Medical School · Year 3 · Pediatrics · includes a quiz and discussion video

Seminar 17: Neonatal Emergencies

Unit 3: Pediatrics Clerkship

Learning Objectives

1. Perform neonatal resuscitation following the Neonatal Resuscitation Program algorithm with appropriate interventions at each step
2. Recognize respiratory distress presentations in neonates and differentiate between common etiologies including transient tachypnea, respiratory distress syndrome, and meconium aspiration
3. Identify congenital heart disease presentations including ductal-dependent lesions requiring emergent prostaglandin therapy
4. Evaluate and manage neonatal sepsis including risk stratification, appropriate workup, and empiric antibiotic selection
5. Diagnose and treat metabolic emergencies including hypoglycemia, hypocalcemia, and inborn errors of metabolism
6. Recognize surgical emergencies in neonates including congenital diaphragmatic hernia, intestinal obstruction, and malrotation with volvulus

Lecture Outline

Section 1: Neonatal Resuscitation Principles

The transition from intrauterine to extrauterine life represents one of the most dramatic physiologic events in human development, requiring successful adaptation of multiple organ systems within minutes of birth. In utero, fetal lungs are filled with fluid while pulmonary vascular resistance remains high, directing blood away from the pulmonary circulation through the patent ductus arteriosus and foramen ovale. The placenta serves as the organ of gas exchange, with oxygenated blood returning to the fetus through the umbilical vein while the low-resistance placental circulation maintains low systemic vascular resistance. At birth, lung expansion, establishment of functional residual capacity, and rising oxygen levels trigger pulmonary vasodilation while cord clamping increases systemic vascular resistance, fundamentally reversing the circulatory pattern.

The initial steps of neonatal resuscitation focus on providing warmth, positioning, clearing the airway, drying, and stimulating the newborn to breathe. The infant should be placed on a radiant warmer immediately after birth, dried thoroughly to prevent evaporative heat loss, and positioned with the neck in slight extension to optimize airway patency. Gentle stimulation by rubbing the back or flicking the soles of the feet often induces spontaneous respirations in apneic infants. Assessment of breathing and heart rate determines the need for further intervention, with the initial evaluation performed within the first 30 seconds of life to guide subsequent management steps.

The Neonatal Resuscitation Program algorithm provides a systematic approach based on heart rate and respiratory effort assessed at 30-second intervals. Infants who are breathing with heart rates above 100 beats per minute require only routine care and monitoring. Those who are apneic or have heart rates below 100 despite adequate breathing should receive positive pressure ventilation for 30 seconds with reassessment. If the heart rate remains below 60 despite effective ventilation, chest compressions are initiated using a 3:1 compression-to-ventilation ratio that differs from the pediatric and adult algorithms.

Key interventions in neonatal resuscitation include positive pressure ventilation, intubation, chest compressions, and medication administration when indicated. Positive pressure ventilation at 40-60 breaths per minute represents the single most important intervention in neonatal resuscitation, with initial oxygen concentration of 21% for term infants and 21-30% for preterm infants. Intubation is indicated when bag-mask ventilation proves ineffective, for prolonged ventilation, or when specific conditions such as congenital diaphragmatic hernia are suspected. Epinephrine at a dose of 0.01-0.03 mg/kg is administered intravenously or intraosseously when heart rate remains below 60 despite 60 seconds of coordinated chest compressions with effective ventilation.

<image>Panel A: Cross-sectional diagram showing fetal circulation with labeled shunts and direction of blood flow through ductus arteriosus and foramen ovale. Panel B: Step-by-step illustration of initial newborn assessment and stimulation techniques. Panel C: NRP algorithm flowchart with decision points at 30-second intervals showing progression through interventions. Panel D: Demonstration of proper hand positioning for neonatal chest compressions using two-thumb encircling technique.</image>

Section 2: Respiratory Distress - Signs and Differential Diagnosis

Respiratory distress in the newborn manifests through a constellation of clinical signs reflecting increased work of breathing and inadequate gas exchange. Tachypnea, defined as a respiratory rate exceeding 60 breaths per minute, represents one of the earliest and most sensitive indicators of respiratory compromise. Grunting occurs when the infant exhales against a partially closed glottis to maintain functional residual capacity, producing an audible noise with each expiration. Nasal flaring reflects recruitment of accessory muscles to maximize airway opening, while retractions at the intercostal, subcostal, and suprasternal locations indicate increased negative intrathoracic pressure generation to overcome poor lung compliance or airway obstruction.

