Week 10 - Neurosurgery, Thoracic, General abdominal an urology surgery. Flashcards
Neurosurgery
Developmental Considerations
Central Nervous System
- In the preterm infant, brain stem evoked potentials are ________; as they mature, respiratory control mechanisms mature also.
- In the neonate, the myelination of nerve fibers is _________; the cerebral cortex is less developed.
- _________ may be elicited that are not seen in older children.
- prolonged
- incomplete
- Reflexes
Neurosurgery
Cranium and Intracranial Pressure
- Skull is less ______ in infants as compared to adults.
- Increases in volume (blood, CSF and brain tissue) can be accommodated by expansion of the fontanelles and separation of the suture lines.
- Palpation of the _________ can be used to assess intracranial pressure in infants.
- rigid
- fontanelles
Neurosurgery
Cerebral Blood Flow and Intravascular Hemorrhage
- Cerebral blood flow (CBF) is pressure dependent.
- In sick neonates, autoregulation of CBF is ________.
- Hypotension may lead to cerebral ischemia.
- In preterm infants, rupture of fragile capillaries may cause an intracerebral hemorrhage leading to an ____________.
- impaired
- intraventricular hemorrhage (IVH)
Neurosurgery
- _______________ injury is a major cause of persistent brain injury in small preterm infants.
- This may occur as a result of IVH or as a consequence of prematurity, hypoxia, ischemia, and inflammation.
- ______________ therapy may reduce the incidence of severe IVH.
- Periventricular white matter
*Indomethacin (NSAID)
Neurosurgery
- IVH (grades 1 – IV) can occur during the _________ days of life.
- IVH is the leading cause of morbidity and mortality in ____________.
- Predisposing factors to IVH include: hypoxia, _______,________, fluctuations in arterial or venous pressure, low hematocrit, overtransfusion, and rapid administration of ______________.
- first few
- small, preterm infants
- hypercarbia, hypernatremia, hypertonic solutions (i.e., sodium bicarbonate).
Neurosurgery
- Avoid procedures that increase ICP, blood pressure and anterior fontanelle pressure such as ________ intubations and aggressive _______ of the ETT.
- Analgesia and anesthesia should be provided during surgery and painful procedures.
Consider ____________ in the infant population.
- “awake” , suctioning
- 24% glucose (i.e., “Sweet-Ease”)
Neurosurgery
Cerebrospinal fluid (CSF) and hydrocephalus
- CSF, which occupies the cerebral ventricles and the subarachnoid spaces surrounding the brain and spinal cord, is formed by the choroid plexus in the temporal horns of the lateral ventricles, the posterior portion of the third ventricle, and the roof of the fourth ventricle.
- ________ and _________ vessels and blood vessels of the brain and spinal cord also contribute small amounts of CSF.
- Meningeal and ependymal
Neurosurgery
- The choroid plexuses are cauliflower-like structures consisting of blood vessels covered by thin epithelium through which CSF continuously exudes.
- In the adult, the rate of secretion is ~_______ mL/day.
- About ~________ mL circulating at any given time.
- In the adult, CSF is formed at ~ ___ - ____ mL/hr.
- 500;
- 150
- 20-21
Neurosurgery
- CSF flow is initiated by pulsation in the ___________.
- From the lateral ventricles, CSF passes into the third ventricle via the foramen of Monro and along the aqueduct of Sylvius into the fourth ventricle, with each ventricle contributing more fluid by secretion from its choroid plexus.
- CSF then flows through the two lateral foramina of Luschka and the midline foramen of Magendie into the cisterna magna and throughout the subarachnoid spaces.
- CSF is reabsorbed into the blood by ____________ through the __________, which project from the subarachnoid space into the venous sinuses.
- choroid plexus
- hydrostatic filtration, arachnoid villi
Neurosurgery
Goals of anesthesia for neurosurgery are neuroprotective.
Avoid cerebral edema
Avoid cerebral hypoxia
Avoid cerebral hypoperfusion
Avoid cerebral hypermetabolism
Avoid neuronal membrane damage
Neurosurgery
General principles of intraoperative management
- Increased ICP with:
- Risk for bleeding
Adequate IV access, Type & Cross with blood available in the OR
Consider monitoring CVP and/or arterial line - Difficult airway
Have difficult airway cart in the room; have additional experienced staff on hand; have multiple back up plans in accordance with the difficult airway algorithm - Risk for ________
- Possible CVL to aspirate air
- Precordial doppler: __________.
