesthesia in patients having an anticipated difficult intubation., Procedures: Thirty-two patients with ENT cancer, and having at least two criteria for anticipated difficult intubation were prospectively included. All patients received topical lidocaine 2% and propofol by plasma target control infusion (initial target concentration 3 microg ml(-1), then adjusted to maintain loss of consciousness without apnoea). They were randomly assigned between two groups: spontaneous breathing (SB) or pressure support ventilation (with a support level set at 10 cm H(2)O) both using Fi(o(2))=1. Conditions for fibreoptic intubation, respiratory parameters (pulse oxymetry, ventilatory frequency, tidal volume and PetCO2 after intubation) and haemodynamic parameters were recorded., Results: Patient characteristic data and intubation conditions were similar between both groups. All patients had a successful fibreoptic intubation and none needed a rescue procedure because of desaturation. In spite of a longer duration of intubation, PE'CO2 after intubation was lower and tidal volume during intubation was higher with pressure support ventilation than in SB patients [38.1 (4.2) vs 42.3 (4.7) mm Hg and 371 (139) vs 165 (98) ml, respectively]. Desaturation episodes were observed in two SB patients conversely to no episode during pressure support ventilation, probably because of the higher minute ventilation., Conclusion: Pressure support represents a useful method to improve ventilation during fibreoptic intubation under propofol anaesthesia in patients with an anticipated difficult intubation.

We report a case of acute tongue and uvula ulcerations consecutive to the use of a laryngeal tube Sonda (LTS) for airway management. The LTS was used during general anaesthesia for hysteroscopy and resection of endometrial hyperplasia. No trouble occurred during LTS insertion and anaesthesia. Symptomatic treatment provided complete resolution within a few days. This event points out the potential risk of more serious lesions.

Objectives: To compare the Classic laryngeal mask airway (MLC) and the ProSeal LMA (MLP), size 2 and 2.5 in terms of ease of insertion, leak pressure and side effects during insertion and extraction in the recovery room., Study Type: Randomised prospective., Material and Method: All children between 10 and 30 kg scheduled for general anaesthesia with laryngeal mask (ML) were included. There was no imposed protocol for the anaesthesia. The ML size was determined according to the child's weight. The MLC was inserted using the standard technique. The MLP was inserted following the recommendations, with or without the handle according to the operator's choice. The data analysed were: insertion type, ease of insertion of the mask, of the nasogastric tube (SG), number of attempts of mask insertion, complications, gastric leaks., Results: One hundred (and) twenty children were included. There was no statistical difference in terms of difficulty of insertion, number of failed attempts, leak pressure or side effects. The use of the handle did not make insertion easier. Insertion of a nasogastric tube was possible in 92% cases., Conclusion: MLP is as easy to use in children as the MLC. MLP has the advantage of allowing rapid access to the stomach. It seems that the MLP is safer since its correct position is confirmed by easy gastric tube insertion.

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.

Background and Objective: Inhalation induction with sevoflurane provides acceptable conditions for tracheal intubation. Opioids significantly decrease the alveolar concentration needed to achieve tracheal intubation. The purpose of this study was to determine the target concentration of remifentanil providing excellent conditions for tracheal intubation with sevoflurane at 1 minimum alveolar concentration without muscle relaxant., Methods: Twenty-four consecutive patients, aged 18-50 yr, ASA I or II, were studied. Induction of anaesthesia was performed with sevoflurane at age-adjusted minimum alveolar concentration. Remifentanil was simultaneously administered using target-controlled infusion with the Minto model. Target plasma concentration of remifentanil was selected for each patient according to an up-and-down method., Results: The mean target concentration of remifentanil for successful tracheal intubation was 3.3 ng mL(-1) (95% confidence interval: 2.6-3.9 ng mL(-1)). Arterial pressure, heart rate and bispectral index did not increase after tracheal intubation in the group of patients with successful intubation., Conclusions: Remifentanil at 3.3 ng mL(-1) together with sevoflurane at 1 minimum alveolar concentration provides excellent conditions for tracheal intubation in 50% of patients.