Transient tachypnea of the newborn represents the most common cause of respiratory distress in term and late preterm infants, resulting from delayed clearance of fetal lung fluid. Risk factors include cesarean delivery without labor, which prevents the catecholamine surge that promotes fluid absorption, and late preterm birth between 34-37 weeks gestation. The infant presents with tachypnea and mild-to-moderate respiratory distress within hours of birth, typically without severe hypoxemia. Chest radiograph reveals fluid in the minor fissure, perihilar streaking, and sometimes small pleural effusions, with findings typically resolving within 24-72 hours with supportive care including supplemental oxygen as needed.

Respiratory distress syndrome results from surfactant deficiency primarily affecting premature infants, though it can occur in term infants with certain risk factors. Surfactant normally reduces alveolar surface tension, preventing collapse at end-expiration, and its absence leads to progressive atelectasis and hypoxemia beginning shortly after birth. The classic radiographic appearance demonstrates diffuse ground-glass opacification with air bronchograms representing air-filled bronchi outlined against collapsed lung parenchyma. Prevention through antenatal corticosteroid administration and treatment with exogenous surfactant replacement have dramatically improved outcomes, though many affected infants still require respiratory support ranging from continuous positive airway pressure to mechanical ventilation.

Other causes of neonatal respiratory distress require consideration based on clinical presentation and risk factors. Meconium aspiration syndrome occurs in infants born through meconium-stained amniotic fluid, particularly those who are post-term or have experienced perinatal stress, presenting with severe respiratory distress and heterogeneous infiltrates on chest radiograph. Pneumonia may develop from organisms acquired during passage through the birth canal, particularly when maternal risk factors such as prolonged rupture of membranes or chorioamnionitis are present. Pneumothorax should be suspected when sudden deterioration occurs with asymmetric breath sounds, while congenital diaphragmatic hernia presents with a scaphoid abdomen and bowel sounds audible in the chest.

<image>Panel A: Clinical photographs showing progressive signs of respiratory distress including nasal flaring, grunting expression, and visible retractions. Panel B: Comparison of chest radiograph appearances in TTN versus RDS with labeled distinguishing features. Panel C: Cross-sectional diagram of alveoli showing surfactant function in normal versus deficient states. Panel D: Differential diagnosis algorithm based on timing of symptom onset and associated clinical features.</image>

Section 3: Congenital Heart Disease - Classification and Presentation

Congenital heart disease encompasses a spectrum of structural cardiac abnormalities with presentations ranging from asymptomatic to life-threatening, depending on the specific lesion and its hemodynamic consequences. Classification schemes organize lesions based on physiologic effects, distinguishing between cyanotic lesions with right-to-left shunting and acyanotic lesions that produce left-to-right shunting or outflow obstruction without mixing. The concept of ductal dependence provides crucial clinical relevance, as certain lesions rely on patency of the ductus arteriosus to maintain either pulmonary or systemic blood flow. Recognition of ductal-dependent lesions in the first days of life, before the ductus closes, enables life-saving intervention with prostaglandin E1.

Ductal-dependent lesions requiring the patent ductus arteriosus for pulmonary blood flow include pulmonary atresia, critical pulmonary stenosis, and tricuspid atresia with restrictive ventricular septal defect. In these lesions, obstruction to right ventricular outflow prevents adequate pulmonary blood flow through normal pathways, and the ductus provides an alternative route from the aorta to the pulmonary arteries. As the ductus closes over the first hours to days of life, affected infants develop progressive cyanosis as pulmonary blood flow diminishes. Urgent administration of prostaglandin E1 reopens the ductus, restoring pulmonary blood flow and improving oxygenation while definitive surgical or interventional treatment is planned.

Ductal-dependent lesions requiring the patent ductus arteriosus for systemic blood flow include hypoplastic left heart syndrome, critical coarctation of the aorta, and interrupted aortic arch. These lesions feature severe obstruction to left ventricular outflow such that adequate systemic perfusion depends on blood flowing from the pulmonary artery through the ductus to the descending aorta. Affected infants may appear well initially while the ductus remains widely patent, then develop shock, poor perfusion, and metabolic acidosis as ductal constriction limits systemic blood flow. The presentation may mimic sepsis, and high clinical suspicion with early prostaglandin administration can be life-saving in suspected cases.

