MedCosmos Surgery
Surgery Lecture Notes, Books, MCQ and Good Articles
Saturday, September 6, 2008
Pediatric Surgery MCQ
1. Polyhydramnios is frequently observed in all of the following
conditions except:
A. Esophageal atresia.
B. Duodenal atresia.
C. Pyloric atresia.
D. Hirschsprung's disease.
E. Congenital diaphragmatic hernia.
Answer: D
DISCUSSION: Polyhydramnios is defined as excessive amounts of fluid
(>2000 ml.) in the amniotic sac during pregnancy. The amniotic pool is
a dynamic pool with a relatively rapid turnover. In the fourth
intrauterine month the fetus begins to swallow amniotic fluid (25% to
40% of the volume) and absorbs the fluid from the upper
gastrointestinal tract. The fluid is urinated back out into the amniotic
pool by the fetal kidneys and a functioning bladder. Although there
are maternal causes of polyhydramnios (cardiac failure, renal failure,
other causes of fluid retention) and some idiopathic cases, many
instances are related to the presence of fetal anomalies. These
include central nervous system problems such as anencephaly, which
prevents normal swallowing, and any high alimentary tract
obstruction that blocks the passage of the amniotic fluid and prevents
its absorption (including esophageal atresia, pyloric atresia, and
duodenal atresia). In addition, infants with congenital diaphragmatic
hernia have obstructions due to herniation of the stomach and bowel
into the thoracic cavity. This is a poor prognostic finding in these
infants. Hirschsprung's disease is a form of low intestinal obstruction,
and therefore an adequate length of proximal patent intestine is
available for absorption of the swallowed amniotic fluid and
polyhydramnios is usually not present.
2. Which of the following statements about Hirschsprung's disease
is/are true?
,A. There are no ganglion cells seen in Auerbach's plexus.
B. There is an increased incidence of Down syndrome.
C. It is more common in girls.
D. It may be associated with enterocolitis.
E. It may involve the small intestine.
Answer: ABDE
DISCUSSION: The affected segment of bowel in patients with
Hirschsprung's disease has hypertrophic nerves in Auerbach's
intermyenteric plexus, but no ganglion cells are present. Ganglion
cells are also absent in Meissner's submucosal plexus. Some 3% to 5%
of babies with Hirschsprung's disease also have Down syndrome.
Hirschsprung's disease should be suspected in infants with Down
syndrome that manifest evidence of abdominal distension and
constipation. Hirschsprung's disease is much more common in boys
(4:1). The enterocolitis of Hirschsprung's disease is a condition
associated with delay in diagnosis, low bowel obstruction, severe
abdominal distension, explosive diarrhea, and colonic mucosal
ulceration. The course may be fulminant. This complication is
associated with increased morbidity and mortality. Bacterial
translocation and endotoxemia may complicate the condition.
Treatment includes nasogastric suction, intravenous fluids, antibiotics,
and rectal tube decompression of the obstructed rectosigmoid
segment. In approximately 10% of cases aganglionosis extends into
varying lengths of small bowel. In rare instances, the entire small
bowel and colon may be aganglionic.
3. Which of the following statements is/are true of infants with
gastroschisis?
A. It is associated with malrotation.
B. There is a high incidence of associated anomalies.
C. There is prolonged adynamic ileus following repair.
D. It is complicated by intestinal atresia in 10% to 12% of cases.
E. It is associated with chromosomal syndromes.
Answer: ACD
DISCUSSION: Because of intrauterine herniation of bowel to an extra-
abdominal location, normal intestinal rotation and fixation do not
occur. Most infants with gastroschisis have nonrotation. In contrast to
infants with omphalocele, in which a high incidence of associated
anomalies coexist, babies with gastroschisis have little else wrong.
Following repair of the abdominal wall defect, infants with
gastroschisis have a long delay in return of intestinal function. They
usually require total parenteral nutrition to supply adequate caloric
intake until gut function returns (3 to 4 weeks). Intestinal atresia is
observed in 10% to 12% of neonates with gastroschisis. This is caused
,by bowel ischemia due to intrauterine volvulus or compression of the
herniated viscera in a small, tight defect in the abdominal wall.
