IntroductionPneumothorax and pneumomediastinum have both been noted to complicate cases of COVID-19 requiring hospital admission. We report the largest case series yet described of patients with both these pathologies that includes non-ventilated patients.MethodsCases were collected retrospectively from UK hospitals with inclusion criteria limited to a diagnosis of COVID-19 and the presence of either pneumothorax or pneumomediastinum. Patients included in the study presented between March and June 2020. Details obtained from the medical record included demographics, radiology, laboratory investigations, clinical management and survival.ResultsSeventy-one patients from 16 centres were included in the study, of whom 60 patients had pneumothoraces (six also with pneumomediastinum), whilst 11 patients had pneumomediastinum alone. Two of these patients had two distinct episodes of pneumothorax, occurring bilaterally in sequential fashion, bringing the total number of pneumothoraces included to 62. Clinical scenarios included patients who had presented to hospital with pneumothorax, patients who had developed pneumothorax or pneumomediastinum during their inpatient admission with COVID-19 and patients who developed their complication whilst intubated and ventilated, either with or without concurrent extracorporeal membrane oxygenation. Survival at 28 days was not significantly different following pneumothorax (63.1%±6.5%) or isolated pneumomediastinum (53.0%±18.7%; p=0.854). The incidence of pneumothorax was higher in males. The 28-day survival was not different between the sexes (males 62.5%±7.7% versus females 68.4%±10.7%; p=0.619). Patients above the age of 70 had a significantly lower 28-day survival than younger individuals (≥70 years 41.7%±13.5% survival versus <70 years 70.9%±6.8% survival; p=0.018 log-rank).ConclusionThese cases suggest that pneumothorax is a complication of COVID-19. Pneumothorax does not seem to be an independent marker of poor prognosis and we encourage active treatment to be continued where clinically possible.

National Institute of Health Research, Imperial College London.

Computer-based computed tomography (CT) analysis can provide objective quantitation of disease in idiopathic pulmonary fibrosis (IPF). A computer algorithm, CALIPER, was compared with conventional CT and pulmonary function measures of disease severity for mortality prediction.CT and pulmonary function variables (forced expiratory volume in 1 s, forced vital capacity, diffusion capacity of the lung for carbon monoxide, transfer coefficient of the lung for carbon monoxide and composite physiologic index (CPI)) of 283 consecutive patients with a multidisciplinary diagnosis of IPF were evaluated against mortality. Visual and CALIPER CT features included total extent of interstitial lung disease, honeycombing, reticular pattern, ground glass opacities and emphysema. In addition, CALIPER scored pulmonary vessel volume (PVV) while traction bronchiectasis and consolidation were only scored visually. A combination of mortality predictors was compared with the Gender, Age, Physiology model.On univariate analyses, all visual and CALIPER-derived interstitial features and functional indices were predictive of mortality to a 0.01 level of significance. On multivariate analysis, visual CT parameters were discarded. Independent predictors of mortality were CPI (hazard ratio (95% CI) 1.05 (1.02-1.07), p<0.001) and two CALIPER parameters: PVV (1.23 (1.08-1.40), p=0.001) and honeycombing (1.18 (1.06-1.32), p=0.002). A three-group staging system derived from this model was powerfully predictive of mortality (2.23 (1.85-2.69), p<0.0001).CALIPER-derived parameters, in particular PVV, are more accurate prognostically than traditional visual CT scores. Quantitative tools such as CALIPER have the potential to improve staging systems in IPF.

