The COVID-19 pandemic has increased the demand for disposable N95 respirators. Re-usable elastomeric respirators may provide a suitable alternative. Proprietary elastomeric respirator filters may become depleted as demand increases. An alternative may be the virus/bacterial filters used in anaesthesia circuits, if they can be adequately fitted onto the elastomeric respirators. In addition, many re-usable elastomeric respirators do not filter exhaled breaths. If used for sterile procedures, this would also require modification. We designed a 3D-printed adaptor that permits elastomeric respirators to interface with anaesthesia circuit filters and created a simple modification to divert exhaled breaths through the filter. We conducted a feasibility study evaluating the performance of our modified elastomeric respirators. A convenience sample of eight volunteers was recruited. Quantitative fit testing, respiratory rate and end-tidal carbon dioxide were recorded during fit testing exercises and after 1 h of wear. All eight volunteers obtained excellent quantitative fit testing throughout the trial. The mean (SD) end-tidal carbon dioxide was 4.5 (0.5) kPa and 4.6 (0.4) kPa at baseline and after 1 h of wear (p = 0.148). The mean (SD) respiratory rate was 17 (4) breaths.min(-1) and 17 (3) breaths.min(-1) at baseline and after 1 h of wear (p = 0.435). Four out of eight subjects self-reported discomfort; two reported facial pressure, one reported exhalation resistance and one reported transient dizziness on exertion. Re-usable elastomeric respirators to utilise anaesthesia circuit filters through a 3D-printed adaptor may be a potential alternative to disposable N95 respirators during the COVID-19 pandemic.
Bleeding and blood transfusion are common after scoliosis surgery. Fibrinogen is essential for blood clot formation and depletes quickly during haemorrhage. We randomly allocated 102 children 12-18 years old having surgery for idiopathic scoliosis, 51 to intra-operative fibrinogen concentrate 30 mg.kg(-1) (maximum 2 g) and 51 to saline placebo. Fibrinogen reduced peri-operative blood loss by a median (95%CI) volume of 155 (5-320) ml, from a median (IQR [range]) of 1035 (818-1420 [400-3030]) ml to 885 (755-1155 [270-2645]) ml, p = 0.04. Seven and four children received allogeneic red blood cell transfusion after fibrinogen and placebo, respectively, p = 0.34. There were no side-effects.
Previous studies on the safety of peri-operative transoesophageal echocardiography seem to suggest a low rate of associated morbidity and mortality. That said, there has been a paucity of prospective multicentre studies in this important area of clinical practice. We carried out a one-year prospective study in 2017, co-ordinated by the Association of Cardiothoracic Anaesthesia and Critical Care, to determine the rate and severity of complications associated with peri-operative transoesophageal echocardiography in anaesthetised cardiology and cardiac surgical patients. With the help of clinicians from 28 centres across the UK and Ireland, we recorded the total number of examinations conducted in anaesthetised patients during the study period. All major complications at each centre were prospectively reported and recorded. Of the 22,314 examinations, there were 17 patients diagnosed with a major complication which caused either palatal injury or gastro-oesophageal disruption. This corresponds to an incidence of 0.08% (95%CI 0.05-0.13%) or approximately 1:1300 examinations. There were seven deaths reported during the study period which were directly attributed to these complications, corresponding to an incidence of 0.03% (95%CI 0.01-0.07%) or approximately 1:3000. These figures are higher than previously reported and suggest a high probability of death following the development of a complication (~40%). Most complications occurred in patients without known risk factors for transoesophageal echocardiography associated gastro-oesophageal injury. We suggest clinicians and departments review their procedural guidelines, especially in relation to probe insertion techniques, together with the information communicated to patients when the risks and benefits of such examinations are discussed.
Propofol-based total intravenous anaesthesia is well known for its smooth, clear-headed recovery and anti-emetic properties, but there are also many lesser known beneficial properties that can potentially influence surgical outcome. We will discuss the anti-oxidant, anti-inflammatory and immunomodulatory effects of propofol and their roles in pain, organ protection and immunity. We will also discuss the use of propofol in cancer surgery, neurosurgery and older patients.
Healthcare workers involved in aerosol-generating procedures, such as tracheal intubation, may be at elevated risk of acquiring COVID-19. However, the magnitude of this risk is unknown. We conducted a prospective international multicentre cohort study recruiting healthcare workers participating in tracheal intubation of patients with suspected or confirmed COVID-19. Information on tracheal intubation episodes, personal protective equipment use and subsequent provider health status was collected via self-reporting. The primary endpoint was the incidence of laboratory-confirmed COVID-19 diagnosis or new symptoms requiring self-isolation or hospitalisation after a tracheal intubation episode. Cox regression analysis examined associations between the primary endpoint and healthcare worker characteristics, procedure-related factors and personal protective equipment use. Between 23 March and 2 June 2020, 1718 healthcare workers from 503 hospitals in 17 countries reported 5148 tracheal intubation episodes. The overall incidence of the primary endpoint was 10.7% over a median (IQR [range]) follow-up of 32 (18-48 [0-116]) days. The cumulative incidence within 7, 14 and 21 days of the first tracheal intubation episode was 3.6%, 6.1% and 8.5%, respectively. The risk of the primary endpoint varied by country and was higher in women, but was not associated with other factors. Around 1 in 10 healthcare workers involved in tracheal intubation of patients with suspected or confirmed COVID-19 subsequently reported a COVID-19 outcome. This has human resource implications for institutional capacity to deliver essential healthcare services, and wider societal implications for COVID-19 transmission.
Cataract surgery is usually of short duration and is associated with minimal pain when employing topical or regional anaesthesia. Patient education regarding the peri-operative process may help alleviate anxiety and avoid the need for sedation. However, sedation may be required, and we discuss the various options. Many consider that pre-operative fasting is necessary due to the risk of aspiration but fasting may not be required if minimal sedation is administered. If the use of sedatives, hypnotics or analgesics is required, then their associated adverse events should be considered.