Although infants with omphalocele frequently have chromosomal
syndromes such as Beckwith syndrome or trisomy 13 to 15 or 16 to
18, babies with gastroschisis do not.
4. In neonates with congenital diaphragmatic hernia, which of the
following statements is true?
A. The defect is more common on the right side.
B. Survival is significantly improved by administration of pulmonary
vasodilators.
C. An oxygen index of 20 is an indication for extracorporeal
membrane oxygenation (ECMO).
D. Oligohydramnios is a frequent occurrence.
E. Mortality is the result of pulmonary hypoplasia.
Answer: E
DISCUSSION: In infants with congenital diaphragmatic hernia the
defect is more common on the left side (85%). Polyhydramnios is
sometimes noticed and is a poor prognostic indicator of survival.
Oligohydramnios is noted in fetuses with urinary tract obstruction and
may be associated with pulmonary hypoplasia with an intact
diaphragm. Although pulmonary vasodilators were used extensively
in babies with congenital diaphragmatic hernia, they have not
significantly improved survival. An oxygen index of greater than 40 is
the usual indication for ECMO. Pulmonary hypoplasia is the main
cause of mortality in babies with congenital diaphragmatic hernia.
5. Which of the following statements are true regarding the
premature neonate?
A. A 15% to 20% right-to-left shunt occurs across the foramen ovale
and patent ductus arteriosus.
B. Surfactant levels are normal after 30 weeks' gestation.
C. Fluid requirements are higher than in a full-term baby.
D. Rectal temperature is the best indicator of core body temperature.
E. They are more at risk for infection than the full-term infant.
Answer: ACE
DISCUSSION: The newborn infant has a relatively elevated pulmonary
artery pressure and shunts a significant amount of unoxygenated
blood through the foramen ovale and patent ductus arteriosus. The
normal PaO 2 below the ductus, as measured through an umbilical
artery catheter, would be between 60 and 80 mm. Hg. Surfactant
levels do not approach normal until after the 34th week of gestation,
when enzyme levels in the surfactant pathway mature. Amniocentesis
, is performed to measure the lethicin-to-sphingomyelin ratio (L:S ratio)
and determine whether maturation has occurred. Fluid requirements
in the premature infant are between 140 and 150 ml. per kg. per day
in comparison with those of the normal neonate in whom 80 ml. per
kg. per day would be adequate. Increased insensible losses and the
need for overhead warmers play a role in this increase. Axillary or skin
probe temperature monitoring is more accurate than the rectal
temperature in the neonate. The rectal temperature is not a good
indicator of core body temperature until approximately 18 months of
age. Premature infants lack immunoglobulin A (IgA) and have low
levels of IgM, the C3b component of complement, and decreased
opsonins. In addition, the leukocytes have reduced phagocytic ability,
creating an increased risk of infection. Escherichia coli and
beta-hemolytic streptococcus are the two most common infectious
agents affecting the neonate.
6. In neonates with necrotizing enterocolitis, which of the following
findings is an indication of significant bowel ischemia?
A. Increased gastric residuals.
B. Septic shock.
C. Cardiac failure due to a patent ductus arteriosus.
D. Elevated platelet count.
E. Erythema of the abdominal wall.
Answer: E
DISCUSSION: Necrotizing enterocolitis (NEC) is a condition that occurs
in 2% of babies admitted to neonatal intensive care facilities.
Increased gastric residuals can occur for a number of reasons and are
seen as an early indicator of NEC, but they may not reflect the
presence of ischemic bowel. Septic shock may be due to a wide
variety of causes besides NEC. Cardiac failure due to patent ductus
arteriosus may predispose to NEC but is not necessarily an indicator
of ischemic bowel. Most babies with NEC have a progressive decrease
in their platelet count in association with bowel ischemia. Erythema of
the abdominal wall is an indication for surgical exploration and is
consistent with NEC with perforation and inflammation of the
peritoneum and abdominal wall.
7. The treatment of choice for neonates with uncomplicated
meconium ileus is:
A. Observation.
B. Emergency laparotomy, bowel resection, and Bishop-Koop
enterostomy.
