Knowledge Navigator Flashcards
scoliosis:
lateral deviation of the normal vertical line of the spine greater than ___ degrees
10
anterior angulation of the spine in the sagittal plane
lordosis
posterior angulation of the spine of a side view
kyphosis
which curves in scoliosis are the earliest to appear and where are they?
- primary curves in scoliosis are the earliest to appear
- mostly thoracic or lumbar
secondary curves scoliosis
secondary curves develop above or below the primary curve and evolve to maintain normal body alignment
how is scoliosis curve measured
- The magnitude of the curve measured by the Cobb method; measured from anteroposterior radiographs from the upper and lower end vertebra involved with the curve.
- The vertebrae tilt most severely toward the concavity of the curve
Children younger than 5 with early onset scoliosis or with independent cardiac or pulmonary disease appear to be at increased risk for ____________
respiratory failure
infantile (< 3 yrs) scoliosis key anesthetic risk factors
- repeat operations
- small size
- expected high blood loss
- respiratory complications
key anesthetic risk factors for scoliosis surgery in patients with cerebral palsy/hypoxia
- upper airway obstruction
- recurrent pneumonia
- postop pain mngt
- expected high blood loss
- respiratory complications
key anesthetic risk factors for surgery in pts with Duchenne Muscular Dystrophy
- cardiomyopathy
- mitral valve prolapse
- conduction abnormalities
- increased K with succinylcholine
- expected high blood loss
- respiratory compromise
key anesthetic risk factors for surgery in pts with spinal muscular atrophy
- EKG abnormalities
- increased K with succinylcholine
- expected high blood loss
- respiratory compromise
key anesthetic risk factors for surgery in patients with Facioscapulohumeral muscular dystrophy (3)
- hypertrophic cardiomyopathy
- cardiac failure
- increased K with succ’s
key anesthetic risk factors for surgery in patients with Friedreich ataxia
increased K with succ’s
key anesthetic risk factors for surgery in patients with arthrogryposis
- difficult intubations
- severe contractures
- expected high blood loss
Lenke Classification
- In types 1 through 4, the main thoracic curve is the major curve
- In types 5 and 6, the thoracolumbar/lumbar curve is the major curve.
anesthesia goals of scoliosis surgery (2)
- minimize blood loss by the use of antifibrinolytics and intraop cell salvage
- use of SSEPs and MEPs (standard of care perioperatively)
Harrington Rod System
segmental fixation of the rods treating the lateral curve but not the correction of axial rotation
MOE Method (Scoliosis)
The vertebral rotation can be determined by measurement of the position of the pedicles from the midline
On the convex side of the curve, the ribs are pushed____________ , which ____________
posteriorly; narrows the thoracic cavity and causes the characteristic hump.
On the concave side, the same rotation forces the ribs ____________ , with consequent ____________
laterally; crowding toward their lateral margins- these changes result in increasingly restrictive lung defect
Children with idiopathic scoliosis with mild decrease in vital capacity also have reduced: (3)
- FEV1
- gas transfer factor
- maximal static expiratory airway pressures (PEmax).
____________ % of idiopathic scoliosis and appears between birth and 3 years of age.
less than 1%
how does idiopathic scoliosis present in children
Usually in the thoracic spine and curves to the left
scoliosis management of children with idiopathic scoliosis
- bracing when the curve reaches 30 degrees
- serial casting (even for severe curves [60 degrees] when casting started before 20 months)
Juvenile Idiopathic Scoliosis
incidence & age
- represents 10% to 15% of idiopathic scoliosis
- is defined as scoliosis that is first diagnosed between the ages of 4 and 10 years.
20% of children and those with infantile scoliosis with a curve greater than 20% have an underlying spinal condition, most commonly ____________ and ____________
Arnold-Chiari malformation and syringomyelia
bracing decreases progression but is associated with worse pulmonary function test in what kind of scoliiosis
adolescent idiopathic scoliosis
what is hemivertebra
- Congenital spinal anomaly
- caused by failure of formation
- progressive deformity during rapid spinal growth in the first 5 years of life
Congenital scoliosis is associated with
malformation of ribs, chest wall and hemifacial microsomia
Children with congenital scoliosis have an associated risk of
(aside from respiratory issues)
- 25% risk of urologic abnormalities
- 10% risk of cardiac abnormalities
50% of children who have extensive thoracic fusions or have fusions involving the proximal thoracic spine develop …..
