1. Name of Specialty PEDIATRICS

2. Name of Case 2 months old male child

presenting as vomiting after

feed

3. Name of Expert Dr. D. P. Pande

Sr. Pediatrician

4. Name of Hospital Northern Railway Central Hospital

Basant Lane , New Delhi-110001

Introduction and Case Summary:

A 2 months old first born, male infant, product of a non-consanguinous marriage was brought to us by his mother with c/o vomiting soon after feeds for last two weeks. Initially they believed it to be usual small regurgitation as the child was getting hungry more frequently and trying to overfeed. However, for last 3 to 4 days the vomitus was immediately after feeds and the entire milk as such was brought out. Child seemed hungry but was otherwise normal. Mother had a normal pregnancy and full term normal vaginal delivery. There was no H/o fever, rash, diarrhoea, cough or respiratory distress. Child was passing urine normally and did not appear constipated. He had been seen by a local practitioner, who had given him domperidone drops, but his problem did not resolve. On examination, the infant appeared alert and playful. Physical examination was unremarkable except for a doubtful upper abdominal mass. During feeding upper abdominal fullness was noted and he vomited milk as such after a few minutes. There was no bile in the vomitus. Child was hopitalised and put on i.v. fluids evaluated further and managed.

How will you attempt to make a diagnosis in this case?

(Differential diagnosis)

• When an infant presents with persistent vomiting of a short duration, bowel obstruction is an important differential diagnosis, volvulus an important cause and a surgical emergency. An infant with volvulus presents with bilious vomiting and appears very sick. Since none of these features were present in this child, this possibility is ruled out.

• Atresia of a part of digestive tract can present as vomiting. Infant with this condition usually present with vomiting since birth as milk cannot pass beyond atretic part. As our patient remained well for 1 ½ months, this possibility is remote.

• Gastroesophageal reflux is very common in this age group because of a lax gastroesophageal sphincter. However, the usual findings in such cases are that these infant, regurgitate some milk, not whole feed and do not lose weight. These infants do not develop lump or other physical findings. Therefore this diagnosis is also unlikely.

• Infectious causes of vomiting in infants also cause other symptoms viz. diarrhea, fever, cough, rash etc. In addition these infants appear sick. So an infection as a possibility is very unlikely in this infant.

• Inborn errors of metabolism can cause recurrent vomiting but usually the infant is alkalotic or acidotic and in addition may also have lethargy, coma or seizures. Presentation of our case does not resemble such an illness.

Our patient has presented with non-bilious vomiting, ? an upper abdominal mass and a visible distension of upper abdomen after feed. These symptoms and signs fit most likely with a diagnosis of Idopathic hypertrophic pyloric stenosis (IHPS).

What is IHPS & what is it’s etiology ?

IHPS is a form of gastric outlet obstruction which occurs is the first few months of life with a frequency of approximately 1:500 births. This is more common in whites, less in blacks and rare in Asians. First-born males are affected four times more than females. Incidence is higher in infants with Blood groups B & O and among infants of mothers with IHPS. It is uncommon in immediate neonatal period, however 10 to 20% infants are symptomatic in first few days and some do well for months.

Hypertrophy of smooth muscles of the pylorus results in gastric out let obstruction. Gastric antrum is unusually long and thickened. Stomach undergoes vigorous peristalsis in order to overcome the outlet obstruction and push the contents forwards. Severity of symptoms is directly related to degree of obstruction.

Etiology remains unknown, however many theories have been proposed. Abnormalities of muscle innervation, elevated gastrin and prostaglandin levels and reduced pyloric nitric oxide synthase have all been implicated. Shima et al demonstrated in pyloric muscle specimens are increased level of epidermal growth factor (EGF), EGF receptors and heparin binding EGF like growth factors, suggesting a local upregulation of the synthesis of EGF and EGF related peptides.

Clinical features of IHPS.

• The hallmark of IHPS is an infant presenting with non-bilious vomiting as an initial symptoms in first few months of life. In severe cases, there is significant weight loss and the infant becomes quickly dehydrated. Emesis usually follows each feeding. Immediately after vomiting, infant is hungry again and wants to feed again. Continued vomitings result in progressive dehydration and hypochloremic metabolic alkalosis as a result of loss of Hydrogen and Chloride ions in vomitus.

• An olive shaped lump and visible gastric peristalsis are usual finding which can make a diagnosis with reasonable certainty on clinical ground alone.

Diagnostic studies to establish diagnosis of IHPS

• Ultrasonography of abdomen can easily identify hypertrophied pylorus and antrum and distended stomach.

• Barium studies can also demonstrate narrow pyloric channel and poor passage of contrast.

• Upper GI endoscopy can be done to establish the diagnosis and to obtain biopsy if some other diagnosis of mass lesion being considered.

Other abnormalities usually are:-

• Hypochloremic metabolic alkalosis and hypokalemia in infants with dehydration.

• 5% of such infants present with hyperbilirubinemia. In a study, it was found that 43.8% of infants with pyloric stenosis and icterus had HGT1A1* 28 mutations- a cause of Gilbert syndrome, compared with 10.7% infants with non-icteric pyloric stenosis (Hua 2005).

How to treat an infant with IHPS

• Initial stabilization with rehydration and correction of electrolyte disturbance.
• Corrective surgeries include:-

1. Surgical pyloromyotomy is treatment of choice. It can now be done laproscopically. In this procedure , muscle is incised longitudinally. This weakens muscle tone and leads to regression of hypertrophy. The mucosa is kept intact to allow rapid healing and early feeding within hours of surgery.

2. Endoscopic Pyloromyotomy- may offer an effective option (Ibarguen-Secchia 2005).

3. Endoscopic Balloon dilatation – is not considered a standard treatment option for infants.

· Erythromycin should be avoided in IHPS because it is a motilin agonist and at

doses used as an antibiotic can result in strong , non propagated contractions that

may lead to hypertrophy of the pylorus.

• Recently use of atropine for IHPS has been described. Intravenous atropine given 6 times a day lead to regressions of hypertrophy in 17 of 19 infants with clinical recovery. Infants who responded to i/v atropine were switched over to oral atropine therapy for a median of 44 days. They were doing well at 6 months of age (Kawahara-2002).

Bibliography

1. Behrman: Pyloric Stenosis and Congenital Anomalies of the Stomach ; Nelson Textbook of Pediatrics 17^th ed.

2. Hermanz-Schulman M. Infantile hypertrophic pyloric stenosis. Radiology 2003;227:319-331.

3. Hua L, Shi D, Bishop PR, et al. The role of UGT1A1*28 mutation in jaundiced infants with hypertrophic pyloric stenosis, Pedatr Res. 2005;58:881-884.

4. Hulka F, Campbell TJ, Campbell JR, Harrison MW. Evolution in the recognition of infantile hypertrophic pyloric stenosis. Pediatrics. 1997;100:E9.

5. Ibarguen-Secchia E. Endoscopic Pyloromyotomy for congenital pyloric stenosis. Gastrointest Endoscopy. 2005;61:598-600.

6. Kawahara H, Imura K, Nishikawa M, et al. Intravenous atropine treatment in infantile hypertrophic pyloric stenosis. Arch Dis Child. 2002;87:71-74.

7. McCollough M, Sharieff GQ. Abdominal surgical emergencies in infants and young children. Emerg Med Clin N Am. 2003;21:909-935.

8. Shima H, Oshshiro K, Puri P. Increased local synthesis of epidermal growth factors in infantile hypertrophic pyloric stenosis. Pediatr Res.2000;47:201-207.