C. Intravenous hydration and a gastrograffin enema.
D. Emergency laparotomy, bowel resection, and anastomosis.
Surgery Lecture Notes, Books, MCQ and Good Articles
Saturday, September 6, 2008
Pediatric Surgery MCQ
1. Polyhydramnios is frequently observed in all of the following
conditions except:
A. Esophageal atresia.
B. Duodenal atresia.
C. Pyloric atresia.
D. Hirschsprung's disease.
E. Congenital diaphragmatic hernia.
Answer: D
DISCUSSION: Polyhydramnios is defined as excessive amounts of fluid
(>2000 ml.) in the amniotic sac during pregnancy. The amniotic pool is
a dynamic pool with a relatively rapid turnover. In the fourth
intrauterine month the fetus begins to swallow amniotic fluid (25% to
40% of the volume) and absorbs the fluid from the upper
gastrointestinal tract. The fluid is urinated back out into the amniotic
pool by the fetal kidneys and a functioning bladder. Although there
are maternal causes of polyhydramnios (cardiac failure, renal failure,
other causes of fluid retention) and some idiopathic cases, many
instances are related to the presence of fetal anomalies. These
include central nervous system problems such as anencephaly, which
prevents normal swallowing, and any high alimentary tract
obstruction that blocks the passage of the amniotic fluid and prevents
its absorption (including esophageal atresia, pyloric atresia, and
duodenal atresia). In addition, infants with congenital diaphragmatic
hernia have obstructions due to herniation of the stomach and bowel
into the thoracic cavity. This is a poor prognostic finding in these
infants. Hirschsprung's disease is a form of low intestinal obstruction,
and therefore an adequate length of proximal patent intestine is
available for absorption of the swallowed amniotic fluid and
polyhydramnios is usually not present.
2. Which of the following statements about Hirschsprung's disease
is/are true?
,A. There are no ganglion cells seen in Auerbach's plexus.
B. There is an increased incidence of Down syndrome.
C. It is more common in girls.
D. It may be associated with enterocolitis.
E. It may involve the small intestine.
Answer: ABDE
DISCUSSION: The affected segment of bowel in patients with
Hirschsprung's disease has hypertrophic nerves in Auerbach's
intermyenteric plexus, but no ganglion cells are present. Ganglion
cells are also absent in Meissner's submucosal plexus. Some 3% to 5%
of babies with Hirschsprung's disease also have Down syndrome.
Hirschsprung's disease should be suspected in infants with Down
syndrome that manifest evidence of abdominal distension and
constipation. Hirschsprung's disease is much more common in boys
(4:1). The enterocolitis of Hirschsprung's disease is a condition
associated with delay in diagnosis, low bowel obstruction, severe
abdominal distension, explosive diarrhea, and colonic mucosal
ulceration. The course may be fulminant. This complication is
associated with increased morbidity and mortality. Bacterial
translocation and endotoxemia may complicate the condition.
Treatment includes nasogastric suction, intravenous fluids, antibiotics,
and rectal tube decompression of the obstructed rectosigmoid
segment. In approximately 10% of cases aganglionosis extends into
varying lengths of small bowel. In rare instances, the entire small
bowel and colon may be aganglionic.
3. Which of the following statements is/are true of infants with
gastroschisis?
A. It is associated with malrotation.
B. There is a high incidence of associated anomalies.
C. There is prolonged adynamic ileus following repair.
D. It is complicated by intestinal atresia in 10% to 12% of cases.
E. It is associated with chromosomal syndromes.
Answer: ACD
DISCUSSION: Because of intrauterine herniation of bowel to an extra-
abdominal location, normal intestinal rotation and fixation do not
occur. Most infants with gastroschisis have nonrotation. In contrast to
infants with omphalocele, in which a high incidence of associated
anomalies coexist, babies with gastroschisis have little else wrong.
Following repair of the abdominal wall defect, infants with
gastroschisis have a long delay in return of intestinal function. They
usually require total parenteral nutrition to supply adequate caloric
intake until gut function returns (3 to 4 weeks). Intestinal atresia is
observed in 10% to 12% of neonates with gastroschisis. This is caused
,by bowel ischemia due to intrauterine volvulus or compression of the
herniated viscera in a small, tight defect in the abdominal wall.
