| Pulmonary hemorrhage | |
|---|---|
 | |
| Micrograph showing a pulmonary hemorrhage.H&E stain. | |
| Specialty | Pulmonology  |
Pulmonary hemorrhage (orpulmonary haemorrhage) is anacutebleeding from thelung, from the upperrespiratory tract and thetrachea, and thepulmonary alveoli. When evident clinically, the condition is usually massive.[1] The onset of pulmonary hemorrhage is characterized by a cough productive ofblood (hemoptysis) and worsening of oxygenation leading tocyanosis.[1] Treatment should be immediate and should include tracheal suction, oxygen,positive pressure ventilation, and correction of underlying abnormalities such as disorders ofcoagulation. Ablood transfusion may be necessary.[1]
Infant prematurity is the factor most commonly associated with pulmonary hemorrhage. Other associated factors are those that predisposed toperinatal asphyxia orbleeding disorders, includingtoxemia of pregnancy, maternalcocaine use,erythroblastosis fetalis,breech delivery,hypothermia,infection (likepulmonary tuberculosis),Infant respiratory distress syndrome (IRDS), administration of exogenoussurfactants (in some studies) andextracorporeal membrane oxygenation (ECMO).[1]
Although thepathogenesis is uncertain, it is probable that the symptoms are a consequence of hemorrhagicpulmonary edema, as thehematocrit is lower than normal blood (usually 15-20% less) and the concentration of small proteins is higher than in plasma.[1] It is postulated that the infant suffers from asphyxia with resultantheart attack; this increases pulmonary microvascular pressure, resulting in pulmonary edema.[1] Contributing factors include factors that favor increased filtration of fluid from pulmonarycapillaries (e.g., low concentration ofplasma proteins, highalveolar surface tension, lung damage,hypervolemia).[1]
Diffuse alveolar hemorrhage is bleeding from manyalveoli throughout the lungs. Common causes include autoimmune diseases and connective tissue diseases.[2] Diagnosis of DAH is often given following observation of a patient presenting with hemoptysis, anemia, and cough,[3] along with a chest X-ray showing alveolar infiltrates in the lungs,[4] which are areas of air space in the lungs that are opacified and of higher density that normal, usually indicating that they are filled with a substance such as pus, blood, or another fluid.[5]
The outcome of treatment is dependent on causality. Pulmonary Hemorrhage is present in 7 to 10% of neonatal autopsies, but up to 80% of autopsies of very preterm infants.[1] The incidence is 1 in 1,000 live births.[1] Pulmonary hemorrhage has a high mortality rate of 30% to 40%.[1]