Pyloric Stenosis

Pyloric stenosis is associated with non-bilious vomiting.

Important points

1. Males (especially first born) are affected approximately four times as often as females.

2. The incidence of pyloric stenosis is increased in infants with type B and O blood groups.

3. Pyloric stenosis is associated with other congenital defects like tracheoesophageal fistula.

4. Exogenous administration of prostaglandin E to maintain patency of the ductus arteriosus is associated with pyloric stenosis.

5. Due to continuous vomiting, a progressive loss of fluid, hydrogen ion and chloride, leads to a hypochloremic metabolic alkalosis.

6. The diagnosis is traditionally established by palpating the pyloric mass.

7. After feeding, there may be a visible gastric peristaltic wave that progresses across the abdomen.

8. Ultrasound examination confirms the diagnosis in the majority of cases.

9. Barium studies reveal an elongated pyloric channel, a bulge of the pyloric muscle into the antrum (shoulder sign) and parallel streaks of barium seen in the narrowed channel, producing a “double tract sign”.

10. The surgical procedure of choice is the Ramstedt pyloromyotomy.

Aciduria REF: Bailey and love 25th edition page 79, Fundamentals of Pediatric Surgery by Peter Mattei Page 341, Clinical cases in surgery – Michelle Li, Stephanie C. Lin, Aaron B. Caughey Page 104

“The classical electrolyte abnormality associated withpyloric stenosis is hypokalemic, hypochloremic metabolic alkalosis, presumably due to ongoing gastric acid loss from vomiting. Paradoxical acidurea is sometimes noted (with progressive Hypokalemia and hypovolemia) because the kidney excretes protons in exchange of sodium in an attempt to conserve fluid”

NOTE: Paradoxical aciduria is seen only after body stores of Sodium & Potassium get depleted. Initially there is alkaliuria, not aciduria.

Correction of electrolyte disturbances [Ref. Schwartz 9/e p1425 (8/e, p1486; 7/e, p1728); Rudolph’s Pediatrics, 21st Edition Chapter 17; Bailey & love 25/e p78 (24/e p1033; 23/e, p 899)]

Pyloric stenosis is never a surgical emergency although dehydration and electrolyte abnormalities may present a medical emergency

Fluid resuscitation and correction of electrolyte abnormalities and metabolic alkalosis is essential before surgery. Surgery done is Fredet-Ranzstedt pyloromyotomy. (In it the pyloric mass is split without cutting the mucosa)

More about Hypertrophic Pyloric Stenosis (HPS)

• The musculature of the pylorus and adjacent antrum is grossly hypertrophied, the hypertrophy being maximum in the pylorus itself.
• It occurs in approximately 3 in 1000 live birth and is the most common surgical cause of vomitting in infancy.
• M > F (4 I)*
• Characterstically the first born male child is affected.
• The conditon is most commonly seen at 4 wks after birth ranging from the 3^rd wk to on rare occasion, the 7th. However, 20% of infants are symptomatic from birth, and most are symptomatic within the first 2 months after birth.
• Non-bilious vomiting, becoming increasingly projectile, occurs over several days to weeks. Eventually the infant will develop a nearly complete obstruction by the second to fourth week of life and will not be able to hold down even clear liquids. This invariaby proceeds to severe dehydration if not tlt.
• These infants develop a metabolic alkalosis with severe depletion of potassium and chloride ions.
• ” The diagnosis of pyloric stenosis usually can he made on physical examination by palpation of the typical ‘olive’ in the right upper quadrant and the presence of visible gastric waves on the abdomen.
• When the olive cannot be palpated, ultrasound in experienced hands will diagnose the condition accurately in 95 percent of pts.” – Schwartz.
• Also know
• Administration of erythromycin in early infancy has been linked to the subsequent development of HPS.
• Jaundice may be seen in HPS, although cause is not clear.

