Thoracic Empyema in HIV-Infected Patients: Polymicrobial and BP-associated empyemas
As in other series, polymicrobial and BP-associated empyemas required longer periods of hospitalization and pleural drainage. Moreover, the presence of endocarditis-thrombophlebitis and bacteremia was more common. The delay in arranging closed drainage was correlated to a longer period of hospitalization and a longer drainage time. However, there was no significant difference between loculated and nonloculated effusions or in the use of intrapleural SK with respect to length of hospitalization or drainage time.
Patients with an AIDS diagnosis required a significantly longer hospitalization period. However, on analyzing the delay in hospital admission, the delay or duration of pleural drainage, the days with fever and complications, as severity indicators, no differences were found, although the number of patients studied was small. Other factors, such as the presence of BP (40% vs 15%) and bacteremia (60% vs 46%), were more common in this group and were probably responsible for prolonged hospitalization.
Although pleural effusions are thought to be relatively uncommon, several authors have found a high incidence in AIDS patients (27%) admitted to hospital. Bacterial parapneumonic effusions were the most common cause of this, but reports of thoracic empyema are unusual in these series. It seems that the impact of HIV on mononuclear cells (lymphocytes and monocytes), their subsequent cytokine production, and their indirect impact on neutrophils impair the development of empyema despite the increased incidence of bacterial infections in these patients.
In our series, aminoglycosides (57%), cephalosporins (52%), and antistaphylococcal penicillins (43%) comprised the empiric therapy commonly used. Among patients in whom at least one pathogen was identified (20/23), resistant organisms were isolated in 10 (50%).