restrictive pulmonary disease
(FEV1 < 50%)
Respiratory deterioration alone is not commonly a reason for surgery in those with scoliosis after 5 years old because
respiratory alveoli are mature at this age
age of onset and scoliosis
The earlier the age of onset ➔ the more immature bone growth ➔ the more severe the outcome
The FVC and FEV1 decrease with a nadir at 3 days and are about ____________
60% of preoperative values 7 to 10 days after surgery
with infantile onset scoliosis: spinal instrumentation does not ____________
prevent the reappearance of the deformity or the decrease in pulmonary function
Pulmonary impairment correlates directly with the magnitude of ____________
the thoracic curve
SEVERITY OF SCOLIOSIS MOST ACCURATE PREDICTOR OF IMPAIRED LUNG FUNCTION
most significant predictor of impaired respiratory function
The number of vertebrae in the thoracic curve is the most significant predictor of impaired respiratory function
(> 8 vertebral levels greater risk pulm. impairment)
children with adolescent idiopathic scoliosis may have pulmonary impairment that is ____________
- disproportionate to the severity of the scoliosis since it occurs before the curve reaches 100 degrees.
Forced vital capacity (FVC) may decrease below normal (< 80% of predicted) after the magnitude of the thoracic curve exceeds ____________
70 degrees
what is neuromuscular scoliosis
crowding of ribs on the concave side of the curve limits chest wall expansion and sitting restricts diaphragmatic excursion
DMD patients are usually wheelchair bound by
8-10 yrs ➔ early steroids and noninvasive PPV help overall management
worries with DMD patients
- nocturnal hypoventilation in ~15%
- dilated cardiomyopathy in up to 90% ➔ scoliosis masks symptoms of heart failure
- FVC < 50% of predicted indicates an increase in postoperative respiratory complications
what population is likely to need postoperative ventilation that is often prolonged
children
DMD children with scoliosis surgery:
long term prognosis
the benefits of long-term survival and respiratory function is uncertain - median survival of 30 years old
Posterior spinal fusion for scoliosis in DMD was associated with ____________
a significant slowing in the rate of decrease in respiratory function
Post-op visual loss w scoliosis surgery
- uncommon 0.2%
- most commonly due to ischemic optic neuropathy
4 mechanisms of spinal cord injury with scoliosis
- direct contusion
- contusion by hooks, wires
- distraction by rods or halo traction
- reduction in spinal cord blood flow
what pathways are most vulnerable to ischemic injury in spinal surgery
motor pathways because supplied by a single anterior spinal artery
artery of adamkiewicz arises from
T8-L4
Watershed area (T4-T9) is prone to ischemia because
the blood supply is the poorest
what increases the risk of nerve damage with spinal cord surgery
pedicle screws
what scoliosis patients are at greatest risk for complications
Patients with curves > 100 degrees and congenital scoliosis are at greatest risk for complications
Intracranial space is occupied by
- brain and interstitial fluid (80%)
- cerebrospinal fluid (10%)
- blood (10%).
what is the Monro-Kellie hypothesis
- the sum of all intracranial volumes is constant
- an increase in the volume of one compartment must be accompanied by an approximately equal decrease in the volume of the other compartments
Slow-growing tumors or hydrocephalus can be compensated by ____________
the complaint nature of the fontanelle an sutures in young children
Herniation can occur with open fontanelles with ____________
an acute increase in ICP
Children CSF volume & rate of production
- smaller CSF volumes but production is similar to adult
- (0.35ml/minute or 500 ml/day)
what meds transiently ↓ CSF production
Acetazolamide, furosemide, corticosteroids
craniosynostosis and ICP
- can lead to compression and increased ICP and neurological damage if not repaired
- > 1 suture involvement ↑ ICP
how to minimize increase of ICP
avoid straining, coughing, crying, hypoventilation, hypoxemia
what agents increase ICP
- Nitrous oxide ***
- Halothane **
- Iso, Sevo, Des *
- Ketamine ***
- Succinylcholine
what agents decrease ICP
Thiopental **
Propofol **
Etomidate **
Benzo
Opioids
Droperidol
Mannitol
3% saline
There is an inverse relationship between the rate of CSF production and ____________
serum osmolality;
an increase in serum osmolality causes a decrease in CSF production.
where is CSF produced and at what rate
Choroid plexus
20-21 ml/hr
flow of CSF
choroid plexus → lateral ventricles → 3rd ventricle via foramen of Monro → aqueduct of Slyvius → 4th ventricle → lateral foramina of Luschka and the midline foramen of Magendie → cisterna magna → Subarachnoid spaces
function of arachnoid villi
site for reabsorption of CSF into the venous system
cerebral blood flow in children
100 mL/100 g of the brain which = 25% of CO in a child
cerebral blood flow in neonate and preterm infants
40 mL per 100 g of brain tissue
CBF remains constant with what MAP range?
