Respiratory Distress in the Term Newborn

Introduction

Infants suffering from breathing difficulties frequently exhibit symptoms of respiratory distress. Respiratory distress syndrome (RDS) is brought on by the infant's lungs not producing adequate surfactant. Around week 26 of pregnancy, the lungs produce a liquid called surfactant. The lungs produce more surfactant as the fetus develops. Most RDS cases affect infants who are delivered before 37 to 39 weeks. The likelihood of RDS after birth increases with infant prematurity. Full-term newborns rarely have the issue (after 39 weeks).

How Is Respiratory Distress Syndrome Caused?

Small air sacs in the lungs are protected from collapsing by a layer of surfactant. The air sacs must remain open for oxygen from the lungs to enter the blood and for carbon dioxide to be released into the lungs. Because their lungs are still developing, newborns with respiratory distress syndrome (RDS) produce less surfactant than healthy infants. The infant's organs might not get enough oxygen as a result. If a full-term newborn has genetic defects that affect how their bodies manufacture surfactant, they may have RDS. RDS can affect other neonates, but preterm newborns are more likely to develop it.

What Are the Risk Factors of Respiratory Distress Syndrome?

The respiratory distress syndrome risk factors include

• A brother or sister who had RDS.

• Diabetes in the mother.

• Cesarean delivery or induction of labor before the baby is full-term.

• Problems with the delivery that reduces blood flow to the baby.

• Multiple pregnancies (twins or more).

• Rapid labor.

• Infection.

• Prenatal ultrasonographic findings include oligohydramnios (decreased amniotic fluid for the gestational age) or structural lung abnormalities.

• A newborn infant who is unwell at the time of delivery.

• Hypothermia (abnormally low temperature).

What Are the Sign and Symptoms of RDS?

The various signs and symptoms of respiratory distress syndrome are

• Tachypnea - Respiratory rate greater than 60 breaths per minute.

• Cyanosis - Bluish skin and mucous membrane discoloration, like around the mouth, inside the lips, and in fingernails.

• Grunting - Every time the person exhales, a grunting (ugh) noise may be heard. The body uses this grunting to keep the air in the lungs to keep them open.

• Nasal Flaring - Flaring (widening) of nostrils while breathing.

• Retraction - With each breath, the chest seems to sink in beneath the breastbone, just below the neck, or both.

• Wheezing - A tight, whistling, or melodic sound made with each breath, indicating a narrower (tighter) airway.

• Body Position - While seated, a person may inadvertently lean forward to aid in taking deeper breaths. This is a red flag indicating they are about to pass out.

• Apnea - Brief stop in breathing.

• Urine Output - Decreased.

What Are the Other Related Disorders of Respiratory Distress in Newborns?

The various disorders related to respiratory distress in newborns are as follows:

Airway Diseases

1. Nasal obstruction.

2. Choanal atresia (narrowing of nasal airway by tissue).

3. Micrognathia (small lower jaw).

4. Pierre Robin syndrome.

5. Macroglossia (large tongue).

6. Congenital high airway obstruction syndrome, including laryngeal or tracheal atresia.

7. Subglottic stenosis (narrowing of the upper airway).

8. Laryngeal cyst or laryngeal web.

9. Vocal cord paralysis.

10. Airway hemangiomas or papillomas (large mass of blood vessels in the airway).

11. Laryngomalacia (baby’s voicebox is soft and floppy).

12. Tracheobronchomalacia (weak airway walls).

13. Tracheoesophageal fistula (an abnormal connection between windpipe and food pipe).

14. Vascular rings (abnormal formation of the aorta).

15. External compression from a neck mass.

Pulmonary Diseases

1. TTN (transient tachypnea of the newborn - respiratory disorder seen in neonates).

2. MAS [meconium aspiration syndrome - newborn breathing mixture of meconium (fetus’s first poop) and amniotic fluid into the lungs during delivery].

