Unexpected difficult airway management in a transgender female patient

A transgender female patient, who had previously undergone gender-confirming feminisation surgery to the face and larynx, was scheduled for thoracic surgery requiring one-lung ventilation. We encountered unexpected difficult airway management and difficulty inserting an appropriately-sized double-lumen tube. A size 41Fr double-lumen tube, which is selected commonly for biological males, was used eventually for lung isolation and subsequently exchanged for a size 6.5 single-lumen tracheal tube at the end of the case, before successful extubation with a staged extubation set. It is important to highlight the challenges faced, as the care of transgender patients is likely to be unfamiliar to most anaesthetists, despite the increase in the number of gender-confirming procedures performed. Many of these procedures involve the face and airway and can result in significant challenges for airway management, including appropriate sizing of tracheal tubes and their correct placement. It is also possible that patients may not volunteer a history of these procedures and it should be enquired about specifically as part of the anaesthetic pre-assessment.

The impact of respiratory protective equipment on difficult airway management: a randomised, crossover, simulation study

The current international COVID‐19 health crisis underlines the importance of adequate and suitable personal protective equipment for clinical staff during acute airway management. This study compares the impacts of standard air‐purifying respirators and powered air‐purifying respirators during simulated difficult airway scenarios. Twenty‐five anaesthetists carried out four different standardised difficult intubation drills, either unprotected (control), or wearing a standard or a powered respirator. Treatment times and wearer comfort were determined and compared. In the wearer comfort evaluation form, operators rated mobility, noise, heat, vision and speech intelligibility. All anaesthetists accomplished the treatment objectives of all study arms without adverse events. Total mean (SD) intubation times for the four interventions did not show significant differences between the powered and the standard respirator groups, being 16.4 (8.6) vs. 19.2 (5.2) seconds with the Airtraq™; 11.4 (3.4) vs. 10.0 (2.1) seconds with the videolaryngoscope; 39.2 (4.5) vs. 40.1 (4.8) seconds with the fibreoptic bronchoscope scope; and 15.4 (5.7) vs. 15.1 (5.0) seconds for standard tracheal intubation by direct laryngoscopy, respectively. Videolaryngoscopy allowed the shortest intubation times regardless of the respiratory protective device used. Anaesthetists rated heat and vision significantly higher in the powered respirator group; however, noise levels were perceived to be significantly lower than in the standard respirator group. We conclude that standard and powered respirators do not significantly prolong simulated advanced intubation procedures.

Awake tracheal intubation in a suspected COVID-19 patient with critical airway obstruction

We report the airway management of a patient with suspected COVID-19 with impending airway obstruction requiring urgent surgical tracheostomy. To our knowledge, this is the first reported case of an awake tracheal intubation in a suspected COVID-19-positive patient. Various modifications were put in place during the awake tracheal intubation and surgical tracheostomy procedures to minimise aerosol generation from the patient, such as avoiding high-flow nasal oxygen, establishing conscious sedation with remifentanil before commencing airway topicalisation and avoiding transtracheal local anaesthetic infiltration. A multidisciplinary team discussion before performing the case highlighted aspects of both the airway management and the surgical procedure where particular care and modifications are required. There is a lack of national and international guidance for awake tracheal intubation and tracheostomy in COVID-19 cases. This report nevertheless addresses the key procedural modifications required.

Numerical Simulation of Non-Axisymmetric Homann's Stagnation-Point Flow of Nanofluid

This paper addresses numerical results for nanofluid near Homann's non-axisymmetric stagnation-point flow. The nanofluids model shows Brownian motion and thermophoresis effects. Recently, Weidman modify the Homann's stagnation-point problem to non-axisymmetric on rigid surface by superposing additional periodic terms to outer potential flow. The numerical results for couple differential system are obtained by means of shooting method. The solution is achieved for diverse values of involved parameter and ratio γ = b/a (b is shear and a is strain rate), which ranges from (–∞, ∞). The distributions for shear stresses, heat and mass transfer rate, temperature and nanoparticle concentration compared to their large- asymptotic behaviors also presented. For nanofluids, properties may vary considerably near solid boundary due to thermophoresis and Brownian motion of the fluid particles. These effects can result in decreasing viscosity within the boundary layer for heated fluids, thus leading to heat transfer enhancement.

