Association between respiratory distress time and invasive mechanical ventilation in COVID-19 patients: A multicentre regional cohort study

AIM

To determine whether the duration of respiratory distress symptoms in severe COVID-19 pneumonia affects the need for invasive mechanical ventilation and clinical outcomes.

MATERIALS AND METHODS

An observational multicentre cohort study of patients hospitalised in five COVID-19-designated ICUs of the University Hospitals of Emilia-Romagna Region. Patients included were adults with pneumonia due to SARS-CoV-2 with PaO₂/FiO₂ ratio <300 mmHg, respiratory distress symptoms, and need for mechanical ventilation (invasive or non-invasive). Exclusion criteria were an uncertain time of respiratory distress, end-of-life decision, and mechanical respiratory support before hospital admission.

MEASUREMENTS AND MAIN RESULTS

We analysed 171 patients stratified into tertiles according to respiratory distress duration (distress time, DT) before application of mechanical ventilation support. The rate of patients requiring invasive mechanical ventilation was significantly different (p < 0.001) among the tertiles: 17/57 patients in the shortest duration, 29/57 in the intermediate duration, and 40/57 in the longest duration. The respiratory distress time significantly increased the risk of invasive ventilation in the univariate analysis (OR 5.5 [CI 2.48-12.35], p = 0.003). Multivariable regression analysis confirmed this association (OR 10.7 [CI 2.89-39.41], p < 0.001). Clinical outcomes (mortality and hospital stay) did not show significant differences between DT tertiles.

DISCUSSION

Albeit preliminary and retrospective, our data raised the hypothesis that the duration of respiratory distress symptoms may play a role in COVID-19 patients' need for invasive mechanical ventilation. Furthermore, our observations suggested that specific strategies may be directed towards identifying and managing early symptoms of respiratory distress, regardless of the levels of hypoxemia and the severity of the dyspnoea itself.

Inhaler mishandling is very common in patients with chronic airflow obstruction and long-term home nebuliser use

Inhalers and nebulisers are devices used for delivering aerosolised drugs in subjects with Chronic Airflow Obstruction (CAO). This multicentre, cross-sectional observational study was performed in a large population of outpatients with CAO regularly using home aerosol therapy and referring to chest clinics. The aims of the study were to compare the characteristics of the group of subjects with CAO who were using home nebulisers but also experienced with inhalers vs. those only using inhalers and to investigate whether the first group of subjects was particularly prone to inhaler misuse. Information was gained evaluating the responses to a standardised questionnaire on home aerosol therapy and the observations of inhaler technique. We enrolled 1527 patients (58% males; mean ± SE; aged 61.1 ± 0.4 years; FEV1% pred 69.9 ± 0.6; 51% and 44% respectively suffering from COPD and asthma) who were only inhaler users (OIU group) and 137 (85% males; aged 67.7 ± 1.3 years; FEV1% pred 62.3 ± 2.9; 60% and 23% respectively suffering from COPD and asthma) who were using both nebulisers and inhalers (NIU group). Nebuliser users were older, had more severe obstruction, related symptoms and health care resources utilisation. Nebulisers users performed more critical inhalers errors than those of the OIU group (49% vs. 36%; p = 0.009). We conclude that our patients with CAO and regular nebuliser treatment had advanced age, severe respiratory conditions and common inhaler misuse.

Smoking cessation in patients requiring bronchoscopy: the Bronchoscopy AntiSmoking Study (BASIS)

We investigated the readiness to quit and the smoking cessation rates of smokers requiring bronchoscopy and receiving advice quitting. This randomized controlled trial evaluated the effectiveness of two smoking cessation interventions, either a brief advice (control group), or a longer support, delivered at the time of bronchoscopy. We consecutively enrolled 233 adult smokers, regardless of the initial level of motivation to quit. Their mean (SD) age was 57 (12) years; males were 192. They had smoked a median of 44.5 pack-years. Their mean (SD) Fagerstrom score was 8 (2). There was no difference between groups. Surprisingly, 45% of participants were in the action stage at baseline; these 105 subjects had quit in the week immediately prior to the bronchoscopy. At 6- and 12-months follow-up visits, respectively 41% and 29% of participants in the intervention group and 27% and 13% in the control group objectively showed a 1-week point prevalence abstinence. The difference was significant at 6 months (p<0.05) but not at 1-year visit (p=0.052), even if there was a trend towards greater cessation rate in the intervention group. In multivariable logistic models, at the final visit being a quitter was positively associated with having been in the action stage at baseline and negatively with the Fagerstrom score and the presence of smokers in household. We conclude that the time of bronchoscopy may possibly predispose smokers to quit. Further efforts are needed to clear whether more protracted support might achieve higher long-term smoking cessation rates.