Anaesthesia
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Comparative Study
Clinical validation of bioreactance for the measurement of cardiac output in pregnancy.
Maternal cardiac dysfunction is associated with pre-eclampsia, fetal growth restriction and haemodynamic instability during obstetric anaesthesia. There is growing interest in the use of non-invasive cardiac output monitoring to guide antihypertensive and fluid therapies in obstetrics. The aim of this study was to validate thoracic bioreactance using the NICOM® instrument against transthoracic echocardiography in pregnant women, and to assess the effects of maternal characteristics on the absolute difference of stroke volume, cardiac output and heart rate. ⋯ Similar results were found when the analyses were confined to each individual trimester. The absolute difference between NICOM and echocardiography was not affected by maternal age, weight, height, race, systolic or diastolic blood pressure. In conclusion, NICOM demonstrated good agreement with echocardiography, and can be used in pregnancy for the measurement of cardiac function.
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Guideline
Audio/visual recording of doctors in hospitalsGuideline from the Association of Anaesthetists.
Guidelines are presented that summarise the legal position regarding the audio/visual recording of doctors and others in hospitals. In general, there are few, if any, legal grounds for refusing a request by patients to record procedures and/or discussions with clinicians, although some staff may feel uncomfortable being recorded. Trusts and others are advised to draw up local policies and ensure staff and patients are adequately informed.
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The COVID-19 pandemic has led to the production of novel devices intended to protect airway managers during the aerosol-generating procedure of tracheal intubation. Using an in-situ simulation model, we evaluated laryngoscopist exposure of airborne particles sized 0.3 - 5.0 microns using five aerosol containment devices (aerosol box; sealed box with and without suction; vertical drape; and horizontal drape) compared with no aerosol containment device. Nebulised saline was used as the aerosol-generating model for 300 s, at which point, the devices were removed to assess particle spread. ⋯ Compared with no device use, neither horizontal nor vertical drapes showed any difference in any particle size exposure at any time. Finally, when the patient coughed, use of the aerosol box resulted in a marked increase in airborne particle exposure compared with other devices or no device use. In conclusion, novel devices intended to protect the laryngoscopist require objective testing to ensure they are fit for purpose and do not result in increased airborne particle exposure.
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Spinal hypotension is a common and clinically important problem during caesarean section. Current consensus recommendations for resource-rich settings suggest the use of a titrated phenylephrine infusion, in combination with fluid coloading, for prevention of maternal hypotension. In resource-limited settings, where syringe drivers are unavailable, these recommendations advise the addition of 500 μg phenylephrine to the first 1 l of intravenous fluid given after initiation of spinal anaesthesia, with additional vasopressor boluses as required. ⋯ The six highest systolic arterial pressure readings occurred in the phenylephrine infusion group (range 166-188 mmHg), and there were four instances of bradycardia (heart rate < 50 beats.min-1 ) with preserved systolic arterial pressure in each group. There were no adverse clinical sequelae, and no differences in neonatal Apgar scores in either group. The consensus recommendation for phenylephrine and fluid co-administration in resource-limited settings appears effective in preventing maternal hypotension, but at the cost of sporadic systolic hypertension.
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The number of patients requiring tracheal intubation rose dramatically in March and April 2020 with the COVID-19 outbreak. Our thoracic surgery department has seen an increased incidence of severe pneumomediastinum referred for surgical opinion in intubated patients with COVID-19 pneumonitis. ⋯ We hypothesise that the mechanism for this is the aggressive disease pathophysiology with an increased risk of alveolar damage and tracheobronchial injury, along with the use of larger-bore tracheal tubes and higher ventilation pressures. We present this case series in order to highlight the increased risk of this potentially life-threatening complication among the COVID-19 patient cohort and offer guidance for its management to critical care physicians.