Pediatrics - Surgical Emergencies Flashcards
What is the increased O2 consumption for a neonate?
7 mL/kg/min
What are the diaphragmatic and chest wall differences in the ped population?
- Lung tissue less compliant
- - Chest wall more compliant
What is significant about fetal hemoglobin?
It binds O2 more tightly than adult hemoglobin
What does CO in peds depend on?
HR (SV is constant)
Which autonomic nervous system is more developed in the neonate?
Parasympathetic, which means they are more prone to bradycardia, etc.
At birth, how does neonatal GFR compare to that of adults?
25%
At what age does regular kidney function occur?
6 months
What ability do neonates gain at 32 weeks gestational age?
Sodium retaining ability
What is TBW?
What % water are premies?
Term Baby?
Adult?
Total Body Water
Premies: 75-85% water
Term Baby: 70%
Adult: 60%
How do renal and hepatic function in neonates compare to that of adults?
Why is this important in anesthesia?
- Decreased renal function and blood flow, decreased liver blood flow, decreased enzymes, decreased protein binding
- All important to drug metabolism–drugs will last longer in neonates
How do blood vessels aka IV access compare to that of adults?
Small, fragile vessels –> more difficult IV access (if very desperate, go to intraosseus method)
What are the two defects in the abdominal wall that allow a portion of the intestinal viscera to remain outside the abdominal cavity?
Omphalocele and Gastroschisis
What management considerations relate to Omphalocele and Gastroschisis? (3)
- Impaired blood supply to visceral organs
- Bowel obstruction
- Extreme fluid shifts/deficits
What are the characteristics of omphalocele?
Definition: failure of gut to migrate into abdomen during gestation
1 in 6000 births
Male:female = 2:1
30% mortality
Where is the defect of an omphalocele?
At the base of the umbilicus
Which has the larger defect?
Omphalocele
Which defect is associated with congenital abnormalities and prematurity? Omphalocele or gastroschisis?
– Omphalocele assoc with congenital abnormalities, such as cardiac, genetic, metabolic, and urologic abnormalities
– Gastroschisis is more assoc with prematurity
True or False: Pts with omphalocele usually have normal bowel function.
True
Describe the bowels of the omphalocele.
Covered by sac and protected amniotic fluid in utero, looks more like a balloon
What are the characteristics of gastroschisis?
Develops as a result of occlusion of the omphalomesenteric artery during gestation
Incidence 1:15k (rare)
Male:female = 1:1
15% mortality
True or false: gastroschisis is associated with other congenital abnormalities.
False (omphalocele is assoc with other congenital abnormalities)
Where is the defect in gastroschisis?
To the right of the umbilicus
Describe the bowels of gastroschisis patients.
- Edematous and inflamed with a “peel”
- Dilated, foreshortened, and functionally abnormal
- Usually very red and angry-looking
Why does the bowel of gastroschisis patients look the way it does?
Tissue reaction from exposure to amniotic fluid
What are the anesthetic considerations for Omphalocele or gastroschisis?
Pts are volume depleted and will have heat and fluid loss from large exposed surface SO:
- Keep warm
- Replenish fluids
- Good IV access in upper extremities
- Get labs to watch out for hypoglycemia and calcemia bc of possible renal dysfunction
What is the greatest cause of pulmonary dysfunction in omphalocele and gastroschisis patients?
RDS assoc with prematurity
What is important to monitor intraop for Omphalocele or gastroschisis correction procedures?
- Intra-abdominal pressures
- Clear drape over legs to monitor low extremity perfusion
- Possible CVP in case compression of large vessels that would result in dec venous return
What are the induction/intubation preferences for Omphalocele or gastroschisis procedures?
- Awake intubation if hypovolemic
- - RSI if normovolemic
At what pressure should the ETT leak be for Omphalocele or gastroschisis patients?
30-40 cm H2O
What is the intraop mgt of Omphalocele or gastroschisis procedures?
- Warm OR to 80 degrees F
- Decompress stomach
- Keep sats bw 94-97 for term baby and 90-94 for premie
- Hematocrit > 30%
- Use fluids D10 1/4 NS at 10-15 cc/kg/hr (free water to help kidneys, dextrose for hypoglycemia)
What is the difference bw primary and secondary closures of Omphalocele or gastroschisis?
Primary: entire bowels put back into abdomen
Secondary: bowels stay exposed and require staged closures that have cinching of silo with definitive closure at 7-10 days
If primary closure has taken place for Omphalocele or gastroschisis, what are postop concerns?
- Pt with no lung disease may be extubated
- - If lung disease present, maintain PPV until intra-abdominal pressures decreases and keep PEEP to improve FRC
What complications can occur from Omphalocele or gastroschisis procedures?
- Most occur when too aggressive when trying to put too much bowel back into abdominal cavity
1) Respiratory failure
2) Bowel ischemia
3) Hypothermia
- Most occur when too aggressive when trying to put too much bowel back into abdominal cavity
What is the failure of embryonic neuroganglion cells to migrate to Auerbach and Meissner plexuses of the colon and will present as a bowel obstruction?