Background and Objective: The target effect-site concentration of propofol to insert a laryngeal mask airway was recently reported as almost 5 microg mL(-1). The present study aimed to determine the target effect-site concentration with target-controlled infusion of propofol to place classical larnygeal mask airway or current laryngeal tube in adult patients., Methods: We included 40 patients scheduled for short gynaecological and radiological procedures under general anaesthesia in a randomized, double-blind manner using the Dixon's up-and-down statistical method. Monitoring included standard cardiorespiratory monitors, and bispectral index monitoring was used for all patients. Anaesthesia was conducted with a target-controlled infusion system: Diprifusor. The initial target plasma concentration of propofol was 5 microg mL(-1), and was changed stepwise by 0.5 microg mL(-1) increments according to Dixon's up-and-down method. Criteria for acceptable insertion were: Muzi's score < or = 2, and mean arterial blood pressure, heart rate or bispectral index variation <20% the baseline values., Results: Target effect-site concentration of propofol required to insert laryngeal tube was 6.3 +/- 0.3 microg mL(-1) with Dixon method and ED50 was 6.1 microg mL(-1) (5.9-6.4) with logistic regression method. In the case of larnygeal mask airway they were 7.3 +/- 0.2 microg mL(-1) (Dixon method) and 7.3 microg mL(-1) (7.1-7.5; with logistic regression) respectively (P < 0.05). ED95 (logistic regression) was 6.8 microg mL(-1) (5.9-7.6) for laryngeal tube and 7.7 microg mL(-1) (7.3-8.0) for larnygeal mask airway (P < 0.05). Haemodynamic incidents were 55% in the larnygeal mask airway group vs. 30% in the laryngeal tube group (P < 0.05)., Conclusions: The target effect-site concentration of propofol for insertion of laryngeal tube was lower than for larnygeal mask airway (P < 0.05), with a consequent reduction of the propofol induced haemodynamic side-effects.

Background and Objective: The purpose of this prospective randomized study was to assess the value of pressure support ventilation during inhalational induction with sevoflurane in adult patients., Methods: Thirty-five adult patients, ASA I-II and scheduled for ear nose throat surgery were studied. Vital capacity induction with 8% sevoflurane in 8 L min-1 oxygen was performed. Pressure support ventilation was used in Group 1 with pressure set at 15 cmH2O. In Group 2, patients breathed spontaneously. After 2 min, sevoflurane was set to 3% and remifentanil 1 microg kg(-1) was injected over 2 min followed by an infusion of 0.1 microg kg(-1) min(-1). Two minutes after the end of the bolus, intubation was performed. Bispectral index, oxygen saturation, respiratory rate, end-tidal carbon dioxide, expired tidal volume and expired sevoflurane concentration were recorded every minute., Results: Eighteen patients were included in Group 1 and 17 in Group 2. Saturation, respiratory rate and end-tidal carbon dioxide were similar in the two groups. Expired tidal volume was significantly higher and bispectral index values significantly lower in Group 1. Intubating conditions were better in Group 1., Conclusions: Pressure support ventilation provides both better ventilation and deeper level of anaesthesia during inhalation induction with sevoflurane.

