Complications of Prematurity: Respiratory Complications in Premature Infants

Complications of Prematurity Respiratory Distress Syndrome (RDS) Apnea of Prematurity (AOP) Bronchopulmonary Dysplasia (BPD) Patent Ductus Arteriosus...

Complications of Prematurity Respiratory Distress Syndrome (RDS) Apnea of Prematurity (AOP) Bronchopulmonary Dysplasia (BPD) Patent Ductus Arteriosus (PDA) Necrotizing Enterocolitis (NEC) Intraventricular Hemorrhage (IVH) Retinopathy of Prematurity (ROP) Respiratory Distress Syndrome (RDS): Characterized by severe impairment of respiratory function, primarily due to a lack of surfactant in immature lungs. A decrease in surfactant production causes low alveolar compliance. Symptoms include abnormal breathing patterns, substernal retractions, grunting, nasal flaring, and respiratory acidosis. Apnea of Prematurity (AOP): A sudden cessation of breathing that lasts for at least 20 seconds or is accompanied by bradycardia or oxygen desaturation in an infant younger than 37 WGA. It is caused by immature neurological and chemical receptor systems. Types include central, obstructive, and mixed apnea. Untreated AOP can lead to neurodevelopmental outcomes. Bronchopulmonary Dysplasia (BPD): A chronic lung disease in neonates, diagnosed by the need for supplemental oxygen for at least 28 days after birth, assessed at discharge or when the baby is close to their estimated full-term age. New BPD is caused by abnormal lung development, resulting from alveolar hypoplasia, arrested airway/alveolar growth, and impaired pulmonary vascularization following premature birth. Risk factors include prematurity, low birth weight, and hypercarbia. Patent Ductus Arteriosus (PDA): Occurs when the ductus arteriosus remains open after birth, allowing abnormal blood flow between the aorta and pulmonary artery. In premature infants, this is due to immature vascular tissue and high circulating prostaglandin levels. The pathophysiology depends on the relationship between pulmonary vascular resistance (PVR) and systemic vascular resistance (SVR). An echocardiogram is the gold standard for diagnosis. Necrotizing Enterocolitis (NEC): A serious complication of prematurity affecting the GI tract. Preterm infants are at higher risk due to immature host defenses and impaired inflammatory regulation. Early signs include mild feeding intolerance, while severe symptoms include temperature instability, tachypnea, and GI symptoms. Management includes bowel rest, parenteral nutrition, and broad-spectrum antibiotics. Intraventricular Hemorrhage (IVH): Bleeding within the brain's ventricles, primarily occurring in the germinal matrix. Premature infants are at the highest risk due to fragile blood vessels and rapid fluctuations in cerebral blood flow. Causes of altered cerebral blood flow include sepsis, acidosis, and hypoxemia. Respiratory management includes adjusting PIP to maintain a pH of 7.25-7.35 and a PaCO2 of 45-55mmHg. Retinopathy of Prematurity (ROP): A complication of prematurity caused by disruption of normal retinal vessel development. Risk factors include early gestational age, low birth weight, and duration of mechanical ventilation. Safe oxygen delivery practices are critical in preventing ROP progression.  RESPIRATORY DISTRESS SYNDROME (RDS) RDS is characterized by severe impairment of respiratory function, caused by immaturity of the lungs, primarily due to the lack of surfactant. It was first characterized (in the early 20th century) as hyaline membrane disease (HMD) because of the unique cellular characteristics of the lung. This was thought to be a rare form of pneumonia. PATHOPHYSIOLOGY of RDS A decrease in surfactant Overly compliant chest Increased distance Lung hypoplasia is the production causes low wall that causes difficulty between alveolar spaces & underdevelopment of lung alveolar compliance. in improving ventilation capillaries, which worsens tissue; this is a primary **biggest issue in RDS** with poor maintenance gas