Hospital-acquired pneumonia is also known as nosocomial pneumonia and it is a type of pneumonia that is acquired during or after hospitalization for treatment of another illness or procedure. The causes, microbiology, treatment and prognosis differ from those of community-acquired pneumonia. It is studied that up to 5% of patients who are admitted in a hospital for other causes, gradually develop pneumonia. Hospitalized patients are at higher risk for pneumonia, including mechanical ventilation, malnutrition for a prolonged time, underlying heart and lung diseases, fewer amounts of stomach acid, and immune system disturbances. In addition, a person is exposed to different types of microorganisms than those at home. Resistant bacteria such as MRSA, Pseudomonas, Enterobacter, and Serratia are some of the hospital-acquired microorganisms. Hospitalized patients are being treated for underlying illnesses and the exposure to the dangerous bacteria in the hospitals, tends to be more fatal than community-acquired pneumonia. Ventilator-associated pneumonia (VAP) is a subset of hospital-acquired pneumonia, which occurs after at least 48 hours of mechanical ventilation and intubation.
Hospital-acquired infections include clinically evident infections that do not originate from patient's original admitting diagnosis. After admission in the hospital, a patient's flora begins to acquire characteristics of the surrounding bacterial pool and this happens within hours. Infections that are clinically evident, after 48 hours of hospitalization are considered hospital-acquired. Patients being infected after the discharge from the hospital are considered to have infection of nosocomial origin, if the organisms were acquired during the hospital stay.
Hospital acquired pneumonia mostly develops in patients who are severely debilitated or who have low immunity.
Given below are the different organisms that are responsible for causing hospital acquired pneumonia:
- anaerobic bacteria affect 9% cases
- gram negative bacilli (particularly Klebsiella spp. and pseudomonas spp.) seen in 50% cases
- streptococcus pneumonia occurs in 6% cases
- staphylococcal aureus present in 15% cases
- other causes, e.g. fungi, legionella 20% cases
The organism may be antibiotic-resistant; an intravenous, broad spectrum agent such as cefotaxmime or ceftazidine is indicated. In addition to the antibiotic, Metronidazole should be used to cover anaerobic infection, if any.
Hospital-acquired pneumonia (HAP) is linked to high morbidity and mortality rate. Early, appropriate, and adequate empiric therapy can ensure and increase the chances of survival. In 1995, the American Thoracic Society provided guidelines to the physicians in the management of HAP. However, these guidelines have certain drawbacks such as lack of recommendations for duration of therapy and no recognition of newer drugs such as cefepime, trovafloxacin, and meropenem. Furthermore, they are not able to distinguish similar compounds (ie, ß-lactam/ß-lactamase inhibitor combinations) or they fail to recommend specific antibiotics. The clinician following these guidelines needs to tackle local patterns of antimicrobial resistance, especially in ICUs. Efficient computerized antibiotic management programs that include information on local patterns of antimicrobial resistance can be of help for physicians in empiric therapy decision making, to improve patient quality of care, and to reduce the medical costs.
Nosocomial Pneumonia Causes
Nosocomial Pneumonia Symptoms
Nosocomial Pneumonia Diagnosis
Nosocomial Pneumonia Treatment