The timing of presentation provides clues to the underlying cardiac lesion. Ductal-dependent lesions typically present in the first 1-2 days of life as the ductus begins closing, though infants with hypoplastic left heart syndrome may present later if their ductus remains patent longer. Lesions producing left-to-right shunting, such as ventricular septal defects and atrial septal defects, do not cause symptoms until pulmonary vascular resistance falls over the first weeks of life, allowing increased pulmonary blood flow and eventual heart failure symptoms. Large shunt lesions may present at 2-6 weeks with tachypnea, diaphoresis with feeding, and failure to thrive.

<image>Panel A: Schematic diagrams comparing cyanotic versus acyanotic heart lesions with direction of blood flow indicated by arrows. Panel B: Illustration of ductal-dependent pulmonary blood flow lesions showing how PDA supplies pulmonary circulation. Panel C: Illustration of ductal-dependent systemic blood flow lesions showing how PDA supplies aorta and systemic circulation. Panel D: Timeline showing typical presentation ages for different categories of congenital heart lesions.</image>

Section 4: Cyanotic Heart Disease - Specific Lesions

The five T's of cyanotic congenital heart disease provide a mnemonic for remembering the major lesions that present with central cyanosis due to right-to-left shunting. Tetralogy of Fallot comprises four anatomic abnormalities: ventricular septal defect, pulmonary stenosis, overriding aorta, and right ventricular hypertrophy, with the degree of pulmonary stenosis determining the severity of cyanosis. Transposition of the great arteries represents the most common cyanotic heart defect presenting in the newborn period, with the aorta arising from the right ventricle and pulmonary artery from the left ventricle, creating parallel rather than series circulation. Tricuspid atresia, total anomalous pulmonary venous return, and truncus arteriosus complete the five T's, each with distinct anatomy and hemodynamic consequences.

Tetralogy of Fallot presents with variable degrees of cyanosis depending on the severity of right ventricular outflow tract obstruction. Infants with severe pulmonary stenosis present with cyanosis at birth, while those with milder obstruction may have a murmur detected incidentally with minimal or no cyanosis initially. Hypercyanotic episodes, known as "tet spells," occur when dynamic obstruction of the right ventricular outflow tract decreases pulmonary blood flow, causing sudden worsening of cyanosis, irritability, and potentially syncope or seizure. Management of acute spells includes knee-to-chest positioning to increase systemic vascular resistance, supplemental oxygen, morphine for sedation, and fluid boluses, with definitive surgical repair scheduled electively or urgently depending on severity.

Transposition of the great arteries creates two parallel circulations that are incompatible with life unless mixing occurs between the systemic and pulmonary circuits. Affected infants present with profound cyanosis shortly after birth that does not improve significantly with supplemental oxygen administration. Survival depends on the presence of mixing sites such as a patent foramen ovale, ventricular septal defect, or patent ductus arteriosus. The chest radiograph may show an "egg on a string" appearance due to the narrow vascular pedicle created by the anteriorly positioned aorta. Initial management includes prostaglandin E1 to maintain ductal patency, followed by balloon atrial septostomy to improve mixing, with definitive arterial switch operation performed within the first week of life.

The hyperoxia test helps differentiate cardiac from pulmonary causes of cyanosis in newborns by assessing the response to supplemental oxygen. The infant is placed on 100% oxygen for 10 minutes, and arterial blood gas is obtained to measure PaO2. In pulmonary disease, ventilation-perfusion mismatch is at least partially overcome by high inspired oxygen, typically producing PaO2 above 150 mmHg. In cyanotic heart disease with fixed right-to-left shunting, oxygen administration cannot significantly increase systemic arterial oxygen content because blood bypassing the lungs remains deoxygenated regardless of inspired concentration, and PaO2 typically remains below 100 mmHg despite maximum oxygen therapy.