50-100 mmHg
s/s of ↑ ICP in children (6)
- papilledema
- pupil dilation
- hypertension, bradycardia
- ↓ LOC, abnormal motor response to pain
- vision changes
- increased head size
(these signs may be late and dangerous!)
chronic increases in ICP s/s
headache, irritability, vomiting
In children with open fontanelles, increased ICP may be seen by:
increasing head circumference
what does hyperventilation do to ICP
Hyperventilation (decrease PaCO2) reduces ICP
but has shown worsening cerebral ischemia in children with compromised cerebral perfusion
effects of decreased partial pressure of O2 < 50 mmHg
increases CBF (can lead to increase ICP)
what population has a lower limit of autoregulation
neonates
normal ICP children and term neonates
children: < 15 mmHg
term neonates: 2-6 mmHg
CPP calculation
CPP= MAP - ICP
When ICP exceeds CVP it replaces CVP in the calculation
what Chiari malformation presents with increased ICP
Chiari II
function of SSEP
Stimulating a peripheral nerve and measuring response to that stimulation using scalp electrodes
subcortical SSEP benefits
more stable, reproducible, and resistant to anesthetic agents
how does SSEP signal travel
peripheral nerve via nerve root up the ipsilateral dorsal column
⬇️
progresses rostrally to the thalamus to the primary sensory cortex
The rationale for SSEP to monitor motor deficits is based on the fact that ____________
the sensory tracts are in proximity to the motor tracts of the spinal cord
Injury to motor tracts indirectly affects ____________
sensory tracts and caused changes in SSEP
____________ with SSEPs constitutes an indication of intervention
10% increase in latency of the first cortical peak (P1)
OR
50% decrease in the peak-to-peak amplitude (P1N1)
SSEP monitoring is associated with ____________ in neurologic deficits
50% decrease
Children with____________ are at high risk for latex sensitivity and possibly anaphylaxis.
myelodysplasia
(bone marrow not producing enough healthy blood cells)
Suspected anaphylaxis from latex should be treated with ____________
IV epinephrine 1-10 mcg/kg, as required.
Children who develop latex allergy exhibit cross-reactivity with some antibiotics and foods, especially ____________ (3)
tropical fruits such as avocados, kiwi fruit, and bananas.
what is primary cause of death in head injury
trauma
most frequent cause of head injury
motor vehicle crash
(domestic violence and sports-related injuries are also common)
Children with head trauma may have minimal neuro abnormalities at initial eval but …
increased ICP and neuro deficits progress quickly
primary insult of head injury
occurs at the time of impact results from the biomechanical forces that disrupt the cranium, neural tissue, and vasculature.
secondary insult of head injury
- is the parenchymal damage caused by the pathologic sequelae of the primary insult.
- these changes can result from hypotension, hypoxia, cerebral edema, or intracranial hypertension
what population are intracranial hematomas common in
common in adults they are less common in children*
Diffuse cerebral edema after blunt head trauma occurs (more/less) in children
more
MOST COMMON HEAD INJURY IN CHILDREN
scalp laceration
why do children lose a lot of blood with scalp lacerations
because a large fraction of CO perfuses the head
Infants < 1 year of age can become hemodynamically unstable from ____________
subgaleal hematoma (closed scalp injury)
epidural hematoma
temporoparietal region from arterial bleed middle meningeal artery
subdural hematoma
cortical damage, direct parenchymal contusion of laceration of venous blood vessels
subdural hematoma is caused by
- Traumatic result of abuse, shaking small child esp. younger than 1 yo
- Occasionally results from birth trauma within the first hours of life (Vitamin K deficiency, congenital coagulopathies, and DIC are considerations in these situations.)
chronic subdural hematoma s/s (3)
- irritability
- vomiting
- increased head circumference
intracerebral hematoma
poor prognosis, extension of cortical contusions with severe neurologic injury
- Rarely can perform surgical decompression
- Start anticonvulsants avoid anticoags
patho of ROP
Oxygen toxicity from hyperoxia leads to the formation of reactive oxygen intermediaries that impair intracellular macromolecules, leading to cell death.
