Pulmonary Interstitial Emphysema - An Overview

Introduction

The condition known as pulmonary interstitial emphysema, or PIE, is characterized by the accumulation of gasses outside of the regular air channels as well as inside the connective tissue of the anatomical structures surrounding the bronchial tubes and blood and visceral pleura (the thin, serous membrane that covers the surface of the lungs). This condition reveals itself when the most compliant part of the terminal airway ruptures, allowing gasses to escape into tissue voids.

What Are the Causes?

Neonatal causes involve:

• Pulmonary dysfunction syndrome.

• Prematurity.

• Syndrome of meconium inhalation (inhaling of the initial stool produced by a neonate, characterized by its deep green color).

• Mechanical ventilation with high peak pressures.

• Respiratory inflammation, with aspiration of amniotic fluid.

• Improper positioning of the endotracheal tube.

• Magnesium sulfate prenatal encounters, as the magnesium has the capacity to reduce calcium levels within uterine muscle cells. Given that calcium is an essential element for facilitating muscle cell contraction, it plays a role in the relaxation of the uterine muscle.

Other adult causes include:

• Asthma.

• Smoking.

• Volutrauma (damage to the structure of the lungs from overstretching that happens during artificial ventilation).

What Are the Complications?

Among the possible problems of PIE are the following:

• Respiratory insufficiency.

• Additional air escapes (such as pneumomediastinum, pneumothorax, pneumopericardium, pneumoperitoneum, and subcutaneous emphysema).

• Huge the presence of air bubbles within the bloodstream, which can potentially cause blockages and disrupt normal blood.

• Chronic pulmonary disease in infancy.

• Intraventricular hemorrhage (IVH) - It refers to the occurrence of bleeding within or in the vicinity of the ventricles, which are the cerebral spinal fluid-filled compartments within the brain.

• Periventricular leukomalacia - A form of brain injury most prevalent in premature infants, it is a lesion to the white matter surrounding the brain's fluid-filled ventricles. White matter is responsible for the transmission of information between nerve cells, the spinal cord, and different regions of the brain.

• Mortality (death).

What Is the Diagnosis?

• Patient History: Pulmonary interstitial emphysema (PIE) is linked with a limited number of clinical symptoms, such as

1. Hypotension - A rise in oxygen (O2) demand that is gradual and occasionally rapid, and retention of carbon dioxide (CO2).

2. The infant may exhibit the symptoms of pneumothorax (a collection of air that exists outside of the lungs but within the pleural cavity) when evaluated.

3. There are conditions of a collapsed lung in response to the discharge of the pneumothorax.

• Examination of the Body: On the affected side, there may be the following evaluation such as:

1. Chest wall hyperinflation (a condition characterized by the entrapment of air within the lungs, resulting in its excessive expansion.)

2. Crepitations (crackling or popping sounds that can be heard during physical examination on a stethoscope when listening to organ sounds for medical diagnosis).

3. Emphysema of the pulmonary interstitium (also known as PIE) can be diagnosed based on radiographic findings as well as pathologic findings.

• Pathological Findings: Interstitial slits are predominantly located within perivenous topography (study and description of the physical features and characteristics of the anatomical location or distribution pattern surrounding or adjacent to a vein.) Air dissects through the artery, which pushes adjacent tissue. Rarely air dissects and separates arterioles and bronchioles from adjacent lobules. The small blood vessels are compressed, but the collagen fibers are constantly torn and compressed.

What Are the Various Imaging Techniques?

• Anteroposterior Supine Projections: The term "anteroposterior supine projections" refers to radiography imaging methods that use an X-ray beam directed from the patient's anterior to posterior in order to obtain images of the body in a supine posture.

• Chest Computed Tomography (CT) Scan: Pulmonary vascular alterations shown on chest radiography correspond well with lung density and can be evaluated by CT. Patients with more severe emphysema CT changes demonstrated considerably lower diffusion capacity than patients with less severe changes.

What Are the Treatments?

Pulmonary interstitial emphysema (PIE) in infants is often very distressing and might require artificial breathing and a pneumothorax (a collection of air that exists outside of the lungs but within the pleural cavity). They are treated in the neonatal ICU. Thoracentesis (a procedure that involves the insertion of a needle into the pleural) chest tubes and close vitals surveillance may be required. PIE management methods differ in their success. Initially, surfactants could reduce PIE in premature infants by preventing respiratory distress syndrome. Besides, high oxygen pressure might damage the infant's immature lungs; therefore, avoid mechanical ventilation.

• Conservative Management: PIE can be avoided with several preventative steps.

1. The prophylactic surfactant could be given to preterm infants that are at elevated risk for respiratory failure because it has been found to reduce the risk.

2. Early use of surfactants with brief ventilation has been reported to lower the frequency of air leaks in premature newborns.

3. Lateral decubitus placement is a more conservative strategy, which is successful and more efficient for newborns with unilateral PIE.

4. There seem to be low failure and recurrence rates. If bilateral PIE is much more impacted, lateral decubitus positioning is beneficial.

5. The unaffected lung will receive more oxygen, allowing the ventilator settings to be decreased.

• Surfactant: Surfactant prevents and treats respiratory distress syndrome in preterm newborns. Intratracheal surfactant is natural or synthetic. Surfactant reduces air-alveolar surface tension, preventing alveoli from collapsing during expiration.

• Higher-Frequency Ventilation: High-frequency positive pressure ventilation reduces air leaks and PIE better than mechanical ventilation. To address acute respiratory distress in newborns, the contralateral bronchi of PIE patients were selectively intubated. Lung tissue should be decompressed. Its lungs will be protected from high positive oxygen pressures as well. The left side bronchus is more difficult to intubate than the right because the endotracheal tube must be positioned 2 to 4 cm farther. In order to intubate, the bevel must face the correct bronchus. In these patients, gas entrapment and airway collapse necessitate continuous monitoring of high-frequency oscillatory ventilation. Low-frequency oscillatory breathing improves PIE.

• Lobectomy: A lobectomy is a surgical intervention involving the complete removal of a lung lobe, which is undertaken for several medical indications.Due to the invasive nature of the process, lobectomy is regarded as a treatment of the last alternative.

• Alternative Ways of Treatment: Artificial pneumothorax, chest therapy with oxygen therapy, a steroid medication, extracorporeal membrane oxygenation (ECMO) is a medical procedure that involves the use of a machine to provide temporary support for the heart and lungs, and even nitric oxide treatment is used as the administration of therapeutic interventions is employed for the management and treatment of hypoxic respiratory failure or persistent pulmonary hypertension in neonates. are among the few uncommon additional techniques of care.

Conclusion

The condition known as pulmonary interstitial emphysema (PIE) is an uncommon form of illness that affects the lungs and is more prevalent in premature and underweight infants. It is imperative that premature infants who are at significant risk of pulmonary interstitial emphysema (PIE) be thoroughly monitored in the NICU. These infants require the assistance of a competent multidisciplinary team to coordinate the treatment that is provided by pediatricians, pulmonologists, intensivists, and surgeons. The continuous positive airway pressure (CPAP) method and synthetic surfactants are the most recent forms of treatment for the prevention of PIE in patients who have respiratory distress syndrome. Following recuperation, patients need to undergo close observation by pediatricians and pulmonologists to detect any potential long-term repercussions. It is possible to keep on schedule with the treatment of these critically ill patients if sufficient communication is maintained.