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 TM ; 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.

Barth syndrome (BTHS) is an X-linked disorder characterised by cardiomyopathy, neutropenia, skeletal myopathy and growth delay. This study describes the UK national clinical experience and outcome of cardiomyopathy in BTHS. The clinical course and echocardiographic changes of all patients with BTHS in the UK were reviewed from 2004 to 2014. In addition, strain analysis using 2D speckle tracking echocardiography was performed to further assess left ventricular function in the most recent follow-up. At last follow-up, 22 of 27 patients were alive with a median age of 12.6 (2.0-23.8) years; seven underwent cardiac transplantation at a median age of 2 (0.33-3.6) years, and five died (18.5%) at a median age of 1.8 (0.02-4.22) years. All deaths were related to cardiomyopathy or its management. Left ventricular diastolic dimension and systolic function measured by fractional shortening tended to normalise and stabilise after the first 3 years of life in the majority of patients. However, patients with BTHS (n = 16) had statistically significant reduction in global longitudinal and circumferential strain compared to controls (n = 18), (p < 0.001), despite apparent normal conventional measures of function. There was also reduced or reversed apical rotation and reduced left ventricular twist. Sustained ventricular arrhythmia was not seen at follow-up. Cardiac phenotype in BTHS is variable; however, longer-term outcome in our cohort suggests good prognosis after the first 5 years of life. Most patients appeared to have recovered near normal cardiac function by conventional echocardiographic measures, but strain analysis showed abnormal myocardial deformation and rotational mechanics.

BackgroundConsecutive treatment of normal heart with a high dose of isoproterenol and adenosine (Iso/Ade treatment), confers strong protection against ischaemia/reperfusion injury. In preparation for translation of this cardioprotective strategy into clinical practice during heart surgery, we further optimised conditions for this intervention using a clinically-relevant dose of Iso and determined its cardioprotective efficacy in hearts isolated from a model of surgically-induced heart failure.MethodsIsolated Langendorff-perfused rat hearts were treated sequentially with 5 nM Iso and 30 μM Ade followed by different durations of washout prior to 30 min global ischaemia and 2 hrs reperfusion. Reperfusion injury was assessed by measuring haemodynamic function, lactate dehydrogenase (LDH) release and infarct size. Protein kinase C (PKC) activity and glycogen content were measured in hearts after the treatment. In a separate group of hearts, Cyclosporine A (CsA), a mitochondria permeability transition pore (MPTP) inhibitor, was added with Iso/Ade. Failing hearts extracted after 16 weeks of ligation of left coronary artery in 2 months old rats were also subjected to Iso/Ade treatment followed by ischaemia/reperfusion.ResultsRecovery of the rate pressure product (RPP) in Iso/Ade-treated hearts was significantly higher than in controls. Thus in Iso/Ade treated hearts with 5 nM Iso and no washout period, RPP recovery was 76.3 ± 6.9% of initial value vs. 28.5 ± 5.2% in controls. This was associated with a 3 fold reduction in LDH release irrespective to the duration of the washout period. Hearts with no washout of the drugs (Ade) had least infarct size, highest PKC activity and also showed reduced glycogen content. Cardioprotection with CsA was not additive to the effect of Iso/Ade treatment. Iso/Ade treatment conferred significant protection to failing hearts. Thus, RPP recovery in failing hearts subjected to the treatment was 69.0 ± 16.3% while in Control hearts 19.7 ± 4.0%. LDH release in these hearts was also 3 fold lower compared to Control.ConclusionsConsecutive Iso/Ade treatment of normal heart can be effective at clinically-relevant doses and this effect appears to be mediated by glycogen depletion and inhibition of MPTP. This intervention protects clinically relevant failing heart model making it a promising candidate for clinical use.

