Pulmonary hemorrhage is an acute

Acute (medicine)

In medicine, an acute disease is a disease with either or both of:# a rapid onset, as in acute infection# a short course ....

 bleeding

Bleeding

Bleeding, technically known as hemorrhaging or haemorrhaging is the loss of blood or blood escape from the circulatory system...

 from the lung

Lung

The lung is the essential respiration organ in many air-breathing animals, including most tetrapods, a few fish and a few snails. In mammals and the more complex life forms, the two lungs are located near the backbone on either side of the heart...

, especially in the upper respiratory tract

Respiratory tract

In humans the respiratory tract is the part of the anatomy involved with the process of respiration.The respiratory tract is divided into 3 segments:*Upper respiratory tract: nose and nasal passages, paranasal sinuses, and throat or pharynx...

 and the endotracheal tube. When evident clinically, the condition is usually massive, associated with bleeding in other sites as well as more than one third of the lungs. The onset of Pulmonary Hemorrhage is characterized by oozing of bloody fluid from the nose

Human nose

The visible part of the human nose is the protruding part of the face that bears the nostrils. The shape of the nose is determined by the ethmoid bone and the nasal septum, which consists mostly of cartilage and which separates the nostrils...

 and endotracheal tube, as well as to a lesser extent in other places, accompanied by rapid worsening of patient respiration, cyanosis

Cyanosis

Cyanosis is the appearance of a blue or purple coloration of the skin or mucous membranes due to the tissues near the skin surface being low on oxygen. The onset of cyanosis is 2.5 g/dL of deoxyhemoglobin. The bluish color is more readily apparent in those with high hemoglobin counts than it is...

 and, in severe cases, shock. Treatment should be immediate and should include tracheal suction, oxygen, positive pressure ventilation, and correction of underlying abnormalities (e.g. disorders of coagulation

Coagulation

Coagulation is a complex process by which blood forms clots. It is an important part of hemostasis, the cessation of blood loss from a damaged vessel, wherein a damaged blood vessel wall is covered by a platelet and fibrin-containing clot to stop bleeding and begin repair of the damaged vessel...

). A blood transfusion

Blood transfusion

Blood transfusion is the process of receiving blood products into one's circulation intravenously. Transfusions are used in a variety of medical conditions to replace lost components of the blood...

 may be necessary.

Incidence

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. The incidence is 1 in 1,000 live births. Pulmonary hemorrhage has a high mortality rate, 30% to 40%.

Etiology and Pathogenesis

Infant prematurity is the factor most commonly associated with Pulmonary Hemorrhage. Other associated factors are those that predispose to perinatal asphyxia

Perinatal asphyxia

Perinatal asphyxia or neonatal asphyxia is the medical condition resulting from deprivation of oxygen to a newborn infant that lasts long enough during the birth process to cause physical harm, usually to the brain...

 or bleeding disorders, including toxemia

Toxemia

Toxemia may refer to:* A generic term for the presence of toxins in the blood, see Bacteremia* An outdated medical term for Pre-eclampsia...

 of pregnancy, maternal cocaine use, erythroblastosis fetalis, breech delivery, hypothermia

Hypothermia

Hypothermia is a condition in which core temperature drops below the required temperature for normal metabolism and body functions which is defined as . Body temperature is usually maintained near a constant level of through biologic homeostasis or thermoregulation...

, infection

Infection

An infection is the colonization of a host organism by parasite species. Infecting parasites seek to use the host's resources to reproduce, often resulting in disease...

, Infant respiratory distress syndrome

Infant respiratory distress syndrome

Infant respiratory distress syndrome , also called neonatal respiratory distress syndrome or respiratory distress syndrome of newborn, previously called hyaline membrane disease, is a syndrome in premature infants caused by developmental insufficiency of surfactant production and structural...

 (IRDS), administration of exogenous surfactant

Surfactant

Surfactants are compounds that lower the surface tension of a liquid, the interfacial tension between two liquids, or that between a liquid and a solid...

s (in some studies) and Extracorporeal membrane oxygenation

Extracorporeal membrane oxygenation

In intensive care medicine, extracorporeal membrane oxygenation is an extracorporeal technique of providing both cardiac and respiratory support oxygen to patients whose heart and lungs are so severely diseased or damaged that they can no longer serve their function...

 (ECMO).

Although the pathogenesis

Pathogenesis

The pathogenesis of a disease is the mechanism by which the disease is caused. The term can also be used to describe the origin and development of the disease and whether it is acute, chronic or recurrent...

 is uncertain, it is probable that the symptoms are a consequence of hemorrhagic pulmonary edema

Pulmonary edema

Pulmonary edema , or oedema , is fluid accumulation in the air spaces and parenchyma of the lungs. It leads to impaired gas exchange and may cause respiratory failure...

, as the hematocrit

Hematocrit

The hematocrit or packed cell volume or erythrocyte volume fraction is the percentage of the concentration of red blood cells in blood. It is normally about 45% for men and 40% for women...

 is lower than normal blood (usually 15-20% less) and the concentration of small proteins is higher than in plasma. It is postulated that the infant suffers from asphyxia with resultant heart attack

Myocardial infarction

Myocardial infarction or acute myocardial infarction , commonly known as a heart attack, results from the interruption of blood supply to a part of the heart, causing heart cells to die...

; this increases pulmonary microvascular pressure, resulting in pulmonary edema. Contributing factors include factors that favor increased filtration of fluid from pulmonary capillaries (e.g., low concentration of plasma proteins, high alveolar

Pulmonary alveolus

An alveolus is an anatomical structure that has the form of a hollow cavity. Found in the lung parenchyma, the pulmonary alveoli are the dead ends of the respiratory tree, which outcrop from either alveolar sacs or alveolar ducts, which are both sites of gas exchange with the blood as well...

 surface tension, lung damage, hypervolemia

Hypervolemia

Hypervolemia, or fluid overload, is the medical condition where there is too much fluid in the blood.The opposite condition is hypovolemia, which is too little fluid volume in the blood.-Causes:Excessive sodium or fluid intake:* IV therapy...

).