Impact of COVID 19 on bacterial respiratory isolates (2018-2021) from a UK tertiary cardio-thoracic ICU

Aim: To study the impact of COVID-19 admissions during 1st and 2nd surges on bacteriology of ICU respiratory isolates. Method(s): Retrospective time trend analysis of bacterial respiratory isolates from a single centre, tertiary cardiothoracic ICU (CT-ICU) from patients admitted from Jan 2018- June 2021. We compared pre-COVID-19 (January 2018- March 2020) and COVID-19 periods (April 2020- June 2021) and surge periods (surge 1: March 2020- June 2020, surge 2: January- March 2021) to similar time frames in previous years. Chi-square test used to compare proportions. Result(s): 4974 respiratory isolates (Sputum-4230, BAL-563, ET secretions-181) included. During surge 2, culture positivity and gram-negative rates tripled from baseline (20% to 75%;p<0.05). Comparing the pre- pandemic to pandemic period, rates of Klebsiella sp, Acinetobacter sp and Stenotrophomonas sp increased from 12% to 21.3%, 2.4% to 6.2% and 10.5% to 14.3% respectively, while Pseudomonas sp dropped from 30.7% to 23.1% (all p<0.05). MDR Pseudomonas increased significantly from 38.9% to 47.9% (p<0.05), with a non-significant increase in MRSA (5.2% to 9.3%;p=0.34) and MDR enterobacterales (22.6% to 23%;p=0.48). Conclusion(s): This is the first report from a UK CTICU showing a marked epidemiological shift in the bacteriology of respiratory isolates in terms of organism profile, increase in culture positivity and MDR Pseudomonas rates during the pandemic. Analyzing trends on longevity of the findings will help guide changes to infection control and antibiotic policies. This emphasizes the importance of unit specific ecology in choosing appropriate timely antimicrobial therapy and therefore improving patient outcome.

Pneumothorax in hospitalized COVID-19 patients with severe respiratory failure: Risk factors and outcome.

PNX was described as an uncommon complication in COVID-19 patients but clinical risk predictors and the potential role in patient's outcome are still unclear. We assessed prevalence, risk predictors and mortality of PNX in hospitalized COVID- 19 with severe respiratory failure performing a retrospective observational analysis of 184 patients admitted to our COVID-19 Respiratory Unit in Vercelli from October 2020 to March 2021. We compared patients with and without PNX reporting prevalence, clinical and radiological features, comorbidities, and outcomes. Prevalence of PNX was 8.1% and mortality was >86% (13/15) significantly higher than in patients without PNX (56/169) (P < 0.001). PNX was more likely to occur in patients with a history of cognitive decline (HR: 31.18) who received non-invasive ventilation (NIV) (p < 0.0071) and with low P/F ratio (HR: 0.99, p = 0.004). Blood chemistry in the PNX subgroup compared to patients without PNX showed a significant increase in LDH (420 U/L vs 345 U/L, respectively p = 0.003), ferritin (1111 mg/dl vs 660 mg/dl, respectively p = 0.006) and decreased lymphocytes (HR: 4.440, p = 0.004). PNX may be associated with a worse prognosis in terms of mortality in COVID patients. Possible mechanisms may include the hyperinflammatory status associated with critical illness, the use of NIV, the severity of respiratory failure and cognitive impairment. We suggest, in selected patients showing low P/F ratio, cognitive impairment and metabolic cytokine storm, an early treatment of systemic inflammation in association with high-flow oxygen therapy as a safer alternative to NIV in order to avoid fatalities connected with PNX.

Lung cancer screening provides a unique opportunity for early diagnosis and management of interstitial lung diseases

P4 Table 1Characteristics of the subjectsCharacteristics Subjects with ILAs on LDCT (n = 39) Age, yr, mean (± SD) 68.8 (± 4.3) Gender, n (%) Female 15 (38.5) Male 24 (61.5) Smoking status, n (%) Current 7 (17.9) Ex 32 (82.1) Respiratory symptoms, n (%) None 19 (48.7) Cough 3 (7.7) Dyspnoea 9 (23.1) Cough & dyspnoea 6 (15.4) N/A 2 (5.1) Physical examination findings, n (%) None 5 (12.8) Crackles 17 (43.6) N/A 17 (43.6) Baseline lung function,%pred, median (range) FEV1,% pred 91 (58 – 130) FVC,% pred 94.8 (65 – 143) TLco,% pred 57.6 (28.4 – 98.8) Kco,% pred 79.5 (36.4 – 94) MDT Diagnosis ILAs, n (%) 8 (20.5) ILD, n (%) IPF 14 (35.9) Smoking-related ILD 6 (15.4) Hypersensitivity pneumonitis 4 (10.3) PPFE 3 (7.7) Sarcoidosis 1 (2.6) Post-COVID ILD 1 (2.6) Vasculitis 1 (2.6) Unclassifiable 1 (2.6) Treatment, n (%) Smoking cessation advice 6 (15.4) Antifibrotic 7 (17.9) Immunomodulatory treatment 2 (5.1) None 23 (59) ResultsILAs of >5% extent on LDCT were identified in 39/1853 (2.1%) subjects screened between August 2018 and April 2021 (table 1). Respiratory symptoms were present in 18/39 (46.1%) and crackles were auscultated in 17 of 22 subjects (77.3%) undergoing physical examination. Past exposure to potential environmental triggers was noted in 21/39 (53.8%). Diagnostic bronchoalveolar lavage was performed in 7/39 (17.9%) and one patient underwent transbronchial lung cryobiopsy. After MDT discussion, ILD was concluded in 31/39 (79.5%) cases, of which 14/31 (45.2%) were diagnosed with IPF. In the IPF subgroup, antifibrotics were initiated in 7/14 (50%) of cases. In those diagnosed with other ILDs, immunomodulatory treatment was initiated in 2/25 (8%) subjects.ConclusionA large proportion of individuals with newly identified ILAs have an abnormal clinical examination and respiratory symptoms, consistent with the widely held suspicion that ILD is underdiagnosed in the community. Lung cancer screening in this demographic provides a unique opportunity to address this unmet health metric. Earlier identification of ILD, specifically IPF, allows institution of antifibrotic therapies proven to modify the natural history of the disease by preserving lung function and extending life. The cost-effectiveness of this approach for ILD screening warrants detailed evaluation.