Hypokalemic alkalosis [Ref^. Schwartz 9/e p1426 (8/e, p1486; 7/e, p 1728); Maingot’s 10/e, p 2067; Bailey & love, 24/e, p 1033 (23/e, p 899)]

Repeat from Nov 09

• Repetitive vomiting leads to hypochloremic, hypokalemic metabolic alkalosis. The urine is alkaline initially but eventually it becomes acidic (paradoxical aciduria)
• Cause of paradoxical aciduria

– Initially the kidney compensate for metabolic alkalosis by reabsorbing hydrogen and chloride ions in exchange for sodium, potassium and bicarbonate. But gradually as the body stores of sodium and especially potassium become depleted, kidney starts retaining these ions in exchange of hydrogen ions. thus the urine becomes acidic and metabolic alkaline state is further aggravated.

Hypertrophic Pyloric Stenosis (HPS)

• The musculature of the pylorus and adjacent antrum is grossly hypertrophied, the hypertrophy being maximum in the pylorus itself.
• It occurs in approximately 3 in 1000 live birth and is the most common surgical cause of vomitting in infancy.
• M > F (4 : 1)*
• Characterstically the first born male child is affected.
• The conditon is most commonly seen at 4 wks after birth ranging from the 3^rd wk to on rare occasion, the 7th. However. 20% of infants are symptomatic from birth, and most are symptomatic within the first 2 months after birth.
• Non-bilious vomiting, becoming increasingly projectile, occurs over several days to weeks. Eventually the infant will develop a nearly complete obstruction by the second to fourth week of life and will not be able to hold down even clear liquids. This invariaby proceeds to severe dehydration if not t/t.
• These infants develop a metabolic alkalosis with severe depletion of potassium and chloride ions.
• ” The diagnosis of pyloric stenosis usually can be made on physical examination by palpation of the typical ‘olive’ in the right upper quadrant and the presence of visible gastric waves on the abdomen.
• When the olive cannot be palpated, ultrasound in experienced hands will diagnose the condition accurately in 95 percent of pts.” – Schwartz.
• Treatment

– Pyloric stenosis is never a surgical emergency although dehydration and electrolyte

– abnormalities may present a medical emergency

– Fluid resuscitation and correction of electrolyte abnormalities and metabolic alkalosis is essential before surgery.

– Surgery : Fredet-Ramstedt pyloromyotomy. (In it the pyloric mass is split without cutting the mucosa)

• Also know
• Administration of erythromycin in early infancy has been linked to the subsequent development of HPS.
• Jaundice may be seen in HPS, although cause is not clear.

Metabolic alkalosis with paradoxical aciduria 1Ref Schwartz 9/e p1426 (8/e, p 1486): Maingot’s. 10/e, p 2067]

• Repetitive vomiting leads to hypochloremic, hypokalemic metabolic alkalosis. The urine is alkaline initially but eventually it becomes acidic (paradoxical aciduria)
• Cause of paradoxical aciduria

– Initially the kidney compensate for metabolic alkalosis by reabsorbing hydrogen and chloride ions in exchange for sodium, potassium and bicarbonate. But gradually as the body stores of sodium and especially potassium become depleted, kidney starts retaining these ions in exchange of hydrogen ions. thus the urine becomes acidic and metabolic alkaline state is further aggravated.

Hypochloremic hypokalemic metabolic alkalosis [Ref: Schwartz 9/e p1426 (8/e, p 1486); Maingot’s 10/e. p 2067 Bailey & love 25/e p78 (24/e p1033; 23/e p899)]

Repeated vomiting leads to hypochloremic, hypokalemic metabolic alkalosis. The urine is alkaline initially but eventually it becomes acidic (paradoxical aciduria)

• Cause of paradoxical aciduria

– Initially the kidney compensate for metabolic alkalosis by reabsorbing hydrogen and chloride ions in exchange for sodium, potassium and bicarbonate. But gradually as the body stores of sodium and especially potassium become depleted, kidney starts retaining these ions in exchange of hydrogen ions. thus the urine becomes acidic and metabolic alkaline state is further aggravated

Erythromycin

Due to vomiting of the gastric contents, infants develop a hypochloremic, hypokalemic metabolic alkalosis.

The urine pH is high initially but eventually drops because hydrogen ions are preferentially exchanged for sodium ions in the distal tubule of the kidney as the hypochloremia becomes severe.

Ref: Schwartz’s Principles of Surgery, 9th Edition, Chapter 39

Hypochloremic alkalosis develops due to vomiting.

Ref: Text Book of Pediatrics By Nelson, 19th Edition, Page 1274; Bailey and Love’s Short Practice of Surgery, 22nd Edition, Page 674 and 23rd Edition, Page 899.

