Pleural effusions in febrile medical ICU patients: chest ultrasound study.
OBJECTIVE
To assess the necessity of thoracentesis in febrile medical ICU (MICU) patients, and to evaluate the efficiency and reliability of sonographic effusion patterns for diagnosing empyema.


METHODS
A prospective, 1-year, tertiary-care hospital study of febrile MICU patients with physical, radiographic, and ultrasonographic evidence of pleural effusion.


METHODS
During this study period, we screened 1,640 patients who had been admitted to the MICU; of these, 94 patients had a temperature > 38 degrees C for > 8 h with evidence of pleural effusion proven by chest radiography and ultrasound.


METHODS
Routine thoracentesis and pleural effusion cultures were performed in 94 febrile patients under portable chest ultrasound guidance. Three days later, if the first pleural effusion culture was inconclusive and the patient still had persistent fever of > 38 degrees C, we repeated the diagnostic thoracentesis and pleural effusion culture. In total, 118 procedures were performed in those 94 febrile patients.


RESULTS
In all, 58 patients (62%) had infectious exudates (parapneumonic, n = 36; empyema, n = 15; urosepsis, n = 3; liver abscess, n = 2; deep neck infection, n = 1; and wound infection, n = 1), 28 patients (30%) had transudates, and 8 patients (8%) had noninfectious exudates. The prevalence of empyema in febrile patients admitted to the MICU was 16% (15 of 94 patients). Analyses of the sonographic patterns of the 15 patients with empyema out of the 118 thoracenteses performed showed the following: anechoic pattern, 0% (0 of 47 procedures); complex nonseptated and relatively nonhyperechoic pattern, 0% (0 of 36 procedures); complex nonseptated and relatively hyperechoic pattern, 100% (2 of 2 procedures); complex septated pattern, 35% (11 of 31 procedures); and homogeneously echogenic pattern, 100% (2 of 2 procedures). Hemothorax was the only complication, and it occurred in two patients (2%). Both patients had a favorable outcome after drainage.


CONCLUSIONS
Portable chest ultrasound examination and ultrasound-guided thoracentesis in febrile MICU patients are safe, feasible, and useful methods for diagnosing thoracic empyema. Our results suggest that only some sonographic patterns of pleural effusion (homogeneously echogenic, complex nonseptated and relatively hyperechoic, and complex septated) deserve aggressive assessment and rapid management.
Department of Internal Medicine, China Medical University Hospital, Taichung, Taiwan. hsuwh@www.cmuh.org.tw
Chih-Yen
CY
Tu
Wu-Huei
WH
Hsu
Te-Chun
TC
Hsia
Hung-Jen
HJ
Chen
Kuen-Daw
KD
Tsai
Chung-Wen
CW
Hung
Chuen-Ming
CM
Shih
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D004322:Drainage; D016724:Empyema, Pleural / Q000000981:diagnostic imaging* / Q000382:microbiology; D005260:Female; D006801:Humans; D007362:Intensive Care Units; D008297:Male; D008875:Middle Aged; D010996:Pleural Effusion / Q000000981:diagnostic imaging* / Q000628:therapy; D011446:Prospective Studies; D014463:Ultrasonography