34.Prematurity.pptx

Prematurity Hassan Alshehri Associate Professor of Pediatrics College of Medicine (IMSIU) Objectives  Definition of Prematurity and gestational age assessment  Spectrum of Prematurity  Causes of Preterm delivery  System-related short and long-term complications of Prematurity Famous people born...

Prematurity Hassan Alshehri Associate Professor of Pediatrics College of Medicine (IMSIU) Objectives  Definition of Prematurity and gestational age assessment  Spectrum of Prematurity  Causes of Preterm delivery  System-related short and long-term complications of Prematurity Famous people born prematurely Prematurity Definition: < 37 completed Gestational weeks Gestational age: The number of weeks between the first day of the mother's last normal menstrual period and the day of delivery. Gestational Age Assessment: 1. Obstetric information (LMP, early ultrasound) 2. Newborn information: neurological and physical signs (New Ballard Score) Prematurity Spectrum of Prematurity There are sub-categories of preterm birth, based on gestational age:  Extremely  Very preterm (less than 28 weeks) preterm (28 to 32 weeks)  Moderate to late preterm (32 to 36weeks) Spectrum of Prematurity , Cont. Premature infants are categorized by birth weight: < 1000 g: Extremely low birthweight (ELBW)  1000 to 1499 g: Very low birthweight (VLBW)  1500 to 2500 g: Low birthweight (LBW)  The incidence and severity of complications of prematurity increase with decreasing gestational age and birth weight Interactive Question  The severity of prematurity complications is inversely related to the gestational age  True  False Preterm delivery Causes and Associations Preterm delivery could be Elective or Spontaneous  Elective preterm delivery E.g multiple gestation with complications such as preeclampsia, placenta previa/placenta accreta  Spontaneous preterm delivery  Prior premature births (Main risk factor)  Trigger e.g: infection (Intra-Amniotic Infection)  Prior multiple pregnancies  Cervical insufficiency  Low socioeconomic status >>>> Lack of prenatal care  Substance abuse and smoking Preventive measures  No successful strategy to prevent the preterm labor so far  The following measures may minimize the impact of preterm birth:  Obstetric Management: maternal illness, treat infection  Inhibition of preterm labour (Tocolytic agents)  Steroids to facilitate fetal lung maturation Resuscitation Thresholds (periviable period)  Age of viability: the earliest stage of fetal maturity when there is a reasonable chance of extrauterine survival.  Fetal viability is possible after 22 weeks of gestational age  Most of the Neonatal practice guidelines recommends resuscitation of infants who delivered at 24 weeks of gestation , Birth weight 500 gm and above  Shared medical decision between parents and the medical team is very crucial in decision-making about resuscitation for extremely preterm infants (EPI) in the ‘grey zone’ of viability (22– 23+6 weeks) Neonatal outcomes of ELBW Scenario At 23 weeks of gestation , The mother presented in labor with dilated cervix 3 cm , Estimated fetal weight 498 gm by ultrasound , Mother is 40 yrs old , primigravida , Achieved by In Vitro Fertilization (IVF) ,the Staff Neonatologist called for counselling the parents  Very difficult situation  Detailed explanation must be provided for the parents regarding the long and short-term outcomes and their wishes must be considered and respected always ‫‪Religious Aspects‬‬ ‫قول الله تعالى(وحمله وفصاله ثالثون شهراً)‬ ‫وقوله تعالى (والوالدات يرضعن أوالدهن‬ ‫حولين كاملين)‬ Complications & Management of prematurity Initial, Short term: - Temperature regulation - Respiratory - Cardiovascular - Neurologic - Gastrointestinal & Nutritional - Ophthalmologic - Infection - Psychosocial Long term: Developmental disability Temperature Regulation Issues Poor temperature control due to : 1. Immature heat regulatory center 2. Impaired heat production :poor muscular activity, poor O2 consumption 3. Increased heat loss­surface area (large surface area to body weight) Management Achieve neutral thermal zone i.e. environmental temperature at which O2 consumption is minimal yet sufficient to maintain body temperature Heat shield, plastic wrap, head cap Overhead radiant warmer Closed incubator Interactive Question  The preterm