Objectives: The Laryngeal Tube (LT) is a supra-laryngeal device indicated to manage upper airway during anaesthesia. Leak pressures were lately reported higher for the LT as compared to the LMA. A recent study found a small amount of proteinaceous material on LMA after classical sterilization suggesting a risk of contamination by unconventional transmissible agents (prions). The aim of this study was to evaluate the effectiveness of the single use Laryngeal Tube: the LTD., Study Design: Prospective study realized after ethical committee agreement and patient consent for participation., Patients and Methods: Adults, ASA score< or =3, 18 to 75-year-old, without upper airway abnormality or difficult intubation criteria, anaesthesia< or =2 h, free access to patient's head and LTD. The following criteria were evaluated: easiness of insertion, assisted (AV), controlled (CV) and spontaneous ventilation (SV); leak pressure (LP) 5 and 15 min after insertion; complications during anaesthesia conducted with propofol and remifentanil under bispectral index monitoring., Results: 55 patients were included; only one failure was reported at insertion. AV and CV were easy, SV difficult in 4 patients with chin lift necessary for adequate ventilation. LP was 28.92+/-8.4 and 30.87+/-8.68 cmH2O 5 and 15 min after insertion respectively. No major incident was noticed throughout the study., Conclusion: the use of the LTD was easy and successful. Moreover the LTD totally excluded the risk of contamination by unconventional transmissible agents.

Objectives: To evaluate if the new anaesthesia platform ZEUS (Dräger Medical) allows the induction of anaesthesia with target-controlled inhalation of sevoflurane., Study Design: Prospective clinical study., Patients: Adult ASA I or II patients scheduled for elective surgery under general anaesthesia., Methods: After preoxygenation during 3 min at 100% oxygen, patients were asked to breathe normally; the target end-tidal concentration of sevoflurane was fixed at 4% without priming of the circuit. Sufentanil (target concentration 0.5 ng/ml) was administered 40 s after., Results: Ten patients (48+/-22 yrs) were included. Sevoflurane was detected in the circuit after 36+/-5 s; the target end-tidal concentration of sevoflurane was obtained at 130+/-19 s. Loss of consciousness was observed after 119+/-7 s. The induction was achieved in all patients without any incident., Conclusion: This new anaesthesia system make available the induction of anaesthesia with sevoflurane without priming of the circuit.

A case report is presented of an unknown epileptic child, who developed convulsive movements during inhalation of 3.9% sevoflurane for 45 minutes associated with moderate hyperventilation. Epilepsy was discovered on the EEG, which was performed postoperatively.

Background: The aim of this study was to evaluate a new device for airway management in children: the laryngeal tube (LT)., Methods: The LT is available in sizes S0-S3 for pediatric anesthesia. This prospective open study included 70 children ASA 1. The local Ethics Committee approval and parental consent were collected. The primary criterion was the success rate for insertion and ventilation. Secondary criteria were additional maneuvers and incidents elicited from LT use., Results: Seventy children were included: S0 = 5, S1 = 8, S2 = 36, and S3 = 21. Insertion was successful: at the first attempt in 78.6%, second in 17.1%, and third or more in 4.3%. In 12% of cases it was not possible to successfully insert the LT and proceed to adequate ventilation. Failures were explained by: inability to obtain satisfying ventilation (n = 4), hypoxemia (n = 1), gastric insufflation (n = 6), cough (n = 1), and laryngospasm or stridor (n = 2), some with the same child. Minimal additional maneuvers for adequate ventilation were necessary in 35% of cases (all groups), but <20% when considering only sizes 2 and 3. Moreover, after five cases, the anesthesiologists became more proficient at inserting the LT (respectively 73.3% failure before five cases vs 13% afterwards). Gastric insufflation occurred in eight cases (11.4%). Controlled ventilation was used in 30 children and peak inspiratory pressure was 19.2 +/- 4 cmH(2)O., Conclusions: The LT is not recommended for children <10 kg. Over 10 kg, it provides a clear airway in most children, with a low rate of minimal additional maneuvers for sizes 2 and 3. The failure rate also decreases with the operator's training.