exchange along with cause of respiratory of FRC a thick AC membrane. distress. SYMPTOMS of RDS in Preterm Infants: Abnormal breathing patterns Substernal and/or Grunting – the noise produced by breathing (Tachypnea, apnea) intercostal retractions against a partially closed glottis, occurring during each exhalation Nasal flaring Blood gas (respiratory acidosis) Atelectasis Hypoxemia See-saw breathing pattern – stomach and chest are moving out of synch with each Cyanosis Hypercarbia other during breathing attempts DELIVERY ROOM INTERVENTION Considerations for Preterm Infants PERSONNEL and Ensure trained personnel are present and prepared to perform complex resuscitation. ENVIRONMENT Increase room temperature to 23ºC–26ºC to maintain thermal stability. Utilize thermal management techniques: Chemically activated warming pad. Prewarmed radiant warmer. Place newborn in a reclosable, food-grade polyethylene bag immediately after birth. TRANSPORT and Use a transport incubator for transferring the newborn to the special care nursery. O2 MANAGEMENT Administer oxygen using an air-oxygen blender. Continuously monitor oxygenation with pulse oximetry HANDLING and Handle the infant gently to minimize stress and prevent complications. FLUID Avoid the Trendelenburg position (head down). MANAGEMENT ○ Risk of rupturing Germinal Matrix and causing IVH. Prevent rapid fluid infusions to avoid circulatory overload and related complications. ○ Increased volume = increase risk of rupture at germinal matrix RESPIRATORY Provide noninvasive CPAP at 5–6 cmH2O. SUPPORT If necessary, initiate PPV at 20–25 cm H2O (avoid excessive pressures) Once intubated, provide PEEP at 5 cm H2O. Administer surfactant early to improve lung function and risk of respiratory distress INITIAL RESPIRATORY SUPPORT for Preterm Infants If respirations and HR are adequate, but baby has WOB, cyanosis, or a low SpO2: provide CPAP. CPAP will provide alveolar stability and increase FRC (ERV + RV) for babies with surfactant deficiency. PPV will be needed if CPAP can’t provide adequate oxygenation. 20-25 cmH2O is an adequate PIP. If intubated, provide positive end expiratory pressure (PEEP) at 5 cmH2O. Consider giving surfactant in the delivery room if the baby is significantly premature (< 30 weeks gestation).  APNEA OF PREMATURITY (AOP) Apnea of prematurity (AOP) is a sudden cessation of breathing that lasts for at least 20 seconds or is accompanied by bradycardia or O2 desaturation (cyanosis) lasting ≥ 4 sec in an infant younger than 37 WGA. Finer et al. came up with a simplified clinical evaluation for AOP: Apnea for at least 10 seconds Apnea for at least 20 seconds or and (i) HR < 100BPM or (ii) SpO2 < 80% CAUSES OF APNEA in Premature Infants Incorrect neural signaling caused by the physiological immaturity of the Airway obstruction neurological and chemical receptor systems of the body that regulate respiration and respond to hypoxemia and hypercapnia. AOP can also be a sign of underlying pathology: sepsis, meningitis is, NEC, ICH, HTN, GERD, RDS, etc. Periodic breathing is a common but benign form of abnormal breathing. It’s characterized by cycles of hyperventilation followed by short apneic pauses of 21% b. < 28% c. = 28% d. >28% 4. Which of the following is the gold standard for diagnosing Patent Ductus Arteriosus (PDA)? a. Electrocardiogram (EKG) b. CXR c. Pre-ductal & post-ductal saturation testing d. Echocardiogram 5. Which of the following is NOT a risk factor for Necrotizing Enterocolitis (NEC) in full-term infants? a. Maternal cocaine use b. Congenital heart disease c. Umbilical catheters d. Maternal preeclampsia 6. Where does Intraventricular Hemorrhage (IVH) primarily occur in the brain? a. Cerebellum b. Brainstem c. Germinal matrix d. Cerebral cortex 7. Which of the following is a critical factor in preventing Retinopathy of Prematurity (ROP) progression? a. Maintaining high FiO2 levels b. Safe oxygen delivery practices c. Prolonged mechanical ventilation d. Avoiding