Vomiting in the Newborn Jessica Hughes Kisicki, M.D. Emergency Medicine Resident, St. John Hospital and Medical Center A three-day-old infant named Chloe presented to the emergency room with her parents one hour after repeatedly vomiting bright green fluid. The initial exam demonstrated an alert, crying infant with normal vital signs and physical exam findings, including a normal abdominal exam. ER staff immediately placed an intravenous line, started fluids, kept her NPO, and placed a nasogastric tube. In addition, an emergent upper gastrointestinal x-ray series was completed, which showed malrotation without volvulus. At this point, the ER physician urgently consulted the pediatric surgeon; however, Chloe's volvulus had resolved, and she no longer required emergent surgery. Her doctors admitted her to the NICU and performed surgery the next day to repair the malrotation. Vomiting is a common reason for presentation to the pediatric emergency department with causes ranging from benign processes to serious, life-threatening conditions as outlined above. Repeated, forceful vomiting or bilious vomiting in newborns should always prompt serious and thorough evaluation, especially when accompanied by signs such as lethargy, fever, weight loss, or feeding refusal. Many conditions involve vomiting in the newborn, but the potential life-threatening sequelae of certain processes associated with vomiting necessitate a structured approach to the problem by the emergency room physician. Initially, when a newborn presents to the emergency room with vomiting, the physician must determine if the vomiting is secondary to a life-threatening process, such as intestinal obstruction, and implement immediate intervention. Next, the physician must assess the degree of dehydration and initiate appropriate rehydration strategies. Initial factors to use include vital signs and calculating weight loss during illness. An estimation of the degree of dehydration centers on specific findings such as a general ill appearance, capillary refill greater than two seconds, dry mucous membranes, and absent tears, with a combination of two or three of these findings correlating with a 5% or 10% dehydration status, respectively. After appropriate initial stabilization, the ER physician's focus should turn to a more thorough history and physical exam of the patient. Important historical components include number, color, and projectile nature of the vomiting, associated symptoms such as irritability, fever, diarrhea, and number of wet diapers to assess urine output. In addition, inquiries about the type of food consumed help assess for food allergies. Additionally, factors such as protracted vomiting, severe dehydration, premature birth, or underlying medical conditions in the newborn should prompt further evaluation such as a blood draw to evaluate electrolytes and blood glucose levels. As mentioned previously, certain life-threatening illnesses that result in vomiting in the newborn exist and should remain fresh in the emergency physician's differential in these settings. One such group of disease processes involves the various causes of intestinal obstruction. The most common signs on presentation are crying and irritability, with other common signs including pain, vomiting, abdominal distention, and absence of bowel movements. Vomiting may be bilious or non-bilious depending on the location of the obstruction and flat and upright x-rays of the abdomen show dilated loops of bowel with air fluid levels. Appropriate management of these patients includes full resuscitation and surgical consultation, along with NPO status and placement of a nasogastric tube. A few major conditions resulting in intestinal obstruction in a newborn include malrotation with volvulus, incarcerated inguinal hernia, pyloric stenosis, and Hirschsprung's disease. The gestational abnormality malrotation results from improper rotation and fixation of the duodenum and cecum during development, thus leaving the cecum in the right side of the abdomen with peritoneal attachments forming across the duodenum. Malrotation with volvulus occurs when this abnormality leads to twisting of the bowel on the mesentery resulting in a small bowel obstruction and ischemia of the bowel wall. Volvulus presents with the sudden onset of an acute abdomen and bilious vomiting, and can occur at any point in a patient's life; however, most cases of volvulus present in the first month of life. Laboratory results may show an elevated white blood cell count, electrolyte abnormalities, or an acidosis, and an upper gastrointestinal x-ray series is diagnostic. Malrotation without volvulus requires urgent surgical repair of the malrotation, while those with volvulus need an emergent laparotomy to repair the obstruction. Newborns with incarcerated hernia may present with vomiting if intestinal obstruction occurs. The highest incidence occurs in the first year of life, and patients typically present with irritability, poor