<image>Panel A: Anatomic diagrams of the five T's of cyanotic heart disease with arrows showing blood flow patterns. Panel B: Comparison of normal great vessel relationship versus transposition with parallel circuits illustrated. Panel C: Clinical photograph showing infant in knee-to-chest position for management of hypercyanotic spell. Panel D: Hyperoxia test interpretation flowchart with PaO2 thresholds and likely diagnoses.</image>

Section 5: Neonatal Sepsis - Classification and Risk Factors

Neonatal sepsis represents a significant cause of morbidity and mortality in the newborn period, with classification based on timing of onset relative to birth. Early-onset sepsis occurs within the first 72 hours of life and results from organisms acquired from the maternal genital tract during labor and delivery. Late-onset sepsis occurs after 72 hours and may result from organisms acquired from the environment, including healthcare-associated infections in hospitalized preterm infants. Very late-onset sepsis, occurring after 3 months, primarily affects preterm infants with prolonged hospitalization and often involves catheter-associated bloodstream infections.

Risk factors for early-onset sepsis relate primarily to maternal colonization and conditions that increase exposure or decrease infant defenses. Maternal Group B Streptococcus colonization represents the most significant modifiable risk factor, with intrapartum antibiotic prophylaxis dramatically reducing transmission and infant infection rates. Prolonged rupture of membranes exceeding 18 hours increases the risk of ascending infection even in the absence of clinical chorioamnionitis. Chorioamnionitis, indicated by maternal fever, uterine tenderness, foul-smelling amniotic fluid, and fetal tachycardia, significantly elevates infection risk. Prematurity increases susceptibility due to immature immune function and reduced transplacental immunoglobulin transfer.

The microbiology of neonatal sepsis differs between early and late presentations, guiding empiric antibiotic selection. Group B Streptococcus and Escherichia coli account for the majority of early-onset infections, with Listeria monocytogenes occurring less commonly but requiring consideration in empiric coverage. Late-onset sepsis involves a broader spectrum of organisms including coagulase-negative staphylococci (particularly in infants with central venous catheters), Staphylococcus aureus, gram-negative enteric organisms, and Candida species in very preterm infants or those with prolonged antibiotic exposure. Knowledge of local antimicrobial resistance patterns informs appropriate empiric therapy selection.

Clinical presentation of neonatal sepsis is notoriously nonspecific, requiring a high index of suspicion for timely diagnosis and treatment. Temperature instability may manifest as either fever or hypothermia, with hypothermia more common in preterm infants. Respiratory symptoms including apnea, tachypnea, and increased oxygen requirement may be the earliest manifestation. Feeding intolerance, lethargy, and irritability represent common but nonspecific findings. Cardiovascular signs include tachycardia, delayed capillary refill, and hypotension in advanced cases. The nonspecific nature of these findings means that sepsis must be considered in any infant with clinical deterioration, even when an alternative explanation seems plausible.

<image>Panel A: Timeline diagram showing classification of neonatal sepsis by age of onset with typical organisms for each period. Panel B: Risk factor assessment flowchart for early-onset sepsis with associated probability estimates. Panel C: Comparative bar graph showing relative frequency of organisms in early versus late-onset sepsis. Panel D: Clinical photograph composite showing subtle signs of neonatal sepsis including lethargy, mottling, and respiratory distress.</image>

Section 6: Sepsis Evaluation and Management

The evaluation of suspected neonatal sepsis involves systematic assessment including laboratory studies and cultures to identify infection while initiating timely empiric therapy. Complete blood count with differential provides supportive data, though normal values do not exclude infection; concerning findings include neutropenia, elevated immature-to-total neutrophil ratio, and thrombocytopenia. Blood culture remains the gold standard for diagnosis, with sufficient volume ideally obtained before antibiotic administration. Lumbar puncture for cerebrospinal fluid analysis is recommended for infants with positive blood cultures, clinical signs concerning for meningitis, or those who will receive antibiotic therapy, as bacteremia may seed the meninges. C-reactive protein may be useful serially to guide duration of therapy in culture-negative cases.

Empiric antibiotic therapy for early-onset sepsis typically consists of ampicillin combined with gentamicin, providing coverage for Group B Streptococcus, Listeria, and most gram-negative organisms. Ampicillin provides excellent activity against GBS and Listeria while contributing synergistic gram-negative coverage when combined with an aminoglycoside. Gentamicin dosing requires attention to gestational and postnatal age with therapeutic drug monitoring to ensure adequate levels while avoiding toxicity. Duration of therapy ranges from 48-72 hours for culture-negative cases with rapid clinical improvement to 7-14 days for confirmed bacteremia, with longer courses required for meningitis or deep-seated infections.

