No abstract

In this study, we compared three gas compositions to determine if the duration of apnoea for SpO2 to decrease is proportionate to the oxygen fraction of the gas prior to apnoea. Twenty-five patients ASA physical status 1-2 aged two months to 12 years were included in the study. Anaesthesia was induced via a mask with 5% sevoflurane and 66% N2O in oxygen. After paralysis with vecuronium (0.12 mg.kg-1, i.v.) the trachea was intubated and anaesthesia was maintained with sevoflurane and N2O in oxygen. When cardiovascular stability was obtained, the patient was randomly set to breathe one of three gas compositions: 1. oxygen (FiO2 1.0), 2. N2O/O2 (FiO2 0.4), and 3. air/O2 (FiO2 0.4). All three gas compositions included 2-4% of sevoflurane to maintain anaesthesia. After more than eight min of each gas breathing, apnoea was begun by disconnecting the breathing circuit from the tracheal tube. The time from the start of apnoea (SpO2 100%) to SpO2 of 95% (T95) was measured. T95 measured after breathing N2O/O2 and air/O2 were 34.6 +/- 5.7 and 28.8 +/- 4.7% of that measured after oxygen breathing (P < 0.001 vs oxygen breathing, P < 0.001 vs oxygen and N2O/O2 breathing), respectively. Preoxygenation before intubation was validated to delay the haemoglobin desaturation brought about by apnoea. An induction technique using a low FiO2 will allow rapid haemoglobin desaturation.

We made a paediatric anaesthesia mask suitable for fibreoptic intubation by modifying a commercially available disposable mask with a ventilation port (Vent port) on a side. We added a large fibreoptic port (FO port, 22 mm in ID) in the middle of the mask to allow the passage of all sizes of paediatric tracheal tubes. This FO port was covered with an elastic rubber membrane to allow air-tight fibrescopic manipulation Fibreoptic intubation was performed safely through the FO port under continuous manual ventilation with anaesthetic gases via a Vent port connected to the breathing circuit. We succeeded in tracheal intubation in several infants and children with difficult airway in less than ten min, mainly via the nasotracheal route. This fibreoptic mask provides a safer technique for fibreoptic intubation in patients with difficult airways, especially in infants and small children.

A four-month-old male infant with basal encephalocele of the transsphenoidal type presented with upper airway obstruction and facial midline deformity, including cleft lip, cleft palate, hypertelorism and exophthalmos. Basal encephalocele is a rare disease, and usually not detectable from the outside. In this case, initially the cause of an upper airway obstruction was considered to be posterior rhinostenosis, and posterior rhinoplasty with inferior nasal conchectomy was scheduled. However, in preoperative examination, computed tomography (CT) and magnetic resonance imaging (MRI) revealed a bony defect in the sphenoidal bone and a cystic mass in communication with cerebrospinal fluid, herniating into the nasal cavity through the bony defect. The mass was diagnosed as a transsphenoidal encephalocele, the scheduled operation cancelled, and tracheostomy performed for airway management. The possibility of basal encephalocele should be considered in the case of upper airway obstruction with facial midline deformity.

C(post), but not C(pre), may be useful to predict the need for prolonged postoperative mechanical ventilation in neonates with left-sided CDH.