Common intestinal occlusive disorder appearing during the first
weeks of life typically characterized explosive vomiting following feeding,
progressive dehydration, and hypochloremic alkalosis. It is a common
infantile disorder characterized by enlarged pyloric musculature leading to gastric
Infantile Hypertrophic Pyloric Stenosis
1:300 live births with considerable regional variation.
Of the affected infants, 85% are male, with 5.7:1 male-to-female ratio.
Approximately 10% are premature infants.
Mendelian inheritance of pyloric stenosis
cannot be established.
Physiopathologic mechanism is not known, but a
defect in pyloric relaxation (pylorospasm) has been postulated. The
pylorospasm may be the result of a lack of nitric oxide synthase in pyloric
Nonbilious projectile vomiting, palpable pyloric tumor
with visible peristalsis in the upper abdomen in a male infant aged 3 to 8
weeks. Confirmed diagnosis by ultrasonography. Typical laboratory finding is
Dehydration and electrolyte derangement are
common (hypochloremic hypokalemic metabolic alkalosis). Full correction of
the intravascular volume and of chloride and potassium deficits must be done prior to
surgery and may require several days to ensure safe anesthesia and surgery.
Pyloromyotomy (Ramstedt operation) remains the only satisfactory treatment,
with a very low perioperative mortality rate of 0.4 to 3%. Occasional
vomiting occurs postoperatively in more than half of patients, but the value
of graded postoperative feeding regimen is not proven. Associated renal
anomalies may occur in a small percentage of patients.
This is a medical emergency,
not a surgical one.
Ensure that the intravascular volume
and electrolyte deficits are fully corrected prior to anesthesia. Investigations include serum
electrolytes, urea, creatinine, and blood sugar levels. Arterial blood gas
analysis for acid-base values might be indicated in severe cases. Urine
chloride concentration is indicative of the degree of hypokalemia.
All precautions should be taken to
protect against a full stomach. The nasogastric tube should be aspirated
prior to induction of anesthesia. A rapid-sequence induction with
preoxygenation, cricoid pressure, thiopental, and succinylcholine is often
used. Inhalation induction with cricoid pressure applied until orotracheal intubation is achieved
is another alternative. Awake tracheal intubation is not
superior to anesthetized, paralyzed tracheal intubation technique in maintaining adequate
oxygenation and heart rate or in reducing complications. Most important for
the anesthesiologist is to use the airway management technique that he/she
is most comfortable with. It is not time to improvise! Blood loss usually is minimal. The infant should
have his/her trachea extubated fully awake at the end of the procedure in the left lateral position.
Postoperative analgesia can be provided by wound infiltration with local
anesthetics and administration of acetaminophen. Postoperative hypoglycemia
2 to 3 hours after the procedure and respiratory depression have been
described. Consequently, the child should be monitored closely in the
immediate postoperative period.
There are no specific implications
except for a significant increase in susceptibility to opiates.
Bissonnette B, Sullivan PJ: Pyloric stenosis. Can ...