TABLE 2.

Risk factors and correlation with empyema

Risk factor	Impact on empyema	Univariate analysis, P	Multivariate analysis, P
Injury severity score
With residual hemothorax	31.4±26	0.09	0.03
Without residual hemothorax	22.6±13
Systolic blood pressure on admission to the ER, mmHg
With residual hemothorax	102.7±40	0.1	0.88
Without residual hemothorax	121±30
Stab wound, n (%)
With residual hemothorax	5 (33)	0.006	0.16
Without residual hemothorax	4 (5)
Left-sided hemothorax, n (%)
With residual hemothorax	7 (15)	0.05	0.25
Without residual hemothorax	2 (4)
Diaphragmatic injury, n (%)
With residual hemothorax	4 (36)	0.005	0.1
Without residual hemothorax	5 (5)
Residual fluid after one or more chest tubes, n (%)
With residual hemothorax	7 (33)	0.001	0.001
Without residual hemothorax	2 (2)

Data are presented as mean ± SD unless otherwise indicated. ER Emergency room