Difficult airway management for the anaesthetist

This article reviews the key considerations when managing a patient with a difficult airway. The difficult airway may be anticipated from preassessment allowing time for investigations and preparation. Alternatively, the unanticipated difficult airway can present in an emergency situation, or unexpectedly during a routine anaesthetic. The main airway management techniques are discussed with a description of their advantages and limitations. Current guidelines are included that demonstrate how the techniques are incorporated into an overall strategy with a plan A-D when failure occurs. It is critical to progress through such an algorithm in a timely manner to prevent the onset of hypoxia.

Difficult Airway Society guidelines for awake tracheal intubation (ATI) in adults

Awake tracheal intubation has a high success rate and a favourable safety profile but is underused in cases of anticipated difficult airway management. These guidelines are a comprehensive document to support decision making, preparation and practical performance of awake tracheal intubation. We performed a systematic review of the literature seeking all of the available evidence for each element of awake tracheal intubation in order to make recommendations. In the absence of high‐quality evidence, expert consensus and a Delphi study were used to formulate recommendations. We highlight key areas of awake tracheal intubation in which specific recommendations were made, which included: indications; procedural setup; checklists; oxygenation; airway topicalisation; sedation; verification of tracheal tube position; complications; management of unsuccessful awake tracheal intubation; post‐tracheal intubation management; consent; and training. We recognise that there are a range of techniques and regimens that may be effective and one such example technique is included. Breaking down the key practical elements of awake tracheal intubation into sedation, topicalisation, oxygenation and performance might help practitioners to plan, perform and address complications. These guidelines aim to support clinical practice and help lower the threshold for performing awake tracheal intubation when indicated.

A systematic review and cost effectiveness analysis of reusable vs. single-use flexible bronchoscopes

The cost effectiveness of reusable vs. single‐use flexible bronchoscopy in the peri‐operative setting has yet to be determined. We therefore aimed to determine this and hypothesised that single‐use flexible bronchoscopes are cost effective compared with reusable flexible bronchoscopes. We conducted a systematic review of the literature, seeking all reports of cross‐contamination or infection following reusable bronchoscope use in any clinical setting. We calculated the incidence of these outcomes and then determined the cost per patient of treating clinical consequences of bronchoscope‐induced infection. We also performed a micro‐costing analysis to quantify the economics of reusable flexible bronchoscopes in the peri‐operative setting from a high‐throughput tertiary centre. This produced an accurate estimate of the cost per use of reusable flexible bronchoscopes. We then performed a cost effectiveness analysis, combining the data obtained from the systematic review and micro‐costing analysis. We included 16 studies, with a reported incidence of cross‐contamination or infection of 2.8%. In the micro‐costing analysis, the total cost per use of a reusable flexible bronchoscope was calculated to be £249 sterling. The cost per use of a single‐use flexible bronchoscope was £220 sterling. The cost effectiveness analysis demonstrated that reusable flexible bronchoscopes have a cost per patient use of £511 sterling due to the costs of treatment of infection. The findings from this study suggest benefits from the use of single‐use flexible bronchoscopes in terms of cost effectiveness, cross‐contamination and resource utilisation.

Pathogenesis and tissue tropism of Newcastle disease virus and avian influenza virus (H9N2) in single and mixed infections

Newcastle disease (ND) and avian influenza (AI) are globally considered as a serious threat to the chicken and other avian species. The paramyxovirus type 1 and orthomyxovirus type A are RNA viruses, which cause ND and AI infection, respectively.