Anesthesia Considerations for Premie, Neonate, and Peds Flashcards
1
Q
special anesthesia considerations for kids
A
- infection risk
- IVH
- apnea risk
- temperature control
- ventilation/oxygenation
- saturation goals 90-94%
- glucose, fluid and lyte management
2
Q
MAC
A
inhaled anesthetic depth at which 50% of patients respond to painful stimulus with movement
3
Q
MAC in prematurity
A
- varies with age and espeically in premies and critically ill infants
- more susceptible to cardio-depressant effects of inhalational anesthetics
4
Q
fetal hemoglobin
A
- main oxygen transport moelecule in utero and persists to 6 months of age
- functionally able to bind oxygen with greater affinity than adult hemoglobin
- results in leftward shift of oxy-hgb dissociation curve
- concentration of HbF in utero is 50% greater than that of the mother
5
Q
physiologic anemia in the newborn
A
- healthy term infants, fetal hemoglobin concentration falls during the 9th and 12th weeks
- due to decrease in erythropoiesis and shorter RBC lifespan
- premies have slightly lower hgb levels at brith
- nadir lower and reached earlier around 4-8 weeks
6
Q
nadir of hgb in term infants
A
10-11 g/dL
7
Q
nadir of Hgb in premies
A
7-9 g/dL
8
Q
when does Hgb stabilize
A
3rd month of life at around 11-12 g/dL
9
Q
PDA ligation
A
- PDA may incur significant L to R shunting –> excess pulmonary blood flow –> CHF –> resp failure
- pulm HTN or RDS of infant may cause R to L shunting –> cyanosis
- surgical therapy = left thoracotomy, retraction of L lung
10
Q
PDA medical therapy
A
- admin of COX inhibitor
- indomethacin or ibuprofen
11
Q
preop for PDA ligation
A
- assess art pressure, HR, ABG, vent settings, and FiO2
- severe bleeding may occur quickly due to the close proximity to aorta and pulmonary artery –> HAVE PRBCs ready to go!!
- ABX (risk for endocarditis)
12
Q
introp management of PDA ligation
A
- BP monitoring (R arm = cerebral perfusion)
- pulse ox on R arm and lower extremity (to monitor pre and post ductal sats)
- ETCO2 monitoring
- ETT minimal leak because surgical retraction of lung may mean increased inspiratory pressure and inspired oxygen
- opioids, amnestic and muscle relaxation
- intercostal nerve block by surgeon at completion of surgery
13
Q
complications of PDA ligation
A
- inadvertent ligation/lac of aorta or pulmonary artery
- aortic clamp = loss of signal to lower extremity pulse ox
- pulm artery clamp = decrease oxygen sat to both extremities and end tidal CO2
14
Q
what happens if PDA ligation is successful?
A
- increased arterial diastolic and mean pressure
- PDA murmur disappears
15
Q
NEC (necrotizing enterocolitis)
A
- illness most often found in LBW with mortality of 50%
- 85% cases infants <1500g
- morbidity with NEC = short gut, sepsis, adhesions
16
Q
NEC cause
A
- uncertain and mutlifactoral
- result = intestinal mucosa injury secondary to ischemia and ulceration of bowel
17
Q
early signs of NEC
A
- abdominal distention
- bloody diarrhea
- temperature instability
- lethargy
18
Q
what is indication of urgent/emergent surgery for NEC?