Late-onset and healthcare-associated sepsis requires broader empiric coverage reflecting the different spectrum of causative organisms. Vancomycin provides coverage for coagulase-negative staphylococci and methicillin-resistant Staphylococcus aureus, which are common in neonatal intensive care settings. An aminoglycoside or third-generation cephalosporin adds gram-negative coverage, with selection based on local resistance patterns and patient factors. Empiric antifungal therapy with fluconazole or amphotericin B is considered for very low birth weight infants with prolonged antibiotic exposure or other risk factors for invasive candidiasis. Therapy is modified once culture and sensitivity results are available.

Prevention of neonatal sepsis centers on identification and appropriate management of maternal risk factors, particularly Group B Streptococcus colonization. Universal prenatal GBS screening at 36-37 weeks gestation identifies colonized women who should receive intrapartum antibiotic prophylaxis, typically with intravenous penicillin or ampicillin. Prophylaxis is considered adequate if administered at least 4 hours before delivery. Women with GBS bacteriuria during pregnancy or a previous infant with invasive GBS disease receive prophylaxis regardless of colonization status at delivery. Infants born to mothers with inadequate prophylaxis require enhanced monitoring or empiric antibiotic therapy depending on clinical status and institutional protocols.

<image>Panel A: Laboratory evaluation algorithm showing which tests to obtain based on clinical presentation and risk factors. Panel B: Antibiotic selection diagram showing empiric regimens for early versus late-onset sepsis with dosing considerations. Panel C: Treatment duration decision tree based on culture results and clinical course. Panel D: GBS prevention flowchart showing screening, prophylaxis, and newborn management pathways.</image>

Section 7: Hyperbilirubinemia

Neonatal hyperbilirubinemia represents one of the most common clinical findings in newborns, with the distinction between physiologic and pathologic jaundice guiding evaluation and management. Physiologic jaundice results from increased bilirubin production from normal red blood cell turnover combined with immature hepatic conjugation capacity, typically peaking at days 3-5 in term infants and resolving by 2 weeks. Pathologic jaundice is suggested by onset within the first 24 hours of life, rapid rate of rise exceeding 5 mg/dL per day, peak levels above established thresholds, prolonged duration beyond 2 weeks, or presence of direct hyperbilirubinemia. The distinction matters because pathologic jaundice requires investigation for underlying causes that may need specific treatment.

Causes of pathologic hyperbilirubinemia span categories of increased production, decreased conjugation, and decreased excretion. Hemolytic diseases including ABO and Rh incompatibility, glucose-6-phosphate dehydrogenase deficiency, and hereditary spherocytosis increase bilirubin production through accelerated red blood cell destruction. Conjugation disorders include Crigler-Najjar syndrome and Gilbert syndrome, though the latter typically presents later in life. Decreased excretion characterizes biliary atresia and other cholestatic conditions that produce direct hyperbilirubinemia. Breast milk jaundice and breastfeeding jaundice represent distinct entities: breastfeeding jaundice results from inadequate intake causing increased enterohepatic circulation, while breast milk jaundice involves substances in breast milk that inhibit conjugation and typically presents after the first week.

Evaluation of hyperbilirubinemia includes measurement of total and direct bilirubin fractions, blood typing and direct antiglobulin (Coombs) testing, complete blood count with reticulocyte count, and additional studies based on clinical suspicion. Direct hyperbilirubinemia exceeding 1 mg/dL or 20% of total bilirubin warrants evaluation for cholestatic liver disease including biliary atresia, which requires early surgical intervention for optimal outcomes. The peripheral smear may reveal spherocytes in immune hemolysis or hereditary spherocytosis. G6PD testing should be performed in infants of appropriate ethnic backgrounds or those with unexplained hemolysis. Sepsis workup is indicated in ill-appearing infants with jaundice.

Treatment of indirect hyperbilirubinemia is guided by hour-specific nomograms that account for the infant's age in hours, gestational age, and risk factors for bilirubin neurotoxicity. Phototherapy converts unconjugated bilirubin in the skin to water-soluble photoisomers that can be excreted without conjugation, and is initiated when bilirubin levels reach age-specific thresholds on published nomograms. Exchange transfusion is indicated when bilirubin levels reach critical thresholds despite intensive phototherapy, particularly in the presence of signs of acute bilirubin encephalopathy such as hypertonia, arching, or high-pitched cry. Prevention strategies include early, frequent feeding to promote gastrointestinal motility and bilirubin excretion, close follow-up after hospital discharge, and parental education about jaundice warning signs.

