Community acquired pneumonia in patients requiring hospitalization

Community-acquired pneumonia (CAP) represents a major health issue and similar to 20% of the patients require in-hospital attention. The main objective of the study was to determine clinical-imaging features of CAP episodes requiring hospitalization. The secondary objectives were to determine the diagnostic yield of microbiological analyses and the medical complications. A retrospective analytical study was conducted on adults admitted due to CAP in a third-level hospital in the period 2017-2019. Pregnant women were excluded. A total of 340 CAP episodes were identified in 321 patients; the median age was 75 years old (interquartile range 57-85). The most frequent risk factors were immunocompromise 102 (30%), neurological disease 75 (22%), and chronic kidney disease 58 (17%). According to three prognostic scores, CURB65, qSOFA and PSI/PORT, 216 (63.5%), 290 (83.5%) and 130 (38%) patients were identified as low risk, respectively. A total of 49 (14.4%) episodes required admission at the critical care unit and 39 (11.5%) required mechanical ventilation; 30 patients (8.8%) died during hospitalization. The radiologic patterns most frequently found were consolidation in 134 (39.4%), interstitial-alveolar pattern in 98 (28.8%), and the combination of both patterns in 67 (19.7%) episodes. Identification of the causal agent was achieved in 79 (23.2%) episodes. The most frequently isolated microorganisms were influenza virus in 37 (10.9%) episodes and Streptococcus pneumoniae in 11 (3.2%). Most of the hospitalized CAP patients were elderly with consolidative radiological patterns. The causal agent could be identified in less than a quarter of the patients, with the influenza test being the method with the highest diagnostic yield.