- PaCO2; volatile anesthetics; induction/emergence
- VAE
- (millwheel murmur)
Neurosurgery
- Ask the surgeon if nerve monitoring is planned before choosing to use a NMB.
- Surgeon may need to identify nerve roots before patient is paralyzed.
- Do you need to use a paralytic? Low dose Rocuronium (_________) may be used to facilitate endotracheal intubation.
- In infants and children, _______ or __________ may be given before intubation to prevent reflex bradycardia and to decrease secretions.
- 0.3mg/kg
- atropine or glycopyrrolate
Myelodysplasias
- _____________causingdefective developmentofanypartofthespinal cord
- Results from failure of the neural tube to fuse during early fetal development (during the first _______weeks of gestation).
- Neuraltubedefect
- 4
Encephalocele
- A protrusion of the _______ and _______ through a defect in the skull, resulting in a sac-like structure.
- Most occur in the ______ area; however, it may also occur in the _______,________, and _________ regions.
- brain and meninges
- occipital
- frontal, parietal, and nasopharyngeal
Myelomeningocele
- The ______, _______, _________ and _________ protrude through the defect in the posterior arch of the vertebrae.
- It appears as a covered sac-like cyst or open protrusion in the ______ or ___________ regions of the neonate.
- A type of ___________
- meninges, spinal fluid, spinal cord, and nerves
- lumbar or lumbosacral
- Spina Bifida
Neurosurgery
- Both conditions (encephalocele and myelomeningocele) may be detected before birth by elevated maternal serum _________, fetal _______ scans, and high resolution ________.
- While the primary cause is unknown, it is linked to a maternal _________ deficiency.
Pre-conception folic acid supplements reduce neural tube defects by up to ________%.
- alpha fetoprotein, MRI, ultrasound.
- folic acid; 70
Encephalocele Repair Procedure
- Most often repaired through ________: The dura is opened, the sac is removed, the dura is closed, and the skull is closed with bone or artificial plate applied to repair the skull defect.
- Encephalocele protrusion in the nasopharynx is repaired _________ by visualization of the defect, a layered repair using bone or cartilage, followed by a free muscosal graft.
- __________ surgery is performed for protrusions in the skull (nose, sinuses, forehead) affecting the cribiform plate and nasal defect.
- craniotomy
- endoscopically (FESS)
- Craniofacial
Myelomeningocele Repair Procedure
- 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. The ________ is not reconstructed.
- The lamina defect may be addressed when the child is older if _______ or _________ develops.
- An attempt is made to separate and repair the lumbosacral fascia.
- Finally, the subcutaneous tissue and skin layers are arranged and closed. For more severe cases, skin or muscle flaps may be used to cover the spinal defect.
- lamina defect
- kyphosis
- vertebral angulation
Neurosurgery: encephalocele and myelomeningocele
- Maintain “defect” covered with ___________.
- 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 _______________ 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: __________.
- sterile dressing.
- left lateral decubitus
- prone
Neurosurgery: encephalocele and myelomeningocele
- Body temperature maintenance may be challenging:
- Pre-warm OR to _______.
- Avoid unnecessary exposure of body parts
Warm all fluids; warm and humidify all gases - Use ______________ (during induction and emergence)
- Warm skin preparation solutions to __________
Use warm incubator postoperatively. - Blood loss may be significant: Have cross-matched blood available
- Only use _________ equipment/supplies
- 24ºC (75ºF)
- infrared heating lamp
- 40ºC
- latex free
Neurosurgery: encephalocele and myelomeningocele
Maintenance
* Muscle relaxation as needed and allowed by surgeon.
* Controlled ventilation to maintain EtCO2 ____-____.
- Check positioning, padding, and ETT placement after every position change and periodically.
- Maintain body temperature and hemodynamic stability.
Monitor & maintain fluid balance carefully. - ________ and ______ can be used as guide for replacement as accurate measurement of blood loss may be difficult.
Emergence:
* Patients almost always remain intubated for the first _______ hours.
- 35-40.
- Arterial systolic blood pressure and HCT
- 24
Arnold-Chiari Malformation
- is an anatomic anomaly of the _____,_____ and _____.
- Results in a downward displacement of the _______ through the foramen magnum into the _________.
- cerebellum, brainstem and craniocervical junction.
