Background Information

 
Bronchopulmonary Dysplasia or BPD is a complication seen in premature infants who:
Have a history of Respiratory Distress Syndrome (RDS)
Have received mechanical ventilation
Inversely related to birthweight--the lower the birthweight the greater the risk/occurrence of BPD
Northway and associates, in the late 1960s, were the 1st to describe the disease process that we know as BPD today
They diagnosed it in infants who had:
Received assisted ventilation for Respiratory Distress Syndrome/Hyaline Membrane Disease AND who Developed chronic lung changes
They based their diagnosis on 4 different stages* involving:
When the lung changes occurred during the 1st 30 days of life
What type of alveolar and bronchial damage and repair that happened
In the late 1970's Bancalari and associates presented different criteria for diagnosing BPD:
Oxygen dependency for greater than 28 days
Clinical signs associated with changes in the chest x-ray after receiving mechanical ventilation
Again in the mid-80s, Toce and associates suggested another method of diagnosing BPD based on:
Clinical signs and  changes in the chest x-ray at 21 days of age

In 2004, Walsh and group suggested a physiologic definition for BPD

Under took a study to demonstrate their physiologic definition would:

Reduce the rates of reported BPD by neonatal centers

Limit variations in diagnosing BPD across the neonatal population

Study did confirm physiologic definition safe and supported their theory

Despite changes, revisions, updates in the criteria for how, what, or when the diagnosis of BPD is made
3 criteria have remained constant:
Premature birth--Born 3 or more months before their due date
Oxygen use--High concentrations can damage lung cells
Mechanical ventilation
Respiratory Infections/Pneumonia  
The role of infection continues to be discussed and researched
May or may not contribute to development of BPD depending of source
BPD is a continuous pathological process
A baby is not born with BPD, it happens as a result of being born prematurely and developing progressive inflammatory lung changes

*Northway's Stages

Stage 

X-Ray Findings
Stage 1 Consistent with RDS/HMD
Stage 2 Opaque lung fields with air bronchograms

Interstitial air common
Stage 3 Cystic lung changes with areas of hyperinflation and areas of atelectasis
Stage 4 Massive lung fibrosis & edema

Areas of consolidation and areas of over-inflation

 

Incidence

Incidence varies depending on the criteria used to diagnose and/or the terminology used
Generally believed to affect between 5,000 and 10,000 infants in the United States annually
With advances in care, most infants do survive
They may remain hospitalized for several weeks to months
May experience
A greater incidence of complications from usual childhood infections
Increased  hospitalizations with usual childhood infections

 

Who's At Risk?

Infants born with a birth weight of less than 2000 grams

Infants weighing 1500 grams or less at birth:  majority will develop BPD

Infants weighting 1000 grams or less at birth:  at very high risk

Infants born prior to 34 weeks' gestation

A history of RDS, Congenital Heart Disease, or any other illness requiring supplemental oxygen and/or respiratory support

Caucasian male infants seem more prone