<image>Panel A: Comparative diagram showing bilirubin metabolism pathway with sites of dysfunction in various pathologic conditions. Panel B: Hour-specific bilirubin nomogram showing treatment threshold zones with risk factor modifications. Panel C: Clinical photographs showing progression of jaundice distribution from face to trunk to extremities with increasing levels. Panel D: Phototherapy unit illustration showing proper positioning and mechanisms of bilirubin photoisomerization.</image>

Section 8: Metabolic Emergencies

Hypoglycemia represents the most common metabolic emergency in the newborn period, with risk factors including abnormal glucose regulation, increased glucose utilization, and inadequate glycogen stores. Infants of diabetic mothers experience hyperinsulinism from fetal exposure to maternal hyperglycemia, with continued high insulin levels after birth causing rapid glucose consumption. Small-for-gestational-age and growth-restricted infants have limited glycogen reserves and may also have impaired gluconeogenesis. Large-for-gestational-age infants, premature infants, and those experiencing perinatal stress represent additional high-risk populations. Definition of hypoglycemia remains somewhat controversial, with most experts recommending intervention for blood glucose below 45-50 mg/dL, though symptomatic infants warrant treatment regardless of specific level.

Clinical manifestations of neonatal hypoglycemia range from asymptomatic biochemical findings detected on routine screening to severe neurologic dysfunction. Jitteriness, tremors, and irritability represent early signs that may progress to lethargy, hypotonia, and poor feeding if hypoglycemia persists. Severe or prolonged hypoglycemia can cause seizures, apnea, and cyanosis. The nonspecific nature of these symptoms means that hypoglycemia should be considered in any ill-appearing newborn, with immediate bedside glucose testing. Treatment involves oral feeding if the infant is asymptomatic and feeding well, or intravenous dextrose bolus followed by continuous infusion for symptomatic infants or those who cannot maintain levels with oral feeding.

Hypocalcemia in the newborn period follows distinct patterns based on timing of onset. Early hypocalcemia occurring within the first 72 hours of life is associated with prematurity, infant of diabetic mother, and perinatal asphyxia, resulting from interrupted maternal calcium supply combined with immature parathyroid hormone response. Late hypocalcemia occurring after 72 hours may result from high phosphate intake from cow's milk-based formulas, hypomagnesemia, or DiGeorge syndrome with parathyroid hypoplasia. Symptoms include jitteriness, tetany, and seizures, with QT prolongation on electrocardiogram. Treatment involves intravenous calcium gluconate infusion with cardiac monitoring, as rapid administration can cause bradycardia.

Inborn errors of metabolism may present acutely in the neonatal period with nonspecific symptoms mimicking sepsis or other common conditions. Concerning features include unexplained encephalopathy, metabolic acidosis with elevated anion gap, hyperammonemia, hypoglycemia with or without appropriate ketosis, and unusual body odors. Triggers for metabolic decompensation include fasting and catabolism during illness, or introduction of formula containing substrates the infant cannot metabolize, such as galactose in galactosemia. Newborn metabolic screening identifies many conditions before symptoms develop, though results may not yet be available when acutely ill newborns present, requiring empiric management and specialized metabolic testing including plasma amino acids, urine organic acids, and acylcarnitine profile.

<image>Panel A: Risk factor identification chart for neonatal hypoglycemia with recommended monitoring protocols for each category. Panel B: Treatment algorithm for neonatal hypoglycemia with oral versus intravenous management pathways. Panel C: Electrocardiogram strip showing QT prolongation in hypocalcemia compared to normal tracing. Panel D: Clinical features suggesting inborn error of metabolism with associated testing strategy.</image>

Section 9: Surgical Emergencies

Congenital diaphragmatic hernia results from incomplete formation of the diaphragm, allowing abdominal contents to herniate into the thoracic cavity and impair lung development. The most common location is posterolateral on the left side, known as a Bochdalek hernia, which allows stomach, intestines, and sometimes liver to occupy the left hemithorax. Affected infants present with respiratory distress immediately after birth, with a scaphoid (concave) abdomen due to absence of abdominal viscera and decreased breath sounds on the affected side. Chest radiograph demonstrates loops of bowel in the thorax with mediastinal shift to the opposite side. Initial management involves endotracheal intubation (avoiding bag-mask ventilation which can distend intrathoracic bowel), nasogastric decompression, and stabilization before surgical repair.