We sought to determine the type of pulmonary involvement in microscopic polyangiitis (MPA), primarily focusing on pulmonary fibrosis (PF), its prevalence, temporal relationship with other disease manifestations and outcome.33 patients (16 males) with biopsy proven perinuclear anti-neutrophilic cytoplasmic antibodypositive MPA (age 63.5 yrs) participated in the study. Pulmonary involvement was assessed using standard methods, including radiographic imaging (chest radiographs and high-resolution computed tomography), pulmonary function testing, bronchoscopy and bronchoalveolar lavage, and, if indicated, lung biopsy. All-cause mortality was analysed by the Kaplan-Meier method and was compared between MPA patients with and without PF.At the time of diagnosis, renal involvement was detected in all patients, with renal biopsies being consistent with segmental necrotising glomerulonephritis in all patients. The most common respiratory symptom was haemoptysis, which was found in nine (27%) patients. PF was present in 12 (36%) patients at the time of diagnosis, whereas one patient developed PF while on therapy ,10 yrs after disease diagnosis. In seven patients with PF, respiratory symptoms related to fibrosis preceded other disease manifestations by a median (range) period of 13 (5-120) months. Patients were followed up for a period of 38¡30 months. Presence of PF was associated with increased mortality (p50.02), with six deaths occurring in the fibrotic group and one in the nonfibrotic group. In the fibrotic group most deaths were related to PF.PF occurs frequently in MPA, may precede other disease manifestations by a variable length of time and has a poor prognosis.

Rationale: The impact of COVID-19 on patients with Interstitial Lung Disease (ILD) has not been established. Objectives: To assess outcomes in patients with ILD hospitalized for COVID-19 versus those without ILD in a contemporaneous age, sex and comorbidity matched population. Methods: An international multicenter audit of patients with a prior diagnosis of ILD admitted to hospital with COVID-19 between 1 March and 1 May 2020 was undertaken and compared with patients, without ILD obtained from the ISARIC 4C cohort, admitted with COVID-19 over the same period. The primary outcome was survival. Secondary analysis distinguished IPF from non-IPF ILD and used lung function to determine the greatest risks of death. Measurements and Main Results: Data from 349 patients with ILD across Europe were included, of whom 161 were admitted to hospital with laboratory or clinical evidence of COVID-19 and eligible for propensity-score matching. Overall mortality was 49% (79/161) in patients with ILD with COVID-19. After matching ILD patients with COVID-19 had higher mortality (HR 1.60, Confidence Intervals 1.17-2.18 p=0.003) compared with age, sex and comorbidity matched controls without ILD. Patients with a Forced Vital Capacity (FVC) of <80% had an increased risk of death versus patients with FVC ≥80% (HR 1.72, 1.05-2.83). Furthermore, obese patients with ILD had an elevated risk of death (HR 2.27, 1.39−3.71). Conclusions: Patients with ILD are at increased risk of death from COVID-19, particularly those with poor lung function and obesity. Stringent precautions should be taken to avoid COVID-19 in patients with ILD.

CALIPER was superior to visual scoring as validated by functional correlations with PFTs. The pulmonary vessel volume, a novel CALIPER CT parameter with no visual scoring equivalent, has the potential to be a CT feature in the assessment of patients with IPF and requires further exploration.

UK National Institute for Health Research.

This study aimed to investigate whether the combination of fibrosis and emphysema has a greater effect than the sum of its parts on functional indices and outcome in idiopathic pulmonary fibrosis (IPF), using visual and computer-based (CALIPER) computed tomography (CT) analysis.Consecutive patients (n=272) with a multidisciplinary IPF diagnosis had the extent of interstitial lung disease (ILD) scored visually and by CALIPER. Visually scored emphysema was subcategorised as isolated or mixed with fibrotic lung. The CT scores were evaluated against functional indices forced vital capacity (FVC), diffusing capacity of the lungs for carbon monoxide (), transfer coefficient of the lung for carbon monoxide (), composite physiologic index (CPI)) and mortality.The presence and extent of emphysema had no impact on survival. Results were maintained following correction for age, gender, smoking status and baseline severity using , and combined visual emphysema and ILD extent. Visual emphysema quantitation indicated that relative preservation of lung volumes (FVC) resulted from tractionally dilated airways within fibrotic lung, ventilating areas of admixed emphysema (p<0.0001), with no independent effect on FVC from isolated emphysema. Conversely, only isolated emphysema (p<0.0001) reduced gas transfer ().There is no prognostic impact of emphysema in IPF, beyond that explained by the additive extents of both fibrosis and emphysema. With respect to the location of pulmonary fibrosis, emphysema distribution determines the functional effects of emphysema.