Empyema in the critical care patient

Introduction

The purpose of this study is to determine the incidence, mechanisms, causing pathogens and treatment of empyema in ICU patients.

Methods

Over a 6-year period, 22 ICU patients developed empyema (1.5% of total admissions). Mean age: 41.1 ± 16.2 years. Mean stay: 21.4 ± 8.7 days. Initial APACHE II score: 17.1 ± 3.1. All patients underwent mechanical ventilation. Empyema was diagnosed at admission in four patients (18.2%) or during the ICU stay in 18 patients (81.8%). In all patients pus or bacteria was present in the pleural cavity. Besides the daily chest X-ray, a CT scan was performed at least twice during their stay.

Results

Causes of empyema: pneumonia 10, mediastinitis 4, subphrenic abscess 3, hematogenous spread 3, soft tissue infection 2. Underlying diseases: chest injury in multiple trauma patients 15, chest surgery 5, other 2. Radiographic pattern: free pleural effusion: 18 patients (81.8%), loculated four patients (18.2%). In cultures of pleural fluid and blood were isolated: P. aeruginosa 38%, A. baumannii 26%, S. aureus 18%, S. epidermidis 7%, K. pneumoniae 7%, E. coli 4% (in eight patients polymicrobial, while two patients had frank pus but no bacteria were isolated). Pericardial effusion was present in five patients (22.7%). Twelve patients (54.5%) were treated with chest drainage alone (single or multiple), while in 10 patients (45.5%) several thoracosurgical procedures were required (four patients were operated twice and one patient three times). Antibiotics were administered according to sensitivity tests. Mortality rates: 3/22 = 13.6%.

Conclusion

Empyema is rare in the ICU, but it presents severe clinical features and increases the length of stay. Pneumonia is the commonest cause of empyema, followed by mediastinal and abdominal surgical infections. In more than 80% the chest X-ray revealed free pleural effusion. In more than 45% tube chest drainage alone was not effective to treat empyema. Causative pathogens of empyema did not differ from common ICU isolates.