Hereditary mucoepithelial dysplasia (HMD), or simply mucoepithelial dysplasia, is a rare autosomal dominant multiepithelial disorder causing systemic maldevelopment of the epithelia and mucous membranes that line the surface of tissues and structures throughout the body, particularly affecting systems affiliated with mucosa, which includes the respiratory, digestive, urinary, reproductive and immune systems. The disorder is attributed to improper formation of desmosomes and gap junctions, which prevents proper cornification of the epithelial layer of the skin.

Desmosomes are extracellular protein structures responsible for cellular adhesion, whereby cells of the same type are held closely together. Gap junctions are specialized channels located within the cell membrane of many animal cell types, which serve as gateways that connect the cytoplasmic interior of two adjacent cells, allowing the passage of small molecules such as ions, nucleotides, second messengers and others. The movement and exchange of small molecules between cells is an important part of intracellular communication processes like cell signaling.

Hepatic microvascular dysplasia (HMD or MVD) or portal atresia is a disorder where mixing of venous blood and arterial blood in the liver occurs at the microscopic level. It occurs most commonly in certain dog breeds such as the Cairn and Yorkshire terriers although any dog breed may be at risk.

This disease may also be found in cats.

HMD is sometimes misdiagnosed as Portosystemic vascular anomaly (PSVA) or a "Liver Shunt" (portosystemic shunt). HMD can be diagnosed with an MRI, using a tracing dye in the subject's blood, and observing the flow of blood through the subject's liver and surrounding areas (stomach, intestine) for anomalies. It can also be diagnosed using a bile-acid level test; or more accurately, a "fasting-blood ammonia levels" test. Symptoms include stunted growth in the first 6–9 months, vomiting, seizures, and hydro-encephalitic episodes (from ammonia concentrating in the blood). HMD is usually treated non-surgically with antibiotics (metronidazole) and stool-softeners (lactulose).

Oxygen is given with a small amount of continuous positive airway pressure ("CPAP"), and intravenous fluids are administered to stabilize the blood sugar, blood salts, and blood pressure. If the baby's condition worsens, an endotracheal tube (breathing tube) is inserted into the trachea and intermittent breaths are given by a mechanical device. An exogenous preparation of surfactant, either synthetic or extracted from animal lungs, is given through the breathing tube into the lungs. Some of the most commonly used surfactants are Survanta or its generic form Beraksurf, derived from cow lungs, which can decrease the risk of death in hospitalized very-low-birth-weight infants by 30%. Such small premature infants may remain ventilated for months. A study shows that an aerosol of a perfluorocarbon such as perfluoromethyldecalin can reduce inflammation in swine model of IRDS. Chronic lung disease including bronchopulmonary dysplasia are common in severe RDS. The etiology of BPD is problematic and may be due to oxygen, overventilation or underventilation. The mortality rate for babies greater than 27 weeks gestation is less than 20%

Extracorporeal membrane oxygenation (ECMO) is a potential treatment, providing oxygenation through an apparatus that imitates the gas exchange process of the lungs. However, newborns cannot be placed on ECMO if they are under 4.5 pounds (2 kg), because they have extremely small vessels for cannulation, thus hindering adequate flow because of limitations from cannula size and subsequent higher resistance to blood flow (compare with vascular resistance). Furthermore, in infants aged less than 34 weeks of gestation several physiologic systems are not well-developed, specially the cerebral vasculature and germinal matrix, resulting in high sensitivity to slight changes in pH, PaO, and intracranial pressure. Subsequently, preterm infants are at unacceptably high risk for intraventricular hemorrhage (IVH) if administered ECMO at a gestational age less than 32 weeks.

- The INSURE Method

Henrik Verder is the inventor and pioneer of the INSURE method, a very effective approach to managing preterm neonates with respiratory distress. The method itself has been shown, through meta-analysis; to successfully decrease the use of mechanical ventilation and lower the incidence of bronchopulmonary dysplasia (BPD). Since its conception in 1989 the INSURE method has been academically cited in more than 500 papers. The first randomised study about the INSURE method was published in 1994 and a second randomised study in infants less than 30 weeks gestation was published by the group in 1999. In the last 15 years Henrik has worked with lung maturity diagnostics on gastric aspirates obtained at birth. By combining this diagnostic method with INSURE, Henrik has worked to further improve the clinical outcome of RDS. The lung maturity tests used have been the microbubble test, lamellar body counts (LBC) and measurements of lecithin-sphingomyelin ratio (L/S) with chemometrics, which involved a collaboration with Agnar Höskuldsson.

Giving the mother glucocorticoids speeds the production of surfactant. For very premature deliveries, a glucocorticoid is given without testing the fetal lung maturity. The American College of Obstetricians and Gynecologists (ACOG), Royal College of Medicine, and other major organizations have recommended antenatal glucocorticoid treatment for women at risk for preterm delivery prior to 34 weeks of gestation. Multiple courses of glucocorticoid administration, compared with a single course, does not seem to increase or decrease the risk of death or neurodevelopmental disorders of the child.

In pregnancies of greater than 30 weeks, the fetal lung maturity may be tested by sampling the amount of surfactant in the amniotic fluid by amniocentesis, wherein a needle is inserted through the mother's abdomen and uterus. Several tests are available that correlate with the production of surfactant. These include the lecithin-sphingomyelin ratio ("L/S ratio"), the presence of phosphatidylglycerol (PG), and more recently, the surfactant/albumin (S/A) ratio. For the L/S ratio, if the result is less than 2:1, the fetal lungs may be surfactant deficient. The presence of PG usually indicates fetal lung maturity. For the S/A ratio, the result is given as mg of surfactant per gm of protein. An S/A ratio 55 indicates mature surfactant production(correlates with an L/S ratio of 2.2 or greater).