Near total intrathoracic airway obstruction managed with a Tritube® and flow-controlled ventilation

We describe the management of a case of near total airway obstruction in a 79-year-old man who presented with a 2-week history of increasing shortness of breath and stridor. Computed tomography imaging revealed a mid-tracheal mass of unknown aetiology with critical airway obstruction. We secured the patient's airway using a TriTube^® (Ventinova, Eindhoven, the Netherlands). While this facilitated a secure airway past the lesion, various issues were encountered which complicated the safe conduct of anaesthesia. We conclude that while the TriTube and Evone^® flow-controlled ventilation (Ventinova) are useful for critical airway obstruction, they can be problematic and thorough planning is essential.

Laryngectomy with a Tritube® and flow-controlled ventilation

We describe the novel use of the TriTube^® and Evone^® ventilator (Ventinova, Eindhoven, Netherlands) to facilitate curative resection of a transglottic squamous cell carcinoma. A 43-year-old man presented with acute laryngeal and subglottic airway obstruction secondary to a stage 4 transglottic squamous cell carcinoma. The patient underwent magnetic resonance imaging followed by a diagnostic panendoscopy. It was decided that tumour resection was appropriate and a management plan was established by a multi disciplinary team. A total laryngectomy was performed. It was determined that failure of translaryngeal tracheal intubation could be rescued with emergency surgical front-of-neck airway. General anaesthesia was induced using a total intravenous anaesthesia technique, oxygenation was achieved with high-flow nasal oxygen and the airway was secured using the TriTube and flow-controlled ventilation was delivered throughout the procedure using the Evone ventilator. This avoided an awake or emergency tracheostomy, with the associated theoretical risk of tumour seeding, allowed for excellent gas exchange throughout and permitted the surgeons to maintain a closed system during much of the procedure, including during fashioning of the stoma. When traditional laryngectomy tubes are used, this process ordinarily involves multiple extubations and apnoeic periods. Furthermore, the small subglottic tube allowed intra-operative assessment of the extent of the subglottic tumour, facilitating curative en bloc resection.

Depot and oral antipsychotics: patient preferences and attitudes are not the same thing

Some clinicians believe that antipsychotic depot injections are unacceptable to patients. This cross-sectional study investigated patients' attitudes regarding antipsychotics, and included within-participant comparisons. Two hundred and twenty-two out-patients with schizophrenia/schizoaffective disorder completed the Drug Attitude Inventory (DAI-10), scales on insight, side effects and treatment preferences. Formulation preference was associated with current medication formulation: depots were preferred by 43% (33/76) on depot vs 6% (8/146) on orals (P < 0.001). Attitudes (DAI scores) regarding current formulation were influenced by illness duration, extrapyramidal symptoms and insight but not by formulation (depot vs oral). For those with experience of both formulations, participants currently on tablets scored depots less favourably than oral (4.27 vs 6.89, P < 0.001); those on depot did not differentiate. When voluntary patients on maintenance antipsychotics are asked about their attitudes to their current medication, those on depot respond similarly to those on oral. However, when asked to state a preference for formulation (depot vs oral), patients tend to favour their current formulation. Whatever leads some to switch from depot to oral, leaves a lasting negative impression of the depot and this may limit uptake of newer depots.

Peripheral nerves in the rat exhibit localized heterogeneity of tensile properties during limb movement

Peripheral nerves in the limbs stretch to accommodate changes in length during normal movement. The aim of this study was to determine how stretch is distributed along the nerve relative to local variations in mechanical properties. Deformation (strain) in joint and non-joint regions of rat median and sciatic nerves was measured in situ during limb movement using optical image analysis. In each nerve the strain was significantly greater in the joint rather than the non-joint regions (2-fold in the median nerve, 5- to 10-fold in the sciatic). In addition, this difference in strain was conserved in the median nerve ex vivo, demonstrating an in-built longitudinal heterogeneity of mechanical properties. Tensile testing of isolated samples of joint and non-joint regions of both nerves showed that joint regions were less stiff (more compliant) than their non-joint counterparts with joint: non-joint stiffness ratios of 0.5 +/- 0.07 in the median nerve, and 0.8 +/- 0.02 in the sciatic. However, no structural differences identified at the light microscope level in fascicular/non-fascicular tissue architecture between these two nerve regions could explain the observed tensile heterogeneity. This identification of localized functional heterogeneity in tensile properties is particularly important in understanding normal dynamic nerve physiology, provides clues to why peripheral nerve repair outcomes are variable, and suggests potential novel therapeutic targets.