Acute Lung Injury

A syndrome of lung-specific damage (without contribution from cardiac causes), thought to be caused by inflammatory processes. Acute Lung Injury (ALI) is a bit of an “out-of-date” term today. It was defined in a 1994 consensus conference as the acute onset of hypoxemia with chest x-ray evidence of pulmonary edema and WITHOUT evidence of left atrial hypertension (wedge pressure less than 18, if available). Since that time, ALI has been redefined as a milder form of the “Acute Respiratory Distress Syndrome” or ARDS (this reclassification is not really my focus, but you can find many articles describing this change).

Even though the term itself is now passe’, I want you to remember “Acute Lung Injury,” because it gave rise to a very important transfusion reaction known as “Transfusion-related Acute Lung Injury (TRALI).” TRALI was defined in 1995 by a consensus group convened by the National Heart, Lung, and Blood Institute (NHLBI) as “acute lung injury occurring during or within six hours of transfusion, with a clear temporal relationship to the transfusion” (Critical Care Med. 2005 Apr;33(4):721-6), and was redefined again in 2004 and 2019 (our current definition).

I have much more information on TRALI in several different podcasts, including episodes 089 and 069.

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