Objectives: To clarify how pharmacokinetics explains the speed and quality of mask induction with sevoflurane alone or associated with adjuvants. To describe the various techniques to obtain adequate anaesthesia for laryngeal mask or tracheal tube insertion. To give the indications, contra-indications and complications of this technique., Data Sources: Data were obtained from Medline and authors clinical experience., Data Synthesis: Inhalation induction in adults affords rapid loss of consciousness similar to the intravenous route if high concentrations of sevoflurane are delivered to the patient. Time of laryngeal mask or tracheal tube insertion is longer but may be reduced by adding N(2)O and/or a low opioid dose. The interest of benzodiazepine as premedication is not established but is highly probable when considering its potentiating effect on halogenated agents. Without any adjuvant, inhalation induction maintains spontaneous ventilation better than propofol. This justifies favouring this technique when difficult intubation is anticipated. This technique is associated to less or similar cardiovascular effects than intravenous propofol. However, some patients exhibit dramatic tachycardia and arterial pressure increase that should lead to caution in cardiovascular disabled patients. This sympathetic hyperactivity occurs with epileptiform EEG activity that was never associated with postanaesthesia mental dysfunction. In aged or cardiac patients, by reducing sevoflurane concentrations from 8% to 2% (or by 2% decreasing steps), the cardiovascular effect of this inhalation induction is better than propofol. This technique is contra-indicated in HMS susceptible patients and those suffering from a myopathy, or patients with intracranial hypertension, a full stomach or active gastro-oesophageal reflux., Conclusion: Inhalation induction in adults remains little used in common clinical practice. Technical improvement by adding opioids and education of anesthetists should increase the diffusion of this alternative method to intravenous induction of anaesthesia.

High frequency jet ventilation (HFJV) is an alternative ventilatory mode during anaesthesia for laryngeal microsurgery. This procedure ensures good visualization of the operating field but is not without risk. Thus, its use in paediatric patients requires sound knowledge of respiratory physiology of children and infants. In children up to 8 years, the jet ventilator adjustments must take into account the lower pulmonary compliance and the higher airway resistance (time-constant). In order to avoid barotrauma, which is the main HFJV complication, the jet ventilator has to include a monitoring airway pressure system. The driving pressure and the frequency must be gradually increased while checking thoracic expansion. Total intravenous anaesthesia with profound muscular relaxation using a thin transglottic catheter is the most commonly used technique. Standard monitoring of anaesthesia does not preclude strict clinical supervision so as to detect any pulmonary distension. The air-oxygen mixture must be adjusted to provide the lowest FIO2 possible (< or = 30%) when using the CO2 laser. The main indications for the use of HFJV in paediatric laryngeal microsurgery are laryngomalcia, laryngeal papillomatosis and subglottic haemangioma. HFJV is a reliable and useful technique in airway paediatric surgery providing the operator has good knowledge of the physiological particularities in children.

Laryngeal dyspnea is a life-threatening emergency situation. The diagnosis is clinical and made from the association of: inspiratory bradypnea, intercostal and sus-sternal inspiratory depression, with or without stridor. The aetiologies are most often laryngeal tumours or inflammatory oedema; incidence of epiglottitis has decreased due to vaccine against Haemophilus influenzae. Airway obstruction due to foreign body includes acute laryngeal dyspnea and reflex paroxysmal coughing without fever. Management of a laryngeal dyspnea depends on the aetiology and the severity of clinical symptoms. Medical treatment associates racemic epinephrine aerosol, steroids, and oxygenation. In the presence of severe dyspnea, intubation after anaesthetising the patient and positive pressure ventilation is required.