babies are more liable to develop hypothermia due to:  Small body surface area  Impaired heat production Respiratory Complications of Prematurity  Respiratory distress syndrome (RDS)  Apnea of Prematurity Respiratory distress syndrome (RDS)  Pulmonary surfactant is a complex mixture of phospholipids (PL) and proteins (SP) secreted by Type II pneumocytes, which differentiate between 24 and 34 weeks of gestation in the human  The major hallmark in RDS is a deficiency of surfactant, which leads to higher surface tension at the alveolar surface and causes collapse of alveoli  The higher surface tension requires greater distending pressure to inflate the alveoli, according to LaPlace’s law: Clinical Presentation of RDS  Affecting mostly preterm babies  Tachypnea , nasal Flaring  Grunting: this is an attempt by the infant to produce positive end-expiratory pressure (PEEP) by exhaling against a closed glottis.  Subcostal retractions  Hypoxemia and Cyanosis Grunting Laboratory and Radiological findings in RDS  Blood gas : Respiratory acidosis +- metabolic acidosis  CBC,CRP, Blood culture : to cover the possibility of sepsis , pneumonia  CXR: Ground glass appearance with air bronchogram A: Normal Neonatal Chest X-ray B: Chest X-ray of 27 weeks Preterm infant with RDS("ground glass" appearance, which represents diffuse microatelectasis and air bronchograms (Arrows) Management of RDS  Maternal antenatal steroid improve fetal lung maturity and minimize the severity of RDS  Non-invasive ventilation: Nasal Continuous Positive Airway Pressure (NCPAP) to prevent alveolar atelectasis and improve the gas exchange  Surfactant administration : In cases of hypoxemia with increase in oxygen requirement (Fio2 > 40% )  Avoid high oxygen concentration for preterm (oxygen free radicals may induce pathological consequences mainly on the lung (BPD) and Retina (ROP) Interactive Question  26 weeks preterm baby girl , birth weight 700 gm , had respiratory distress and high oxygen requirement up to 60% , which of the following is the most likely underlying cause for the respiratory distress ?  Surfactant administration  Increase Fio2 to 100% Respiratory issues of prematurity,cont Apnea of prematurity  Apnea : cessation of breathing by a premature infant that lasts for more than 20 seconds and/or is accompanied by hypoxia or bradycardia. Contributing Factors for Apnea of Prematurity : - Immature respiratory centre - Small nasal passages and airways - Weak respiratory muscles Respiratory Issues of Prematurity,cont  Apnea could be manifestations of other systemic diseases in preterm e.g sepsis , meningitis, seizure and necrotizing enterocolitis (NEC)  Treatment :  Address its cause to provide appropriate medical management.  Assisted ventilation if severe  CNS stimulant (Caffeine Citrate) : used in all preterm less than 32 weeks gestation and/or less than 1500 gm birth weight Interactive Question  Apnea in preterm infants is always explained by apnea of prematurity  True  False Neurologic complications of prematurity Intraventricular haemorrhage (IVH) – Germinal layer preterms is vascular with little supporting tissue – Impaired ability to regulate cerebral blood flow with changes in systemic blood pressure (Autoregulation) – Measures to minimize the risk of IVH : midline head positioning, minimal handling , avoid rapid fluid boluses ,avoid BP fluctuations , maintain normoglycemia and normothermia – Routine ultrasound surveillance for all preterm babies born at less than 32 weeks gestation and/or less than 1500 gm Periventricular leukomalacia (PVL)  (PVL) is the most common ischemic brain injury in premature infants.  The ischemia occurs in the border zone (Watershed areas) at the end of arterial vascular distributions.  The incidence increases with decreasing gestational age and peaks at 24-32 gestational weeks  Occurs most commonly in premature infants born at less than 32 weeks' gestation who have a birth weight below 1500 g. Periventricular leukomalacia (PVL),cont More common in these infants with any of the following risk factors:  History of maternal chorioamnionitis.  Severe respiratory distress syndrome with prolonged mechanical ventilation  Cardiovascular compromise with hypotension and patent ductus arteriosus during their first days of life.  