Thursday, June 23, 2011

Prematurity - Risks of prematurity on short teremen

Deficiency of respiratory function:The respiratory impairments recorded a series of morpho-functional whose gravity is even more intense as the birth occurred earlier than normal time. At a gestational age ranging between 24 to 28 weeks, newborn lung to breathe air subject to change.The alveolar surface-substance is lacking lipoprotein surfactant molecules penetrate between the molecules of which the fluid covering the surface of alveoli, decrease their cohesion and thus lowers the surface tension, facilitating detachment of alveoli and pulmonary ventilation. Thus, surfactant deficiency will cause respiratory distress.Immaturity of the respiratory center leads to crises of apnea. These together with poor blood circulation causes hypoxia. It produces alterations in the vascular wall, alveolar epithelial injury occurs, with swelling and transudat with intraalveolar fibrin and ultimately the formation of hyaline membranes. Fibrinolytic system is deficient, there is deficiency of plasminogen and plasmin, thus explaining the absence of membranes resobtiei formats.
Chest narrow premature poorly mineralized ribs and muscle weakness are limited greatly favored trip lung circulation. The vesicular murmur is barely audible listening.
From these early impairments of fetal hemoglobin is protected with a high affinity for oxygen. Such is maintained oxygen saturation of 50-60% being covered about 15 volumes of oxygen in the 22 to 100 cm3 blood volume.
Hypoxia premature baby has severe consequences on the body, carbohydrates are consumed reserves used to liberate the energy needed and there is an accumulation of lactic acid and metabolic acidosis with hypercapnia. Acidosis will cause inhibition and cronotropismului inotropismului myocardium diminurea glomerular filtration and decreased tubular reabsorption. Also, metabolic acidosis disturb brain activity, inhibit glucose utilization and disrupts the function of sodium pump.Central nervous system (CNS) premature ventricular at risk of cerebral hemorrhage.
In the cardiovascular risk of producing a neonatal shock, especially septic shock. Botal hole permeability and is accompanied by the breaths arterialcare channel facilitates proper heart failure. Heart sounds are irregular and the pulse is 14-160/minut values. Low blood pressure 45-70 mmHg Tnsiunea mmHg/30-45 cause a slow and reduced irrigation in the extremities.
Hematology due hipofunctiei hemolysis and bone marrow may be premature in the first 2 months of life anemia normocitara normocroma called "anemia premature". After depletion of iron anemia is hypochromic, microcytic.
Nutritional deficiency function comprises several aspects. Due to the low amount of saliva dries the mouth and is easing stomatitis.Sucking reflex is missing in most premature and swallowing reflex is absent only in those with a birth weight less than 2000 g.In early gastric capacity is greatly reduced (30-90 ml), hypotonic intestinal muscles and promotes slow peristaltic movements flatulence and constipation.The liver has a structure of type embryo, the synthesis of serum proteins and clotting factors deficiency presenting large. Liver biochemical deficiency disorders will attract as hypoglycemia, hipoprotrombinemia, hypoproteinaemia, hipoglobulinemia.
Early gastrointestinal ulcerative-necrotic enterocolitis may present with a higher incidence of both gestational age is lower.
In the thermoregulatory function registers various changes. After nsatere, decreases body temperature by 2-3 degrees and return to normal of 37 degrees for 2-3 days or a week. The premature to fight cold is essential chemical thermogenesis. For this purpose we notice an increase in fatty acid oxidation in brown fat in the neck and mediastinum is releasing a large amount of heat to be distributed throughout the entire body through the bloodstream.The thermolysis is enhanced premature, he lost large amounts of heat due to greatly increased body surface compared with adipose panicle.Thermogenesis comes to balancing high energy losses by eating large amounts of oxygen and energy substances.Hypothermia to 32 degrees Celsius for 12 hours is fatal. Also, prolonged hypothermia cause serious tissue disorder called sclera (waxy induration of the skin and subcutaneous cellular tissue that does not allow formation of the skin fold, giving the feeling of plucking rubber skin).
Kidney deficiency can manifest itself in increased embryonic lobulatie kidney, heart ugly pronounced albuminuria increased glomerular permeability due to positive. Glomerular filtration is low and the dilution capacity and poor concentration. Premature dysfunction has a sodium pump, which you retain and make edema.
Specific humoral immunity of premature baby is much reduced.Immunoglobulin G from mother to fetus during passing last month of pregnancy, such as premature birth only to 0, 5-1 g / l IgG, compared with term newborn who arrives with 9-10 g / l .Cellular immune defense deficiency exposes the risk of nosocomial infections early. Lack blanket horny and absence of acidity on the sweat glands causes the skin to act as a barrier not being an open wound.
Ophthalmology can be found in newborns with low birth weight in prematurity retinopathy.
Risks of prematurity term frequently mental retardation and cerebral palsy register. The early distinction between gray and white matter is hardly possible. Development of brain cells is weak and almost nonexistent myelination process. Vasculature is low in cortex and subcortex.There is also a risk of damage to sensory (deafness, blindness to vision loss with retinopathy in prematurity) and bronchopulmonary dysplasia.

No comments:

Post a Comment