In patients receiving total parenteral nutrition via central venous catheters, erosion has an incidence per catheter of 0.17% and is more likely to occur in left-sided catheters and elderly patients.

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BackgroundSimulation-based medical education has rapidly evolved over the past two decades, despite this, there are few published reports of its use in critical care teaching. We hypothesised that simulation-based teaching of a critical care topic to final-year medical students is superior to lecture-based teaching.MethodsThirty-nine final-year medical students were randomly assigned to either simulation-based or lecture-based teaching in the chosen critical care topic. The study was conducted over a 6-week period. Efficacy of each teaching method was compared through use of multiple choice questionnaires (MCQ) - baseline, post-teaching and 2 week follow-up. Student satisfaction was evaluated by means of a questionnaire. Feasibility and resource requirements were documented by teachers.ResultsEighteen students were randomised to simulation-based, and 21 to lecture-based teaching. There were no differences in age and gender between groups (p > 0.05).Simulation proved more resource intensive requiring specialised equipment, two instructors, and increased duration of teaching sessions (126.7 min (SD = 4.71) vs 68.3 min (SD = 2.36)).Students ranked simulation-based teaching higher with regard to enjoyment (p = 0.0044), interest (p = 0.0068), relevance to taught subject (p = 0.0313), ease of understanding (p = 0.0476) and accessibility to posing questions (p = 0.001).Both groups demonstrated improvement in post-teaching MCQ from baseline (p = 0.0002), with greater improvement seen among the simulation group (p = 0.0387), however, baseline scores were higher among the lecture group. The results of the 2-week follow-up MCQ and post-teaching MCQ were not statistically significant when each modality were compared.DiscussionSimulation was perceived as more enjoyable by students. Although there was a greater improvement in post-teaching MCQ among the simulator group, baseline scores were higher among lecture group which limits interpretation of efficacy. Simulation is more resource intensive, as demonstrated by increased duration and personnel required, and this may have affected our results.ConclusionsThe current pilot may be of use in informing future studies in this area.

Editor-Vallecular cysts are a rare cause of difficulty in intubating the trachea. We describe a case of difficult intubation in a patient, after inhalation induction, for examination under anaesthesia of an infected vallecular cyst. A 31-yr-old male presented with a year-long history of dysphagia, anorexia, and 13 kg weight loss. He had a 3 week history of shortness of breath on exertion and associated dysphonia. There was no evidence of stridor or hoarseness. He was apryexial, haemodynamically stable with oxygen saturation of 98% on room air. His medical history was significant for a 6 yr history of i.v. drug usage and heavy smoking. On examination, there were no palpable masses on his neck or visible abnormalities in his oral cavity. He was Mallampati score 1, and had good mouth opening and neck movement. Flexible fibreoptic nasolaryngoscopy revealed a well-circumscribed pedunculated mass arising from the vallecula. He was taken to the theatre for examination under anaesthesia, pharyngoscopy, and oesphagoscopy. Inhalation induction was carried out with upward titration of 1-8% sevoflurane in 100% oxygen. Anaesthesia was maintained with bolus doses of propofol, in addition to sevoflurane in oxygen via face mask. Spontaneous respiration was maintained. Three attempts at laryngoscopy using Mackintosh blade 3, McCoy blade 3, and Miller laryngoscope were all unsuccessful. Oxygen saturations throughout remained stable and the patient was easy to bag-mask ventilate. Endotracheal intubation was finally obtained by the ENT surgeon using the ENT rigid laryngoscope. Being longer than anaesthetic laryngoscopes, it was possible to pass distal to the cyst, displacing it to one side allowing visualization of the vocal cords. The remainder of the anaesthetic was uneventful. Definitive treatment included aspiration of thick pus followed by excision. IV dexamethasone was administered to limit airway oedema. At the end of the procedure, the patient was extubated uneventfully. Microbiology culture grew Staphylococcus aureus. Histological examination revealed that of a benign cyst. He was treated with i.v. antibiotics and discharged home on the fifth postoperative day. Most laryngeal cysts are asymptomatic. However, all have the potential to present with airway compromise. Non-infected cysts usually present with mild symptoms related to pressure effect on surrounding tissues. Infection of cysts can cause acute epiglottitis or abscess formation and subsequent acute airway obstruction. A review published in 2008 describes an increased incidence of airway obstruction in infected compared with non-infected cysts. 1 There are case reports of patients with vallecular cysts proving difficult to intubate. 2 3 Several describe complications encountered during intubation attempts: bleeding requiring abandonment of the procedure 4 and laryngospasm. 2