- cerebellum, spinal canal
Patients with Arnold Chiari malformations may present with:
- Apneic episodes
- Depressed or absent gag reflex
- Difficulty Swallowing
- Recurrent aspiration
- Elevated ICP
- Stridor
- Pain (mainly neck and occipital headaches)
- Tongue atrophy
Neurosurgery: Arnold Chiari malformations
Abnormal control of ________
- Stridor –> may intubate preoperatively
- May not improve immediately postoperatively
- Possible _____________
Recurrent aspiration
- Impaired ________ –> difficult ventilation possible
Patient positioned prone with neck ________
- Nasotracheal tube may be used; less likely to kink; tape is unlikely to be loosened by saliva
- ventilation
- postoperative apnea
- pulmonary function
- flexed
Neurosurgery: Arnold Chiari malformations
- Increased _________ may be present resulting in N/V, electrolyte disturbances.
- Blood loss may be rapid, massive and difficult to measure accurately requiring invasive monitoring, IV access, have blood products available
- Intraoperative neurophysiologic studies or __________ may be necessary; high concentrations of inhalational agents may interfere with the recording; consider ________.
- ICP
- cortical SSEPs; TIVA
Neurosurgery: Arnold Chiari malformations
Prone position
* Consider a nasotracheal tube in small children —> secure appropriately
* Prone on a frame or pins or bolsters with __________° head-up tilt
* Monitor vital signs carefully during manipulation in the region of the _______.
Sitting position
* Concern for air embolism —> use precordial Doppler probe and capnograph; place CVP line to aspirate air in case of embolism and to guide fluid therapy
* Zero arterial transducer at level of the ear and CVP transducer at level of the heart
* CV stability —> Lower limbs ________ to promote venous return
- 15
- brain stem
- bandaged
Neurosurgery: Arnold Chiari malformations
- Procedure may be performed in ____ or______ position.
- Head placed in __________.
- Midline incision made and dissection is carried down to the skull and the posterior arch of __________.
- Paramedian _________are placed to aid in the suboccipital craniectomy.
- prone or seated
- Mayfield pin fixation
- C1
- burr holes
Neurosurgery: Arnold Chiari malformations
Full recovery from anesthesia for extubation.
Smooth extubation
- IV _________ mg/kg
If patient is unresponsive, or shows signs of respiratory depression, then patient should remain intubated.
- Lidocaine 1.5
Neurosurgery: Arnold Chiari malformations
Preserve Optimal Intracranial Conditions:
* Blood Pressure (MAP – ICP = CPP)
* Support Cerebral Autoregulation
* Fluid Status
* Routine Monitoring of Neurologic Signs
* Anticonvulsants
Alterations in Neuro-Hormonal Regulatory Systems (i.e., ADH)
Bleeding, Infection
Local anesthesia (___________ with ___________ epinephrine _______ ml/kg)
Postoperative Analgesia
0.25% bupivacaine w/ 1:200,000 (0.5)
Neurosurgery: Tumors
- Clinical presentation:
- Tumor infiltration into hypothalamus leads to disturbances of :
- Visual impairment
- Endocrine deficits:
Growth hormone, gonadotropins, ACTH, TSH, ADH
Memory,
Attention,
Motivation,
Impulse control,
Socialization
Neurosurgery: Tumors
- _____,______, and ________ have been shown to increase intra- and post- operative morbidity rates
- Children were found to be more likely to present with headache, nausea/vomiting, and papilledema (swelling of the optic nerve), reflecting the increased incidence of increased ________ and _______ in this patient population.
- Diabetes insipidus, hypoadrenalism and hypothyroidism
- intracranial pressure and hydrocephalus
Neurosurgery: Tumors
Endocrine Disturbances (6)
- Increased thirst or urination
- Unusual sleepiness or change in energy level
- Unusual changes in personality or behavior
- Short stature, slow growth, or delayed puberty
- Hearing loss
- Obesity
Neurosurgery: Tumors
Increased ICP s/s: (5)
- Headaches including morning headache or headache that goes away after vomiting
- Vision changes
- Nausea and vomiting
- Loss of balance or trouble walking
- Increased head size
Neurosurgery: Tumors
________ therapy may be warranted as part of the anesthetic care plan
- Corticosteroid therapy may begin preoperatively
Agents to help decrease ICP:
- Steroid
Mannitol
3% saline
Propofol
Isoflurane
Neurosurgery: Tumors
Avoid the following:
* Agents that may increase ICP:
- Overstimulation
- Prolonged laryngoscopy
- Noisy environment
- _________________ because it is more difficult for the surgeon to confirm that the entire tumor has been removed.
- SCh, Ketamine, etc.
- Hyperventilation
Neurosurgery: Tumors
be ready with:
Standard monitors plus:
A-line
CVP
Urine output
± Doppler
Long surgery
Positioning
Semi-sitting (possible VAE)
Pressure points
Table turned 180⁰
Minimal blood loss unless there is accidental perforation of ________ or ______.
