Table 1.

Neutropenic pleural fluid test characteristics

Parameter	Sample Size, n	Sensitivity, %	Specificity, %	LR+	LR−
Light’s criteria	78	92	55	2.07	0.14
Pleural fluid protein/serum ratio >0.5	77	58	89	5.22	0.47
Pleural fluid LDH/serum LDH ratio >0.6	67	68	59	1.67	0.54
Pleural fluid LDH >⅔ ULN	76	60	73	2.23	0.55
Two-test rule*	77	84	38	1.37	0.41
Three-test rule†	77	90	40	1.51	0.24
Pleural fluid protein >2.9	78	42	96	11.12	0.61
Pleural fluid/serum protein gradient >3.1 g/dl	77	52	82	2.82	0.59
Pleural fluid LDH >0.45 ULN	76	83	42	1.42	0.42

Definition of abbreviations: LDH = lactate dehydrogenase; ULN = upper limit of normal.

^*Two-test rule identifies an exudate by meeting at least one of the following criteria: either pleural fluid cholesterol >45 mg/dl or pleural fluid LDH >0.45 × ULN for serum LDH.

^† Three-test rule identifies an exudate by meeting at least one of the following criteria: either pleural fluid protein >2.9 g/dl, pleural fluid cholesterol >45 mg/dl, or pleural fluid LDH >0.45 × ULN for serum LDH.