Diagnosis of congenital hypertrophic pyloric stenosis can be made with a test feed, which produces a characteristic peristaltic wave which is seen to pass across the upper abdomen.

Palpation of the abdomen at that time reveals the lump.

Ref: Bailey and Love’s Short Practice of Surgery, 24th Edition, Page 1033.

Pyloric stenosis is never a surgical emergency although dehydration and electrolyte abnormalities may present as medical emergency.

Treatment of dehydration and electrolyte imbalance is mandatory before surgical treatment, even if it takes 24–48 hours.

Fredet-Ramstedt pyloromyotomy is the treatment of choice and consist of incision down to the mucosa along the length of pylorus.

In hypertrophic pyloric stenosis, the musculature of the pylorus and adjacent antrum is grossly hypertrophied, the hypertrophy being maximum in the pylorus itself.

• It occur in approximately 3 in 1000 live births and is the most common surgical cause of vomiting in infancy. Males are affected more commonly as compared to females and characteristically the first born male child is affected.
• The condition is most commonly seen at 4 week after birth ranging from 3rd week to 7th week in rare occasions. Only 20% of infants are symptomatic from birth.
• The diagnosis of pyloric stenosis usually can be made on clinical examination by palpation of the typical “olive” in the upper quadrant and the presence of visible gastric waves on the abdomen. In healthy infants when palpation is difficult, feeding can help in the diagnosis. After feeding peristalsis waves may be visible. After the infants vomits, the abdominal musculature is more relaxed and the mass is easier to palpate.
• “When the olive cannot be palpated, USG can diagnose the condition accurately in 95% of patients”.
• Surgical operation done for hypertrophic pyloric stenosis is Fredet- Ramstedt pyloromyotomy. (In it the pyloric mass is split without cutting the mucosa)

Ref: Schwartz 9/e, Page 1425; Bailey & Love 25/e, Page 78; Rudolph’s Pediatrics 21/e, Chapter 17

Metabolic alkalosis, not acidosis is seen in hypertrophic pyloric stenosis due to loss of hydrogen ions in repeated vomiting.
 

Ref: Schwartz 9/e, Page 1426 ; Maingot’s 10/e, Page 2067.

The vomiting in pyloric stenosis may or may not be projectile, however non bilious vomiting after feed is the characteristic feature.
In about 10-15% of infants vomiting may contain blood.

This bleeding is due to reflux esophagitis, a common association with hypertrophic pyloric stenosis.

Also know:

Associated anomalies occur in 6-20% of patients.

These includes esophageal atresia, Hirschsprung’s disease, anorectal anomalies, and intestinal malformation.

Ref: Nelson 17/e, Page 1229.

Hypertrophic pyloric stenosis is more common in males. Male : female incidence is 4:1.

• Peristalsis is seen from left to right across the upper abdomen.
• Retention vomiting means vomiting due to any mechanical obstruction occurring usually hours after ingestion of a meal. In hypertrophic pyloric stenosis the vomiting usually occur 10 to 30 min after the feed.

Laboratory Findings of congenital hypertrophic pyloric stenosis:

Infants with HPS present with nonbilious vomiting that becomes increasingly projectile over the course of several days to weeks.

Infants with HPS develop a hypochloremic, hypokalemic metabolic alkalosis.

Dehydration causes elevated hemoglobin and hematocrit. Mild unconjugated bilirubinemia occurs in 2%–5% of cases.

The urine pH is high initially but eventually drops because hydrogen ions are preferentially exchanged for sodium ions in the distal tubule of the kidney as the hypochloremia becomes severe. 

Infants with hypertrophic pyloric stenosis (HPS) present with nonbilious vomiting that becomes increasingly projectile over the course of several days to weeks.

The diagnosis of pyloric stenosis usually can be made on physical examination by palpation of the typical “olive” in the right upper quadrant and the presence of visible gastric waves on the abdomen.

When the olive cannot be palpated, ultrasonography can diagnose the condition accurately in 95% of patients.

Criteria for ultrasonographic diagnosis include a channel length of >16 mm and pyloric thickness of >4 mm.

Ramstedt pyloromyotomy is the treatment of choice and consists of incision down to the mucosa along the pyloric length.