feeding, vomiting, and an inguinal/scrotal mass. After resuscitation, the physician should attempt manual reduction of the hernia by using sedation and placing the patient in the reverse Trendelenburg position, then gently manually reducing the hernia. With a successful manual reduction, the newborn needs follow-up in one to two days for elective repair of the hernia. No response to manual reduction warrants surgical reduction. Pyloric stenosis, caused by hypertrophy of the pylorus, most commonly affects a three-to-six-week-old, first-born, male infant. The hypertrophy leads to narrowing of the antrum of the stomach causing obstruction of the gastric outlet. Usually, the infant displays mild regurgitation after feedings, which progresses to post-prandial, non-bilious, projectile vomiting within one week. These patients may appear hungry, lethargic, malnourished, and dehydrated, with peristaltic waves possibly seen across the abdomen. The palpation of an olive-like mass at the lateral aspect of the rectus abdominus muscle just below the liver is pathognomonic for this condition. Laboratory evaluation may show a hypochloremic, hypokalemic, metabolic alkalosis secondary to persistent vomiting. The first step in fully evaluating these patients involves an ultrasound, which typically shows thickening of the pylorus. If this proves non-diagnostic, an upper GI series will show delayed gastric emptying and pyloric channel narrowing. These newborns need full resuscitation and surgical consultation for a pyloromyotomy. Hirschsprung's disease, also a congenital abnormality, can also present with vomiting in the newborn. Absence of the enteric nerves normally present in the large bowel results in enlargement of the colon and subsequent obstruction. Failure of a newborn to pass meconium within the first 48 hours of life strongly suggests this diagnosis, and these patients typically present with signs of a distal bowel obstruction such as bilious emesis and abdominal distension. Biopsy of the affected colon shows absence of ganglion and confirms the diagnosis. Neonates with Hirschsprung's disease need surgical resection of the affected area of colon. Management of vomiting in the newborn depends on the underlying disease process and the degree of dehydration. As above, treatment should be initiated for any life-threatening illnesses. If a benign process exists, the focus can turn to correcting dehydration or any electrolyte, metabolic, or nutritional abnormalities. In general, antiemetics are contraindicated in the newborn and vomiting is managed with oral rehydration therapy (ORT, such as pedialyte) or intravenous fluids. Vomiting is not a contraindication to ORT, however, the key is to give 5ml of fluid at a time every 2-3 minutes. Adequately hydrated newborns with vomiting should be continued on age appropriate feedings (with either breast milk or full concentration formula) with ORT given at 10ml/kg. When a neonate presents with mild dehydration (3-5%), they should receive 50ml/kg of ORT and age appropriate feedings should be continued after the dehydration is corrected. For neonates with moderate dehydration (6-9%) after vomiting, intravenous fluid or 100ml/kg of ORT may be given. When presenting with severe dehydration or an abdominal emergency, neonates must receive intravenous fluid replacement. Fluid resuscitation should begin with 20ml/kg boluses of normal saline or lactated ringers plus maintenance fluids. Appropriate maintenance fluid administration for newborns is based on weight and consists of D5.25NS or D5.45NS at 4cc/kg/hr for first 10kg, 2cc/kg/hr for next 10kg, and 1cc/kg/hr for every kg after that. It is important to remember that neonates should receive additional fluids for ongoing losses and for each episode of vomiting. As a rule, when managing a newborn with vomiting, ongoing assessment of fluid status should occur hourly to monitor appropriate fluid resuscitation. Overall, vomiting is frequently encountered in the pediatric emergency department and although most cases of vomiting represent a benign disease process, certain life-threatening illnesses should be forefront in the mind of the emergency physician when treating a neonate with vomiting. Generally, in the absence of serious pathology and only mild dehydration, it is appropriate to discharge the newborn home with a hydration check within 24 hours. Any neonate with a life-threatening cause of vomiting or newborns with moderate and severe dehydration should be admitted to the hospital for continued fluid replacement and/or surgical consultation. References: Emergency Medicine, a Comprehensive Study Guide, 6th edition, Judith E. Tintinalli, MD, MS: chapter 127: Pediatric abdominal emergencies, chapter 132: fluid and electrolyte therapy, chapter 126: vomiting and diarrhea in children Uptodate: Approach to the infant or child with nausea and vomiting, Carlo Di Lorenzo, MD Byline: Jessica Hughes Kisicki, M.D. # # # Posted: Wednesday, February 3, 2010 Back to CME Exam