Common Pediatric Surgeries -GI Flashcards
What is Gastroschisis?
-Defect of the anterior abdominal wall of the right of the umbilical cord
-no sac- bowel is exposed to the intrauterine environment
-bowel is matted, thickened and covered w an inflammatory coating
-malabsorption issues
-results in peritonitis, extracellular fluid loss, significant heat loss
-fascial defect in 2-5 cm
-usually involves only large and small intestines
What is Gastroschisis a result of?
A vascular event resulting from an abnormality of a right omphalomesenteric artery or right umbilical vein
results in ischemia to the right paraumbilical area and dysplastic abdominal wall growth
Weakened area ruptures as abdominal organs grow
What are the risk factors for gastroschisis?
young maternal age, exposure to tobacco and alcohol during development
What are the risk factors for gastroschisis?
young maternal age, exposure to tobacco and alcohol during development
How is gastroschisis diagnosed?
before birth via ultrasound- associated w increased maternal serum alpha fetoprotein
What is Omphalocele?
Central defect of umbilical ring/base of umbilical cord
Abdominal contents are within a sac
umbillical cord embedded in sac
fascical defect >4cm
Sac contains stomach, large and small intestine, liver (30-50%)
(less than 4cm- considered umbilical hernia)
What is the embryology or omphalocele?
week 7-12: midgut herniated into umbilical cord
Week 12: abdominal cavity is large enough, gut re-enters abdomen.
- failure of gut to return to abdominal cavity
What anomalies is gastroschisis associated with?
- isolated lesion
What associated anomalies is omphalocele with?
50-70% incidence of other anomalies
20-30% chromosomal abnormalities
Beckwith- Wiedemann syndrome, Reiger syndrome, Prune belly syndrome
Trisomy 13, 15, 18, 21
Cardiac 20%
What symptoms/anomalies does Beckwith-Wiedemann Syndrome come with?
-omphalocele
-visceromegaly
-macroglossia
-mild microcephaly
-hypogycemia
What symptoms/anomalies does Beckwith-Wiedemann Syndrome come with?
-omphalocele
-visceromegaly
-macroglossia
-mild microcephaly
-hypogycemia
What is the surgical management for these pts?
-replacing the viscera and repairing the defect
-Primary vs. Staged repair w silo/mesh chimney
-staged- organs gradually returned to the abdominal cavity over 3-14 days
What are the factors that determine surgical management?
- size of the defect
-development of the abdominal wall
-presence of anomalies
What are the negative effects of tight abdominal closure?
-impairs diaphragmatic excursion- inadequate ventilation, increased airway pressure
- impedes venous return- profound HoTN
-aortocaval compression -bowel ischemia, decreased CO, renal and hepatic dysfunction
What are the negative effects of tight abdominal closure?
-impairs diaphragmatic excursion- inadequate ventilation, increased airway pressure
- impedes venous return- profound HoTN
-aortocaval compression -bowel ischemia, decreased CO, renal and hepatic dysfunction
What is considered unsafe for primary closure?
Intragastric pressure >20 mmHg
Change in CVP > 4mmHg above baseline
ETCO2 >50 mmHg
Peak inspiratory pressure > 35 cm h2o
What is considered unsafe for primary closure?
Intragastric pressure >20 mmHg
Change in CVP > 4mmHg above baseline
ETCO2 >50 mmHg
Peak inspiratory pressure > 35 cm h2o
What is the reasoning for massive fluid losses?
Peritonitis, edema, ischemia, protein loss, third space loss, which results in dehydration metabolic acidosis, hypovolemic shock
How should you fluid resuscitate?
Maintenance fluid: D5 or D10 in 0.2NS
replacement fluid: isotonic at 2-4 times maintenance rate
NS or LR as replacement (8-15 ml/kg/hr)
What should UOP be maintained at?
1-2ml/kg/hr
How should you maintain normothermia
prevent heat loss from exposed viscera
- cover abdominal contents w warm, saline-soaked gauze
-cover w plastic bowel bag
Where should the two pulse ox monitors be placed?
pre-ductal (right arm)
Post ductal (left foot)
What gas should be avoided?
