Pulmonary apoplexy

Pulmonary apoplexy (apoplexia pulmonum) is a hemorrhagic pulmonary edema with an invasion of erythrocytes and capillary infiltrate into the lungs. It is defined as bleeding into two or more pulmonary lobes, which can be interstitial and / or intraalveolar. It most often occurs between the 2nd and 4th day of life in acutely ill low birth weight newborns on artificial lung ventilation.

Pathogenesis
Massive bleeding into the lungs is an extreme picture of neonatal pulmonary edema. The main triggers are increased pulmonary capillary pressure (in heart failure), decreased intravascular oncotic pressure (in extremely premature infants, in hydrops), increased permeability of pulmonary capillaries (in sepsis) and decreased lymphatic drainage (in PIE).


 * The hematocrit of the fluid aspirated from the airways rarely exceeds 0.1,
 * bleeding into the lungs is the result of capillary filtration into the interstitium, when the interstitium is full → the bleeding continues into the alveoli,
 * if the hematocrit of the aspirated fluid is close to the venous hematocrit, the bleeding is likely from a larger blood vessel.

Clinical picture
The child´s ventilation suddenly worsens – it becomes pale, dyspnoic or even apnoic with bradycardia and cyanosis, hypotonic and hyporeflexive.
 * at the same time a pink-red discharge flows out of the oral cavity or cannula,
 * however, in some cases, bleeding is the first symptom in a healthy-looking child and the overall condition worsens later,
 * out of cardiac symptoms we detect tachycardia and often hear a murmur from an open duct, gradually appear symptoms of heart rhythm disorders (mostly bradyarrhythmias), symptoms of heart failure, hypoxemia and MAC,
 * we hear moist phenomena or impaired breathing above the affected lungs.

Differential diagnosis

 * Trauma - airway injury caused by naso- or endotracheal intubation or suctioning; lung injury during chest drain insertion.
 * Aspiration of maternal blood swallowed during a caesarean section.
 * Coagulopathy based on sepsis or congenital.
 * Acute left-sided heart failure due to hypoxia/asphyxia.
 * Hypervolemia caused by excessive transfusion or fluid intake.
 * Congenital heart disease or congestive heart failure (PDA).
 * Respiratory distress syndrome, pulmonary interstitial emphysema, pneumothorax, meconium aspiration, pneumonia (especially caused by Gram-negative bacteria).
 * Surfactant administration - probably due to a rapid increase in blood flow through the lungs while improving lung function. Studies show that prophylactic administration of surfactant increases the incidence of pulmonary apoplexy and „rescue“ administration does not.
 * Artificial lung ventilation or oxygen therapy (oxygen toxicity).
 * Hematological disorders – severe Rh incompatibility, thrombocytopenia, haemorrhagic disease of the newborn (from vitamin K deficiency).
 * Prematurity, IUGR, multiple pregnancy.
 * Severe hypothermia.
 * Infection/sepsis (and associated DIC).
 * Urea cycle disorders with hyperammonemia.

Diagnosis

 * Typical clinical picture: respiratory deterioration accompanied by airway bleeding.
 * Laboratory examination:
 * differential blood count (thrombocytopenia ?, decreased hematocrit?, infection?);
 * coagulation (PT, APTT, TT, FBG);
 * acid-base balance (hypoxia?, metabolic acidosis?).
 * X-ray of the lungs to rule out pneumonia, RDS, congestive heart failure and to determine the extent of the bleeding (focal or massive - white lungs with a negative aerobronchogram).
 * ECHO to detect the presence of a PDA.

Therapy

 * Suctioning from the respiratory tract as needed (there is a risk of clogging the ET cannula with blood).
 * Optimization of ventilation and oxygen therapy.
 * Increasing PEEP (positive end-expiratory pressure) to 6–8 cm H2O – may cause a capillary tamponade.
 * Increasing PIP (peak inspiratory pressure) as needed to ensure adequate ventilation.
 * General measures:
 * Maintaining blood pressure (volume expansion, catecholamines).
 * Erymass transfusion (be careful not to administer too much fluid, as an increase in systemic pressure may worsen the pulmonary edema).
 * Correction of acidosis with bicarbonate under conditions of adequate ventilation.
 * Treatment of the primary cause.
 * Hemorrhagic disease of the newborn – vitamin K (1 mg/kg i.v.), coagulopathy – fresh frozen plasma (10 ml/kg), thrombocytopenia – platelet transfusion, sepsis - antibiotics, PDA - ibuprofen or ligation.
 * Other measures (controversial):
 * High frequency oscillations.
 * Intratracheal administration of surfactant.
 * Intratracheal administration of adrenaline.
 * Corticosteroids (methylprednisolone).
 * Recombinant activated coagulation factor VII i.v. (panhemostatic effect; used to treat severe bleeding in hemophilia A and B).
 * Intratracheal administration of hemocoagulase during artificial lung ventilation.
 * Diuretics (furosemide) to treat volume overload.

Related Articles

 * Neonatal pneumopathies