Transient Tachypnea of the Newborn CMNRP Feb 29,2012 Prakash K Loganathan (Fellow- Neonates) Overview TTN- pathogenesis, clinical findings, radiology, management. Overview of common conditions causing respiratory distress in newborn. Supervisor: Dr Jana Feberova Why discussing TTN? TTN is very common and is a frustrating condition that -sometimes requires transfer of the baby -separation from the mother if she cannot be transferred, -multiple diagnostic studies, - delay in discharge -increased healthcare costs and -occasionally associated with complications. Case As a nurse working in a small nursery, where the paediatrician is not in house: -32 yr old G3 L2 mother, -Serologies all were protective & No maternal fever. -Antenatal USS: normal. -Baby boy was delivered by elective C-section (Ind: repeat C-section). -APGAR of 9(1 ),9(5 ). -He developed respiratory distress within 1hr of birth. Questions? What is your differential diagnosis? What is your next step? How will you monitor the baby? Will you do any investigations at this point? What will you do if the baby continued to have respiratory distress? Questions? What investigations will you do at this point? What treatment will you give as the initial measure? When should tertiary care center/ neonatologist be consulted? 1
Why do need fluid in the lungs? (During fetal life) (1) During fetal life, fluid is secreted into the alveoli to maintain normal lung growth and function, (2) fetal lung volume approximates the functional residual capacity that would be established once air breathing is initiated. How the lung fluid is Cleared? Decreased lung Fluid production prior to spontaneous vaginal delivery. Onset of labor: the high circulating concentration of epinephrine activates the switch within the lungs from net secretion to net reabsorption. Vaginal squeeze of the thorax contribute to a very small proportion of lung fluid resorption. Epidemiology 3.6 to 5.7 per 1,000 term infants. Retention of fetal lung fluid may be more common in preterm infants (up to 10 per 1,000births). Late preterm delivery increases the risk for TTN Risk factors for TTN cesarean section with or without labor, male sex, family history of asthma (especially in mother), lower gestational age, macrosomia, maternal diabetes. Mode of delivery & TTN Vaginal delivery is protective. C-section increases the risk. Labor before C-section may not provide sufficient protection. Arch Gynecol Obstet. 2011 Amer Jo of Perinatology.2010 2
SPECTRUM RETAINED LUNG FLUID TRANSITION TTN COMPLICATIONS 2 TO 12HRS Clinical Features Cxray - TTN Tachypnea, retractions, nasal flaring. Grunting is common. Barrel shaped chest due to hyperinflation, which may push down the liver and spleen, making it palpable. Auscultation: crackles. Diagnosis-By exclusion (Don t assume its TTN) Prominent perihilar vascular markings due to engorged periarterial lymphatics Edema of the interlobar septae Fluid in the fissures Some degree of hyperinflation Fluid in the fissure 3
Management of TTN Because it is difficult to exclude pneumonia at presentation, many babies who have TTN are treated with antibiotics for the first 24 to 48 hours until the blood culture is negative, along with improved clinical status. SUPPORTIVE - keep NPO, may require IV fluids. - Cxray: performed to support the diagnosis of TTN and rule out other conditions - Gas, CBC, Diff, Blood c/s and consider antibiotics. Management of TTN - Oxygen support, CPAP or ventilatory support if needed. - Keep saturation in normal range for the gestational age. - Consider transfer to higher center based on the clinical situation. Complications Pulmonary hypertension with right-to-left shunting. Severe hypoxemia and may require high concentrations of oxygen Air leaks (rare). Experimental therapies Furosemide (systemic, Nebs) and epinephrine (nebs). Fluid restriction was shown to have some success. All these treatment options were from small studies & experimental. Currently recommended management is supportive. Differential Diagnosis: TRACHEA 4
PPHN PPHN usually occurs in :term infants, (less common in late preterm & post term). Abnormal persistence of elevated pulmonary vascular resistance (PVR) -- right-to-left shunting--hypoxemia. PPHN :severe cyanosis, tachypnea, and systolic murmur (tricuspid insufficiency). PPHN The appearance of the chest radiograph in PPHN will be consistent with underlying lung disease. Echocardiography is required to confirm the diagnosis of PPHN and differentiate it from structural cyanotic heart disease. RDS RDS is primarily a disease of preterm infants, some near-term infants may be affected. Surfactant deficiency that leads to alveolar collapse and diffuse atelectasis. Risk factors for RDS Preterm, Maternal diabetes, Multiple birth, Cesarean section prior to the onset of labor, Perinatal asphyxia, Cold stress. Infants whose siblings suffered from RDS. Low lung volumes Chest Xray: RDS Diffuse, reticulogranular, ground glass appearance Air bronchograms 5
MAS Defined as respiratory distress in an infant born through meconium-stained amniotic fluid whose symptoms cannot otherwise be explained. 13% of all live births are meconiumstained amniotic fluid, and of these, 4% to 5% of infants develop MAS. More Common In Post Term. Diagnosis of MAS Meconium-stained infant, respiratory distress, and characteristic radiographic features. The chest appears barrel-shaped (increase anterior-posterior diameter) due to over-inflation. Streaky, linear densities. Hyperinflation. Alternating diffuse patchy densities. Cxray-MAS Management of MAS Aim: to prevent development of PPHN. Treatment is mainly supportive :includes IV fluids, oxygen therapy, ventilatory support, and antibiotics. Surfactant treatment reduces the need for ECMO and may reduce the risk for pneumothorax. Pneumonia Pneumonia : in utero, during delivery (or perinatally), or postnatally. It may be classified as either early- (7 d of age) or late onset (7 d of age). At autopsies of both stillbirths and live-born neonatal deaths, pneumonia was found to be present in 20% to 60% in different centers. Intrauterine infection :rubella, cytomegalovirus, herpes simplex virus, human immunodeficiency virus. 6
Pneumonia Pneumonias (acquired): GBS, E.coli, Klebsiella & C.trachomatis. Pneumonias acquired after birth :respiratory viruses, streptococci or Staphylococcus aureus, and Gram neg bacteria. Management: oxygen therapy, ventilatory support, antibiotics, and other supportive measures. Radiological features of Different conditions Air bronchograms Diffuse parenchymal infiltrates TTN Radiological features of Different conditions Reticular granular pattern Loss of lung volume Fluid accumulations in interlobar spaces TTN Pulmonary lymphangiectasia Lobar consolidation Patchy areas alternating with emphysema Pneumonia Lobar sequestration CCAM Hyperinflation Pneumothorax/pneumomediastinum TTN Spontaneous THANK YOU 7