blood transfusions Fill in the Blank 8. In preterm infants, a decrease in __________ production causes low alveolar compliance, which is the biggest issue in RDS 9. __________ is a stimulant medication commonly used for stimulating the CNS and cardiac muscles to treat AOP 10. New BPD is caused by abnormal lung development, resulting from __________, arrested airway/alveolar growth, and impaired pulmonary vascularization following premature birth 11. A patent ductus arteriosus occurs when the __________ remains open after birth, allowing abnormal blood flow between the aorta and pulmonary artery 12. __________ is a serious complication of prematurity affecting the GI tract, characterized by tissue necrosis 13. __________ is a neonatal complication characterized by bleeding within the brain's ventricles 14. __________ is a complication of prematurity caused by disruption of normal retinal vessel development True or False 15. True or False: Increasing the room temperature to 23ºC–26ºC is recommended to maintain thermal stability for preterm infants in the delivery room 16. True or False: Central apnea is characterized by some attempt to ventilate, resulting in chest wall movement but without gas entry 17. True or False: Caffeine citrate has a wider therapeutic index, making it safer with a lower risk of toxicity compared to theophylline 18. True or False: Prone positioning is recommended at home to help stabilize the chest wall of infants with AOP. 19. True or False: The only guaranteed way to prevent BPD is surfactant therapy 20. True or False: An echocardiogram should confirm a L-to-R PDA shunt before treatment 21. True or False: C-reactive protein is decreased in Necrotizing Enterocolitis Short Answer 22. List three symptoms of Respiratory Distress Syndrome (RDS) in preterm infants a. b. c. 23. What are the three types of apnea? a. b. c. 24. List three risk factors for the development of new BPD. a. b. c. 25. Explain why premature babies are at a higher risk of developing NEC 26. List three causes of altered cerebral blood flow, which is a risk factor for IVH21. a. b. c. 27. List three risk factors for Retinopathy of Prematurity (ROP) a. b. c. ANSWER KEY 1. C - Decrease in surfactant production 2. C - 20 seconds 3. D - >28% 4. D - Echocardiogram 5. D - Maternal preeclampsia 6. C - Germinal matrix 7. B - Safe oxygen delivery practices 8. Surfactant 9. Caffeine Citrate 10. Alveolar hypoplasia 11. Ductus arteriosus 12. Necrotizing Enterocolitis (NEC) 13. Intraventricular Hemorrhage (IVH) 14. Retinopathy of Prematurity (ROP) 15. True 16. False 17. True 18. False 19. False 20. True 21. False 22. 3 of the following: a. Abnormal breathing patterns (Tachypnea, apnea) b. Substernal and/or intercostal retractions c. Grunting d. Nasal flaring e. Blood gas (respiratory acidosis) f. Atelectasis g. Hypoxemia h. See-saw breathing pattern i. Cyanosis j. Hypercarbia 23. Central apnea, Obstructive apnea, Mixed apnea 24. 3 of the following: a. Prematurity: ≤ 28 WGA b. Birth weight ≤ 1000g c. Hypercarbia (PaCO2 > 50mHg) d. Hypothermia and/or hypotension at admission e. Preeclampsia f. Need for prolonged MV g. RDS requiring mechanical ventilation > 2 hours in infants > 26WGA h. Need for exogenous surfactant i. Higher fluid therapy j. Nosocomial infection k. Chorioamniotis (even without RDS) 25. Preterm infants have immature host defenses and impaired inflammatory regulation, making them more susceptible to hypoxic-ischemic and inflammatory damage, which can lead to tissue necrosis. 26. 3 of the following: a. Sepsis b. Acidosis c. Hypoxemia d. Adrenal insufficiency e. Hypovolemia & volume expansion f. Anemia & transfusion g. Glucose imbalances (hypo/hyperglycemia) h. PDA with shunting i. CO2 imbalances (hypo/hypercarbia) 27. 3 of the following: a. Early Gestational Age (Prematurity) b. Low Birth Weight (associated with prematurity) c. Duration of mechanical ventilation d. Requirement for supplemental O2 e. Comorbidities associated with prematurity