Neonatal Pneumonia - An Overview

Introduction

Pneumonia is a pulmonary infection that is caused by microorganisms, significantly bacteria. There is consolidation and inflammation of the lung tissue. The respiratory bronchiole and alveoli are infected due to microorganisms. The alveoli are sacs present in the lungs that absorb oxygen. The microorganism includes bacteria and mycobacteria. Neonatal pneumonia is one of the most common causes of neonatal infections and perinatal deaths. The symptoms of the infections appear within hours of birth. In addition, it is one of the most common invasive bacterial infections that cause generalized sepsis. The infection can be mild and, if left untreated, becomes severe. It causes respiratory distress, which progresses to shock and death. In severe cases, intensive care units with prolonged endotracheal tubes are indicated.

What Is Neonatal Pneumonia?

Neonatal pneumonia is an inflammatory respiratory infection of neonates. It has an early onset within an hour or late after seven days of birth. It originates from the lung or results from focal complications of the systematic inflammatory process.

What Are the Causes of Neonatal Pneumonia?

Listed below are the causes of neonatal pneumonia:

Bacterial Pathogens

Gram-positive Bacteria

1. Streptococcus.

2. Escherichia coli.

3. Staphylococcus aureus.

4. Streptococcus aureus.

5. Streptococcus pyrogens.

Gram-negative Bacteria

1. Mycobacterium tuberculosis.

2. Enterobacter.

3. Pseudomonas.

4. Listeria monocytes.

Viral Pathogens

1. Herpes simplex virus.

2. Congenital cytomegalovirus.

3. Congenital rubella.

4. Influenza virus.

5. Parainfluenza virus.

6. Adenovirus.

7. Enterovirus.

Fungal Pathogens

1. Candida tropicalis.

2. Candida albicans.

What Is the Pathogenesis of Neonatal Pneumonia?

The pathogenesis of neonatal pneumonia depends upon the type of microorganism. Viral infection causes interstitial pneumonia. Alveoli and bronchioles are involved. In bacterial infection, bronchopulmonary cells are destroyed, and inflammation of the pleura is seen. There is the presence of leucocyte and fibrinous exudate seen in the alveoli. An epithelial injury to the airways results in leakage of the interstitial proteinaceous fluid. Bacterial infiltration is seen in interstitial spaces and bronchioles.

What Are the Clinical Features of Neonatal Pneumonia?

Listed below are the clinical manifestations of neonatal pneumonia.

• Persistent fever.

• Shaking chills of the sudden onset.

• Respiratory distress.

• Cough.

• Malaise.

• Resistance to feeding and lethargy.

• Sternal retraction.

• Deep breathing.

• Grunting during exhalation.

• Oliguria.

• Chest pleuratic pain.

• Marked tachypnea.

• Poor appetite.

• Diaphoresis.

• Purulent sputum.

• Flaring of the alae nasi. (a lateral portion of the nose dividing the nostrils).

• Cyanosis.

• Pallor.

• Abdominal distension.

• Jaundice.

• Circulatory collapse.

What Are the Risk Factors of Neonatal Pneumonia?

Listed below are the risk factor of neonatal pneumonia:

• Premature birth of the child.

• Improper mucociliary clearance.

• Lowered host defense.

• Low weight birth of the child.

• Intraamniotic infections.

• Membrane rupture before labor onset.

• Infection of the maternal genitourinary tract.

• Meconium in amniotic fluid.

• Streptococcus colonization.

• Intrapartum maternal fever.

• Prolonged invasive mechanical ventilation.

• Prolonged hospitalization and hospital-acquired infections.

• Airways anomalies include choanal atresia, cystic adenomatoid malformations, and tracheoesophageal complications.

• Severe pulmonary infections.

• Invasive procedures include barotrauma, tracheal intubation, and hyperoxic damage to the respiratory tract.

• Asphyxia.

• Environmental factors such as nosocomial flora hospitals and unwashed hands of caregivers.

What Are the Complications of Neonatal Pneumonia?

Listed below are the complication of neonatal pneumonia.

• Meconium aspiration syndrome.

• Wilson milky syndrome (lung condition in premature infants).

• Pulmonary hemorrhage.

• Pulmonary edema (fluid in lungs).

• Primary pulmonary lymphangiectasia.

• Congestive heart failure.

• Restrictive pleural effusion.

• Empyema (lung condition causing shortness of breath).

• Airway injury.

• Hypoperfusion (reduced amount of blood flow).

• Hypoxic ischemic organ injury.

• Infected pleural infusion.

• Persistent pulmonary hypertension.

How Is Neonatal Pneumonia Diagnosed?

Listed below are the methods of diagnosis of neonatal pneumonia.

• Physical Examination - The signs of respiratory distress are observed. The chest is observed for expansion on the affected side. Auscultation is done for bronchial breathing through inflamed lungs. Crackle is present in the affected region during expiration. Due to pleural effusion, there is difficulty in breathing and it results in respiratory distress.

• Radiological Investigation - An X-ray of the chest reveals abnormal lung changes. The presence of obscured areas of lung inflammation is noted in bacterial infection. In viral infections, the presence of streaky and patchy changes is seen.

• Laboratory Investigation - Complete blood cell count, white blood cell count, and arterial blood gas are indicated. Inflammation markers such as C reactive protein, procalcitonin, and cytokines are investigated.

• Cultures - A culture of blood sputum and cerebrospinal fluid is obtained. Gram staining and culture of tracheal aspirate are advised for investigation. Tracheal aspiration shows colonization.

What Are the Treatment Plans for Neonatal Pneumonia?

Children with neonatal pneumonia rapidly deteriorate due to respiratory compromise. Therefore, they should be managed in intensive care units. Listed below is the treatment plan for neonatal pneumonia:

• Supportive Care - Neutral thermal environment should be maintained. Normal fluid maintenance, electrolyte status evaluation, and adequate oxygenation are indicated. If the child is severely ill, ventilation and vasopressor support are required for perfusion. Prevention of metabolic acidosis and hypoglycemia is essential.

• Respiratory Support - Adequate oxygen supply is essential for alveolar ventilation. Airway patency should be maintained. A mucolytic agent is indicated for relief from tracheal secretions. Deep suctioning should be avoided to prevent airway trauma and swelling.

• Antibiotic Therapy - Initial empiric therapy is advised before the culture results. The choice of antibiotic is based on the type of neonatal pneumonia. The pattern of susceptibility is considered for antibiotics. For early onset, Ampicillin and Gentamycin are advised. Aminoglycoside is also given with a combination of Ampicillin. The dose of antibiotics depends upon the postnatal age, renal function, and infant weight. For late-onset neonatal pneumonia, Ampicillin, Vancomycin, and Cefotaxime, extended-spectrum Cephalosporin is given.

• Definitive Therapy - It is indicated when the culture is positive. The medications are prescribed according to the susceptibility testing of pathogens. The duration of treatment for uncomplicated pneumonia is seven to ten days. An appropriate starting regime of Gentamycin, Ampicillin, and Aminoglycoside for fourteen days is given for early-onset pneumonia. The combination of Cefotaxime and Ampicillin is given as an alternative.

Conclusion

Neonatal pneumonia is one of the most significant causes of infant mortality. Preterm infants with severe lung infections and immunodeficiency are at high risk of morbidity. It is an early onset disease of the newborn that causes respiratory distress and low appearance, pulse grimace activity, and respiration score in the child. The sign and symptoms of illness can be subtle in newborns. Parents should observe the signs and symptoms of the child and report to health care as early as possible. Proper diagnosis and treatment plans should be followed. The prognosis depends upon the severity of the disease.