Shared Airway Research Articles

Thyroplasty under total intravenous anaesthesia with intermittent positive pressure ventilation

Medialization thyroplasty is a surgical technique for improving voice quality, cough effort and laryngeal competence in patients with unilateral vocal fold paralysis. Precision surgery is enabled by operating under total intravenous anaesthesia with controlled ventilation and by using a laryngoscopic video-assisted technique. The anaesthetic challenge is to manage the shared airway with the surgeon, provide a stable operative field and ensure patient safety throughout the procedure. The objective of this case series was to evaluate the use of a modified general anaesthetic technique using the laryngeal mask airway, total intravenous anaesthesia with controlled ventilation. In all, 29 patients underwent medialization thyroplasty using a disposable laryngeal mask airway, total intravenous anaesthesia and controlled ventilation. Standard anaesthetic monitoring including capnography was used intraoperatively. Total intravenous anaesthesia was achieved using effect site target-controlled infusions of propofol and remifentanil. The technique proved safe with stable haemodynamic observations and only two minor complications. It also provided the surgeon with stable view of the vocal folds in order to perform this precision surgery under an operating microscope.

Anaesthesia for thyroid and parathyroid surgery

In the UK, Stanley Rowbotham pioneered anaesthesia for thyroid surgery in the 1940s. He combined local anaesthesia with light general anaesthesia, and even attempted to make the patient strain to test haemostatic sutures using one breath of ether. Anaesthesia for thyroid surgery requires an anaesthetist who is experienced in the recognition, assessment, and management of a potentially difficult, shared airway, in a patient who may also have significant co-morbidity. Complexity of the procedure may vary from excision of a simple nodule to removal of retrosternal goitre to relieve tracheal compression. The latter can be excised through a standard collar incision, but it may be necessary to split the sternum to access the inferior pole of the enlarged gland. Although blood loss is usually minimal, there is potential for major haemorrhage from large blood vessels closely related to the gland, particularly if the thyroid extends retrosternally.

Tracheal tubes for maxillofacial and dental surgery

Maxillofacial and dental surgery have developed with anaesthesia. This is because of the mutual understanding that is necessary for safe and successful surgery on the ‘shared airway’. The choice of airway management technique is influenced by patient factors, surgical requirements and anaesthetic preferences. Good communication between surgeon and anaesthetist is imperative for the safety of the patient and the smooth running of the surgery. The anaesthetic considerations include: dealing with the difficult airway; the risk of obstruction, transection, disconnection or removal of the airway intraoperatively; the risk of soiling of the airway due to bleeding and surgical debris such as tooth or bone fragments; and the potential for airway compromise postoperatively. A cuffed tracheal tube with a throat pack provides the highest level of airway protection in shared airway surgery, but may not always be the most suitable technique. A north polar nasal tube provides a secure airway and excellent surgical access for surgery on the jaws, teeth, oral cavity and neck; it also allows intermaxillary fixation (wiring of the jaws) and assessment of dental occlusion. South facing preformed oral (RAE) tubes are suitable for procedures involving the nose, upper mid face and forehead. Submental intubation provides an alternative to oral and nasal tracheal intubation and is useful in selected procedures. The laryngeal mask airway (LMA) has an important role intraoperatively and provides smooth emergence from anaesthesia. Transtracheal catheter and jet ventilation is seldom used in maxillofacial anaesthesia, but is an important rescue technique. An elective tracheostomy should be considered if significant postoperative airway compromise is anticipated and may occasionally be necessary under local anaesthesia before induction. It requires surgical expertise and carries a high incidence of morbidity. This article discusses how to select appropriate tracheal tubes for maxillofacial and dental surgery.

Les anesthésiologistes pédiatriques canadiens préfèrent l’anesthésie par inhalation dans les cas de problèmes des voies aériennes: une enquête

To survey Canadian pediatric anesthesiologists to assess practice patterns in managing pediatric patients with difficult airways. Canadian pediatric anesthesiologists were invited to complete a web survey. Respondents selected their preferred anesthetic and airway management techniques in six clinical scenarios. The clinical scenarios involved airway management for cases where the difficulty was in visualizing the airway, sharing the airway and accessing a compromised airway. General inhalational anesthesia with spontaneous respiration was the preferred technique for managing difficult intubation especially in infants (90%) and younger children (97%), however, iv anesthesia was chosen for the management of the shared airway in the older child (51%) where there was little concern regarding difficulty of intubation. Most respondents would initially attempt direct laryngoscopy for the two scenarios of anticipated difficult airway (73% and 98%). The laryngeal mask airway is commonly used to guide fibreoptic endoscopy. The potential for complete airway obstruction would encourage respondents to employ a rigid bronchoscope as an alternate technique (17% and 44%). Inhalational anesthesia remains the preferred technique for management of the difficult pediatric airway amongst Canadian pediatric anesthesiologists. Intravenous techniques are relatively more commonly chosen in cases where there is a shared airway but little concern regarding difficulty of intubation. In cases of anticipated difficult intubation, direct laryngoscopy remains the technique of choice and fibreoptic laryngoscopy makes a good alternate technique. The use of the laryngeal mask airway was preferred to facilitate fibreoptic intubation.

Another cause of obstruction of a ‘shared airway’

Another cause of obstruction of a ‘shared airway’

Althesin in shared airway anaesthesia.

The anaesthetic management for surgical procedures involving the larynx and/or trachea and the problem of the shared airway are outlined. The use of intravenous Althesin on 31 patients (43 administrations) is described. It is suggested that Althesin has a place in the management of these patients.