Tracheoesophageal fistula and esophageal atresia represent a spectrum of congenital anomalies affecting esophageal continuity and tracheal communication. The most common configuration features proximal esophageal atresia with a distal tracheoesophageal fistula connecting the trachea to the distal esophagus, occurring in approximately 85% of cases. Affected infants present with excessive oral secretions, choking and coughing with feeding attempts, and inability to pass a nasogastric tube to the stomach. Prenatal polyhydramnios may suggest the diagnosis when the fetus cannot swallow amniotic fluid. The VACTERL association describes the common co-occurrence of vertebral, anorectal, cardiac, tracheoesophageal, renal, and limb anomalies, prompting evaluation for associated malformations. Surgical repair involves division of the fistula and primary esophageal anastomosis when feasible.

Intestinal obstruction in neonates has multiple etiologies with distinct presentations and management approaches. Duodenal atresia presents with bilious vomiting on the first day of life with the classic "double-bubble" sign on abdominal radiograph representing air in the stomach and proximal duodenum; association with Down syndrome occurs in approximately 30% of cases. Jejunal and ileal atresias present similarly with multiple air-fluid levels on radiograph. Meconium ileus, characterized by inspissated meconium causing distal small bowel obstruction, should prompt evaluation for cystic fibrosis through sweat chloride testing. Hirschsprung disease, caused by absence of enteric ganglion cells, typically presents with failure to pass meconium within 48 hours of birth and may progress to life-threatening enterocolitis.

Malrotation with midgut volvulus represents a true surgical emergency requiring immediate recognition and intervention to prevent irreversible intestinal necrosis. Malrotation results from incomplete rotation and fixation of the intestine during fetal development, leaving the midgut suspended on a narrow mesenteric pedicle susceptible to twisting. When volvulus occurs, the entire midgut blood supply through the superior mesenteric artery is compromised. The classic presentation is bilious vomiting in a previously well newborn, and this symptom should always prompt urgent evaluation. Upper gastrointestinal contrast study demonstrates the characteristic "bird's beak" or "corkscrew" appearance of the twisted duodenum. Emergent laparotomy with Ladd procedure (counterclockwise detorsion, broadening of the mesenteric base, and appendectomy) is indicated without delay.

<image>Panel A: Anatomic diagram of congenital diaphragmatic hernia showing abdominal contents in thorax with lung hypoplasia and mediastinal shift. Panel B: Comparison of tracheoesophageal fistula variants with most common type highlighted and radiographic findings. Panel C: Abdominal radiograph examples showing double-bubble sign of duodenal atresia versus multiple air-fluid levels in distal obstruction. Panel D: Upper GI series image showing corkscrew sign of malrotation with volvulus compared to normal duodenal course.</image>

Section 10: Other Neonatal Emergencies

Necrotizing enterocolitis represents the most common and serious gastrointestinal emergency affecting preterm infants, characterized by intestinal inflammation that may progress to necrosis and perforation. Risk factors include prematurity (the dominant risk factor), formula feeding, and intestinal ischemia, though the precise pathophysiology involves complex interactions between the immature intestine, abnormal bacterial colonization, and inflammatory responses. Clinical presentation includes feeding intolerance, abdominal distension, bloody stools, and systemic signs of sepsis including temperature instability and lethargy. Abdominal radiograph findings progress from nonspecific ileus to pneumatosis intestinalis (air within the bowel wall, the pathognomonic finding), portal venous gas, and pneumoperitoneum in cases of perforation. Medical management includes bowel rest, gastric decompression, broad-spectrum antibiotics, and supportive care, with surgical intervention indicated for perforation or failure of medical therapy.

