Wilson–Mikity syndrome, a form of chronic lung disease (CLD) that exists only in premature infants, leads to progressive or immediate development of

respiratory distress Shortness of breath (SOB), also medically known as dyspnea (in AmE) or dyspnoea (in BrE), is an uncomfortable feeling of not being able to breathe well enough. The American Thoracic Society defines it as "a subjective experience of breathing di ...

. This rare condition affects low birth babies and is characterized by rapid development of lung emphysema after birth, requiring prolonged ventilation and oxygen supplementation. It is closely related to

bronchopulmonary dysplasia Bronchopulmonary dysplasia (BPD; part of the spectrum of chronic lung disease of infancy) is a chronic lung disease in which premature infants, usually those who were treated with supplemental oxygen, require long-term oxygen. The alveoli that are ...

(BPD), differing mainly in the lack of prior ventilatory support. All the initial patients described with Wilson–Mikity syndrome were very low birth weight infants that had no history of

mechanical ventilation Mechanical ventilation, assisted ventilation or intermittent mandatory ventilation (IMV), is the medical term for using a machine called a ventilator to fully or partially provide artificial ventilation. Mechanical ventilation helps move a ...

, yet developed a syndrome that clinically resembled BPD. Upon the death of some of these infants, autopsies showed histologic changes similar to those seen in BPD. It was characterized by Miriam G. Wilson and Victor G. Mikity in 1960.

Symptoms and signs

The onset of respiratory difficulty occurs at the first day of life and continues up to three weeks into the infant's life, at which point treatment is needed for infant survival.

Complications

Mothers who have developed

chorioamnionitis Chorioamnionitis, also known as intra-amniotic infection (IAI), is inflammation of the fetal membranes ( amnion and chorion), usually due to bacterial infection. In 2015, a National Institute of Child Health and Human Development Workshop expert ...

during pregnancy put their infant at higher risk for development of Wilson-Mikity syndrome. It is a rare complication that requires prolonged treatment. Infection, however, is not shown to be an

etiological Etiology (pronounced ; alternatively: aetiology or ætiology) is the study of causation or origination. The word is derived from the Greek (''aitiología'') "giving a reason for" (, ''aitía'', "cause"); and ('' -logía''). More completely, e ...

factor, but a correlation to

is identified as a risk.

Cause

The cause of Wilson-Mikity syndrome is unknown.

Diagnosis

The diagnosis of Wilson-Mikity syndrome can be made through two distinct symptoms: analogous characteristics of respiratory distress syndrome and presence of diffuse and streaky infiltrates with small cystic changes, seen through a chest X-ray. Early screening allows for the identification of a collapsed lung, cystic changes within the lung, and possible start of right-sided heart failure. Upon autopsy, alveolar collapse and alveoli rupture can be seen. This can reduce the number of capillaries within the system and lead to cyanosis. Cyanosis occurs from chronic or intermittent respiratory distress and episodes of

dyspnea Shortness of breath (SOB), also medically known as dyspnea (in AmE) or dyspnoea (in BrE), is an uncomfortable feeling of not being able to breathe well enough. The American Thoracic Society defines it as "a subjective experience of breathing di ...

(or apnea). Symptoms can develop within hours post-birth or be gradual; infants will experience transient respiratory distress, causing a lapse in diagnosis by around 30 to 40 days. Dangerous recurrent apnea (or

) can occur in the first two to six weeks

postpartum The postpartum (or postnatal) period begins after childbirth and is typically considered to end within 6 weeks as the mother's body, including hormone levels and uterus size, returns to a non-pregnant state. The terms puerperium, puerperal pe ...

. This cessation of breathing can progress to cyanosis and lung collapse. Infants display deteriorating respiratory symptoms along with early chronic lung changes which can be seen on

chest radiography A chest radiograph, called a chest X-ray (CXR), or chest film, is a projection radiograph of the chest used to diagnose conditions affecting the chest, its contents, and nearby structures. Chest radiographs are the most common film taken in med ...

. These changes are diagnosed either directly upon birth or within the first month, as the premature infant requires mechanical ventilation for survival.

Treatment

When caught early enough, continuous, mechanical oxygen therapy can be used to reverse the infant's poor circulation and decreased blood oxygen, a symptom known as cyanosis. Improvement is gradual; however, cases show that after the first year of treatment using oxygen therapy and mechanical ventilators, infants show normal respiratory activity and are free from chest infiltrates with small cystic changes. Absence of fever (

febrile Fever, also referred to as pyrexia, is defined as having a temperature above the normal range due to an increase in the body's temperature set point. There is not a single agreed-upon upper limit for normal temperature with sources using val ...

), and normal white blood cell count correspond to successful reversion and allow for a positive prognosis. When not treated properly, methods of reversion using oxygen supplementation and ventilation have the possibility to put the infant at risk for rare complications. If not enough oxygen is administered to the infant, the apnea continues and the infant is unable proper recovery. In contrast, too much oxygen administered can lead to higher risk for

retrolental fibroplasia Retinopathy of prematurity (ROP), also called retrolental fibroplasia (RLF) and Terry syndrome, is a disease of the eye affecting prematurely born babies generally having received neonatal intensive care, in which oxygen therapy is used due t ...

and/or

oxygen toxicity Oxygen toxicity is a condition resulting from the harmful effects of breathing molecular oxygen () at increased partial pressures. Severe cases can result in cell damage and death, with effects most often seen in the central nervous system, lu ...

within the lungs. Continued

is a sign that Wilson-Mikity syndrome is still affecting the infant. Increased ventilation to allow proper

respiration Respiration may refer to: Biology * Cellular respiration, the process in which nutrients are converted into useful energy in a cell ** Anaerobic respiration, cellular respiration without oxygen ** Maintenance respiration, the amount of cellul ...

is then required. Patients in recovery are slowly taken off oxygen support and eventually are able to ventilate with minimal to no

. There is a lack of research on the long-term effects of Wilson-Mikity into adulthood.

Epidemiology

Around 75% of affected infants survive and are able to receive oxygen therapies and treatments to overcome this disease. In fatal cases, infants do not have noticeable or substantial respiratory recovery and can develop right-sided heart failure, ultimately leading to death. Patients that are not recovering will also continue to show signs of

, respiratory distress, and continued low body weight, heightening the risk of death. Infants that survive six months or longer have substantially better prognosis.

References

External links

{{DEFAULTSORT:Wilson-Mikity syndrome Neonatology Syndromes affecting the lung Respiratory and cardiovascular disorders specific to the perinatal period