Korean J Intern Med.  2015 Nov;30(6):829-836. 10.3904/kjim.2015.30.6.829.

Clinical manifestations of pneumonia according to the causative organism in patients in the intensive care unit

• Lee JK
• Lee J
• Park YS
• Lee CH
• Yim JJ
• Yoo CG
• Kim YW
• Han SK
• Lee SM

• KMID: 2381587
• DOI: http://doi.org/10.3904/kjim.2015.30.6.829

Abstract

BACKGROUND/AIMS
Whether the causative organism influences the clinical course of pneumonia in the intensive care unit (ICU) is controversial. We assessed the clinical manifestations and prognosis of pneumonia according to the causative pathogens in patients in a medical ICU.
METHODS
A retrospective observational study was performed in a medical ICU. Among 242 patients who were admitted to the ICU, 103 who were treated for pneumonia were analyzed.
RESULTS
The causative pathogen was identified in 50 patients (49.0%); 22 patients (21.6%) had multidrug-resistant (MDR) pathogens. The distribution of causative micro-organisms was Staphylococcus aureus (20%), Pseudomonas species (16%), Klebsiella pneumoniae (14%), and Acinetobacter baumannii (12%). No significant difference in ICU mortality rate, duration of ICU stay, duration of mechanical ventilation, or frequencies of re-intubation and tracheostomy were detected based on the identification of any pathogen. In sub-analyses according to the pneumonia classification, the number of pathogens identified did not differ between pneumonia types, and a higher incidence of identified MDR pathogens was detected in the hospital-acquired pneumonia group than in the community-acquired or healthcare- acquired pneumonia groups. However, the clinical outcomes of pneumonia according to identification status and type of pathogen did not differ significantly between the groups.
CONCLUSIONS
Neither the causative micro-organism nor the existence of MDR pathogens in critically ill patients with pneumonia was associated with the clinical outcome of pneumonia, including ICU mortality. This result was consistent regardless of the pneumonia classification.

Keyword

Pneumonia; Pathogenicity; Drug resistance, multiple; Intensive care units

MeSH Terms

Acinetobacter Infections/diagnosis/*microbiology/mortality/therapy
Aged
Anti-Bacterial Agents/therapeutic use
Critical Illness
Drug Resistance, Multiple, Bacterial
Female
Hospital Mortality
Humans
Intensive Care Units
Klebsiella Infections/diagnosis/*microbiology/mortality/therapy
Length of Stay
Male
Middle Aged
Pneumonia, Bacterial/diagnosis/*microbiology/mortality/therapy
Proportional Hazards Models
Pseudomonas Infections/diagnosis/*microbiology/mortality/therapy
Respiration, Artificial
Retrospective Studies
Risk Factors
Staphylococcal Infections/diagnosis/*microbiology/mortality/therapy
Time Factors
Tracheostomy
Treatment Outcome
Anti-Bacterial Agents