[Anesthesia in spontaneous ventilation for difficult intubation]. / Quelle technique d'anesthésie en ventilation spontanée pour l'intubation difficile?

Difficult intubation in children is rare and often predictable during anesthesia consultation. This allows to establish a strategy to provide fiberoptic guided tracheal intubation with spontaneous ventilation in function of age and children pathology. A good knowledge of physiologic and anatomic children particularities, of fiberoptic technique and the respect for some principles lead to ensure the security of this procedure. First principle is to use only one anesthetic inhaled or intravenous agent in order to limit an important decrease of ventilation. The anesthetic technique recommended for pediatric fiberoptic guided intubation is inhaled anesthesia with sevoflurane. But it is possible to use an intravenous agent, like propofol, with a continuous infusion (bolus of 0.1 to 0.3 mg/kg then 0.1-0.3mg/kg per hour for maintenance) or with target controlled infusion (Schnider model, initial concentration 2.5 µg/mL, then increase by 0.5 µg/mL steps) particularly in children older than 5 years with an anesthetic depth control. Whatever the agent, the dose must to be titrated to maintain spontaneous ventilation. Second principle is to combine an airway local anesthesia with general anesthesia to limit airway reactivity. First, a nose topical anesthesia is administered with lidocaine plus naphazoline in children older than 2 years. Then, a laryngeal topical anesthesia is realized with lidocaine 1% (1-2 mL, 2mg/kg) through operating channel of fiberoptic bronchoscope. Finally, third principle is to ensure patient oxygenation with several techniques like use of endoscopic facial mask or nasopharyngeal tube. The use of laryngeal mask is a rescue technique in case of spontaneous ventilation lost. In conclusion, each institution has to establish an algorithm with his own knowledge, constantly feasible and regularly taught.

[Acute hemolysis following perioperative blood salvage in chldren operated for the surgical correction of craniosynostosis]. / Hémolyse aiguë au décours d'une chirurgie de correction d'une craniosténose utilisant l'autotransfusion périopératoire chez un nourrisson.

We report the case of a 6-month-old child, who suffered from acute haemolysis following transfusion of salvaged blood. This complication, of favourable outcome, was related to the accidental aspiration of benzalkonium chloride into the cell saver. This case emphasizes that any adjunction of antiseptic solution is contraindicated during blood saving. The use of a cell saver must be associated with written protocols, describing clearly the contraindications, precautions of use, and the different steps of use of this method of autologous blood transfusion.

Perioperative blood salvage during surgical correction of craniosynostosis in infants.

Surgical correction of craniosynostosis in infants is a very haemorrhagic procedure. The aim of this study was to determine whether the perioperative use of the continuous autotransfusion system (CATS) would reduce homologous transfusion during repair of craniosynostosis. Two groups of patients were studied according to the availability of the CATS in our hospital. The control group had surgery before the system was introduced and the study group had operations subsequently. Use of CATS was associated with a significant decrease in the median (95% confidence interval) volume of homologous blood transfused [413 (250-540) ml in the control group versus 317 (150-410) ml in the CATS group, P = 0.02] and in the median (95% confidence interval) number of packed red cell units transfused [2 (1-2) in the control group versus 1 (1-2) in the CATS group, P = 0.04] in the perioperative period. Use of CATS is associated with a reduction in homologous transfusion during the surgical correction of craniosynostosis in infants.

Norepinephrine but not epinephrine stimulates the release of corticotropin-releasing factor from in vitro superfused rat hypothalamus.

To clarify the controversy concerning the role of catecholaminergic systems in regulating hypothalamic corticotropin-releasing factor (CRF) secretion, we assessed the direct effects of norepinephrine and epinephrine, alone and in association with mixed alpha and beta antagonists on hypothalamic CRF secretion. An in vitro rat mediobasal hypothalamus perifusion system was used, in which CRF secretion from a single explant was evaluated by a specific radioimmunoassay. We found that norepinephrine stimulated CRF secretion, with peak effects at 10(-8) M concentration, whereas epinephrine had no effect on CRF secretion. The effect of norepinephrine was antagonised by the mixed alpha antagonist phentolamine and by the mixed beta antagonist propranolol. We conclude that norepinephrine, but not epinephrine, stimulate hypothamic CRF secretion via alpha and beta receptors. The data support the idea that the central noradrenergic systems are excitatory upon CRF-41 secretion when acting directly at the hypothalamic level.

[Anesthesia for thalamic stimulations: value of flumazenil]. / Anesthésie pour stimulations thalamiques: intérêt du flumazénil.

Five cases are reported of peroperative awakening in order to obtain patient cooperation during stereotaxic procedures. General anaesthesia was induced with 0.25 mg.kg-1 midazolam, 1.5 to 2 micrograms.kg-1 fentanyl, and 0.1 mg.kg-1 vecuronium. Maintenance was obtained with isoflurane, nitrous oxide, and small doses of fentanyl. Isoflurane inhalation was discontinued 30 to 40 min before the time of awakening required by surgery. Once expiratory isoflurane concentration reached a level less than or equal to 0.1%, nitrous oxide administration was stopped, and 0.5 mg flumazenil administered. After surgical checking, on the fully awake patient of the efficiency of thalamic stimulation and the lack of any motor deficit, anaesthesia was deepened again, with either isoflurane or a non benzodiazepine intravenous agent. All five patients recovered rapidly and calmly.