Dr. Holmberg is the pharmacy coordinator at Desert Vista Behavioral Health Center in Mesa, Arizona.
Although CAP affects the elderly more frequently, it is important to remember that patients of all ages are susceptible to the disease.1 Diagnosis should be based on both the presence of clinical features (cough, fever, sputum, and pleuritic chest pain) and infiltrate on chest radiograph.4 Patients with CAP may describe other symptoms, such as shortness of breath, rigors, night sweats, or confusion. Additional signs include increased respiratory rate and focal chest signs, such as decreased expansion, dullness to percussion, decreased air entry, bronchial breathing, and crackles.1
Treatment of CAP is specific to its setting (outpatients, intensive care unit [ICU] patients, and non-ICU inpatients). Location of treatment can be costly—inpatient costs for CAP are estimated to be 25 times the costs of outpatient care.4 Whether or not to admit a patient for inpatient treatment of CAP depends on clinical judgment, and clinicians may find it helpful to use an objective tool to assess the need for hospitalization. Either a severity-of-illness score, such as CURB-65, or a prognostic model, such as the pneumonia severity index (PSI), may help determine if a patient needs inpatient care.
An admission to the ICU should be considered in patients on vasopressors due to septic shock or in patients requiring mechanical ventilation as a result of their respiratory failure.4
Although CAP can be caused by a wide range of organisms, specific pathogens are usually identified and associated with it. Common etiologies for outpatient CAP include Streptococcus pneumoniae, Mycoplasma pneumoniae, Haemophilus influenzae, Chlamydophila pneumoniae, and respiratory viruses, such as influenza A and B, respiratory syncytial virus, and parainfluenza virus. Inpatient CAP in non-ICU patients is often due to infection with S pneumoniae, M pneumoniae, C pneumoniae, H influenzae, Legionella species, and respiratory viruses, or as a result of aspiration. Inpatient CAP in ICU patients is often associated with S pneumoniae, Staphylococcus aureus, Legionella species, gram-negative bacilli, or H influenzae.
Specific diagnostic testing (ie, sputum or blood culture) is not usually recommended for outpatient CAP; however, it may be warranted for inpatients in more critical condition.
If organisms are identified, the antibiotic regimens should be adapted to target the cultured organism as appropriate.
In recent years, drug-resistant S pneumoniae (DRSP) has made the empirical treatment of CAP more difficult. Patients at greater risk for DRSP include those who are <2 or >65 years of age, have received treatment with a beta-lactam or macrolide within the past 3 to 6 months, have alcoholism, have comorbidities, are using immunosuppressive therapies or have an immunosuppressive illness, or have had an exposure to a child in day care.5
CAP resulting from communityacquired methicillin-resistant S aureus (CA-MRSA) is still rare, but its incidence has been increasing lately and is expected to continue to rise. It has been found in both adults and children and seems to follow influenza. Patients with CA-MRSA have cavitary infiltrates without risk factors for aspiration. Both sputum and blood cultures are useful in diagnosis.4
Pharmacists can play an important role in both inpatient and outpatient treatment of CAP. Areas for pharmacist intervention include:
CAP is a prevalent and potentially deadly disease, but it also is one that can be overcome by appropriate diagnosis, monitoring, and treatment. The pharmacist has the potential to participate with the medical team in both an outpatient and inpatient setting to help improve patient outcomes and restore patient quality of life.
Table (click on table for larger image)