Neonatal seizures frequently indicate serious underlying pathology and require prompt evaluation to identify treatable causes. Hypoxic-ischemic encephalopathy represents the most common cause, typically presenting within the first 24-48 hours in term infants with perinatal asphyxia. Metabolic derangements including hypoglycemia, hypocalcemia, and hyponatremia should be immediately evaluated and corrected. Infection, particularly bacterial meningitis, causes seizures that may be accompanied by other signs of sepsis. Structural abnormalities including intracranial hemorrhage and developmental malformations are identified through neuroimaging. Neonatal seizures may be subtle, manifesting as eye deviation, lip smacking, bicycling movements, or apnea rather than the tonic-clonic activity seen in older patients. Treatment addresses the underlying cause while antiepileptic medications, typically phenobarbital as first-line, control seizure activity.

Intraventricular hemorrhage primarily affects premature infants, particularly those born before 32 weeks gestation, with the germinal matrix serving as the source of bleeding due to its fragile vasculature. Grading ranges from I (hemorrhage confined to the germinal matrix) to IV (parenchymal hemorrhage, actually representing venous infarction from compression). Screening head ultrasound is routinely performed in preterm infants to detect asymptomatic hemorrhage, with symptoms in severe cases including apnea, bradycardia, declining hematocrit, and full fontanelle. Prevention focuses on antenatal corticosteroids, delayed cord clamping, and gentle handling with minimal interventions in the first days of life. Complications include post-hemorrhagic hydrocephalus requiring serial lumbar punctures, reservoir placement, or ventriculoperitoneal shunting, and periventricular leukomalacia with associated motor impairment.

Birth injuries occur during the delivery process and range from minor findings that resolve spontaneously to life-threatening emergencies. Caput succedaneum and cephalohematoma represent common scalp injuries; caput involves diffuse edema crossing suture lines and resolving within days, while cephalohematoma is a subperiosteal hemorrhage limited by suture boundaries that may persist for weeks and cause hyperbilirubinemia as it resorbs. Subgaleal hemorrhage, bleeding beneath the galeal aponeurosis, represents a true emergency as the potential space can accommodate the infant's entire blood volume, presenting as a fluctuant, spreading scalp mass with signs of hypovolemia. Brachial plexus injury results from lateral neck traction during delivery, with Erb's palsy (C5-C6 involvement) causing the classic "waiter's tip" posture and Klumpke's palsy (C8-T1) affecting the hand. Clavicle fractures, though common, typically heal without intervention.

<image>Panel A: Abdominal radiograph series showing progression of NEC findings from ileus to pneumatosis intestinalis to pneumoperitoneum. Panel B: EEG tracing showing electrographic seizure activity in neonate with corresponding video still of subtle seizure manifestations. Panel C: Grading system for intraventricular hemorrhage with ultrasound images of each grade. Panel D: Comparative illustration of caput succedaneum, cephalohematoma, and subgaleal hemorrhage with anatomic cross-sections showing layer of accumulation.</image>

Summary

• Neonatal resuscitation algorithm progresses through initial steps, positive pressure ventilation if apneic or HR below 100, chest compressions with 3:1 ratio if HR below 60, and epinephrine for persistent bradycardia
• Transient tachypnea of newborn occurs with cesarean delivery, shows fluid in fissures on radiograph, and resolves within 24-72 hours with supportive care
• Respiratory distress syndrome results from surfactant deficiency in preterm infants, producing ground-glass appearance on chest radiograph, and is treated with exogenous surfactant replacement
• Ductal-dependent cardiac lesions present at days 1-2 as the ductus arteriosus closes; prostaglandin E1 administration reopens the ductus and can be life-saving
• Transposition of great arteries creates parallel circulation requiring mixing sites for survival; presents with profound cyanosis unresponsive to oxygen; requires balloon atrial septostomy
• Early-onset neonatal sepsis is caused by Group B Streptococcus and E. coli; empiric treatment is ampicillin plus gentamicin
• Pathologic jaundice is characterized by onset before 24 hours, rapid rise, prolonged duration, or direct hyperbilirubinemia requiring investigation for underlying cause
• Neonatal hypoglycemia occurs in infants of diabetic mothers, SGA, and preterm infants; symptomatic infants require intravenous dextrose treatment
• Bilious vomiting in a neonate should always prompt consideration of malrotation with midgut volvulus, a surgical emergency requiring immediate intervention
• Necrotizing enterocolitis affects preterm infants, produces pneumatosis intestinalis on radiograph, and is managed with bowel rest, antibiotics, and surgery if perforation occurs

Key Terms

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