Gajic et al developed an algorithm for distinguishing the various types of pulmonary edema associated with a recent blood transfusion. The authors are from the Mayo Clinic and University of California San Francisco.
Patient selection - all of the following:
(1) new onset hypoxemia with PaO2 to FIO2 ratio < 300 or oxygen saturation < 90% on room air
(2) chest imaging study showing new or worsening bilateral infiltrates consistent with pulmonary edema
(3) symptom onset within 6 hours of blood transfusion
Features suggesting increased permeability associated with acute lung injury (ALI) - one or more of the following:
(1) ratio of pulmonary fluid to plasma protein > 0.65
(2) pulmonary artery occlusive pressure < 18 mm Hg
(3) low serum BNP - one of the following:
(3a) < 250 pg/mL
(3b) ratio of post-transfusion BNP divided by pre-transfusion BNP < 1.5)
(4) absence of rapid clinical improvement with volume reduction (diuretics and/or positive pressure ventilation)
(5) at least 2 of the following
(5a) systolic ejection fraction > 45% and absence of severe valvular heart disease
(5b) systolic blood pressure < 160 mm Hg
(5c) vascular pedicle width < 65 mm and cardio-thoracic ratio < 0.55
where:
• In Figure 3 the ratio for BNP reads "pre/post transfusion BNP ratio < 1.5". In the text on page S111 it says that an increase >= 50% in the post-transfusion BNP compared to the pre-transfusion BNP indicates transfusion-associated circulatory overload.
If the patient has sepsis, aspiration or identifiable cause of acute lung injury, then the diagnosis is acute lung injury. If not, then the diagnosis is transfusion-related acute lung injury (TRALI).
Hydrostatic pulmonary edema due to cardiac ischemia:
(1) absence of features for ALI (above)
(2) evidence of myocardial ischemia or infarction (ECG change, elevated troponin, etc)
Hydrostatic pulmonary edema due to transfusion-associated circulatory overload (TACO):
(1) absence of features for ALI (above)
(2) absence of myocardial ischemia or infarction (ECG change, elevated troponin, etc)
Specialty: Clinical Laboratory