BACKGROUND: The COVID-19 pandemic increased the use of broad-spectrum antibiotics due to diagnostic uncertainty, particularly in critical care. Multiprofessional communication became more difficult, weakening stewardship activities. AIM: To determine changes in bacterial co-/secondary infections and antibiotics used in COVID-19 patients in critical care, and mortality rates, between the first and second waves. METHODS: Prospective audit comparing bacterial co-/secondary infections and their treatment during the first two waves of the pandemic in a single centre teaching hospital ICU. Data on demographics, daily antibiotic use, clinical outcomes, and culture results in patients diagnosed with COVID-19 infection were collected over 11 months. FINDINGS: From 9/3/20 to 2/9/20 (Wave 1), there were 156 patients and between 3/9/20 and 1/2/21 (Wave 2) there were 235 patients with COVID-19 infection admitted to intensive care. No significant difference was seen in mortality or positive blood culture rates between the two waves. The proportion of patients receiving antimicrobial therapy (93.0% vs 81.7%; p<0.01), and the duration of meropenem use (median (interquartile range): 5 (2-7) vs 3 (2-5) days; p=0.01) was lower in Wave 2. However, the number of patients with respiratory isolates of Pseudomonas aeruginosa (4/156 vs 21/235; p<0.01) and bacteraemia from a respiratory source (3/156 vs 20/235 p<0.01) increased in Wave 2, associated with an outbreak of infection. There was no significant difference between waves with respect to isolation of other pathogens. CONCLUSIONS: Reduced broad spectrum antimicrobial use in the second wave of COVID-19 compared with the first wave was not associated with significant change in mortality.
Comparison of Antibiotic Use between the First Two Waves of COVID-19 in an Intensive Care Unit at a London Tertiary Centre: reducing broad-spectrum antimicrobial use did not adversely affect mortality