A nonresolving pneumonia involves:
(1) inadequate resolution of radiographic infiltrates and/or clinical symptoms
(2) despite apparently adequate antimicrobial therapy
(3) after at least 10 days of treatment
Reasons why a pneumonia may fail to resolve:
(1) antimicrobial failure
(2) infectious complication
(3) incorrect diagnosis (pseudo-pneumonia)
Factors that may contribute to
antimicrobial failure
:
(1) noncompliance by the patient
(2) improper dosing regimen
(3) organism resistant to the antimicrobial agent selected (including fungus or virus)
(4) unusual or unsuspected pathogen
Infectious complications
may include:
(1) superinfection
(2) empyema
(3) endocarditis
(4) parasitic infection
Pseudo-pneumonias
may include:
(1) malignancy
(2) pulmonary embolism
(3) drug-induced pneumonitis
(4) radiation pneumonitis
(5) adult respiratory distress syndrome (ARDS)
(6) autoimmune disease
(7) other noninfectious causes (lipoid pneumonia, etc)
Additional conditions to consider:
(1) defective or inactive drug (counterfeit, outdated, etc)
(2) failure of the antimicrobial agent to reach the site of action
(3) bronchial obstruction (foreign body, bronchial tumor, etc)
(4) immunodeficiency or other defect in host defenses
(5) more than one organism involved (polymicrobic)
