A randomised cross-over comparison of the transverse and longitudinal techniques for ultrasound-guided identification of the cricothyroid membrane in morbidly obese subjects.

We compared the transverse and longitudinal approaches to ultrasound-guided identification of the cricothyroid membrane, to determine which was faster and more successful. Forty-two anaesthetists received a one-hour structured training programme consisting of e-learning, a lecture and hands-on training, and then applied both techniques in a randomised, cross-over sequence to obese females with body mass index 39.0 - 43.9 kg.m(-2) . The mean (SD) time to identify the cricothyroid membrane was 24.0 (12.4) s using the transverse technique compared with 37.6 (17.9) s for the longitudinal technique (p = 0.0003). Successful identification of the cricothyroid membrane was achieved by 38 (90%) anaesthetists using either technique. All anaesthetists were successful in identifying the cricothyroid membrane with at least one of the techniques. We advocate the learning and application of these two techniques for identification of the cricothyroid membrane before starting anaesthesia in difficult patients, especially when anatomical landmarks are impalpable. Further use in emergency situations is feasible, if clinicians have experience and the ultrasound machine is readily available.

Tracheal intubation in patients with anticipated difficult airway using Boedeker intubation forceps and McGrath videolaryngoscope.

BACKGROUND: Videolaryngoscopes with sharp angulated blades improve the view of the vocal cords but this does not necessarily result in higher success rates of intubation The aim of this study was to evaluate the efficacy of using Boedeker intubation forceps in conjunction with McGrath Series 5 Videolaryngoscope (MVL) in patients with predictors for difficult intubation. METHODS: The study was conducted at the Department of Anaesthesia, Copenhagen University Hospital from September to December 2013. Patients with one or more predictors of difficult intubation scheduled for general anaesthesia were assessed for eligibility. Patients were intubated using Boedeker intubation forceps and MVL. The primary endpoint was time to intubation. The secondary endpoints were intubation success rate, number of intubation attempts, intubation conditions and post-operative hoarseness. RESULTS: Thirty-three patients were assessed for eligibility, and 25 patients were included in the study with a median SARI score of 3 (IQR 3-4). Twenty-two (88%, 95% confidence interval [74-100%]) of the patients were successfully intubated by the method with a median time to intubation of 115 s (IQR 78-247). Steering and advancement of the tube were reported as acceptable in 21 (84%) and 22 cases (88%), respectively, and excellent in 10 cases (45%) for both measures. Ten cases (40%) were intubated on the first attempt. There were three cases (12%) of failed intubation; in these cases, successful intubation was obtained by using a styletted tube. CONCLUSION(S): Most patients with anticipated difficult intubation can be successfully intubated with Boedeker intubation forceps and MVL. However, endotracheal tube placement failed in 3/25 patients despite a good laryngeal view.

A cost analysis of reusable and disposable flexible optical scopes for intubation.

BACKGROUND: Intubation using a flexible optical scope (FOS) is a cornerstone technique for managing the predicted and unpredicted difficult airway. The term FOS covers both fibre-optic scopes and videoscopes. The total costs of using flexible scopes for intubation are unknown. The recent introduction of a disposable flexible scope for intubation merits closer scrutiny of the total costs associated with both modalities. METHODS: The costs incurred during intubations using FOSs at a large anaesthesia department were identified, and a series of intubations using a disposable scope were analyzed for comparison. Recognized health-economic methodology was applied. RESULTS: During a 1-year period, 360 FOS intubations were performed. In this clinical setting, the average cost of an intubation using a reusable FOS was €177.7. When using the disposable Ambu(®) aScope (Ambu A/S, Ballerup, Denmark), the cost was €204.4. The break-even point, i.e. the number of intubations per month where the cost of using disposable and non-disposable equipment is identical, was 22.5/month. A subgroup analysis looking solely at intubations performed with flexible videoscopes revealed that the cost per intubation was equal for disposable and reusable videoscopes. CONCLUSION: At our institution, the total cost of an intubation is greater when using disposable compared with reusable equipment (€204.4 vs. €177.7). If video equipment with an external monitor is considered mandatory, the expenses are of equal magnitude. The cost analysis is particularly sensitive to the actual number of flexible optic intubations performed; with fewer intubations, the total cost will begin to favour disposable equipment.

It is possible to perform a double-blind hyperbaric session: a double-blinded randomized trial performed on healthy volunteers.

In hyperbaric medicine, blinded trials are remarkably few, making results susceptible to criticism. The scopes of the present study are to present a method for a double-blinded randomized clinical study and evaluate the validity of the method in a hyperbaric setting. Twenty-two healthy volunteers with no diving experience were included. The volunteers were randomized either to a "therapeutic pressure" group (15 msw, 253 kPa) or to a "placebo" group (2 msw, 120 kPa). The two profiles were made equal regarding noise, temperature and ventilation. The volunteers were asked whether they had been exposed to placebo or therapeutic pressure. They were asked to present their certainness of the answer on a visual analogue scale (VAS). Fisher's exact test calculates a probability of P = 0,328, which indicates that the volunteers have no valid opinion as to whether they were exposed to 15 msw or to 2 msw. It is found that it is possible to perform a blinded treatment on healthy volunteers with no prior diving experience.

Postural stability before and after hyperbaric oxygen treatment.

OBJECTIVE: The purpose of this study was to determine the effect of hyperbaric oxygenation (HBO) on postural stability in healthy volunteers. The study was performed in accordance with treatment protocols for divers' decompression sickness and carbon monoxide poisoning. METHODS: Twenty-one healthy male divers, aged 31 +/- 6.88 years (mean +/- SD), were tested with quantitative Romberg's test before and after HBO (90 min in a pressure chamber at an ambient pressure of 253 kPa, approximately 15 m of sea water, breathing pure oxygen). The quantitative Romberg's test is a calculation of the average sway for 50 s. RESULTS: No difference was found between sway before and after the HBO (P < 0.05), i.e. we were unable to show that the results of quantitative Romberg's test are affected by HBO. Thus, the quantitative Romberg's test may be a valuable tool in evaluating patients with decompressions sickness, carbon monoxide intoxication and other neurological diseases normally treated with HBO.