The formation of oxygen free radicals in ROP also promotes ____________
an extensive inflammatory response, leading to secondary tissue damage and cell death.
ROP is associated with (6)
- prematurity
- low birth weight
- supplemental oxygen therapy
- postnatal hypotension
- use of surfactant or inotrope
- need for mechanical ventilation.
It is common practice to reduce the FIO2, if otherwise safe for the neonate, to SpO2 ____________ to minimize the risk of oxygen toxicity without increasing perioperative mortality
91-95%
ROP is thought to be initiated by ____________
oxygen-induced retinal vasoconstriction and endothelial cell death, followed by unchecked neovascularization from angiogenic factors, such as VEGF, that do not respond to normal regulation because of immaturity.
post-op complication of tonsillectomy
include bleeding leading to hypovolemia and airway obstruction
primary bleeding with tonsillectomy
within first 24 hours (75% within first 6 hours)
secondary bleeding with tonsillectomy
- 5 to 10 days when the scab falls off
which bleeding type after tonsillectomy is a bigger problem
- Secondary is a bigger problem because kid has been swallowing blood for days.
- Parents don’t find out until kid is basically bleeding out & doing terrible
Between ____________ who experience postoperative bleeding will return to the OR for surgery.
1-3 % of patients
respiratory obstruction from blood clots with tonsillectomy can cause
hypoxia
hypoxia + hypovolemia=
cardiac arrest
management of tonsillar bleeding
- Considered a full stomach (potential for aspiration) RSI
- Be cautious when ordering opioids for a restless child as the restlessness may be an indication of hypoxia
- Abdominal pain (stomach ache) after T & A are suggestive of swallowing blood from ongoing bleeding
Post Tonsillectomy bleeding is ____________
a surgical emergency!
____________ and ____________ are associated with an increased risk of immediate postoperative hemorrhage after outpatient tonsillectomy
Obesity and older age
77% of cases of postoperative bleeding originate in the ____________
- tonsillar fossa
- 27% in the nasopharynx
- 7% in both
____________ in children was reported to be an independent risk factor for severe bleeding requiring reoperation after a tonsillectomy
IV steroid administration on the day of tonsillectomy
period of observation for primary hemorrhage after tonsillectomy
- 6 hours (cold dissection)
- 4 hours (hot dissection)
A history of dizziness and the presence of orthostatic hypotension may suggest ____________
a loss > 20% of the circulating blood volume AND the need for aggressive fluid resuscitation and crossmatch of blood before induction
Even if severe hypotension not present, the child may be hypovolemic with ____________
a decreased cardiac output secondary to ongoing blood loss.
If blood loss with tonsillectomy is severe, and/or fluid resuscitation is not vigorous, ____________
lactic acidosis and shock will develop.
The compensatory response to acute blood loss is ____________
an outpouring of catecholamines.
When anesthesia induced vasodilation occurs, ____________
profound hypotension may develop.
fluid resuscitation with bleeding in children
- Vigorous resuscitation with crystalloids (repeated boluses of 20 mL/kg of balanced salt solution) and/or colloids
- The key to improving CO & achieving hemodynamic stability before induction!
t/f blood is often the primary solution for volume replacement in bleeding children
false, blood is rarely the primary solution for volume replacement in these children
If severe hypovolemia is suspected or if there may be a delay in obtaining blood, blood should be ____________
crossmatched for two or more units of packed red blood cells before the child reaches the OR.
If a child bleeds after the tonsillectomy and a bleeding blood vessel is not identified, it may be necessary to ____________
measure the prothrombin time, partial thromboplastin time, platelet count, and a bleeding time to rule out a bleeding diathesis.
It cannot be overemphasized that the child must be ____________ before proceeding to the OR
adequately volume resuscitated
A child who is spitting bright red blood may quickly exsanguinate, but the bleeding may be temporarily controlled by ____________
compression of the carotid artery ipsilateral to the bleeding source.
A child who is actively bleeding from the oropharynx should be ____________
preoxygenated while positioned in the left lateral position + head down to drain blood out of the mouth
how to minimize aspiration of blood into lungs with bleeding child
Cricoid pressure/Sellick maneuver
Aspiration of blood into the lungs does not cause the same pathologic changes as acid particulate aspiration unless ____________
the volume of blood aspirated compromises pulmonary oxygenation.
