Severe community-acquired pneumonia: Characteristics and prognostic factors in ventilated and non-ventilated patients

Abstract

BackgroundPatients with severe community-acquired pneumonia (SCAP) and life-threatening acute respiratory failure may require invasive mechanical ventilation (IMV). Since use of IMV is often associated with significant morbidity and mortality, we assessed whether patients invasively ventilated would represent a target population for interventions aimed at reducing mortality of SCAP.MethodsWe prospectively recruited consecutive patients with SCAP for 12 years. We assessed the characteristics and outcomes of patients invasively ventilated at presentation of pneumonia, compared with those without IMV, and determined the influence of risks factors on mortality with a multivariate weighted logistic regression using a propensity score.ResultsAmong 3,719 patients hospitalized with CAP, 664 (18%) had criteria for SCAP, and 154 (23%) received IMV at presentation of pneumonia; 198 (30%) presented with septic shock. In 370 (56%) cases SCAP was diagnosed based solely on the presence of 3 or more IDSA/ATS minor criteria. Streptococcus pneumoniae was the main pathogen in both groups. The 30-day mortality was higher in the IMV, compared to non-intubated patients (51, 33%, vs. 94, 18% respectively, p<0·001), and higher than that predicted by APACHE-II score (26%). IMV independently predicted 30-day mortality in multivariate analysis (adjusted odds-ratio 3·54, 95% confidence interval 1·45–8·37, p = 0·006). Other independent predictors of mortality were septic shock, worse hypoxemia and increased serum potassium.ConclusionInvasive mechanical ventilation independently predicted 30-day mortality in patients with SCAP. Patients invasively ventilated should be considered a different population with higher mortality for future clinical trials on new interventions addressed to improve mortality of SCAP.

Acute respiratory distress syndrome in mechanically ventilated patients with community-acquired pneumonia

“…Indeed, even the propensity-adjusted multivariate analysis did not show an association between ARDS and patient mortality. According to our results, we think that the expected association of ARDS with mortality seems more related to the need for mechanical ventilation in these patients with CAP rather than ARDS itself, as we have recently reported that invasive mechanical ventilation in patients with severe CAP independently predicts mortality [36]. However, we cannot exclude that specific populations of patients with CAP and ARDS may have different mortality, since subphenotypes of ARDS patients with different outcomes related to inflammation [37] or fluid responsiveness [38] have been proposed.…”

Community-acquired pneumonia as an emergency condition

“…After the initial diagnosis of CAP, the biggest challenge in the emergency department is to promptly recognize patients who might develop respiratory failure and multiple organ dysfunctions. Patients requiring mechanical ventilation or vasopressor support should be admitted to ICU as soon as possible, as delays in ICU admission have been related to worse outcomes [16][17][18].…”

Inhibition of the PI3K/AKT Signaling Pathway or Overexpression of Beclin1 Blocks Reinfection of Streptococcus pneumoniae After Infection of Influenza A Virus in Severe Community-Acquired Pneumonia

“…Severe CAP (SCAP) has generally been defined as CAP requiring admission to the intensive care unit due to invasive mechanical ventilation or septic shock requiring vasopressors [4][5][6]. It is related to severe mortality and approximately 16-36% patients with SCAP may die in a short time [7]. It is reported that about one-third of patients with CAP requiring hospitalization present with co-infection of both bacteria and virus, and most of them are Streptococcus pneumoniae (S. pneumoniae) and influenza [8].…”