Neonates with congenital pyloric stenosis develop projectile postprandial vomiting between 2 and 4 weeks of age but may start as late as 12 weeks.

Due to this vomiting they develop hypokalemic hypochloremic metabolic alkalosis. 

Hypertrophic pyloric stenosis (HPS) is postnatal muscular hypertrophy of the pylorus.

HPS occurs in approximately 1–8 per 1000 births and originally was believed to occur in first-born males between 3 and 6 weeks of age.

Ans. is ‘b’ i.e., Erythromycin

o Maternal and infant use of erythromycin and other macrolide antibiotics have been reported as risk factors for infantile hypertrophic pyloric stenosis (IHPS).

Ans. is ‘a’ i.e., Pyloric stenosis 

Ans. is ‘c’ i.e., Around 2 weeks after birth

• The symptoms vomiting usually starts after 3 weeks of age but symptoms may develop as early as 1^st week of life and as late as 5 months of life.  – Nelson
  

Congenital hypertrophic pyloric stenosis

• Hypertrophic pyloric stenosis is the commonest surgical disorder of the stomach during infancy.
• Pylorus is thickened and elongated and its lumen is narrowed due to hypertrophy of circular muscle fibers of pylorus.
• More common in boys.

o More common in infants of blood group ‘B’ and ‘O’.

o Associated congenital defects are —> Tracheoesophageal fistula and hypoplasia or agenesis of inferior labial frenulum.

o May be associated with Turner syndrome, Trisomy 18.

o Symptoms are not present at birth.

The vomiting usually starts after 3 weeks of age.

Ans. is ‘a’ i.e., Hypochloremic alkalosis

Clinical manifestations of congenital hypertrophic pyloric stenosis

• Pyloric stenosis is usually not present at birth.

o Nonbillous vomiting is the initial symptoms of pyloric stenosis.

• The vomiting usually starts after 3 weeks of age, but symptoms may develop as early as the 1st week of life and as late as the 5 months of life.

o Emesis may follow each feeding, or it may be intermittent.

o After vomiting, the infant is hungry and wants to feed again.

• Due to vomiting, there is progressive loss of —> Fluid, Hydrogen ion, Chlorides

This results in hypochloremic metabolic alkalosis.

o Serum potassium levels are usually maintained, but there may be a total body potassium deficit.

o Jaundice (unconjugated bilirubin) is associated with a decreased level of glucuronyl transferase in 5% of patients.

Ans. is ‘c’ i.e., Pyloric stenosis

Diagnosis of congenital hypertrophic pyloric stenosis

o History of vomiting without bile (nonbilious vomiting).

o Physical examination ‑

i)        Palpable mass in the epigastrium

ii)          After feeding, visible gastric peristatic wave that progresses across the abdomen.

• USG confirm the diagnosis

 Criteria —> Pyloric thickness > 4 mm or an overall pyloric length > 14 mm.

o Contrast studies ‑

i) Shoulder sign            A bulge of the pyloric muscle into the antrum.

ii) Double tract sign -> Parallel streaks of barium in the narrowed channel.

iii) Elongated pyloric channel.

• So the boy is having pyloric stenosis. The only problem is age of boy i.e 6 yrs. The hypertrophic pyloric stenosis which we know of, makes its clinical presentation in early infancy (3^rd to 6^th weeks of life)

o But the problem in solved once you know that there is a similar disease in adults – Hypertrophic pyloric stenosis of adults. (Bailey & Love, 22^th/e, p 675).

Ans. is ‘b’ i.e., Hypertrophic pyloric stenosis

Ans. is ‘b’ i.e., Diarrhea

Diarrhea does not occur in pyloric stenosis, there is vomiting.

Treatment of congenital hvpertrophic pyloric stenosis

o The surgical procedure of choice is Pyloromyotomy.

o The traditional Ramstedt procedure is performed through a short transverse skin incision.

o Other methods are —>  i) Atropine therapy         ii) Endoscopic ballon dilatation

Ans. is ‘b’ i.e., Serum protein

o Normal calcium level is 8.9-10.1 nig/dl (total calcium).

• Slightly less than half of the total serum calcium exists in free or ionized form. Remainder is bound to protein (mostly albumin). Ionized calcium is relevant for cell fuction.