Hirschprung’s Disease
Congenital aganglionic megacolon
What is the most common cause of neonatal GI obstruction?
Hirschprung’s Disease
What are the characteristics of Hirschprung’s Disease?
– Usually confined to rectosigmoid (anus to proximal)
– Only 10% of cases involve entire colon
1: 5000 births
Male: female = 4:1
Is associated with congenital defects
What are the ganglion cells of Hirschprung’s Disease needed for?
They are needed to allow relaxation of the internal sphincter to pass a bowel movement
- These babies do not make a bowel movement within first 24 hours of life (emergency)
- Some get not diagnosed and do not come in until adolescents (not an emergency)
What are the 2 diagnoses of Hirschprung’s Disease?
- Barium enema
- - Rectal biopsy
What is the surgical treatment of Hirschprung’s Disease?
- Leveling colostomy in which biopsies are taken and sent to pathology to determine at which level ganglia are present
- Can then reconnect portion of colon that has ganglion cells to the rectum
- Can be a very long procedure waiting on pathology
What is the definitive repair for Hirschprung’s Disease and when can this take place?
- Abdominoperineal resection with colon pull through
- - When child reaches 10 kg
Which disease presents as polyhydramnios (excessive amniotic fluid), excessive oral secretions, and cyanosis with feedings?
Tracheoesophageal Fistula
What are the characteristics of Tracheoesophageal Fistula?
1:3000 live births
Male = female ratio
Mortality: 1-15% depending on prematurity
Associated abnormalities : VACTERL
– Gas noted distally to fistula on x-rays
What is most common type of TEF? (apparently a favorite board question)
Esophageal atresia with distal fistula
90% of cases
What is EA?
Esophageal atresia
the esophagus has not formed fully
How do you discover a TEF ?
– Noted by failure to pass OG tube
What is difference in EA and TEF?
- Pure EA has no gas distal to esophagus and only occurs in 7% of cases
- Pure EA managed with gastrostomy and later anastomosis
EA with air in stomach = ______
No air in bowel, ____ alone
TEF
EA
The most common TEF has what two distinct features?
- Blind esophageal “floating” pouch
- - Fistula off distal trachea to stomach
What are most common associated anomalies associated with Tracheoesophageal Fistula?
1) Prematurity
2) Cardiac
3) Muscoloskeletal
What does VACTERL stand for?
- Vertebral
- Anal
- Congenital heart disease
- TEF
- EA
- Renal or radius abnormalities
- Limb abnormalities
What are induction considerations for Tracheoesophageal Fistula?
- Head up to minimize aspiration
- NG in esophagus to continuous suction
- Warm room
- Good IV access
- Type and cross blood with blood in room
What kind of induction should be performed in Tracheoesophageal Fistula patients?
- Awake if unstable
- - RSI if stable
Where should the ETT be positioned in TEF?
Above carina but below fistula (can be very very difficult to do)
What are intraop considerations for TEF?
- Lower ventilatory pressures
- A line
- Lateral decubitius with incision opposite side as aortic arch
What are postop risks/considerations for TEF?
- Extubation preferable
- Humidified O2
- Highest risk is URI / LRI 75%
- Aspiration develops abnormal swallowing and GERD
- Can develop atelectasis/tracheomalcia
What are the long term complications of TEF?
- Increased bronchial reactivity 18 years after repair
- By 2nd-3rd decade 90% asympotomatic or have mild dysphagia
- Abnormal esophageal motility
What is necrotizing enterocolitits (NEC)?
- Ischemia condition of GI tract of multifactorial etiology (etiology unknown)
- Basically inflammatory and ischemia areas in GI tract
What are characteristics of necrotizing enterocolitits?
Incidence : 5-8% of NICU admissions
>90% are premies < 1500 Gm
Mortality 25%
What are risk factors for NEC?
- Onset of gastric feedings / hypertonic feedings
- Gut hypoperfusion
- Hypoxemia
- Bacterial colonization
What are most common signs of NEC?
- Abdominal distention/discoloration
- Bloody stools
- Temperature instability
- Vomiting or DIC
How does NEC present?
– Distended, tender abdomen in child that appears septic
– Requires intubation, fluids, supportive care, antibiotics
What is treatment plan for NEC?
- Conservative early
- As soon as pt shows signs of getting worse, surgical treatment is performed
- Gastric decompression
- Surgical (as soon as you see free air on film, take to surgery bc this indicates a perforated bowel)
Preop considerations for NEC?
- Urgent fluid/blood resuscitation 150 cc/kg (start in NICU)
- May require inotropes (CHF due to sepsis/acidosis)
- Careful bicarbonate administration to correct acidosis
- HCO3 deficit = BD x weight x 0.3
- Give half of calc deficit SLOWLY in preop - IVH risk due to aggressive fluid resuscitation, lack of autoregulation, wide swings in BP
- RBCs, platelets, FFP, cryo available
Intraop considerations for NEC?