Sepsis Periventricular leukomalacia (PVL),cont  Diagnosis:  Brain Ultrasonography is used to for early evaluation and detection of PVL  MRI  Prognosis&Management :  A significant percentage of surviving premature infants with PVL may develop cerebral palsy (CP), intellectual impairment, or visual disturbances.  Early diagnosis is very important to enroll those infants in early intervention programs and they need close neurodevelopmental follow-up. Cardiovascular Complications of Prematurity Patent ductus arteriosus (PDA) May cause pulmonary congestion and affect the respiratory status – Usually only requires conservative management – Adequate oxygenation, fluid restriction – Medications: Prostaglandin antagonist (indomethacin, ibuprofen) – Surgical : PDA ligation , if failed medical treatment , causing respiratory compromise and unable to wean the infant from the Ventilatory support Gastrointestinal & Nutritional complications of prematurity 1. Feeding intolerance 2. Complications of Parenteral Nutrition 3. Necrotizing Enterocolitis (NEC) Feeding Intolerance  Preterm infants are unable to suck & swallow effectively so they require feeding through tube until 33-34 weeks of gestation when the coordination of suck with swallow starts to develop  The immature function of the preterm GIT causes variable feeding intolerance which may cause delay in progressing the feeding. - Feeding protocol for preterm infants must be implemented in each neonatal practice Complications of Parenteral Nutrition The prolonged exposure to total parenteral nutrition (TPN) may expose the infant to variable complications e.g :  Parenteral nutrition-associated liver disease (PNALD)  Central Line-Associated Bloodstream Infections (CLASBIs)  Electrolyte disturbances Necrotizing Enterocolitis (NEC)  Necrotising Enterocolitis: intestinal inflammation associated with focal or diffuse ulceration and necrosis primarily affecting terminal ileum and colon in preterm  Necrotizing Enterocolitis (NEC) represents a significant clinical problem and affects close to 10% of infants who weigh less than 1500 g Necrotizing Enterocolitis (NEC)  The  exact etiology is unknown Multifactorial (intestinal ischemia, concurrent infection , abnormal intestinal flora , Medications that can affect the splanchnic vasoconstriction leading to impaired intestinal integrity e.g Indomethacin)  Breast milk reduces the incidence of NEC associated with enteral feeding. Clinical Presentations of NEC  Presents  Usually, commonly in the 2nd to 3rd week of life non-specific signs  High index of suspicion in case of one or more of the following symptoms and signs noticed : - Vomiting - Blood in stool - Delayed gastric emptying - Abdominal distention (Increase abdominal girth) - Abdominal tenderness - Apnea - Lethargy - Decreased peripheral perfusion Diagnostic Workup (NEC)  CBC : (WBC) Moderate to profound neutropenia (absolute neutrophil count [ANC] < 1500/μL) , Thromocytopenia  Electrolytes : Hyponatremia – An acute decrease in serum sodium (< 130 mEq/dL) is alarming  Blood gas : metabolic acidosis seen in babies with poor tissue perfusion, sepsis, and bowel necrosis Diagnostic Workup (NEC)  Abdominal radiography - The mainstay of diagnostic imaging - AP and a lateral views are essential for initial evaluation - Pneumatosis intestinalis – Pathognomic for NEC - Abdominal free air – Ominous; usually require emergency surgical intervention 2 weeks old , former 27 weeks , with abdominal distention and bilious gastric residuals , pneumatosis intestinalis Perforated Necrotizing Enterocolitis , pneumoperitoneum Management of NEC The initial course of treatment consists of the following:  NPO  IV hydration  Nasogastric tube for gastric and bowel decompression  Initiate broad-spectrum antibiotics ensure anaerobes and gram negative bacteria  Sick babies may require inotropic and ventilatory support  Surgical intervention if complicated by bowel perforation Interactive Question  Preterm babies can establish the oral feeding skills as early as 31 weeks of gestation  True  False Interactive Question  The most helpful tool to diagnose necrotizing enterocolitis (NEC) is:  Blood gas  CBC  Abdominal X-ray Ophthalmologic complications of prematurity Retinopathy of Prematurity (ROP) ROP : disorder of developing retinal vasculature Risk Factors Low gestational age, birth weight