ABSTRACT
Background: Patients with severe asthma (SA) may be at higher risk of severe COVID-19 (C-19) illness. C-19 vaccines aim to reduce number and severity of infections. Patients with SA are often treated with maintenance oral corticosteroids (mOCS) and/or biologics (mAb)- it is unknown if vaccines will generate the same protective responses in patients with SA on such therapies. Aim(s): To compare magnitude and range of post-vaccination (PV) antibody responses (IgG) in patients with SA on mAb, mOCS or high-dose inhaled corticosteroids (ICS) with healthy controls (HC) without asthma. Method(s): The Virtus finger-prick quantitative C-19 antibody test was used to detect IgG levels 16-24 weeks post second-dose of the C-19 vaccine (123 AstraZeneca, 56 Pfizer, 5 Moderna). IgG>0.2AU was considered positive with range: very high >1.25AU, high 0.751-1.25AU, medium 0.401-0.75AU and low 0.201-0.4AU. SA was defined as per ATS/ERS criteria. Result(s): PV IgG results were obtained from 127 patients with SA (84 mAb, 13 mOCS and 46 ICS) and 57 HC. After adjusting for age, significantly fewer people with SA compared to HC had a positive PV IgG result (81% vs 95% p=0.016). Lower median IgG levels were seen in patients on mOCS (0.40AU) compared to HC (1.24AU) (p=0.051). Patients on mAb had high or very high IgG levels (omalizumab n=25, 0.80AU;mepolizumab n=25, 1.07AU;benralizumab n=34, 1.11AU). Conclusion(s): Overall, a higher proportion of patients with SA had a negative PV IgG level after receiving 2 doses of a C-19 vaccine. This was mainly seen in patients on mOCS while mAb use was associated with high levels of humoral antibody response. These results reinforce the need for booster vaccines in SA, especially in those on mOCS.
ABSTRACT
BackgroundPatients with severe asthma (SA) may be at higher risk of severe COVID-19 (C-19) illness. C-19 vaccines aim to reduce number and severity of infections. Patients with SA are often treated with maintenance oral corticosteroids (mOCS) and/or biologics- it is unknown if vaccines will generate the same protective responses in patients with SA on such therapies.AimsTo compare magnitude and range of post-vaccination (PV) antibody responses (IgG) in patients with SA on biologics, mOCS or high-dose inhaled corticosteroids (ICS) with healthy controls (HC) without asthma.To review temporal trends in PV IgG in patients with SAMethodsThe Virtus finger-prick quantitative C-19 antibody test was used to detect IgG levels 16–24 weeks post second-dose of the C-19 vaccine (123 AstraZeneca, 56 Pfizer, 5 Moderna). PV IgG levels were also measured in a subset of patients 6 weeks PV. IgG>0.2 AU was considered positive with range: very high >1.25 AU, high 0.751–1.25 AU, medium 0.401–0.75 AU and low 0.201–0.4 AU. SA was defined as per ATS/ERS criteria.ResultsPV IgG results were obtained from 127 patients with SA (84 on biologics, 13 mOCS and 46 ICS) and 57 HC. After adjusting for age, significantly fewer people with SA compared to HC had a positive PV IgG result (81% vs 95% p=0.016). Compared to HC (1.24 AU), lower median IgG levels were seen in patients on high dose ICS (1.02 AU, p=0.033) and mOCS (0.40 AU, p=0.017).Patients on biologics had high or very high IgG levels (omalizumab n=25, 0.80 AU;mepolizumab n=25, 1.07 AU;benralizumab n=34, 1.11 AU).Paired temporal measurements in 37 SA patients showed regression coefficient -0.005 (95%CI -0.006,-0.003) and can be interpreted as IgG decreases, on average, by 0.15 AU per month.ConclusionOverall, a higher proportion of patients with SA had a negative PV IgG level after receiving 2 doses of a C-19 vaccine. This was mainly seen in patients on mOCS while biologic use was not associated with reduced humoral antibody response. These results reinforce the need for booster vaccines in SA, especially in those on mOCS.