Objective: This work was carried out to study induction with sevoflurane in adult patients with predictive signs of difficult intubation., Study Design: Randomised prospective study., Patients and Methods: The study had two parts. Part I: 15 patients without predictive signs of difficult intubation but with a cervical collar. Eight patients were anaesthetised with propofol 3 mg.kg-1 and fentanyl 2 micrograms.kg-1, seven with sevoflurane 8%. Part II: 20 patients with predictive signs of difficult intubation anaesthetised with sevoflurane 8%., Results: In part I, all patients were intubated, the time for intubation was longer with sevoflurane, 6 vs 4 min. They were apneic only in the propofol group. After intubation, 7 cases of coughing (4 severe) occurred in the propofol group and 3 moderate coughing in the sevoflurane group. In part II, one patient experienced considerable agitation after oral airway insertion and was excluded. Other patients were intubated with sevoflurane. Seven patients were intubated with a bougie, three patients through an intubating LMA and one patient with a rigid bronchoscope. The other patients were intubated with a Macintosh blade. The mean time for intubation was 10 +/- 7 min and end tidal sevoflurane concentration after intubation was 4 +/- 0.6%. After intubation, 7 cases of coughing (3 severe) occurred but no desaturation < 95%. No significant haemodynamic variations occurred., Conclusion: Induction with sevoflurane 8% allowed tracheal intubation without major incidents. All patients breathed spontaneously. Sevoflurane can be recommended for induction in cases of predictive difficult intubation.

Background: The intubating laryngeal mask airway (ILMA; Fastrach; Laryngeal Mask Company, Henley-on-Thames, UK) may provide an alternative technique to fiberoptic intubation (FIB) to facilitate the management of the anticipated difficult airway. The authors therefore compared the effectiveness of the ILMA with FIB in patients with anticipated difficult intubation., Methods: One hundred patients, with at least one difficult intubation criteria (Mallampati class III or IV, thyromental distance < 65 mm, interincisor distance < 35 mm) were enrolled (FIB group, n = 49; ILMA group, n = 51) in this prospective randomized study. Anesthesia was induced with propofol and maintained with alfentanil and propofol after an efficient mask ventilation has been demonstrated. The success of the technique (within three attempts), the number of attempts, duration of the successful attempt, and adverse events (oxygen saturation < 90%, bleeding) were recorded., Results: The rate of successful tracheal intubation with ILMA was 94% and comparable with FIB (92%). The number of attempts and the time to succeed were not significantly different between groups. In case of failure of the first technique, the alternative technique always succeeded. Failures in FIB group were related to oxygen desaturation (oxygen saturation < 90%) and bleeding, and to previous cervical radiotherapy in the ILMA group. Adverse events occurred significantly more frequently in FIB group than in ILMA group (18 vs. 0%, P < 0.05)., Conclusion: The authors obtained a high success rate and comparable duration of tracheal intubation with ILMA and FIB techniques. In patients with previous cervical radiotherapy, the use of ILMA cannot be recommended. Nevertheless, the use of the ILMA was associated with fewer adverse events.

The sevoflurane alveolar concentration needed for tracheal intubation with remifentanil was studied in 26 adult patients premedicated with 100 mg hydroxyzine. Anaesthesia was induced with sevoflurane in oxygen. The concentration was determined by Dixon's up-and-down method. The first patient was tested at 4.5%. One minute after obtaining the preselected value, remifentanil 1 microg.kg-1 was injected for 60 s followed by an infusion of 0.25 microg.kg-1. min-1. Ventilation was then manually assisted for 2 min and tracheal intubation was attempted. Tracheal intubation conditions and responses to intubation were noted. Heart rate and mean arterial pressure were recorded before induction, before remifentanil injection, and before and 3 min after tracheal intubation. The concentration for acceptable intubating conditions was 2.5 +/- 0.7%. From logistic regression, ED50 and ED95 were 2.0% (95% CI 1.3-2.5) and 3.2% (95% CI 2.6-5.6), respectively. With sevoflurane 2.5%, heart rate and mean arterial pressure decreased by 18% and 15%, respectively, after remifentanil administration and increased slightly after tracheal intubation.