Induction meds for hypovolemic patient:
- either reduced propofol dose, ketamine or etomidate with succinylcholine and roc
- change in systolic BP after induction will provide an indication of the volume status
what kind of ETT should be used to rapidly secure the airway and minimize the chance of aspirating blood
A cuffed ETT (0.5 mm ID smaller than the usual uncuffed for age or weight) with a stylet
Controlling the bleeding vessel in the tonsillar bed can be accomplished rapidly if the blood pressure is maintained ____________
in the normal range.
Suctioning the stomach with a large-bore catheter under direct vision after tonsil procedures does not guarantee an empty stomach, because ____________
much of the blood may be clotted and the clots are often too large to pass through the catheter lumen.
what prophylactic therapy is indicated before tonsil surgery
The use of prophylactic antiemetic therapy (ondansetron 0.1 mg/kg up to 4 mg) is indicated
⭐️
most important postop consideration for tonsil surgery
extubate fully awake and able to control their airway reflexes.
safest extubation position for tonsil surgery
Extubating in the lateral position may be the safest practice to minimize the risk of aspiration.
pectus excavatum may be associated with what 2 disease processes?
- Possible Marfan’s
- Possible CHD
Congenital abnormality of sternum, ribs, and costal cartilages (hollow chest)
pectus excavatum
pectus excavatum surgery assessment
- Chest x-ray (heart displaced to left and compressed)
- PFT’s ( Normal to reduced FVC & TLC, in severe cases, may demonstrate a V/Q mismatch)
- ECG ( arrhythmias, right axis deviation)
- Echocardiogram (increased incidence of MVP)
- Labs (blood loss) and ABG
- exercise tolerance
Surgical Issues/Concerns/Considerations for pectus surgery (5)
- Blood loss minimal to massive
- Pneumothorax
- Flail chest
- Post-operative atelectasis
- Pain management - thoracic or lumbar epidural, ESP blocks, cryoablation
The classic approach to correcting a pectus excavatum involves:
- an open procedure with fracture of the sternum
- removal of multiple costal cartilages
- elevating the sternum with fixation, using one or two stainless steel bars.
the Nuss procedure
- is a less invasive technique where a U-shaped bar is blindly passed through the thorax hugging the undersurface of the sternum
- Once across the chest, the bar is flipped, through which process the sternum is pushed anteriorly without fracturing it, thus avoiding the creation of a flail chest by the removal of the costal cartilages.
Children will return for removal of the pectus bar after several years. Occasionally…
the bar has become adherent to the pericardium or lung, resulting in a severe, sudden, and catastrophic rupture of a major vessel or chamber in the heart when the pectus bar is removed
the most common primary renal tumor in children
Wilms tumor (followed by clear cell sarcoma of the kidney, malignant rhabdoid tumor, congenital mesoblastic nephroma, and renal cell carcinoma)
Up to 8% of children with Wilms tumor have acquired ____________
von Willebrand syndrome at the time of diagnosis.
peak age Wilms Tumor
diagnosed between 6 months-5 years (peak age is 1-3 years)
Syndromes associated with Wilms’ tumor (3)
- WAGR syndrome
- Denys-Drash Syndrome
- Beckwith-Wiedemann Syndrome
WAGR Syndrome characteristics (3)
- Aniridia (absent iris)
- Genital anomalies
- Mental retardation
Denys-Drash Syndrome characteristics (2)
- Gonadal dysgenesis
- Nephropathy renal failure
incidence of Wilms tumor
most common abdominal tumor (1/100,000 < 15 years)
and
most common solid renal tumor beyond the first year of life
patho of Wilms’ tumor
These tumors arise from persistent immature parenchymal renal tissue (referred to as Wilms tumorlet cells), often in the periphery of the kidney (as opposed to the collecting ducts), enclosed by a pseudocapsule.
