ABSTRACT: The risk factors for health care--associated pneumonia (HCAP) include hospitalization for 2 or more days within the past 90 days, residence in a nursing home or extended-care facility, home infusion therapy, and long-term dialysis within the past 30 days. Distinguishing between community-acquired pneumonia (CAP) and HCAP is important because of the implications for therapy. Compared with CAP, HCAP is more likely to be caused by multidrug-resistant organisms and is associated with a higher mortality rate. The management of HCAP requires antimicrobial coverage of Pseudomonas aeruginosa, Acinetobacter species, extended-spectrum [beta]-lactamase--producing Enterobacteriaceae, and methicillin-resistant Staphylococcus aureus. Empirical narrowing of therapy is probably safe in patients with culture-negative HCAP who have improved with broad-spectrum therapy.
KEY WORDS: Pneumonia, Antibiotic resistance, MRSA
More than 1 million patients in the United States are hospitalized annually with community-acquired pneumonia (CAP), at an estimated cost of $26 billion. (1) CAP was the sixth most expensive condition in US hospitals in 20041 and the eighth leading cause of death. (2)
The rate of hospitalization for elderly patients with CAP has increased by 30% since 1988, in contrast to all-cause hospitalization rates, which have remained stable. Furthermore, a study comparing patients hospitalized with pneumonia with those hospitalized with the other top-10 listed admission diagnoses found that elderly patients with CAP were 50% more likely to die during their stay. (3) Adverse outcomes extend beyond the hospital stay; 1-year mortality rates for elderly patients with CAP exceed those of hospitalized controls by 9%. (4)
The impact of CAP on elderly patients has fueled efforts by important regulatory agencies such as The Joint Commission and payers such as the Centers for Medicare & Medicaid Services to improve the quality of care for these patients. Performance data for processes of care such as blood cultures, oxygenation assessment, smoking cessation counseling, vaccination of eligible patients, timing of antibiotic delivery, and selection of appropriate antibiotics for patients with pneumonia have been tracked and reported publicly since 2002, resulting in significant improvement in hospitals' compliance with these standards of care. (5) Recently, the reporting of inpatient and 30-day mortality rates has been added.
The choice of an appropriate initial antibiotic regimen is one of the most important predictors of outcome in patients hospitalized with CAP. Mortensen and associates (6) evaluated the antibiotic regimens administered within 48 hours of admission for 420 inpatients with CAP and classified them as concordant or discordant with existing published guidelines. The risk-adjusted 30-day mortality rate in the group who received guideline-discordant therapy was 21.7%, compared with 6.2% in the guideline-concordant group (odds ratio, 5.7; P < .001). (6)
In a subsequent study, the investigators found that the inpatient mortality rate was reduced from 7% to 4% in patients receiving guideline-concordant therapy (relative risk reduction, 63%; P = .04).7 Furthermore, length of stay and duration of intravenous antibiotic therapy were less in the concordant group.
Given the impact of appropriate antibiotic selection on outcomes, it is imperative that clinicians be familiar with published guidelines that define best practices. The Infectious...