“There are few clinical situations in which the total calcium is not an adequate surrogate for the ionized Ca++ concentration. The most common and severe problem is the presence of hypoalbuminemia”.

o Each 1 gm/dl of albumin in the serum binds about 0.8 mg/dl of calcium.

o A low total calcium concentration may be normal in a patient with significant hypoalbuminemia.

o Now, it is clear from above that a low level of serum protein lowers the total plasma calcium but not the ionized calcium, So, before treating hypocalcemia, measure the serum protein level.

D i.e. High gastric residues

Ultrasonography is the investigation of choice to confirm diagnose of hypertrophic pyloric stenosis with accuracy > 95% (approching almost 100%)Q. USG visualizes thickened and elongated pyloric canalQ. USG criteria for diagnosis include >16 mm pyloric length and >4mm pyloric muscle wall thicknessQ. Gastric residues are low b/o recurrent emesisQ.

The hypertrophied muscle project into gastric antrum. There is a constant assocaition with hyperplasia of antral mucosa.

– It is a common developmental condition (3 in 1000 live births), affecting boys more than girls (M:F = 4/5 :1)Q. There is a familial predisposition.

Affected infant usually presents between 2-6 weeks of age, with projectile non bilious vomiting (D/D include pylorospasm, hiatus hernia & preampullary duodenal stenosis). HPS is never seen beyond 3 months of age except in premature infants in whom enteral feeding has been started late.

– Despite the recurrent vomiting, child has a voracious appetite that leads to cycle of feeding & vomiting that invariably results in severe dehydration, hypochloremic­hypokalemic metabolic alkalosis with eventual decrease in urine PH

Diagnosis can be made clinically on the basis of history and palpation of an olive mass in the subhepatic region (right upper quadrant) and presence of visible gastric (antral peristaltic) wavesQ.

Diagnosis of the HPS can be established (confirmed) by either USG (method of choice)Q or barium study.

Pyloric signs include

1. String sign, is passing of thin barium streak through narrowed & elongated pyloric canal. It is most specific sign.
2. Pyloric canal is almost always curved upward posteriorly
3. Double/triple track sign or double string sign is produced by barium caught between crowded mucosal folds in pyloric canal overlying the hypertrophied muscle & parallel lines may be seen.
4. Diamond sign or twining recess is transient triangular tent like cleft/niche in midportion of pyloric canal with apex pointing inferiorly secondary to mucosl bulging between two seperated hypertrophied muscles on the greater curvature side of pyloric canal.
5. Apple core lesion, pyloric segment looks like apple core with under cutting of distal antral & proximal duodenal bulb.

Antral signs include

1. Pyloric teat sign is out pouching along lesser curvature b/o disruption of antral peristalsis.
2. Shoulder sign is impression of hypertrophied muscle on distended gastric antrum.
3. Antral beaking is noted as thick muscle narrows the barium column as it enters the pyloric canal.
4. Olive pit sign is impression of pyloric muscle upon antrum seen as tiny amount of barium at orifice.
5. Caterpillar sign is gastric hyperperistaltic waves.
6. Kirklin mushroom sign is indentation of base of duodenal bulb.

Ultrasonography (USG)

It is the method of choice to directly visualize the HPS. The examination is typically performed with a high frequency linear transducer (>5MH₂) (as the pylorus & duodenum are very superficial in an infant) with infant in right posterior oblique position (to move any fluid present in fundus into antral & pylorus region. The stomach should not be emptied prior to examination as this makes identification of antropyloric area difficult. If fluid is administered to make visualization better, it should be removed at the end of examination to prevent vomiting/aspiration. Features include)