- Good IV access
- Standard monitor, A-line, urinary catheter +/- CVP
- Warm OR
- EBL 10-100 cc/kg, maintain Hct > 30%
- Anes: ketamine/O2/air/opioid/m. relaxation
- Keep sat 94-95%
Postop considerations for NEC?
- PPV
- Continue opioids & max m. relaxation (will remain intubated)
- Transport w/ extra volume, AW equipment, emergency drugs, & full monitors
What is a congenital diaphragmatic hernia?
At 4-9 wks gestation, the pleuroperitoneal membrane separates the chest and abdominal cavities. This hernia results in incomplete closure of the membrane. Bowels move into chest cavity, impacting lung development.
How is CDH diagnosed?
Possibly by prenatal ultrasound, or diagnosed at birth by presence of scaphoid or sunken abdomen with respiratory failure
What issue is most associated with CDH?
Pulmonary hypoplasia (due to impingement of bowel on lungs)
What is the most prevalent location for CDH?
Foramen of Bochdalek (posterolateral)
Left:right 5:1
What are the consequences of the compression of abdominal contents into the chest in CDH? (5)
- 50% reduction in alveoli
- Mediastinal shift
- Hypoplastic pulmonary artery
- Pulmonary HTN
- Bronchial arrest at 11-13 wks
What are the 3 causes of death associated with CDH?
- Progressive hypoxemia
- Respiratory failure
- Pulmonary HTN
What is the most commonly associated anomaly in CDH?
GI 40-60% (100% have malrotation which presents with bowel obstruction symptoms)
Is CDH a surgical emergency?
No (surgery does not cure lung hypoplasia)
What must you do prep before surgery can take place for CDH pts?
- Stabilize medically or with ECMO
- must be able to oxygenate/ventilate
- Correct acidosis
- Treat pulmonary HTN
- IV access
- Gastric decompression
After weaning from ECMO, what does the surgical repair of CDH consist of?
- Abdominal incision for bowel and diaphragm repair
- - May have to construct an artificial akinetic diaphragm
What is the intraop mgt of CDH?
- Opioid heavy
- Low PIP pressures
- Poss need for pressure-limiting ventilator
- Consider awake intubation
What is the postop mgt of CDH?
- Minimize suctioning to prevent any damage to bowels
- - Maintain PPV and respiratory alkalosis
What are CDH complications?
- Contralateral PTX (do not attempt to expand lungs when mask ventilation)
- Hypothermia
- Metabolic acidosis
- Persistent pulmonary HTN with right to left shunting
What is the prognosis for CDH?
If <35 wks gestation, mortality is 90% (bc of respiratory distress in first hour of life)
What is the bridge used for CDH until definitive repair?
ECMO
What is ECMO?
Extracorporeal Membrane Oxygenation, acts as a lung machine
What is the one definitive indication for ECMO?
- MUST be REVERSIBLE respiratory failure/lung disease
- Must be >34 wks gestation
- Must be >2 kg
What excludes a patient from receiving ECMO?
> Grade II intraventricular hemorrhage
Or other life-threatening anomalies
What is the mortality for CDH?
30-40%
12% for all neonatal ECMO
What are the two myelodysplasias that occur bc of abnormal fusions of neural grooves that leave some portion of brain or cord exposed?
Meningomyelocele and Encephalocele
Which is the more common myelodysplasia?
Meningomyelocele
Occurs 3:1000
(Encephalocele only occurs 0.3:1000)
What is the most common site for myelodysplasias?
lumbosacral (75%)
What is the risks of myelodysplasias and what is subsequent mortality?
- Infection/death due to exposed CNS elements
- Delayed closure worsens motor function later in life
- Mortality 17.6% so correct abnormality AS SOON AS BABY IS BORN
What are preop considerations of myelodysplasias?
- Warm room
- Position to protect neural plaque (no pressure on defect so cannot lie on back)
- Plan AW mgt (intubation may be difficult, poss prone)
What is the anes mgt of myelodysplasias?
- Position important
- Awake intubation safest
- Extubate awake asap in lateral position (want to make sure no neurological deficits)
What is a large, multi-septated cystic lesion that is the result of large lymphatic malformations?
cystic hygroma
What structures could cystic hygroma affect?
- 10-15% extend to the mediastinum
- - Great vessels, tongue, brachial plexus, vagus, phrenic, facial, and hypoglossal nerves
What is morbidity of cystic hygroma associated with?
AW compromise, infection, or bleeding
What are preop considerations for cystic hygroma?
- Potential for AW compromise, prepare for difficult intubation
- Have blood in room & be prepared for large amts of blood loss
- Get labs, crit, glu, calcium, etc.
What are induction and intraop considerations for cystic hygroma?
- Warm room
- Maintain SV
- A-line
- IV access in LOWER extremities
- Can do inhalational induction
- IV atropine before DL
What are postop considerations for cystic hygroma and what should you watch out for?
- Keep intubated and transport to ICU
- Watch out for RLN injury, subglottic/upper AW edema, and bleeding
- May be brought back to OR for extubation