- internal carotid or cavernous sinus
Neurosurgery: Tumors
Look for diabetes insipidus
Fluid replacement
Rapid correction - seizures, coma, cerebral edema
Serial serum osmolalities should be checked
Vasopressin (_____-_______ U/kg/hour)
Look for optimal neurosurgical conditions
Blood pressure control
- High blood pressure leads to higher ICP
- Low blood pressure leads to ischemia
- 0.001-0.01
Neurosurgery: Tumors
Increased ICP may occur and/or be severe
* Avoid use of ______ and/or ________.
* Vomiting may ensue d/t increased ICP –> check electrolytes preoperatively
* Acute symptoms of increased ICP demand ________.
_______ extubation (to permit rapid neurologic assessment)
Large and secure IV access
Latex precautions
- succinylcholine and/or ketamine
- immediate surgery
- Awake
Hydrocephalus
is an abnormal accumulation of CSF within the cranium that may either be _______ or ________.
Obstructive hydrocephalus is caused by a:.
Considered “____________” when the fluid’s pathway proximal to the subarachnoid space is obstructed, as in _______ or _______.
- obstructive or non-obstructive
- blockage in the flow of CSF
- non-communicating; aqueduct stenosis or Arnold-Chiari malformation.
Non-obstructive hydrocephalus, or “_________,” occurs when CSF pathway into the subarachnoid space is open, such as may occur after ______________.
Caused by a reduction in the volume of _________, with secondary dilation of the _______
- and/or an __________of CSF as in choroid plexus papilloma
- and/or reduced ________ of CSF due to scarring.
- communicating; chronic arachnoiditis
- brain substance, ventricles
- over-production
- reduced reabsorption
Neurosurgery: Hydrocephalus
- Hydrocephalus is often managed surgically with placement of a ______.
- Hydrocephalus shunting involves the implantation of two catheters and a flow control valve system to drain the excess accumulation of cerebrospinal fluid (CSF) from the brain’s ventricles (or the lumbar subarachnoid space) to another part of the body where it can be absorbed (the _______ or __________).
- shunt
- peritoneum or the right atrium
Craniosynostosis
- Is the premature fusion of _________ occurring within the first ______ months of life.
- The early fusion prevents normal skull expansion and results in __________. Compression and increased ICP can lead to neurologic damage if not repaired.
- cranial sutures; 20
- facial deformities
Craniosynostosis
- ____________ is the most common form of craniosynostosis and is caused by the fusion of the sagittal suture resulting in elongation in the ___________ direction.
- _____________ is the next most common form and results from the fusion of the coronal suture causing an expansion in the ________ directions. Half of these children also have developmental delays.
- Scaphocephaly; anteroposterial
- Brachcycephaly/Plagiocephaly; lateral
Craniosynostosis post-surgery
Facial edema - may be upsetting to parents
Cerebral edema
* Drain(-s) may be needed, placed under scalp
* Diuretics may be given (______ , _______)
* Head of bed elevation ______
Control of ICP
Avoid straining, crying, coughing, hypoventilation, hypoxemia
Pain - Relatively low pain scores
Helmet
Protection and/or remodeling
Worn for several months and refitted as needed for progress
- Mannitol / Furosemide
- 15
Vascular Malformations
Without capillaries, blood is shunted directly into the vein at a ________ output.
This increases the ________ of the heart.
If left untreated, VOGM often results in abnormal:
high; workload
Brain development,
Mental retardation,
Strokes,
Seizures,
Paralysis,
Learning difficulties,
Hydrocephalus and
ultimately cardiac failure and death.
Advantages of thorascopic versus open chest surgery (8)
Techniques for one-lung ventilation in pediatric patients
Use of Single-lumen Endotracheal tube (intentional main-stem bronchus intubation) .
Use of Balloon – Tipped Bronchial Blockers
Use of Univent tube (Conventional ETT with second lumen containing small blocker catheter)
Traditional double lumen tube
Surgery for Pectus Excavatum
- Chest x-ray (heart displaced to ______ and ________).
- PFT’s ( Normal to reduced _____ & _____, in severe cases, may demonstrate a _________).
- ECG ( ______; _________)
- Echocardiogram (increased incidence of __________)
- Labs (blood loss) and ABGs
- Exercise tolerance
- left; compressed
- FVC & TLC; V/Q mismatch
- arrhythmias, right axis deviation
- MVP
Surgical issues for Pectus Excavatum
- Blood loss minimal to massive
- Pneumothorax
- Flail chest
- Post-operative atelectasis
- Pain management requires a thoracic or lumbar epidural.