1. Doughnut appearance/Bull’s eye or target sign is hypoechoic (black) ring of hypertrophied pyloric muscle around echogenic (reflective) mucosa & submucosa on cross /transverse section images.
2. Shoulder/cervix-sign is indentation of hypertrophied muscle on fluid filled gastric antrum on longitudinal section.
3. Antral nipple sign is protrusion (evagination) of redundant pyloric mucosa into distended antrum.
4. Double tract sign refers to fluid trapped in center of elongated pyloric canal is seen as two sonolucent streaks in center.
5. Exaggerated peristattic waves & delayed gastric emptying of fluid into duodenum
6. Elongated pylorus with thickened muscles (most specific) is indicated by Length > 15mm, muscle thickness >3mm and transverse serosa to serosa diameter >15mm is consistent with HPS. At least 2 values should be positive. A thickness <2mm is unequivocally normal and between 2 & 2.9mm is abnormal but non specific & can be seen in pylorospasm & gastritis also. Though pylorospasm is transient & mostly resolve in 30 minutes and there is considerable variation in measurement or image appearance with time during thickness. (GI imaging) Pyloric canal length  16-17min, muscle wall thickness 2 3-3.2mmQ, pyloric volume > 1.4cm3, pyloric transverse diameter 13mm with pyloric canal closed and length (mm) + 3.64x + 3.64 x thickness (mm) >25 (Wolfgang) Pyloric length >16mm & muscle thickness > 4mm (Swartz)

A i.e. Single bubble appearance

B i.e. Hypertrophic Pyloric Stenosis

Meconium ileus is small bowel obstruction secondary to sticky tenacious meconium d/ t deficiency of pancreatic secretions. It is the earliest clinical manifestation of cystic fibrosis. It usually presents with abdominal distension, bilious vomiting and failure to pass meconium within 48 hours. It has Bubbly/Froathy/Soap BubbleQ/Apple sauce appearanceQ d/t admixture of gas with meconium.

Barium meal (swallow) appearance of Oesophageal Disorders

Ans is ‘d’ ie USG is diagnostic test

Hypertrophic Pyloric Stenosis (HPS)

• The musculature of the pylorus and adjacent antrum is grossly hypertrophied, the hypertrophy being maximum in the pylorus itself.
• It occurs in approximately 3 in 1000 live birth and is the most common surgical cause of vomitting in infancy.
• M > F (4 : 1)*
• Characterstically the first born male child is affected.
• The conditon is most commonly seen at 4 wks after birth ranging from the 3^rd wk to on rare occasion, the 7th. However, 20% of infants are symptomatic from birth, and most are symptomatic within the first 2 months after birth.
• Non-bilious vomiting, becoming increasingly projectile, occurs over several days to weeks. Eventually the infant will develop a nearly complete obstruction by the second to fourth week of life and will not be able to hold down even clear liquids. This invariably proceeds to severe dehydration if not t/t.
• These infants develop a metabolic alkalosis with severe depletion of potassium and chloride ions.
• ” The diagnosis of pyloric stenosis usually can be made on physical examination by palpation of the typical ‘olive’ in the right upper quadrant and the presence of visible gastric waves on the abdomen.
• When the olive cannot be palpated, ultrasound in experienced hands will diagnose the condition accurately in 95 percent of pts.” – Schwartz.
• Treatment

–  Pyloric stenosis is never a surgical emergency although dehydration and electrolyte abnormalities may present a medical emergency

Fluid resuscitation and correction of electrolyte abnormalities and metabolic alkalosis is essential before surgery.

– Surgery : Fredet-Ramstedt pyloromyotomy. (In it the pyloric mass is split without cutting the mucosa)

• Also know
• Administration of erythromycin in early infancy has been linked to the subsequent development of HPS.
• Jaundice may be seen in HPS, although cause is not clear.

Ans is ‘d’ i.e. High gastric residue 

Ultrasound is the investigation of choice. It can diagnose HPS accurately in 95% of patients. Criteria for ultrasound diagnosis of HPS:

a.     channel length of > 16mm

b.  pyloric thickness of > 4mm

“The diagnosis of pyloric stenosis usually can be made on physical examination by palpation of the typical “olive” in the right upper quadrant and the presence of visible gastric waves on the abdomen. When the olive cannot be palpated, ultrasonography can diagnose the condition accurately in 95% of patients. Criteria for ultrasonographic diagnosis include a channel length of >16 mm and pyloric thickness of >4 mm. “- Schwartz

Ans. is ‘b’ i.e., The pyloric tumor is best felt during feeding

Option (a)

– HPS classically presents in a first born male child between 3 and 6 weeks of age. However, children outside this age range also are commonly seen, and the disease is not restricted to either males or first borne children.

Option (d)

–  After vomitting the child has voracious appetite, that leads to a cycle of feeding and vomiting.

