Fig. 47.1 This infant presented with blood-stained vomiting at 12 hours of age. Water‐soluble contrast upper gastrointestinal study demonstrates coiled corkscrew appearance of second and third parts of duodenum due to midgut volvulus from malrotation. (Courtesy of Dr Annemarie Jeanes.)
Fig. 47.2 Abdominal X‐ray showing distended loops of bowel in an infant with persistent vomiting.
Key point
Bile‐stained vomiting in term infants should always be regarded as intestinal obstruction until proven otherwise.
Gastrointestinal disorders 111 Causes:
• Swallowed maternal blood – from delivery or cracked nipple. Can be differentiated from fetal blood with the Apt test (see Table 47.1).
• Trauma – laryngoscopy at resuscitation, passing a nasogastric tube.
• Malrotation – uncommon but important to diagnose early (Fig. 47.2).
• Stress ulcer – hypoxic–ischemic encephalopathy.
• Abnormal coagulation–thrombocytopenia, vitamin K deficient bleeding, liver disease, DIC (disseminated intravascular coagula- tion), etc.
• Drug‐induced – corticosteroids, indomethacin, ibuprofen.
Investigations
Most infants will require no or limited investigations. Those to be considered are listed in Table 47.1.
Management
Depends upon severity and cause. Intravenous fluids may be required to correct electrolyte disturbances, acid–base imbalance and dehydration.
Gastroesophageal reflux Incidence is increased in:
• preterm infants, particularly with bronchopulmonary dysplasia or on caffeine
• following necrotizing enterocolitis and tracheoesophageal fistula repair
• infants with neurodevelopmental delay, e.g. following hypoxic–
ischemic encephalopathy or hypotonia.
Associated features
• Failure to thrive.
• Irritability, arching of the back from esophagitis.
• Anemia (iron deficiency).
• Aspiration pneumonia.
• Apnea.
• Acute life‐threatening events (ALTE).
Investigations
• Usually clinical diagnosis.
• Esophageal pH study, impedance study may show non-acid reflux, sometimes upper gastrointestinal contrast or endoscopy.
Management
Most do not need treatment. If required, use stepwise approach.
• Reduce interval between feeds, thicken feeds, alginate/antacid (Gaviscon), upright positioning.
• Prokinetic e.g. domperidone, but concerns about arrhythmias.
• H2 receptor antagonist, e.g. ranitidine; proton pump inhibitors, e.g. omeprazole – reduce gastric acidity.
• Surgery – fundoplication with or without gastrostomy.
• Evidence of efficacy of medication in neonates is limited.
Fig. 47.3 Abdominal distension from Hirschsprung disease.
Table 47.1 Vomiting – investigations to consider and their purpose.
Imaging Blood tests Urine and stool tests
Plain abdominal X‐ray: Electrolytes and acid‐base – for imbalance Urine – microscopy and culture
• intestinal obstruction – distended loops of bowel, bowel perforation
Sepsis work‐up – to exclude infection Creatinine/blood urea nitrogen (urea) – for
dehydration and renal function
Stool – for blood Other:
• Apt test of vomit/stool – to differentiate between maternal and fetal blood. Fetal hemoglobin is alkali‐
resistant (remains pink on addition of sodium hydroxide)
• NEC (necrotizing enterocolitis) Ultrasound scans:
• cranial for hemorrhage, ventricular dilatation
• abdominal for pyloric stenosis, intra-abdominal fluid collections and cysts.
Contrast X‐rays:
• malrotation, strictures
• site of intestinal obstruction
Glucose – for hypoglycemia
Calcium, magnesium, phosphorus, liver function tests
Coagulation screen – if blood in vomit or sepsis
Consider:
• 17‐hydroxyprogesterone – for congenital adrenal hyperplasia
• blood ammonia – for urea cycle abnormalities
• drug screen – for drug overdose or withdrawal
Esophageal atresia
• More than 85% associated with tracheoesophageal fistula (Fig. 47.4).
• 1 in 3500 live births.