Background COVID‐19 is caused by the coronavirus SARS‐CoV‐2, which uses angiotensin‐converting enzyme 2 (ACE‐2) as a receptor for cellular entry. It is theorized that ACE inhibitors (ACE‐Is) or angiotensin receptor blockers (ARBs) may increase vulnerability to SARS‐CoV‐2 by upregulating ACE‐2 expression, but ACE‐I/ARB discontinuation is associated with clinical deterioration. Objective To determine whether ACE‐I and ARB use is associated with acute kidney injury (AKI), macrovascular thrombosis and in‐hospital mortality. Methods A retrospective, single‐centre study of 558 hospital inpatients with confirmed COVID‐19 admitted from 1 March to 30 April 2020, followed up until 24 May 2020. AKI and macrovascular thrombosis were primary end‐points, and in‐hospital mortality was a secondary end‐point. Results AKI occurred in 126 (23.1%) patients, 34 (6.1%) developed macrovascular thrombi, and 200 (35.9%) died. Overlap propensity score‐weighted analysis showed no significant effect of ACE‐I/ARB use on the risk of occurrence of the specified end‐points. On exploratory analysis, severe chronic kidney disease (CKD) increases odds of macrovascular thrombi (OR: 8.237, 95% CI: 1.689–40.181, P = 0.009). The risk of AKI increased with advancing age (OR: 1.028, 95% CI: 1.011–1.044, P = 0.001) and diabetes (OR: 1.675, 95% CI: 1.065–2.633, P = 0.025). Immunosuppression was associated with lower risk of AKI (OR: 0.160, 95% CI: 0.029–0.886, P = 0.036). Advancing age, dependence on care, male gender and eGFR < 60 mL min −1 /1.73 m 2 increased odds of in‐hospital mortality. Conclusion We did not identify an association between ACE‐I/ARB use and AKI, macrovascular thrombi or mortality. This supports the recommendations of the European and American Societies of Cardiology that ACE‐Is and ARBs should not be discontinued during the COVID‐19 pandemic.

IntroductionRecent terror attacks and assassinations involving highly toxic chemical weapons have stressed the importance of sufficient respiratory protection of medical first responders and receivers. As full-face respirators cause perceptual-motor impairment, they not only impair vision but also significantly reduce speech intelligibility. The recent introduction of electronic voice projection units (VPUs), attached to a respirator, may improve communication while wearing personal respiratory protection.ObjectiveTo determine the influence of currently used respirators and VPUs on medical communication and speech intelligibility.Methods37 trauma anaesthetists carried out an evaluation exercise of six different respirators and VPUs including one control. Participants had to listen to audio clips of a variety of sentences dealing with scenarios of emergency triage and medical history taking.ResultsIn the questionnaire, operators stated that speech intelligibility of the Avon C50 respirator scored the highest (mean 3.9, ±SD 1.0) and that the Respirex Powered Respiratory Protective Suit (PRPS) NHS-suit scored lowest (1.6, 0.9). Regarding loudness the C50 plus the Avon VPU scored highest (4.1, 0.7), followed by the Draeger FPS-7000-com-plus (3.4, 1.0) and the Respirex PRPS NHS-suit scored lowest (2.3, 0.8).ConclusionsWe found that the Avon C50 is the preferred model among the tested respirators. In our model, electronic voice projection modules improved loudness but not speech intelligibility. The Respirex PRPS NHS-suit was rated significantly less favourably in respect of medical communication and speech intelligibility.

We have recently shown that consecutive heart perfusion with isoproterenol and adenosine strongly protects the heart against ischaemia/reperfusion injury. Isoproterenol activates β-adrenergic receptors increasing synthesis of cyclic AMP (cAMP) which in turn activates both protein kinase A (PKA) and a guanine nucleotide exchange factor- Epac- whilst adenosine activates protein kinase C. However, this treatment may not be effective if β-adrenergic sensitivity is impaired by some pathological conditions. We decided to check whether a cardioprotective effect can be achieved by direct activation of PKA and Epac using a cell-permeable cAMP analogue 8-Br-cAMP-AM. Isolated rat hearts were perfused with 1 μM 8-Br-cAMP-AM for 5 min followed by 5 min washout period prior to 30 min ischaemia and 2 h reperfusion. 8-Br-cAMP-AM itself did not change haemodynamic function but resulted in decreased function during the washout period prior to ischaemia and significantly reduced amplitude of ischaemic contracture. During reperfusion, the cell-permeable cAMP analogue decreased end diastolic pressure, lactate dehydrogenase release and infarct size and considerably improved haemodynamic functional recovery. These results demonstrate that the cell permeable cAMP analogue 8-Br-cAMP-AM, at a relatively low dose, can induce cardioprotective effect directly, without β-adrenergic stimulation. This could be the way to activate survival signal transduction pathways if β-adrenergic receptor sensitivity is impaired. Further study is needed in order to elucidate the signalling mechanisms of this protective effect and to optimise this intervention. Supported by the BHF.

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