Objective: To evaluate the success rate of intubation through the intubating laryngeal mask airway (LMA-Fastrach) in patients with predictive signs of difficult airway or after intubation failure., Study Design: Open prospective study., Patients: The study included 33 adults, 21 with predictive signs of difficult airway and 12 after intubation failure., Methods: After induction of anaesthesia, the intubating LMA was inserted. Proper insertion was confirmed by easy bag ventilation and capnography. Intubation through the intubating LMA was then carried out with an armoured endotracheal tube. If intubation failed, a second attempt was carried out after a gentle manipulation of the intubating LMA. After two attempts, if intubation remained impossible, fibrescopic intubation through the intubating LMA was carried out. In case of failure the usual tracheal intubation algorithms were used., Results: Tracheal intubation through the intubating LMA was successful in all patients, in 32 on the first attempt and in one on the second. Successful tracheal intubation was possible on the first attempt in 25 patients (76%), on the second in four (12%) and after fibrescopic intubation through the intubating LMA in the four remaining (12%)., Conclusion: The results of this study confirm that tracheal intubation through the intubating LMA can be recommended in patients with a difficult airway, whether foreseen or not.

Difficult intubation (DI) is a daily problem in a ENT unit. The place of the ENT anesthesiologist in the management of a DI is both in his own unit and in the hospital as an expert in DI. An anesthesiologist working in a ENT unit should be an expert in techniques allowing to manage intubation and oxygenation in every situations: i.e. fiberscopic intubation, LMA and intubating LMA and transtracheal ventilation. The ENT anesthesiologist may also play a role in the management of a DI in the hospital as an expert, both helping to cope with a difficult airway and teaching airway skills and the value of having a plan before managing any airway.

Background: In 1996, experts from the Société Française d'Anesthésie et de Réanimation published guidelines about difficult intubation. We aimed to assess the effectiveness of two diffusion methods of these guidelines, media versus direct mailing plus media diffusion, and the relation between reading of the guidelines and practice behavior and training willingness., Methods: Data were collected in two different samples of 300 anesthetists from three regions for pre and post-intervention surveys (E1 and E2 samples). Half of the anesthetists from E2, randomly chosen, received a direct mailing of the guidelines (E2a sample). The remaining constituted the E2b sample. Three assessment criteria were used, two concerning practice behavior and one training willingness. Relationship between these criteria and diffusion methods and reading was tested using logistic regression., Results: The response rates were respectively 91%, 80% and 78% in the E1, E2a and E2b samples. The socio-professional features were not statistically different between the three samples. There was no relationship between the criteria and the diffusion methods. The direct mailing did not increase the reading rate (81% and 82% respectively in the E2a and E2b samples). The rate of anesthetists who routinely screened for predictive signs of difficult intubation (one of the practice criteria) was higher in E2a than in E2b (28% and 12% respectively). In the multivariate analysis, the difference only appeared among the sub-group of anesthetists who did not receive the direct mailing. The private practice was associated with a lower rate of routine screening., Conclusion: No impact of the diffusion methods on practice behavior and training willingness was found. Reading was inconstantly associated with practice behavior.

Objective: To analyse the management of difficult intubation (DI) by French anaesthetists and the impact of the French experts' conference (EC) on this topic., Study Design: Prospective, comparative, before/after study by questionnaire carried out in Aquitaine, Provence-Alpes-Côte d'Azur and Alsace-Lorraine., Material and Methods: A questionnaire on demographical data, detection of DI, management techniques and desiderata for continuing education on DI, was sent three months before the publication of the EC to 100 randomly selected anaesthetists, in each region (group PRE). Three months after the diffusion of the EC, the questionnaire completed by a survey on the impact of the EC was sent to 100 other randomly selected anaesthetists in each region (group POST). In the latter group, anaesthetists who considered the EC were compared to those who did not., Results: The participation rate was 91% for the group PRE and 79% for the group POST respectively. Both groups were not significantly different for age, gender, position and seniority. Most used techniques that included blind nasal intubation (84%), intubation through laryngeal mask (82%), and intubation with fibrescope (53%). Demands for additional training were for translaryngeal ventilation (68%), intubation with fibrescope (64%), retrograde intubation (52%), and intubation through a laryngeal mask (46%). The EC was known by 71% of anaesthetists. In this group, the EC improved the assessment rate of the three recommended predictive criteria for DI from 12 to 28% (P < 0.02), but neither the management policy, nor the desiderata for additional training., Conclusion: Currently, the search of predictive indicators for DI is not systematically applied. The EC has only slightly modified the practice patterns. The need for additional training is important.