3. Neonatal pneumonia (lung infection in the neonate).

4. Pneumothorax.

5. PPHN (persistent pulmonary hypertension of the newborn).

6. Pleural effusion (congenital chylothorax).

7. Pulmonary hemorrhage (bleeding in the lungs).

8. Bronchopulmonary sequestration (abnormal mass of nonfunctioning lung tissue).

9. Bronchogenic cyst (congenital lesion derived from primitive foregut).

10. Congenital cystic adenomatoid malformation or congenital pulmonary airway malformation.

11. Pulmonary hypoplasia (incomplete development of lungs).

12. Congenital lobar emphysema (malformation of lungs).

13. Pulmonary alveolar proteinosis (surfactant accumulation in the lungs).

14. Alveolar capillary dysplasia (disorder affecting the development of lungs and their blood vessels).

15. Congenital pulmonary lymphangiectasis (congenital disorder causing widening lymphatic vessels in the lung).

16. Surfactant protein deficiency.

Cardiovascular

1. Congenital heart defects.

2. Neonatal cardiomyopathy (heart muscles become stiff).

3. Pericardial effusion or cardiac tamponade.

4. Fetal arrhythmia with compromised cardiac function.

5. High-output cardiac failure.

Thoracic

1. Pneumomediastinum (presence of air in the space in the chest between the lungs).

2. Chest wall deformities and mass.

3. Skeletal dysplasia (a genetic disorder affecting bones and joints).

4. Diaphragmatic hernia or paralysis.

Neuromuscular

1. Central nervous system injury (birth trauma or hemorrhage).

2. Hypoxic-ischemic encephalopathy.

3. Cerebral malformations.

4. Chromosomal abnormalities.

5. Medication (neonatal or maternal sedation, antidepressants, or magnesium).

6. Congenital TORCH infections (toxoplasmosis, syphilis, hepatitis B, rubella, cytomegalovirus, and herpes simplex).

7. Meningitis.

8. Seizure disorder.

9. Obstructed hydrocephalus.

10. Arthrogryposis (congenital joint contracture).

11. Congenital myotonic dystrophy (a genetic disorder causing muscle loss and weakness).

12. Neonatal myasthenia gravis.

13. Spinal muscular atrophy.

14. Congenital myopathies.

15. Spinal cord injury.

Other

1. Sepsis.

2. Hypoglycemia.

3. Metabolic acidosis.

4. Hypothermia or hyperthermia.

5. Hydrops fetalis (abnormal fluid buildup in two or more body parts of the fetus).

6. Inborn error of metabolism.

7. Hypermagnesemia (excess magnesium).

8. Hyponatremia or hypernatremia (excess sodium).

9. Severe hemolytic disease.

10. Anemia.

11. Polycythemia (increased red blood cells).

How Is Respiratory Distress Syndrome Diagnosed?

Respiratory distress is common in preterm infants. To differentiate it from other breathing disorders, specific investigations are necessary.

• Chest X-Ray or Lung Imaging Test - This shows a ‘ground glass’ appearance, a typical disease feature. It develops six to twelve hours after birth.

• Blood-Gas Analysis - Shows low oxygen and excess acid in body fluids.

• Blood Test - To rule out infection as a cause of breathing problems.

• Heart Test - To check for a possible congenital heart defect.

How Is Respiratory Distress Treated?

Some common treatments for respiratory distress are

Oxygen - Babies with RDS need extra oxygen. Some ways to deliver oxygen are

1. Nasal Cannula - A small tube with prongs is placed in the nostrils of the baby.

2. Continuous Positive Airway Pressure (CPAP) - Used to gently push oxygen into the lungs to maintain the air sacs in the open state.

Ventilator - Only the most severe RDS cases make use of this. A ventilator is a device that provides life support by doing the baby’s breathing for them. The device is attached to a breathing tube that enters the baby's windpipe through the mouth or nose. Bronchopulmonary dysplasia is more prone to develop in infants who need ventilation. They might also experience health issues like lung or airway damage due to the breathing tube or ventilator.

Surfactant - To replenish what is missing, surfactant might be administered to the baby's lungs. This is injected directly into the windpipe through the breathing tube.

Intravenous (IV) Catheter Treatments - A very small tube (catheter) is inserted into one or more of the umbilical cord's blood vessels. The infant receives feeding, IV fluids, and medications in this manner. Blood samples are also drawn using this method.

Medication - Antibiotics are occasionally administered when an infection is detected. To help reduce pain during therapy, relaxing medications may be administered.

What Are the Consequences of Untreated RDS?

Depending on how severe RDS is, they could also acquire one or more of the following medical conditions:

• Bleeding in the Brain - Resulting in intellectual disabilities, cerebral palsy, and cognitive (higher brain functions involved in learning) delay.

• Lung Complications - Pneumothorax (air leaking from the lungs into the chest cavity) or pulmonary hemorrhage (bleeding in the lungs).

• Vision - Developmental problems (retinopathy of prematurity) and blindness.

• Infection - Resulting in sepsis (a severe condition brought on by the body's excessive immunological reaction to a bacterial infection).

Prognosis (Outlook) Of the Disease

After birth, the condition frequently deteriorates for the first two to four days before gradually improving. With severe respiratory distress syndrome, some infants will pass away. This typically happens between days two and seven.

Long-term complications may develop due to the following:

• Too much oxygen.

• High pressure delivered to the lungs.

• More severe disease or immaturity. RDS can be associated with inflammation that causes lung or brain damage.

• Periods when the brain or other organs did not get enough oxygen.

How to Prevent Respiratory Distress in Newborns?

Some precautions to avoid RDS are

• Preventing Premature Birth - Neonatal RDS can be avoided by taking precautions to prevent early birth. Premature birth can be prevented with proper prenatal care and regular checks beginning as soon as a woman learns she is pregnant.

• Delivery Time - The right delivery timing can help reduce the incidence of RDS. There may be a need for an induced delivery or cesarean. Before giving birth, a lab test can be performed to determine whether the baby's lungs are prepared. Unless medically required, induced or cesarean deliveries should be postponed until the infant is at least 39 weeks old or until testing reveals that its lungs are fully developed.

• Corticosteroid Therapy - Corticosteroid medications can accelerate lung development before a baby is born. They are frequently administered to pregnant women between 24 and 34 weeks who appear to be due any day. Further investigation is required if corticosteroids may also be advantageous for infants younger than 24 or older than 34 weeks. Sometimes, it could be possible to delay the start of labor and delivery until the steroid medication has had time to take effect. This therapy might lessen the severity of RDS. It also lowers the risk of additional prematurity-related problems. It will not eliminate the risks, though.

Conclusion

The best course of action will be guided by quickly improving newborns' ability to spot respiratory distress and knowing the physiologic abnormalities linked to several causes. Although preventing the occurrence is preferable, early diagnosis and treatment of the prevalent neonatal respiratory disorders will reduce short- and long-term problems and the associated infant mortality.