Although infants with omphalocele frequently have chromosomal
syndromes such as Beckwith syndrome or trisomy 13 to 15 or 16 to
18, babies with gastroschisis do not.
4. In neonates with congenital diaphragmatic hernia, which of the
following statements is true?
A. The defect is more common on the right side.
B. Survival is significantly improved by administration of pulmonary
vasodilators.
C. An oxygen index of 20 is an indication for extracorporeal
membrane oxygenation (ECMO).
D. Oligohydramnios is a frequent occurrence.
E. Mortality is the result of pulmonary hypoplasia.
Answer: E
DISCUSSION: In infants with congenital diaphragmatic hernia the
defect is more common on the left side (85%). Polyhydramnios is
sometimes noticed and is a poor prognostic indicator of survival.
Oligohydramnios is noted in fetuses with urinary tract obstruction and
may be associated with pulmonary hypoplasia with an intact
diaphragm. Although pulmonary vasodilators were used extensively
in babies with congenital diaphragmatic hernia, they have not
significantly improved survival. An oxygen index of greater than 40 is
the usual indication for ECMO. Pulmonary hypoplasia is the main
cause of mortality in babies with congenital diaphragmatic hernia.
5. Which of the following statements are true regarding the
premature neonate?
A. A 15% to 20% right-to-left shunt occurs across the foramen ovale
and patent ductus arteriosus.
B. Surfactant levels are normal after 30 weeks' gestation.
C. Fluid requirements are higher than in a full-term baby.
D. Rectal temperature is the best indicator of core body temperature.
E. They are more at risk for infection than the full-term infant.
Answer: ACE
DISCUSSION: The newborn infant has a relatively elevated pulmonary
artery pressure and shunts a significant amount of unoxygenated
blood through the foramen ovale and patent ductus arteriosus. The
normal PaO 2 below the ductus, as measured through an umbilical
artery catheter, would be between 60 and 80 mm. Hg. Surfactant
levels do not approach normal until after the 34th week of gestation,
when enzyme levels in the surfactant pathway mature. Amniocentesis
, is performed to measure the lethicin-to-sphingomyelin ratio (L:S ratio)
and determine whether maturation has occurred. Fluid requirements
in the premature infant are between 140 and 150 ml. per kg. per day
in comparison with those of the normal neonate in whom 80 ml. per
kg. per day would be adequate. Increased insensible losses and the
need for overhead warmers play a role in this increase. Axillary or skin
probe temperature monitoring is more accurate than the rectal
temperature in the neonate. The rectal temperature is not a good
indicator of core body temperature until approximately 18 months of
age. Premature infants lack immunoglobulin A (IgA) and have low
levels of IgM, the C3b component of complement, and decreased
opsonins. In addition, the leukocytes have reduced phagocytic ability,
creating an increased risk of infection. Escherichia coli and
beta-hemolytic streptococcus are the two most common infectious
agents affecting the neonate.
6. In neonates with necrotizing enterocolitis, which of the following
findings is an indication of significant bowel ischemia?
A. Increased gastric residuals.
B. Septic shock.
C. Cardiac failure due to a patent ductus arteriosus.
D. Elevated platelet count.
E. Erythema of the abdominal wall.
Answer: E
DISCUSSION: Necrotizing enterocolitis (NEC) is a condition that occurs
in 2% of babies admitted to neonatal intensive care facilities.
Increased gastric residuals can occur for a number of reasons and are
seen as an early indicator of NEC, but they may not reflect the
presence of ischemic bowel. Septic shock may be due to a wide
variety of causes besides NEC. Cardiac failure due to patent ductus
arteriosus may predispose to NEC but is not necessarily an indicator
of ischemic bowel. Most babies with NEC have a progressive decrease
in their platelet count in association with bowel ischemia. Erythema of
the abdominal wall is an indication for surgical exploration and is
consistent with NEC with perforation and inflammation of the
peritoneum and abdominal wall.
7. The treatment of choice for neonates with uncomplicated
meconium ileus is:
A. Observation.
B. Emergency laparotomy, bowel resection, and Bishop-Koop
enterostomy.
C. Intravenous hydration and a gastrograffin enema.
D. Emergency laparotomy, bowel resection, and anastomosis.