A case of neuromuscular blockade of about 200 min of duration, in a 9-year-old boy from mivacurium 0.15 mg.kg-1 is reported. The diagnosis was delayed, after onset of the first signs of recovery, due to the lack of monitoring of neuromuscular transmission. The neuromuscular blockade was reversed with neostigmine 0.04 mg.kg-1. Complete reversal required fifty minutes. The presence of an abnormal genetic variant of pseudocholinesterases was demonstrated by the measurements of pseudocholinesterase activity and dibucaine number. The importance of monitoring of neuromuscular transmission for diagnosis and treatment of mivacurium-induced neuromuscular blockade is underlined.

This experimental study was carried out to determine if an alveolar positive end-expiratory pressure (PEEP) could occur during high frequency jet ventilation (HFJV) in infants, and if tracheal pressure is a good estimation of alveolar pressure. We used physical models simulating a 1.5 kg premature (P), a 3 kg newborn (N) and a 6 kg child (C) with normal compliance and normal resistance. Moreover, in the N model, we used two different resistances and lung compliance heterogeneity was studied in the P model. Pressure was measured simultaneously in the tube simulating trachea (Paw) and in the bottle simulating the lung (Palv). HFJV was performed either via an endotracheal tube (ETT) or via a long catheter as in laryngoscopy. The ratio of injection time upon cycle duration (Ti/Ttot) was 20% or 30%, jet frequency was altered from 150 to 300 min-1 and the driving pressure was set as in clinical practice (0.5 and 0.6 bar). PEEP occurred mainly in N (1.1 to 3.2 cm H2O) and C models (0 to 3.5 cm H2O). It was inversely related to expiratory time (Te). The end-expiratory pressure drop between Palv and Paw (delta EEP) was higher in N and increased from 0.5 to 2 cm H2O with the shortening of Te and with airway resistances, i.e. the presence of ETT. In the heterogeneous model, PEEP and delta EEP were greater in the higher compliance alveolus. This study shows that the end-expiratory Palv is underestimated by end-expiratory Paw.(ABSTRACT TRUNCATED AT 250 WORDS)

Patients undergoing ENT surgery, mainly children, are excellent candidates for outpatient anaesthesia. Most surgical procedures are simple and do not require complicated techniques. Patient selection criteria have been defined by the "Société Française d'Anesthésie et de Réanimation" e.g. ASA I or II patients, age > 50 weeks, ability to understand and follow specific instructions. Operation selection criteria ought to take into account the duration of surgery (< 1 h 30), and risks of bleeding, airway obstruction, pain, nausea and vomiting. Myringotomy and adenoidectomy and simple nasal or otologic surgery can be performed on an outpatient basis. Indications can be extended to other procedures that do not require hypotension and that meet selection criteria. Tonsillectomy and direct laryngoscopy could be performed on an outpatient basis in definite circumstances which have to be discussed for each patient.

In order to design a new, performed tracheal tube adapted to the shape of the upper respiratory tract, we have undertaken an anthropometric study from lateral x-rays of the neck in 130 patients with the head in a fixed position. In order to assess different clinical situations, we studied three groups of patients: group 1 = sitting, no tracheal tube; group 2 = supine, no tracheal tube; group 3 = supine, trachea intubated. We defined a standard coordinate system and determined mathematical curves for segments of the upper respiratory tract by a polynomial regression method. With these data it was possible to study the effects of physiological variations on the shape of the curves. It was then possible to determine at which region changes occur and the factors influencing these changes. We found that the relative position of the larynx was constant, whereas the hypopharynx exhibited the greatest change with the position of the head. These observations should allow us to construct a new, performed tracheal tube with elastic compliance properties to fit the changes occurring in the region of the hypopharynx.