A
- bowel perf and free air in the abdominal cavity
- need to resect the dead bowel
19
Q
NEC presentation
A
- metabolic and hematologic abnormalities
- hyperkalemia
- hyponatremia
- metabolic acidosis
- hyper or hypoglycemia
- coagulopathy/DIC
- anemia
- intubated, unstable, NGT/OGT
20
Q
surgical management of NEC
A
- EMERGENCY
- intestine can no longer hold waste, so bacteria may pass into bloodstream –> sepsis
- involves initial primary peritoneal drainage or laparotomy with resection of necrotic bowel
- primary peritoneal drainage = smaller incision, fewer anesthetic requirements, done at bedside
21
Q
anesthetic management of NEC
A
- aspiration risk –> RSI or awake intubation
- inhalation agents poorly tolerated due to low BP; narcotic technique with muscle relaxation for hemodynamic instability
- avoid N2O
- vascular access (at least 2)
- vasopressor infusions (dopa and epi) for maintenance of renal perfusion and CO
- large fluid loss and blood loss
- transfusion in neonates per kg
- correct electrolytes and glucose
22
Q
PRBCs for kiddos
A
10-15 mL/kg
23
Q
FFP for kiddos
A
10-15 mL/kg
24
Q
allowable blood loss formula
A
ABL = [EBV x (starting Hct - allowable Hct)]/starting Hct
25
inguinal hernia repair
- common in premies
- complications = incarcerated bowel, intestinal obstruction, gonadal infarction, infection, hematoma, recurrent hernias
- general and/or regional
- LMA if defect is small
- ETT for large defect
26
Eye surgery for ROP
-treated with cryotherapy, laser photocoagulation, slceral buckling surgery and/or vitrectomy
27
diode laser photocoagulation for ROP
- for moderate ROP, maybe bedside
- 10-30 min treatments in series every few weeks
- topical anesthesia alone, IV sedation, or GA
28
cryotherapy for ROP
- applies a freezing probe to the avascular retina in the OR
- requires GA
- often between 32 and 42 weeks PCA
29
slceral buckling and vitrectomy
- less frequently used with better screening and earlier treatment, performed for severe ROP with retinal detachment in the OR
- requires GA
- child is often older 6 months to 1 year
30
anesthesia for radiologic imaging
- MRI replacing US and CT for assessment of IVH due to lack of radiation exposure and is able to identify congenital lesions, vascular malformations and ischemic injury
- requires immobility
- anesthesia ranges from oral meds, sedation to general
- off site anesthesia considerations along with MRI compatible monitoring
- monitoring for post-op apnea considerations
31
CDH
- congenital diaphragmatic hernia
- diaphragm normally completes formation during 7th-10th week
- anatomic defects permit intrusion of abdominal contents into thoracic cavity
32
early CDH
- abdominal mass inhibits normal cardiopulmonary growth
- severity of lung hypoplasia - associated with severe morbidity and mortality - negatively correlates with gestational age at the time the hernia occurred
33
late CDH
- occurs near or even after delivery
| - associated with mature, well developed lungs and minimal problems with ventilation
34
bochdalek type hernia
- 95% of CDH
| - more likely to have concurrent birth defects including CHD and chromosomal abnormalities
35
hallmark signs of CDH
- hypoxia
- scaphoid abdomen
- evidence of bowel in thorax
36
why is CDH potentially lethal?
- pulmonary HTN
- pulmonary hypoplasia
- associated cardiac or congenital defects
37
CDH surgical approach
- surgery = standard of care in 1980s
- subcostal incision or thoracic laparoscopic
- recurrent defect may be approached through the abdomen and minimally invasive
- primary closure vs synthetic patch
- surgery may be delayed until cardiorespiratory and medically stabilized
- may occur before, after or during ECMO
- surgery transiently worsens pulm HTN and may cause persistent fetal circulation
- CDH outcomes function of the underlying pulm hypoplasia and pulm HTN
38
anesthetic management of CDH repair
- initial management includes definitive airway control and optimization of oxygenation and ventilation
- avoid mask ventilation to limit gastric insufflation
- supine or lateral
- pre and post ductal sat monitoring
- reactive pulmonary vasculature
- PIV x2, +/- CVC, aline (serial ABGs)
- EBL 5-10 mL/kg
- paralysis, narcotics, limited inhalation agent
- limited inspired O2, avoid N2O
- supportive care during transport may be challenging
39
omphalocele & gastroschisis
- external herniation of abdominal contents through an anterior abdominal wall defect
- may present with impaired blood supply to herniated organs, intestinal obstruction, and major intravascular fluid deficits
