Management of parapneumonic pleural effusions and empyema

Parapneumonic pleural effusions, the most common causes of exudative pleural fluid, are a frequent finding with bacterial pneumonia. Progression to empyema is related to delay in appropriate antimicrobial therapy. Once an empyema develops, therapy consists of early sterilization of the empyema space with appropriate antibiotics, early and adequate pleural space drainage, and obliteration of the empyema cavity by adequate lung expansion, surgical decortication, or enzymatic debridement.

[Severe infections due to Streptococcus milleri in children]

Streptococcus milleri (S. milleri) is found in healthy individuals in the mouth, nasopharynx, throat, vagina and in feces, and has been reported to be isolated from several infectious diseases in man, particularly from abscess in various parts of the body. We report two cases of severe infections due to S. milleri isolated from subdural abscess and pleural empyema. [Case 1] 13 year old boy who had been healthy until he was noticed to have meningeal signs and was diagnosed as left subdural abscess with siagonantritis by cranial CT scans. S. milleri was isolated from subdural abscess and maxillary sinus. [Case 2] 10 year old boy who had encephalitis and severe mental retardation after measles at 6 months of age. He had a fever, dyspnea and chest X-ray abnormalities and was diagnosed as right pleural empyema. Three strains of organism, S milleri, Bacteroides spp. and Fusobacterium nucleatum were isolated from the pleural effusion.

Antibiotic therapy of pleural empyema

Most empyemas occur as a complication of pneumonia or lung abscess, but 15% to 30% occur after thoracic surgery and 10% occur in association with an intraabdominal infection. The bacteriology of empyemas that occur in association with lung infections is often polymicrobial and mixed, containing multiple species of both aerobic and anaerobic bacteria, the latter found in up to 75% of cases. In contrast, empyema following thoracic surgery is more likely to be monomicrobial and caused by common nosocomial pathogens such as Staphylococcus aureus and aerobic gram-negative bacilli. Diffusion of antibiotics into both infected and uninfected pleural fluid is good, but certain agents (aminoglycosides and some beta-lactams) may be inactivated in the presence of pus, low pH, and beta-lactamase enzymes. Single antibiotic agents that are likely to be active against the wide spectrum of potential pathogens include imipenem-cilastatin and ticarcillin-clavulanic acid. Combinations of antibiotics should include an effective agent against anaerobic bacteria (clindamycin, metronidazole) coupled with an agent active against aerobic gram-positive cocci and gram-negative bacilli.

[Clinical and radiologic manifestations of pleural and pulmonary complications in sepsis]

Proceeding from the investigation and therapy of 106 patients with pleuropulmonary complications of sepsis the authors described clinical and x-ray features of different types of their course, complications and outcomes. In 58% of cases pulmonary lesions were detected at the stage of pyodestruction and pleural empyema; interstitial-focal and infiltrative pneumonias of considerable spreading with the development of a respiratory type of septic shock were observed less frequently. Pulmonary lesions in 24% were the only sign of septicopyemia, in 58% they prevailed in the clinical picture of polyorganic lesions; pleural complications developed in 32% of the patients. Convalescence was observed in 88 (83%) patients; they had residual bullous-sclerotic pulmonary changes. The lethality rate was 17%.

Clinical and bacterial features of infections caused by Streptococcus milleri

The clinical and bacteriological features of 51 infections due to Streptococcus milleri observed in 43 patients over a 2-year period were reviewed. Clinical syndromes included bacteremia in 6 cases, endocarditis in 4 cases, cellulitis and subcutaneous abscesses in 8 cases, pleural empyema in 8 cases, brain abscesses in 5 cases, abdominal infections in 5 cases, and other miscellaneous infections in 15 cases. An underlying condition was associated with infection in 33/43 patients (77%). S. milleri was the only pathogen isolated in 19 patients (44%). All strains of S. milleri were susceptible to penicillin. Surgery was combined with antimicrobial therapy in 27 (63%) patients. Nine patients died during hospitalization, and death was directly related to S. milleri infection in 4 patients (9%). These results confirm that S. milleri frequently causes serious suppurative infections and that species identification is a clinically useful procedure.

Culture-positive thoracic empyema in adults

Twenty-nine adult patients with culture-positive thoracic empyema were seen at the University Hospital Kuala Lumpur from 1984 to 1988. Cough, fever, chest pain, dyspnoea and weight loss were the common presenting symptoms. The empyema in 16 patients was associated with primary bronchopulmonary infections, nine occurred following thoracentesis of culture-sterile pleural effusions, two occurred as post-thoracic surgery complications, one following a subdiaphragmatic abscess and one as a result of a stab wound. The most common culture isolates were Streptococcus milleri, Pseudomonas aeruginosa and Klebsiella pneumoniae. Closed tube thoracostomy, the most common form of drainage procedure employed, was able to effect a cure or control of the empyema in 11 out of 19 patients in whom it was used.