• Often associated with other abnormalities, e.g. VACTERL syn- drome (vertebral anomalies, anal atresia, cardiac, tracheoesophageal, renal, limb).
Presentation
• Prenatal – polyhydramnios, absent stomach bubble, associated abnormalities.
• Birth onwards – frothing of oral secretions (Fig. 47.5) with choking and cyanosis.
Investigations
• Unable to pass wide‐bore orogastric tube; confirmed on chest X‐ray, shows tube curled in esophageal pouch. Air in the stomach indicates a distal fistula is present.
Management
• Pass large orogastric tube and aspirate pouch to avoid aspiration pneumonia.
• Intravenous fluids for resuscitation and maintenance. Early PN (parenteral nutrition).
• Surgical correction is required.
Abdominal masses
Often detected in utero on ultrasound screening. The causes are shown in Fig. 47.6.
Abdominal wall defects Omphalocele (Exomphalos)
Defect in umbilicus with herniation of abdominal contents. The bowel is covered by peritoneum and amnion (Fig. 47.7). Vary in size, from small defects where some bowel herniates into the umbilical cord to large defects where there is herniation of both bowel and liver.
Occurs in 1 in 5000 fetuses. Most are diagnosed on prenatal ultra- sound screening (see Fig. 3.2); 40% are associated with trisomy 13 or 18, Beckwith–Wiedemann (see Chapter 45) or other syndromes.
86% – atresia with fistula between distal esophagus and trachea
8% – atresia without
fistula 4% – H-type fistula without atresia
Fig. 47.4 Different types of esophageal atresia and tracheoesophageal fistula.
Fig. 47.5 Frothing of oral secretions after birth from esophageal atresia.
Renal 55%
Hydronephrosis
Multicystic dysplastic kidney (MCDK) Polycystic kidney disease Wilms tumor
Renal vein thrombosis Adrenal 5%
Adrenal hemorrhage Neuroblastoma
Retroperitoneal (non-renal) 5%
Teratoma Hepatobiliary 5%
Hepatomegaly – infection, metabolic/storage disease, heart failure
Hemolytic disorders, e.g. spherocytosis Duplication
Obstruction
Mesenteric/omental cysts
Genitalia 15%
Splenomegaly Gastrointestinal 15%
Fig. 47.6 Abdominal masses and their causes.
Fig. 47.7 Omphalocele.
Gastrointestinal disorders 113 Management (see video: Gastroschisis)
• Pass a large‐caliber nasogastric tube at delivery to limit passage of air into the bowel, and nothing by mouth.
• Place infant’s lower body into a sterile plastic wrap (bag) to limit heat and fluid loss and protect the bowel from damage and infection.
• Give intravenous fluids.
• Check for other anomalies, including echocardiography.
• Surgical repair is usually performed on the first day of life. If the defect is large, the viscera may be placed in a silastic silo, and gradually placed in the abdomen over several days.
Gastroschisis
Defect in anterior abdominal wall, usually to right of umbilicus, with herniation of the bowel (Fig. 47.8). In contrast to omphalocele, there is no protective covering of the bowel and the incidence of associated anomalies is low, other than intestinal atresia. The condition is usu- ally diagnosed on prenatal ultrasound screening (Fig. 47.9).
Management
• The infant’s lower body is placed into a sterile plastic wrap (bag or cling film).
• Pass a large‐caliber nasogastric tube at delivery to limit passage of air into the bowel.
• Give intravenous fluids; colloid may be required to replace fluid losses from the exposed bowel. Closely monitor electrolytes. Give broad‐spectrum antibiotics.
• Surgical repair can be performed directly or the abdominal con- tents can be gradually reduced after placing into a silo (Fig. 47.10).
• Prolonged parenteral nutrition is usually required to establish feeds. Prognosis is good.
Imperforate anus
• Incidence 1 in 5000 births. Associated anomalies of genitourinary and gastrointestinal tract common, and seen in VACTERL association.
