The objective of this doctoral thesis is to study the microbiological etiology, the impact of respiratory viruses, and various aspects of the pharmacological treatment of community-acquired pneumonia (CAP) in our setting. To achieve this aim, five studies were conducted and published in scientific journals.
The first article analyzes the microbiological etiology and clinical evolution of patients hospitalized with CAP during two one-year periods, ten years apart (2007–2008 and 2017–2018). A total of 452 patients were included in the first period and 591 in the second. The only difference
regarding bacterial isolates was a higher proportion of S. aureus in the second period (2.9% vs. 0.9%, p=0.026). In terms of clinical presentation, patients in the second period had fewer septic complications, with lower rates of septic shock (6.3% vs. 15.5%), complicated pleural effusion (3.6% vs. 6.4%), and bacteremia (9.6% vs. 14.8%).
The second article evaluates the impact of respiratory viruses on CAP in the pre-COVID era. The study included 590 patients, 63.5% of whom had a microbiological diagnosis: 54.4% bacterial and 20% viral. Patients with viral infection were compared to those without, and no significant differences in baseline characteristics were found. However, patients with viral infection showed a trend toward a higher rate of S. aureus isolation (p=0.07). Moreover, viral infection was more frequently associated with severity criteria such as bilateral consolidation on imaging, respiratory failure, and need for invasive mechanical ventilation.
The third study evaluates the real-life effectiveness of short-course (7 days) versus longer-course (8–10 days) antibiotic treatments in hospitalized patients with CAP. Six-hundred two patients were included: 277 in the short-treatment group and 325 in the long-treatment group. To adjust for potential baseline differences, a propensity score analysis was performed, which confirmed no significant differences in 30-day mortality (OR: 2.23; 95% CI: 0.35–10.9; p=0.35) or readmission rates (OR: 0.90; 95% CI: 0.38–2.09; p=0.79) between the two groups.
The fourth and fifth articles investigate the use of tocilizumab in hospitalized patients with SARS- CoV-2 pneumonia. Both studies suggest a potential benefit of tocilizumab in reducing disease progression and point to a subset of patients who may present greater benefit. The first is an observational study assessing the effect of tocilizumab in patients with SARS-CoV-2 pneumonia. A total of 82 patients treated with tocilizumab were included. By day seven, the mortality rate was 26.8%, with respiratory failure in 75.6% and acute respiratory distress
syndrome (ARDS) in 54.9% of cases. Survival analysis showed a trend toward higher mortality in patients who received tocilizumab after the onset of ARDS compared to those who received it earlier, although this difference was not statistically significant after adjustment for age. The fifth article is a randomized clinical trial evaluating the efficacy of tocilizumab in patients with SARS- CoV-2 pneumonia and elevated IL-6 levels. Sixty-two patients were included: 32 in the tocilizumab group and 30 in the standard treatment group, although the initially calculated sample size was not reached. The group treated with tocilizumab showed a lower rate of the composite outcome of mortality or invasive mechanical ventilation (12.9% vs. 32.3%), although the difference did not reach statistical significance. Regarding safety, 43.5% of patients in the tocilizumab group experienced some adverse event, none of which were serious.
Pneumònia adquirida a la comunitat: una visió pràctica de la etiologia, maneig clínic i impacte de la detecció viral
Sellarès Nadal, J. (Author). 5 Nov 2025
Student thesis: Doctoral thesis
Student thesis: Doctoral thesis