- ultrasound confirms presence
- large defects = C-section
40
gastroschisis
- intestines outside the abdomen through a hole in the abdomen
- just right of the umbilical cord
- exstrophy of belly/viscera through an abdominal wall gap
- results of occlusion of the omphalomesenteric artery during gestation
- 1 in 15,000 births
- not usually associated with other congential abnormalities
- herniated viscera are exposed to air after delivery resulting is worsening inflammation, edema, dilation with abnormal bowel function
41
omphalocele
- the intestines, liver, and other organs remain outside the abdomen in a sac
- usually right by the umbilical ring
- result of failure of the gut to migrate from the yolk sac into the abdomen
- 1 in 6000 births
- associated genetic, cardiac, urologic and metabolic abnormalities
- viscera emerge from the umbilicus and are covered with a membranous sac
42
management for gastroschisis and omphalocele
- maintenance of perfusion and reduction of fluid loss
- closure of abdomen is goal, however often delayed to avoid exposing the viscera to excessive pressure
- high intra-abdominal pressure may result in cardiorespiratory failure, renal failure, decreased hepatic function, ischemic bowel and death
- pressures > 20 mmHg poorly tolerated
- silo = temporary housing for bowel
43
anesthetic considerations for gastroschisis and omphalocele
- assess for associated anomalies
- increased IAP; gastric tube inserted to decompress stomach
- severe electrolyte disturbances, monitor blood glucose
- rehydrate (gastroschisis lose more fluid than omphalocele)
- prevent hypothermia
- aspiration risk maybe RSI, avoid N2O
- risk for infection
44
postoperative considerations for gastroschisis and omphalocele
- assess ability to extubate
- continue gastric suction until bowel function recovers
- continue IV fluids and glucose
- may require IV alimentation (weeks to months)
- often remain intubated with IV sedation, paralytics and opioids until clinical status stabilizes
45
criteria for aborting primary closure
- intragastric pressure > 20 mmHg
- intravesical pressure > 20 mmHg
- end-tidal carbon dioxide 50 mmHg or higher
- max ventilatory pressure of 35 cmH2O or greater
46
TEF
- tracheoesophageal fistula
- 1 in 3500 live births
- due to incomplete separation of the trachea and esophagus that begins during the 4th-5th week gestation
- survival >95%
- risks = pneumonia, poor nutrition, gastric distention (impairs ventilation)
47
S/S used to diagnose esophageal atresia with or without TEF
- excessive secretions
- coughing
- choking after first feeding
- recurrent pneumonias
- OG cannot be passed into the stomach
48
surgical repair of EA and TEF
- ligation of fistula and anastomosis of esophagus
- urgent but not emergent
- +/- G tube
- ligation of fistula
- anastomoese of esophagus atretic segments
- left lateral decubitus and R thoractomy (so effectively 1 lung ventilation due to the retractor)
49
how many types of TEF/EA are there?
5
| vary by the location of the fistula
50
what is the most common type of TEF/EA?
EA with distal TEF
| type C/IIIB
51
TEF and anesthesia
- challenging airway - consider fiberoptic and awake intubation (minimizes gastric distention, allows precise placement of ETT cuff)
- inhalation induction, avoid PPV, maintain spontaneous ventilation
- RSI
- confirm ETT placement
- crucial to place ETT between fistula and carina (distal to fistula; some will R mainstem and slowly withdraw until BBSE)
52
monitoring and hemodynamics for TEF
- left lateral position
- standard monitors
- a line for Q1H abgs
- L sided precordial to assess for tube migration
- minimal blood loss, BUT surgical site is close to some pretty big vessels!
- glucose infusion and monitoring
53
maintenance of anesthesia for TEF
- combination of inhaled and opioids
- avoid N2O
- muscle relaxation
- large surgical surface area (at risk for hypothermia)
- surgical traction may compromise lung, great vessels, trachea, heart and vagus nerve
54
TEF post op
- early extubation because prevents prolonged pressure of ETT on surgical site
- may also remain intubated but again this could cause excessive pressure on new anastomosis and reintubation could be traumatic
55
potential TEF complications
- RLN injury
- overlook additional fistulas
- recurrent fistulas can complicate recovery
56
early TEF complications
- anastomosis leak and strictures
- GERD
- feeding aversions
- esophageal dysmotility
57
long-term TEF complications
- strictures
- pulmonary disease
- tracheomalacia