what suggests a less favorable response to chemotherapy and less favorable long-term prognosis with Wilms tumor
The presence of anaplastic cells (in 4% of Wilms tumors) and, more specifically, whether the cells are focal or diffuse in the tumor, and older age at the time of presentation suggest a less favorable response to chemotherapy and less favorable long-term prognosis
3 distinct tissue cell lines in Wilms tumor
- Epithelial
- Blastemal
- Stromal
With tailored multimodal therapy, the survival from Wilms tumor in the past several decades has increased dramatically, from ____________ to ____________
30% to ~90%
Presentation of Wilms tumor is similar to other intra abdominal tumors →
an incidental mass on physical examination
Congenital anomalies coexist with Wilms tumors in …
12% of children
- genitourinary anomalies (5%)
- hemihypertrophy (2.5%)
- aniridia (1%)
wilms tumor is 2x as frequent in children with ____________
- horseshoe kidneys than with normal kidneys
- also more frequent in those with multicystic dysplastic kidneys.
other s/s Wilms tumor (5)
- Polycythemia
- Acquired vWF disease ( < 10%)
- Microscopic hematuria (25%)
- Overt hematuria = rare
- Systemic HTN (25%)
anesthesia management of Wilms Tumor (3)
- Potential for massive and rapid blood loss must be anticipated
- Invasive monitoring and large-bore IV access (upper extremities should the tumor extend into or compress the inferior vena cava) with adequate blood warming capability is mandatory
- Rapid infusion device should be close
Anticipated Potential Complications during Anesthesia in pts with Wilms Tumors include (6)
- Hypertension (precipitated by tumor handling)
- Coagulopathy (acquired von Willebrand disease)
- Extension of the tumor into the proximal inferior vena cava or right atrium
- Pulmonary tumor emboli
- Acute right heart failure
- Considerations concerning preoperative or previous treatment with chemotherapeutic drugs
Every burn patient, especially those with inhalation injuries, must be considered …
hypoxic and exposed to CO.
during transport to hospital and on admission, pts with inhalation injury should be…
given high inspired concentrations of O2 = mandatory, pending evaluation of the severity of CO poisoning and pulmonary injury
Direct injury to the airway and alveoli occurs in children with inhalation of:
smoke, flames, superheated air, noxious gases, or steam.
When a child is burned in an enclosed space (house, automobile) or if thermal burns or carbonaceous materials are evident about the mouth and nose, ____________________
inhalational injury is probable.
Upper airway obstruction in inhalational injury is caused by… .
edema of the lips, nose, tongue, pharynx, glottis, and subglottis is very common.
The __________________________ beginning in the first hours after the injury and lasting several days, makes delayed intubation hazardous if not impossible
decreasing patency of the airway resulting from rapidly increasing edema,
Prophylactic intubation should be performed in any case of …
severe facial burns or when pulmonary burn and upper airway inhalation injury are suspected
One of the most common manifestations of chronic renal failure is _______________
anemia (the result of erythropoiesis, hemolysis, and bleeding)
Most children are maintained on chronic folic acid therapy to prevent ____________________
megaloblastic erythropoiesis
Children scheduled for erythropoietin therapy should begin oral iron, vitamin C, and folic acid ______________ to ensure adequate iron and folic acid stores to facilitate erythropoiesis.
2-3 weeks in advance
The pediatric appearance of neural tube defects can be due to ____________________.
maternal folic acid deficiency.
Preconceptual folic acid supplementation has reduced the prevalence of NTD by __________________.
30%-50%.
⭐️
red flags for sedation
- Apnea
- Unstable cardiac disease
- Respiratory compromise
- Craniofacial defect
- History of a difficult airway
- Active GERD or vomiting
- Hypotonia and lack of head control
- Allergies to sedatives
- Prior failed sedation
- Tremors, seizure hx, etc.
cardiac issues immediately after burn injury
- CO decreased due to decreased blood volume and compressive effects that impair venous return
- Direct myocardial depression & circulating myocardial depressant factors
what are the circulating myocardial depressant factors (4)
- Interleukins
- TNF
- altered β-adrenergic receptor modulation
- free radicals (severe 3rd degree burns)
what happens 3-5 days after burns
Hypermetabolic state: 2-3x increase in CO
Closure of burn usually __________ metabolic demand.
decreases metabolic demand, therefore decreasing CO
HTN with burns can result from what 6 factors?
- poor pain control
- catecholamines
- ANF
- RAAS
- endothelin-1
- vasopressin
________________ may attenuate hypermetabolic burn response
Propranolol may attenuate hypermetabolic response
what is myelomeningocele
- A type of Spina Bifida
- The meninges, spinal fluid, spinal cord and nerves protrude through the defect in the posterior arch of the vertebrae.