ABSTRACT
Introduction: Respiratory failure is the most common organ failure seen in the intensive care unit1 and is managed with non-invasive or invasive positive pressure ventilation (PPV). Negative pressure ventilation (NPV) could offer a safe and effective alternative, however existing devices, such as the iron lung, are heavy and access to the patient for ongoing care is a limitation. The COVID-19 pandemic necessitated intense focus on the rapid design and manufacture of new ventilators,2 most of which were positive pressure ventilators. However, new, light-weight negative pressure ventilators were also designed and appeared to be safe and effective in an early trial in healthy human volunteers.3 These devices have the potential to offer patients an alternative to PPV, without the limitations associated with the early negative pressure devices. They are cheaper to manufacture, and importantly, do not require a pressurised gas supply, which may be of particular benefit to countries with less well-resourced healthcare facilities in which acute and acute-onchronic respiratory failure continue to cause significant morbidity and mortality.4 Objectives: To address whether acute or acute-onchronic respiratory failure in hospitalised adults can be safely and effectively managed with NPV. Methods: This systematic review was registered with the international prospective register of systematic reviews (ID CRD420200220881). MEDLINE, EMBASE, CENTRAL, medRxiv, bioRxiv and Trip databases were searched (from inception to 22nd April 2021). Eligible studies included non-intubated hospitalised adults who received NPV in the management of acute or acute on chronic respiratory failure. We included randomised controlled trials, non-randomised studies of intervention and case series. Risk of bias was assessed using three separate tools due to differing study designs. Results: 575 unique citations were screened with 14 meeting inclusion criteria. 1032 acute episodes (888 patients) of respiratory failure were managed with NPV, with 234 receiving PPV as a comparator. The majority (n=845, 66.7%) were treated for an acute exacerbation of COPD. 417 patients from four studies were included in the meta-analysis. The effect of NPV on PaCO2, pH and PaO2/FiO2 was similar to PPV with a mean difference -0.39kPa (95% confidence interval (CI): -0.95, 0.18), 0.01 (95% CI: 0.00, 0.02), and -0.16 (95% CI: -1.98, 1.66) respectively. Of those studies not included in the meta-analysis six showed a statistically significantly increase in PaO2 with the use of NPV and 5 showed a statistically significant improvement in PaCO2. Rates of complications were similar with NPV in those studies that compared it to PPV, and NPV appeared to be well tolerated by patients. This systematic review study was limited by a wide range of study designs. Conclusions: NPV appears to be a safe and effective alternative to PPV in the management of acute exacerbation of COPD. Evidence for its use in other forms of respiratory failure is limited but warrants further investigation.
ABSTRACT
Objective.The goal of this study was to use Monte Carlo (MC) simulations and measurements to investigate the dosimetric suitability of an interventional radiology (IR) c-arm fluoroscope to deliver low-dose radiotherapy to the lungs.Approach.A previously-validated MC model of an IR fluoroscope was used to calculate the dose distributions in a COVID-19-infected patient, 20 non-infected patients of varying sizes, and a postmortem subject. Dose distributions for PA, AP/PA, 3-field and 4-field treatments irradiating 95% of the lungs to a 0.5 Gy dose were calculated. An algorithm was created to calculate skin entrance dose as a function of patient thickness for treatment planning purposes. Treatments were experimentally validated in a postmortem subject by using implanted dosimeters to capture organ doses.Main results.Mean doses to the left/right lungs for the COVID-19 CT data were 1.2/1.3 Gy, 0.8/0.9 Gy, 0.8/0.8 Gy and 0.6/0.6 Gy for the PA, AP/PA, 3-field, and 4-field configurations, respectively. Skin dose toxicity was the highest probability for the PA and lowest for the 4-field configuration. Dose to the heart slightly exceeded the ICRP tolerance; all other organ doses were below published tolerances. The AP/PA configuration provided the best fit for entrance skin dose as a function of patient thickness (R2 = 0.8). The average dose difference between simulation and measurement in the postmortem subject was 5%.Significance.An IR fluoroscope should be capable of delivering low-dose radiotherapy to the lungs with tolerable collateral dose to nearby organs.