Table 1.

Transfusion-Related Acute Lung Injury (TRALI) definitions

Definition	Clinical Description
Definitive TRALI15,16	A. No evidence of acute lung injury (ALI) prior to transfusion
	AND
	B. ALI onset during or within 6 hours of transfusion
	AND
	C. Hypoxemia defined by any of these methods:
	a. PaO2 / FiO2 ≤300 mm Hg
	b. Oxygen saturation is < 90% on room air
	c. Other clinical evidence
	AND
	D. Radiographic evidence of bilateral infiltrates
	AND
	E. No evidence of left atrial hypertension (i.e. circulatory overload)
	AND
	F. No temporal relationship to an alternative risk factor* for ALI during or within 6 hours of completion of transfusion
Possible TRALI15,16	Same as above EXCEPT there is a temporal relationship to a specific ALI risk factor*
Delayed TRALI definition, defined in critically ill patients
Delayed TRALI17,18	Same as for possible TRALI except allows for symptom onset within 6 to 72 hours of blood transfusion

^*Alternative risk factors for ALI include: 1) Direct lung injury: Aspiration, pneumonia, toxic inhalation, long contusion, near drowning; 2) Indirect lung injury: severe sepsis, shock, multiple trauma, burn injury, acute pancreatitis, cardiopulmonary bypass, drug overdose