Predictive factors and outcomes of severe community acquired pneumonia in patients with respiratory failure

Objectives: To explore the risk factors, pathogens and outcomes of severe community-acquired pneumonia (SCAP) in patients with respiratory failure.

Methods: A prospective observational study was conducted at Northwest General Hospital & Research Centre, Peshawar, Pakistan from February 2016 to October 2018. All patients with Community-acquired pneumonia (CAP) who fulfilled the inclusion criteria were recorded consecutively. Diagnosis of SCAP was made following the criteria established by the IDSA/ATS in the consensus guidelines on the management of CAP in adults published in 2007. In-hospital mortality was the main outcome.

Results: The final analysis comprised a total of 100 patients with SCAP. The mean age was 60.0±18.01 years, and 54.0% were female patients. Afghani patients represented 22.0% of the total patients. The most common comorbidity associated with SCAP was hypertension (42.0%). The most commonly isolated etiological agents were Acinetobacter baumannii, followed by extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli. In-hospital mortality was 45%. On multivariate analysis, factors associated with in-hospital mortality were age (OR 1.054; 95%Cl 1.01-1.10; p=0.021), presence of two or more complications (OR 4.51; 95%Cl 1.18-17.28; p=0.028), septic shock (OR 6.44; 95%Cl 1.55-26.803; p=0.010), length of mechanical ventilation (OR 1.17; 95%Cl 1.01-1.40; p=0.043), and paO2 (OR 4.51; 95%Cl 1.18-17.28; p=0.004).

Conclusion: A high mortality rate was observed in our study. Age, presence of two or more complications, septic shock, length of mechanical ventilation, and low paO2 were identified to be independent predictors of mortality for patients with SCAP.