Pyloric Stenosis

Question 1

Pyloric Stenosis

Answer 1

Pyloric stenosis is gastric outlet obstruction due to hypertrophy
of the pyloric muscle. It occurs in about 1 in 300 live births and
affects male infants four times more than females. Pyloric
stenosis can also affect adults and is usually due to scarring
from chronic peptic ulceration.
Hines RL, Marschall KE. Anesthesia & Co-Existing Diseases.
6th ed. Philadelphia, PA: Elsevier-Saunders; 2012: 600.

Question 2

What are the symptoms of pyloric stenosis?

Answer 2

In infants, pyloric stenosis typically manifests as projectile
vomiting that appears between 2 and 5 weeks of age.
Electrolyte disturbances depend on the amount of vomiting
involved.
Hines RL, Marschall KE. Anesthesia & Co-Existing Diseases.
6th ed. Philadelphia, PA: Elsevier-Saunders; 2012: 600-601.

Question 3

How is pyloric stenosis typically diagnosed?

Answer 3

Although some clinicians still rely on barium swallow studies,
abdominal ultrasound is now the most commonly used
diagnostic aid.
Hines RL, Marschall KE. Anesthesia & Co-Existing Diseases.
6th ed. Philadelphia, PA: Elsevier-Saunders; 2012: 600-601.

Question 4

How is pyloric stenosis treated?

Answer 4

The definitive treatment for pyloric stenosis is surgical
pyloromyotomy.
Hines RL, Marschall KE. Anesthesia & Co-Existing Diseases.
6th ed. Philadelphia, PA: Elsevier-Saunders; 2012: 601.

Question 5

What acid-base abnormality is most commonly

associated with pyloric stenosis?

Answer 5

Metabolic alkalosis
Hines RL, Marschall KE. Anesthesia & Co-Existing Diseases.
6th ed. Philadelphia, PA: Elsevier-Saunders; 2012: 600-601.

Question 6

What are the primary anesthetic considerations for

the patient undergoing surgery for pyloric stenosis?

Answer 6

Protracted vomiting results in dehydration and electrolyte
disturbances. Because the surgery is not considered an
emergency, the fluid and electrolyte disorders should be
corrected prior to surgery. All patients with pyloric stenosis are
considered to have a full stomach. Barium studies worsen the
risk for pulmonary aspiration. Emptying the stomach via an
orogastric catheter is prudent prior to induction of anesthesia.
Stoelting RK, Dierdorf SF. Anesthesia & Co-Existing Diseases.
5th ed. New York, NY: Churchill-Livingston; 2008: 600.

Question 7

What electrolyte disturbances are associated with

pyloric stenosis?

Answer 7

Chronic vomiting is associated with loss of sodium, potassium,
chloride, and hydrogen ions that are in the gastric fluid. The
kidneys attempt to excrete potassium to compensate for the
loss of hydrogen ions. Sodium and bicarbonate are excreted in
the urine in order to compensate for the loss of chloride.
Hypochloremia, hypokalemia, hyponatremia, hypocalcemia,
hypovolemia and metabolic alkalosis result.
Hines RL, Marschall KE. Anesthesia & Co-Existing Diseases.
6th ed. Philadelphia, PA: Elsevier-Saunders; 2012: 600-601.

Question 8

What postoperative anesthetic complication is
common in infants after surgery to treat pyloric
stenosis?

Answer 8

Postoperative ventilatory depression is common. It is thought
this may be due to alkalosis of the cerebrospinal fluid. Because
of this potential complication, these patients must be fully
awake and responsive prior to tracheal extubation.
Hines RL, Marschall KE. Anesthesia & Co-Existing Diseases.
6th ed. Philadelphia, PA: Elsevier-Saunders; 2012: 601.