• In boys most often with fistula to urethra, in girls to vestibule adjacent to vagina-so may still pass meconium. Some lesions are complex.
• Surgery is with anoplasty or colostomy followed by repair.
Fig. 47.8 Gastroschisis.
Fig. 47.10 Gastroschisis in silastic silo. There is also a central venous catheter for PN.
Fig. 47.9 Gastroschisis on prenatal ultrasound scan. (Courtesy of Dr David Lissauer.)
Neonatology at a Glance, Third Edition. Edited by Tom Lissauer, Avroy A. Fanaroff, Lawrence Miall and Jonathan Fanaroff.
© 2016 John Wiley & Sons, Ltd. Published 2016 by John Wiley & Sons, Ltd.
Most of the conditions causing gastrointestinal obstructions are serious but their prognosis has improved with advances in medical, anesthetic and surgical care. They are relatively uncommon but are important to recognize because:
• failure or delay in diagnosis may result in electrolyte imbalance, dehydration and shock
• malrotation with midgut volvulus is a surgical emergency in order to avoid bowel necrosis.
Causes – see Fig. 48.1
Diagnostic clues Prenatal:
• Polyhydramnios – from obstruction to the passage of amniotic fluid through the gastrointestinal tract.
• Abnormal ultrasound – dilated bowel, hyperechoic bowel, ascites, calcified lesions. May be difficult to diagnose.
• Fetus with trisomy 21 (Down syndrome) – 30% have associated duodenal atresia.
• Family history of cystic fibrosis – associated with meconium ileus.
Delivery room:
• Bubbly oral secretions – esophageal atresia.
• Peri‐umbilical abdominal wall discoloration – in utero bowel perforation.
Clinical presentation
• Vomiting – usually bile (yellow-green) stained. Bile is present if the obstruction is distal to ampulla of Vater. Presents within 24–48 hours of birth with high gastrointestinal lesions, may be delayed for several days for lower lesions. Hematemesis (blood‐stained vomit) may occur with malrotation.
• Feeding intolerance.
• Abdomen – distension with visible loops of bowel or peristalsis, erythema/edema of abdominal wall, abdominal mass, peritonitis and shock.
• Failure to pass meconium within 48 hours of birth.
• Blood in stool (fresh or altered).
Diagnosis Abdominal X‐ray:
• Bowel obstruction – distended loops of bowel with air‐fluid levels, with absence of gas distally (see Fig. 47.2).
• Bowel perforation – free air under diaphragm, intrahepatic or around falciform ligament.
Management
• Abdominal decompression with nasal or orogastric tube. In esophageal atresia, aspirate pouch to avoid aspiration pneumonia.
• Intravenous fluids for resuscitation and maintenance. Early parenteral nutrition (PN).
• Antibiotics preoperatively.
• Evaluate and correct bleeding diathesis.
• Surgical intervention for most lesions.
• Evaluate for other anomalies. Karyotype and microarray analysis may be necessary.
Some specific conditions Esophageal atresia (Chapter 47) Pyloric stenosis
Hypertrophy of circular smooth muscle of pylorus of stomach.
• Presentation – projectile vomiting in a hungry infant at 4–8 weeks of age. Occurs at same age in preterm infants.
• Examination – visible peristalsis. A firm, olive‐like mass is palpable in right upper abdomen during feeds.
• Investigation – abdominal ultrasound – hypertrophy of pylorus.
• Management – correct electrolyte imbalance (hypochloremic hypokalemic alkalosis). Surgery-muscle incision (pyloromyotomy).
Duodenal atresia
• Lesion – obstruction may be due to atresia, webs, stenosis or fibrous cord.
• Incidence – 1 in 7500 births. Check for trisomy 21 and other anomalies.
• Antenatal – polyhydramnios, distended fluid‐filled stomach on ultrasound.
• Presentation – vomiting – bilious or non‐bilious, upper abdom- inal distension and feeding intolerance.
• Diagnosis – double bubble on X‐ray (Fig. 48.2). May be accen- tuated by injecting 20 mL of air through gastric tube.