Option (c)

“Greater awareness of pyloric stenosis has led to earlier identification of patients with fewer instances of chronic malnutrition and severe dehydration” -Nelson I7/e

Option (b)

– The diagnosis of pyloric stenosis is usually made by palpation – of the typical olive shaped hard pyloric mass located in right upper quadrant. In healthy infants when palpation is difficult, feeding can help in the diagnosis. After feeding gastric peristalsis waves may be visible. After the infant vomits, the abdominal musculature is more relaxed and the mass is easier to palpate. Sedation can also be used to facilitate examination but is usually unnecessary. In cases of doubt ultrasound can confirm the diagnosis.

Ans is ‘d’ i.e. Congenital hypertrophic pyloric stenosis 

Ans. is ‘c’ i.e., Metabolic alkalosis with paradoxical aciduria 

• Repetitive vomiting leads to hypochloremic, hypokalemic metabolic alkalosis. The urine is alkaline initially but eventually it becomes acidic (paradoxical aciduria)
• Cause of paradoxical aciduria

– Initially the kidney compensate for metabolic alkalosis by reabsorbing hydrogen and chloride ions in exchange for sodium, potassium and bicarbonate. But gradually as the body stores of sodium and especially potassium become depleted, kidney starts retaining these ions in exchange of hydrogen ions. thus the urine becomes acidic and metabolic alkaline state is further aggravated.

Ans. is ‘b’ i.e., Hypochloremic alkalosis 

Heller’s myotomy is the surgery for Achlasia Cardia, not HPS.

Ans. is ‘d’ i.e. metabolic acidosis 

• Metabolic alkalosis, not acidosis is seen in hypertrophic pyloric stenosis due to loss of hydrogen ions in repeated vomiting.
• As the hypertrophic pyloric stenosis progresses, complete gastric outlet obstruction occurs and not even clear fludis are able to pass. This leads to constipation or passage of small green “starvation” stools.
• Rapid weight loss is seen if the condition is not detected early and treated.

Answer ‘b’ i.e. Non-bilious vomitting ; ‘c’ i.e. Projectile vomitting 

• The vomiting may or may not be projectile, however non-bilious vomiting after feed is the characteristic feature.
• In about 10-15% of infants vomitus may contain blood. This bleeding is due to reflux esophagitis, a common association with hypertrophic pyloric stenosis.
• Also know
• Associated anomalies occur in 6-20% of pts. This includes esophageal atresia, Hirshprung’s disease, anorectal anomalies, and intestinal malrotation.

Ans. is ‘a’ i.e. hypokalemic alkalosis 

• Gastric peristalsis is seen passing from left to right across the upper abdomen.
• Retention vomiting means vomiting due to any mechanical obstruction occurring usually hours after ingestion of a meal. In hypertrophic pyloric stenosis the vomiting usually occurs 10 to 30 min. after the feed (Though in neglected undiagnosed cases the stomach becomes dilated and the vomiting becomes regurgitant in type occurring only once or twice every 24 hrs)

Answer ‘a’ i.e. Hypokalemia; ‘b’ i.e. Hyponatremia

Ans is ‘a’ ie. U/S is not useful for diagnosis

• Option A is absolutely wrong statement as U/S is the inv. of choice for hypertrophic pyloric stenosis.
• Already explained in Previous question.

Ans is ‘b’ i.e. Hypokalemic alkalosis 

Ans is ‘c’ i.e. Correction of electrolyte disturbances 

Pyloric stenosis is never a surgical emergency although dehydration and electrolyte abnormalities may present a medical emergency

Fluid resuscitation and correction of electrolyte abnormalities and metabolic alkalosis is essential before surgery. Surgery done is Fredet-Ramstedt pyloromyotomy. (In it the pyloric mass is split without cutting the mucosa)

Ans is ‘d’ ie Pyloric stenosis

• This is a typical picture of pyloric stenosis

a)       Infant presenting in 4th week

b)       Non-bilious vomitting.

c)       With constipation and wt. loss.

• Lets see other options.
• Esophageal atresia

a)     Infant presents soon after birth with complaints of regurgitation of milk, saliva pours almost continuously from its mouth. Attempt to feed are met with ‘Spitting up’ or frank vomitting.

b)     Persistence in feeding may produce aspiration, choking and respiratory distress.

c)       Diagnosis can be confirmed by passing a rubber catheter into the esophagus through the mouth which will encounter an obstruction.