- It appears as a covered sac-like cyst or open protrusion in the lumbar or lumbosacral regions of the neonate.
myelomeningocele repair
- The defect is dissected and layers are separated and repaired
- The edges of the spinal cord are mobilized from the adjacent epithelium and overlapped to form a closed tube.
- The dura is dissected from the fascia and closed over the spinal cord.
t/f the lamina defect is reconstructed in myelomeningocele repair
The lamina defect is not reconstructed.
The lamina defect may be addressed when the child is older if kyphosis or vertebral angulation develops.
surgery considerations for myelomeningocele repair
- Maintain “defect” covered with sterile dressing
- Positioning for induction and intubation may be challenging:
- Place the meningomyelocele or encephalocele inside a doughnut pillow or in between rolls to prevent pressure injuries. May need additional padding for shoulder and head.
- Alternatively, place patient in the left lateral decubitus position with an assistant applying forward pressure from the back of the head and backward pressure on the shoulders to prevent neck extension
- Position for surgery: prone
Omphalocele vs Gastroschisis
omphalocele incidence
It occurs in 1/5000 births
Infants with omphalocele may have these associated conditions ….
- genetic
- cardiac
- urologic (exstrophy of the bladder)
- metabolic abnormalities (Beckwith-Wiedemann with visceromegaly, macroglossia, hypoglycemia, and polycythemia)
bowel in omphalocele
The bowel is morphologically and usually functionally normal.
Vein of Galen malformation
Rare, congenital brain malformation that occurs when blood from abnormally enlarged cerebral arteries shunts into a dilated vein of Galen
Large malformations, especially those involving the posterior cerebral artery and vein of Galen, may manifest as
- congestive heart failure (high-output heart failure, often with pulmonary hypertension) in the neonate
Consumption of coagulation factors and platelet destruction may further complicate the clinical picture.
prognosis for Vein of Galen malformations
The prognosis for these types of arteriovenous malformations is quite poor.
Saccular dilation of the vein of Galen may manifest later in infancy or childhood as …
hydrocephalus owing to obstruction of the aqueduct of Sylvius.
what is craniosynostosis
the premature fusion of cranial sutures occurring within the first 20 months of life.
how can craniosynostosis cause neurologic damage (2)
- The early fusion prevents normal skull expansion and results in facial deformities.
- Compression and increased ICP can lead to neurologic damage if not repaired.
simple or non syndromic craniosynostosis
- 60%-80%
- involving closure of one suture
complex/syndromic craniosynostosis
- 20%–30%
- involving closure of two or more sutures and is often associated with a variety of clinical features and metabolic diseases
_________________ is the most common form of craniosynostosis
Scaphocephaly (50%)
what is scaphocephaly
the most common form of craniosynostosis and is caused by the fusion of the sagittal suture resulting in elongation in the anteroposterior direction.
plagiocephaly
incidence & cause
- 20%
- results from unilateral synostosis of a coronal suture, producing a unilateral “tilting” forehead and orbital anomalies
trigonocephaly
incidence & cause
(10%) is the result of premature closure of the metopic suture, resulting in a triangular shaped head and hypotelorism
brachycephaly
incidence & cause
(9%) results from the bilateral fusion of the coronal suture causing an expansion in the lateral directions, broadened skull & midface hypoplasia
1/2 of children with ____________ have developmental delays
brachycephaly
Most commonly associated with syndromic craniosynostosis
brachycephaly
Syndromic craniosynostosis is associated with genetic abnormalities and is most commonly seen in what 2 syndromes?
Apert and Crouzon syndromes
syndromic craniosynostosis has been linked to…
alterations in fibroblastic growth factor signaling pathways – involved in bone & cartilage development
syndromic craniosynostosis and IQ
- Timing of surgery may affect the child’s IQ
- Less than 1 year = Higher IQ
what is the oculocardiac reflex
Traction on the extraocular muscles and levator (eyelid elevator) or external pressure applied to the globe triggers an afferent signal through the trigeminal nerve that activates parasympathetic output (efferent signal) through the vagus nerve, resulting in many types of dysrhythmias which include sinus or junctional bradycardia, atrioventricular block, ventricular ectopy, and asystole.
what kind of block may trigger oculocardiac reflex
Retrobulbar block with local anesthetic may precipitate the trigeminovagal (oculocardiac) reflex
as a result of external pressure sensed on the globe, and the local anesthetic may not completely prevent the OCR response to further surgical stimulation or manipulation.
