Сәбилердегі көгілдір синдром: себептері мен белгілері

Two situations that lead to cyanosis in infants

Blue baby syndrome can refer to conditions that cause cyanosis, or blueness of the skin, in babies as a result of low oxygen levels in the blood. This term has traditionally been applied to cyanosis as a result of:. Cyanotic heart disease, which is a category of congenital heart defect that results in low levels of oxygen in the blood. This can be caused by either reduced blood flow to the lungs or mixing of oxygenated and deoxygenated blood. Although these are the most common causes of cyanosis, there are other potential factors that can cause a blue tint to a baby's skin or mucous membranes. These factors include hypoventilation, perfusion or ventilation differences in the lungs, and poor cardiac output of oxygenated blood, among others. The blue baby syndrome or cyanosis occurs when absolute amount of deoxygenated hemoglobin > 3g/dL which is typically reflected with an O2 saturation of < 85 %. Normally, oxygenated blood appears red and deoxygenated blood has more of a blue appearance. In babies with low levels of oxygen or mixing of oxygenated and deoxygenated blood, the blood can have a blue or purple color, causing cyanosis. Failure to thrive
Lethargy
Nasal flaring
Rapid heartbeat
Rapid respiratory rate
Seizures
Shortness of breath

[[File:Oxyhaemoglobin dissociation curve. png|thumb|Hemoglobin oxygenation dissociation curve. In the case of methemoglobinemia the curve is shifted to the left given the higher affinity for oxygen. The sources of nitrate can include fertilizers used in agricultural lands, waste dumps or pit latrines. For example, nitrate levels are subject to monitoring to comply with drinking water quality standards in the United States and other countries. The link between blue baby syndrome and nitrates in drinking water is widely accepted, but as of 2006 some studies indicated that other contaminants or dietary nitrate sources, might also play a role in the syndrome.

When diagnosing blue baby syndrome, it is important to perform a thorough history and physical exam. When obtaining the history, it is important to determine the timing of symptoms and to ask about risk factors/exposures, such as prenatal history or access to well water. thumb|Pulse oximeter on infant's foot. On physical exam it is important to visualize where the cyanosis is present to differentiate between peripheral and central cyanosis. Central cyanosis is typically visible as a blueish discoloration over the entire body and mucous membranes. In contrast, peripheral cyanosis typically has a blueish discoloration over the extremities. Cyanosis can be noted in babies around the lips, tongue, and sublingual area, where the skin is thinnest. In addition, it is important to observe the infant for signs of respiratory distress, visualized as nasal flaring, subcostal retractions, etc. Examination should include a respiratory and cardiac assessment. Additionally an arterial blood gas is useful, for example in the case of methemoglobinemia the PO2 can be expected to be normal even with a low oxygen saturation. Additional work up includes a complete blood count, blood glucose, blood culture, chest X ray, and an echocardiography. If congenital heart disease is suspected in a newborn, doctors will likely perform several tests to evaluate the heart, including a chest x ray, echocardiogram, and electrocardiogram. In tetralogy of Fallot, episodes in which infants become cyanotic are called tet spells, typically occurring during feeding or crying.

Treatment for blue baby syndrome will depend on the underlying cause. When evaluating a patient for cyanosis or respiratory distress, vital signs should be monitored, especially the patient's heart rate and oxygen saturation. It is beneficial to have vascular access established. In newborns, the pulse oximeter is typically placed on the right hand to determine pre ductal oxygenation, referring to oxygenation before the ductus arteriosus (connection between aorta and pulmonary artery).

Some babies born with cyanotic heart disease are treated with prostaglandin E1 after birth to keep the ductus arteriosus open and allow for more oxygenated blood to be pumped to the body. Many also receive oxygen therapy to increase the percentage of oxygen in the blood. Most of these babies will require surgery during infancy to correct their structural heart defect. Methemoglobinemia is considered to be rare, with acquired methemoglobinemia encountered more than the congenital form.

In the case of cyanotic causing heart defects, about 75 % of infants survive to 1 year of age and 69 % survive to 18 years of age. These individuals have an increased risk of developmental delay, heart failure, or heart rhythm disorders.

The first successful operation to treat blue baby syndrome caused by tetralogy of Fallot occurred at Johns Hopkins University in 1944. Through a collaboration between pediatric cardiologist Helen Taussig, surgeon Alfred Blalock, and surgical technician Vivien Thomas, the Blalock Thomas Taussig shunt was created. Dr. Taussig had recognized that children with Tetralogy of Fallot who also had a patent ductus arteriosus (PDA) typically lived longer, so the trio tried to create the same effect as a PDA by joining the subclavian artery to the pulmonary artery, relieving the child's cyanosis. The operation was published in the Journal of the American Medical Association in 1945 and impacted management of blue babies around the world. Anna was the name of the dog who was the first survivor of the surgery, considered an experimental procedure at the time. Anna survived the first pulmonary bypass after having been operated on twice. The second operation was required to replace the original stitches with flexible ones. After their success with Anna, Blalock and Thomas had the courage to perform the very first open heart surgery on Eileen Saxon in 1944. In 1950, Anna's story was made into a movie, and the film has been shown to various schools and other groups.