Thus point (a) helps in ruling out oesophageal atresia.

• Choledochal cyst

a)       Presentation is not so early in infancy. Though its a congenital anomaly only 1/2 the cases present before 20yrs. of age and only 1/3 present in the 1st decade of life.

b)       Classical triad of symptoms —>            

i)        Obstructive jaundice *

ii)       Upper abdominal pain*

iii)     Fever*

(c) A palpable epigastric mass may be discovered.

• Beal atresia

a)       Vomitting will be bilious

b)       Infant presents in the 1st week of life.

Ans. is ‘b’ i.e., Circular muscle fibres 

Ans is ‘a’ i.e. Congenital hypertrophic pyloric stenosis

Biochemical abnormality in congenital hypertrophic pyloric stenosis is a regular feature of AIIMS and AI examinations it has been repeated several times.

• The biochemical abnormalities seen are:

( I ) Hypokalemia               (3) Alkalosis and

(2) Hypochloremia              (4) Paradoxical aciduria

Ans. is ‘a’ i.e. Congenital pyloric stenosis & ‘b’ i.e. Vomiting 

Ans. is ‘b’ i.e., Pyloric stenosis 

Ans. is ‘d’ i.e., Congenital pyloric stenosis 

Answer is B (The pyloric tumor is best felt during feeding)

• First born male child is characteristically most commonly affected
• It is four times more common in males as in females .
• The condition does not present at birth. It is most commonly seen 4 weeks after birth

Presentation

• Vomiting is the presenting symptom (child vomits milk and no bile is presentQ)
• Immediately after vomiting the child is hungry i.e. loss of appetite does not occur.
• Weight loss is striking and rapidly the infant becomes emaciated and dehydrated.

However, greater awareness of pyloric stenosis has led to earlier identification of patients and hence with fewer incidences of chronic malnutrition and severe dehydration – Nelson 10th/1130

• The diagnosis is usually made with a test feed : In this the baby is fed with the bottle by a nurse or mother and surgeon :

– palpates the abdomen with a warm hand to detect the lump

– observes the characteristic peristatic waves pass across the upper abdomen.

• Pathologicall^y musculature of pylorus adjacent to antrum is grossly hypertrophied
• Ultrasonographv is the investigation of choice
• Hyperchloremic alkalosis is common and following diagnosis first concern is to correct metabolic abnormalities -child is rehydrated with dextrose saline & potassiumQ
• Treatment of choice Ramsted’s operation – ‘Pyloromyotomy’

Answer is B (Hypochloremic alkalosis) :

The vomiting of hydrochloric acid results in hypochloremia and alkalosis i.e. hypochloremic alkalosisQ

• Characteristically first born male infant^Qis most commonly affected (Males > Females) Q
• Onset of symptoms, has its, peak incidence between the third & sixth weeks of life^Q and it is almost never present at birth Q.
• Most common presenting symptom is vomiting^e & accounts for the hypochloremic alkalosis.e
• The procedure of choice is a Halsted’s operation^Q & not a Heller’s myotomy.

– Heller myotomy is the procedure of choice for acha/asia cardia.Q

Ans. A i.e. Single bubble appearance

Ans. C i.e. Metabolic alkalosis with paradoxical aciduria

Ans. A i.e. Presence of palpable lump

Ans. B i.e. Diarrhoea

Congenital hypertrophic pyloric stenosis

• Presents about 4 weeks after birth,
• Weight loss,
• Hypochloremic alkalosis,
• Fluid of choice: Isotonic normal saline

Ans. A: Hypokalemic hyponatremic alkalosis

Ans. A: Hypokalemic hyponatremic alkalosis

Because of dehydration, a phase of sodium retention follows and potassium and hydrogen are excreted in preference. This results in the urine becoming paradoxically acidic and hypokalemia ensues

Ans. B: Dilutional thrombocytopenia

Massive blood transfusion causes dilutional coagulopathies especially dilutional thrombocytopenia (stored blood has no platelets and concentration of other clotting factors is also very less)

Ans. A i.e. Single bubble appearance

Ans. All of the above