Congenital Lobar Emphysema
- Abnormally emphysematous lobe that communicates with the bronchial tree
- Over distension of a lobe with ________ and ________ changes in remainder of the lung
- Approximately 10% have associated anomalies
Emergency __________ may be required
* Volatile agents, _________ ventilation and no _________.
- air trapping; compressive
- lobectomy
- spontaneous; nitrous
Congenital Cystic Adenomatoid Malformation
A cystic, solid, or mixed intrapulmonary mass that communicates with the normal _________________.
tracheobronchial tree.
Pulmonary Sequestration
It is a portion of ____________ lung tissue that does not contain ___________.
nonfunctioning; bronchial connection
Pyloric stenosis
- A common surgical problem of infancy and may occur in up to 1 in 500 births.
- First born _______ are more commonly affected – ________ to _______ week of life
- It is defined as hypertrophy of the muscle of the __________ which causes obstruction and persistent vomiting.
- It is a _________ emergency; not a __________ emergency. Therefore, electrolytes need to be normalized prior to surgery.
- males; 2nd to 6th
- pyloric spincter
- medical; surgical
Laboratory Findings for early pyloric stenosis
Laboratory Findings for very late pyloric stenosis
Laboratory Findings for late pyloric stenosis
Wilms Tumor Staging
stage
I
II
III
IV
V
Esophageal Atresia and Tracheoesophageal Fistula
- The incidence of TEF is approximately 1 in 2500-3000 live births with more than 85% are associated with ____________.
- Prenatal diagnosis: ___________ and ultrasound (44%) predictive
- Clinical signs with __________ , OG tube
- More ______; 20-30-% of infants are premature
- Cardiac (29%), GI (14%), GU (14%), musculoskeletal (10%) or craniofacial anomalies
- CHD: most common is ______. Others:
- Esophageal atresia (EA)
- polyhydramnios
- 1st oral feedings
- male
- VSD
also
PDA,
TOF,
ASD,
AV canal,
coarctation of aorta and
Right sided aortic arch
Esophageal Atresia and Tracheoesophageal Fistula : Preop concerns
Airway management
Aspiration
Co-existing diseases – review workup
Ligation of TEF is ________ although not _____ (unless respiratory insufficiency)
Avoid _______
Upright positioning (GI reflux)
Intermittent suctioning of _______.
Antibiotics as indicated
- urgent; emergent
- feeding
- upper pouch
Esophageal Atresia and Tracheoesophageal Fistula : Surgical technique
- ____________ or _________ using posterolateral extrapleural approach
- ________ ventilation
- Fistula ligated and the esophagus is primarily anastomosed
- Precordial stethoscope placed _________ (right thoracotomy)
- Pre-ductal and post-ductal pulse oximetry
- Right thoracotomy or thoracoscopy
- One-lung
- left axilla
Gastroschisis
Omphalocele (exomphalos)
VATER/VACTERL syndrome
Vertebral defects
Anal atresia
C= CARDIAC DEFECTS
Tracheoesophageal fistula
Esophageal atresia
Renal defects/radial abnormalities
L= LIMB (radial) Dysplasia/aplasia
Congenital Anomalies Associated with CDH
Ureteral Reimplantation
- Surgical correction for __________.
- Anesthesia issues:
- Vesicoureteral reflux (VUR) (i.e., reverse flow).
- Length of surgery
- Bladder spasms
Prune-Belly Syndrome
Triad Syndrome or Eagle-Barrett Syndrome
It is caused by agenesis of the abdominal musculature, which results in:
- A thin walled, protrudent abdomen
- Distal urinary tract obstruction
- Cryptorchidism
(undescended testes)
Bladder Exstrophy
- Typically a lengthy procedure
- EBL can be _________; 2 PIV and/or CVL
- Due to evaporative losses and third-space fluid loss can experience ____________
- excessive
- large fluid shifts.
Hypospadias repair
- Congenital defect of abnormal positioning of the urethral meatus. Urethra opens along the ________ of the penis anywhere from just proximal to the glans to the scrotum.
- It is often associated with a __________ (head of the penis curves downward or upward)
- Not usually associated with:
- undersurface
- chordee
- other congenital defects
Testicular Torsion repair
- Acute scrotal pain resulting from twisting of the spermatic cord with _______ compromise of the testicle
- May be associated with ___________.
- Ischemia occurs in ___-____ hours
- vascular
- incarcerated hernia
- 6-8
