早產兒常見之問題(1),IVH (intraventricular hemorrhage): 腦室內出血 PVL (periventricular leukomalacia): 白質軟化症 ROP (retinopathy of prematurity):早產兒視網膜病變 RDS (respiratory distress syndrome): 呼吸窘迫症候群,早產兒常見之問題(2),BPD (bronchopulmonary dysplasia): 支氣管肺發育不全 NEC (necrotizing enterocolitis): 壞死性腸炎 PDA (patent ductus arteriosus): 開放性動脈導管,Gestational age estimation and birth weight classification,Infant are classified by GA as Preterm (37 weeks) Term (37-41 6/7 weeks) Postterm (42 weeks or more) Birth weight classification Normal birth weight (NBW): 2500 gm or more Low birth weight (LBW): 2500 gm Very low birth weight (VLBW): 1500 gm Extreme low birth weight (ELBW): 1000gm,Prematurity,Incidence: 5-10% Etiology: most for unknown reasons,Low socioeconomic status Malnutrition Women under age 16 or over 35 Increased maternal activity Smoking Ac. or chr. maternal illness,Multiple-gestation births Prior poor birth outcome Obstetric factors Fetal conditions Inadvertent early delivery,Problem of prematurity (2),Hematologic Anemia Hyperbilirubinemia Nutritional Feeding problems Type, amount, and route of feeding Gastrointestinal Necrotizing enterocolitis (NEC) Metabolic Acidosis Hyper- or hypoglycemia hypocalcemia,Problem of prematurity (3),Renal Low GFR Inability to handle water, solute, and acid loads Temperature regulation Hypothermia and hyperthermia Immunologic Greater risk for infection Ophthalmologic Retinopathy of prematurity (ROP),Intraventricular hemorrhage (IVH),In premature infant :-occurs in the gelatinous subependymal germinal matrix -highly vascular area with immature blood vessels In term infant : -germinal matrix become attenuated and tissues vascular support has strengthened.,Intraventricular hemorrhage (IVH),The incidence of IVH :-6070% of 500-750 g infants-1020% of 1000-1500 g infants 8090% of cases occur between birth and the 3rd day of life ; 50% occur on the 1st day. 2040% of cases progress during the 1st week of life ; delayed hemorrhage may occur in 1015% of patients after the 1st week of life. New-onset IVH is rare after the 1st month of life regardless of birth weight.,-prematurity-RDS-Hypoxic-ischemic or hypotensive injury-reperfusion of damaged vessels-increased or decreased cerebral blood flow-reduced vascular integrity-increased venous pressure-pneumothorax-hypervolemia-hypertension,Predisposing factors for IVH :,Clinical manifestations,Diminished or absent Mono reflex Poor muscle tone Lethargy Apnea Somnolence Periods of apnea, pallor, or cyanosis Failure to suck well Abnormal eye signs Decreased muscle tone or paralysis Metabolic acidosis Shock Decreased hematocrit or its failure to increase after transfusion,Periventricular leukomalacia (PVL),A common associated cystic finding May be due to prenatal or neonatal ischemic or reperfusion injury The result of necrosis of the periventrucular white matter Damage to the corticospinal fibers in the internal capsule.,Periventricular leukomalacia (PVL),Usually asymptomatic until the neurological sequelae of white matter necrosis become apparent in later infancy as spastic diplegia. May be present at birth but usually occurs later as an early echodense phase (3-10 days of life) followed by the typical echolucent (cystic) phase (14-20 days of life).,Intraventricular hemorrhage (IVH),Grade I - Germinal matrix hemorrhage (subependymal region or less than 10% of the ventricle; 35% of IVH) Grade II - IVH with 10-50% filling of the ventricle (40% of IVH) Grade III more than 50% involvement with dilated ventricles Grade IV - IVH with extension into the parenchyma,Patent ductus arteriosus (PDA),Connect the main pulmonary trunk (or proximal left pulmonary artery) with the descending aorta, 5-10 mm distal to the origin of the left subclavian artery Arising from the distal dorsal sixth aortic arch Is well developed by the sixth week of gestational age Is more prevalent in female than male Is a frequent complication of HMD in preterm infant, in infant born at high altitudes,Normal postnatal closure,First stage : contraction and cellular migration of medial smooth muscle -result functional closure commonly occurred within 12 hours in full term baby Second stage : connective tissue formation and replacement of muscle fibers with fibrosis- ligmentum arteriosum Both PGE2 and PGI2 relax the ductus arteriosus,Incidence,Prematurity: inverse with GA, PDA is found in about 45 % of infant under 1750g and 80% in infants weighting 1000g Risk factor: 1.RDS and surfactant treatment 2.Fluid overload 3.Asphyxia 4.Congenital syndrome,congenital heart disease 5.High altitude,Pathophysiology,Ductal constriction is caused by multiple factors :1. oxygen 2. the level of prostaglandin 3. available ductus muscle mass Within the first hours after birth - fall in pulmonary vascular resistance and a rise in systemic resistance if PDA opened left to right shunt(+) - result in increased pulmonary blood flow ,left ventricular volume overload, increased left ventricular end-diast