Nitrous oxide - bowel distention
what should spo2 and pao2 be maintained at?
spo2: 95-97%
pao2: 50-70mmhg
What should be done to prevent hypothermia?
room temp 80 degrees
bair hugger
fluid warmer
plastic wrap for extremities, head, and leave hat on
What should be done to prevent hypothermia?
room temp 80 degrees
bair hugger
fluid warmer
plastic wrap for extremities, head, and leave hat on
What factors will determine extubation?
size of pt/prematurity
associated anomalies
size defect
type of repair
intraop events
hemodynamic status
What factors will determine extubation?
size of pt/prematurity
associated anomalies
size defect
type of repair
intraop events
hemodynamic status
What is the post-op management for these cases?
-mechanical ventilation for 24-48 hrs
-fluid requirements closely monitored
-circulatory compromise- cyanotic lower limbs, bowel ischemia
-prolonged post-op ileus- TPN required for days to weeks
-prevent infection
What is the post-op management for these cases?
-mechanical ventilation for 24-48 hrs
-fluid requirements closely monitored
-circulatory compromise- cyanotic lower limbs, bowel ischemia
-prolonged post-op ileus- TPN required for days to weeks
-prevent infection
What are some post-op complications?
-pneumonia
-necrotizing enterocolitis (NEC)
-renal insufficiency
-abdominal wall breakdown
-GERD
What is a congenital diaphragmatic hernia (CDH)?
-defect in the diaphragm that allows herniation of abdominal organs into the thoracic cavity
What are the associated anomalies of CDH?
prenatal hx of polyhydramnios
-malrotation of the gut
-CV
-CNS, GI, GU
What are the associated anomalies of CDH?
prenatal hx of polyhydramnios
-malrotation of the gut
-CV
-CNS, GI, GU
What are the classifications of CDH?
Posterolateral (80-90%)
left (75%)
paraesophageal 15-20%
anteromedial 2%
What are the complications of CDH?
-bilateral lung hypoplasia
-pulm HTN and arteriolar reactivity
-Left ventricular dysfunction
What is the pathophysiology of CDH?
Abdominal viscera occupies the left thoracic cavity and interferes w the development of the lung resulting in pulm hypoplasia
Herniation of abdominal contents shifts mediastinum to the right resulting in compression and hypoplasia of the contralateral lung
Structural abnormalities of pulm vasculature resulting in chronic lung disease
-Small number of airways
-Simple arterial branching pattern
-Increased smooth muscle mass in resistance vessels
-Left ventricular abnormalities
What is the pathophysiology of CDH?
Abdominal viscera occupies the left thoracic cavity and interferes w the development of the lung resulting in pulm hypoplasia
Herniation of abdominal contents shifts mediastinum to the right resulting in compression and hypoplasia of the contralateral lung
Structural abnormalities of pulm vasculature resulting in chronic lung disease
-Small number of airways
-Simple arterial branching pattern
-Increased smooth muscle mass in resistance vessels
-Left ventricular abnormalities
What is the clinical presentation of CDH?
-Symptoms appear within mins to hrs.
classic triad:
- dyspnea
-cyanosis
-apparent dextrocardia
physical exam reveals:
-bulding chest and scaphoid abdomen
-decreased breath sounds
-distant or right displaced heart sounds
-bowel sounds in chest
-CXR bowel loops in the chest and mediastinal shift
Dextrocardia- heart points to the right instead of the left
What are the medical management goals of CDH?
medical stabilization for 24-48 hrs before surgery
-maximize arterial oxygenation:
- intubation
-mechanical ventilation - low inflating pressures (<20-30cm h2o)
- maintain muscle relaxation
-improve pulm perfusion
-correct acidosis
-prevent hypothermia
-prevent pain
When can surgery occur for CDH?
when BP normal and stable for 24 hrs
preductal sat >85 (preferably 90-95%) w fio2 less than 50%
lactate < 3
UOP 1-2ml/kg/hr
How can you improve pulm perfusion in CDH?
hyperventialtion (paco2 25-30 mmhg)
fentanyl infusion
minimal handling
nitric oxide
ECMO
early intubation and decompression of stomach is critical
What are the complications of ECMO?
-Bleeding at cannulation sites
-intracranial hemorrhage
-sepsis
-HTN
-brain death
What is the criteria for ECMO?
More than 2kgs
gestation >35 weeks
