Neonatal Flashcards
1
Q
What are some neonatal concerns?
A
- Immaturity of organ systems
- high metabolic rate
- large ratio of body surface area to weight
- ease of miscalculating a drug dose
- nominal amounts of air in lines can be catastrophic
2
Q
What is the timeline for fetal development?
A
- 1st trimester:
- organogenesis- within 8 wks of conception
- injury or stress can cause abnormal organogenesis
- 2nd trimester:
- Organ function
- injury or stress can cause abnormal functional dev of organs
- 3rd trimester
- muscle and fat are gained
- injury or stress can cause smaller organs and reduced muscle or fat mass
- Extrauterine life is possible after ~22-24 wks
3
Q
How do the lungs develop?
A
- Lung development begins in utero at about 4 wks but lungs are functionally immature until term
- Growth occurs in 5 stages:
- embryonic
- pseudoglandular
- canalicular
- saccular
- alveolar
- Growth of parenchyma and surfactant system occurs during the saccular phase from wk 24-40
- 36 wks is magic # for surfactant
- maturation and expansion of alveoli occur during the alveolar period which begins near term and coninues to mature through adulthood
- 24 mil at birth
- 300 mil as adult
4
Q
What is persistent fetal circulation?
Primary cause?
Initial tx?
other treatment
A
- AKA Persistent pulmonary hypertension of the newborn
- PA pressures abnormally elevated causing the DA and FO to remain open or re-open
- leads to hypoxia d/t R-L shunting
- Primary cause: hypoxia and acidosis with concurrent inflammatory mediators
- severe birth asphyxia
- meconium aspiration
- sepsis
- congenital diaphragmatic hernia
- mom’s use of NSAIDS
- idiopathic
- Initial Treatment
- optimal oxygenation (PAO2 60-100)
- correct stressors (hypoglycemia or polycythemia)
- Other tx
- surfactant
- inhaled nitric oxide
- HFOV
- ECMO
5
Q
What happens with the umbilical cord clamping at birth?
What causes the functional closure of the ductus arteriosis?
How might this differ in a preterm infant?
A
- umbilical cord clamping:
- SVR increases
- left atrial pressure increases
- flow through FO ceases
- DA functionally closes due to increase in PaO2 > 60
- A preterm infant DA may remain open for several weeks and cause hemodynamic instability
- treated with prostaglandin inhibitor (indomethacin) or surgical ligation
6
Q
What is the APGAR scoring and how is it done?
A
- 5 signs measured in the newborn at 1 min and 5 minutes after delivery
- HR and resp effort are most important, color least
- HR <100 bpm generally signifies arterial hypoxemia
- Scoring:
- 0-2: severe asphyxia
- 3-4: moderate asphyxia
- 5-7: mild asphyxia
- 7-9: no asphyxia
- Score 3or less, follow NRP algorithm
7
Q
Why do healthy neonates have cyanosis at 1 minute?
What is the most common cause of persistent cyanosis?
A
- Healthy neonates still have cyanosis at 1 min d/t peripheral vasoconstriction in response to cold ambient temps (acrocyanosis)
- Persistent cyanosis most likely caused by acidosis and pulmonary vasoconstriction
8
Q
What is the NRP algorithm?
A
9
Q
How is a newborn/neonatal assessment done?
General
airway
A
- Accurate weight is essential!
- Overall appearance:
- skin color, mucous membranes
- looking for acrocyanosis
- central cyanosis warrants investigation
- Airway:
- tongue size/mobility
- chin (retrognathia)
- nasal patency/discharge
- intact hard/soft palate
- teeth?
*
10
Q
Newborn/neonatal assessment:
heart and lungs
neuro
back
musculoskeletal
A
- Heart and lungs:
- tachypnea
- flaring
- grunting
- retractions
- respirations may be “regularly irregular” (pauses should be <20 sec)
- murmors are common, assess pulses
- Neuro
- posture
- muscle tone
- sz
- head control
- quality of cry
- fontanelles
- Back
- spinal contour
- presence of cysts, sinuses, dimples, tufts of hair
- musculoskeletal
- normal resting position for an infant is inward flexion of upper and lower extremities
11
Q
What labs are relevent during a newborn/neonatal assessment?
A
- POC glucose
- CBC or HCT
- blood type
- Coombs
- bilirubin
12
Q
What is important regarding fluid management in the neonate?
What is newborn fluid requirement?
A
- Amount of incensible water losses are inversely porportional to gestational age
- higher skin permeability, higher ratio of body surface area to weight and higher metabolic demand
- radiant warmers and phototherapy increase insensible losses
- Neonatal kidneys are unable to excrete large amounts of excess water or electrolytes
- Newborn daily fluid requirement is 70 ml/kg/day and gradually increases throughout first week
- use 10% glucose for maintenance but NOT for replacement
13
Q
What is important regarding blood transfusion for neonates?
A
- There is weak expression of ABO antigens at birth so crossmatching is not always needed
- Transfused blood has more hgb A for better release of O2 to tissues
- There is risk of transfusion assoc graft versus host
- give leukoreduced, irradiated blood
- the radiation destroys lymphocytes
- High risk ionized hypocalcemia with FFP
- decreased ability to mobilize calcium and metabolize citrate
- monitor ionized calcium and prepare to replace
- Give calcium gluconate if administering through PIV
14
Q
Venous access:
common sites
site for venous cutdown
common site for central lines
A
- Peripheral:
- dorsum of hand
- AC
- dorsum of foot
- scalp
- Venous cutdowns: saphenous
- Central lines:
- IJ
- subclavian
- femoral
- PICC lines in axillary vein
15
Q
Vascular access via umbilical vein:
how is it done
complications
length of use
contraindications
A
- A small amount of the cord is cut and umbilical tape is applied to stop the bleeding.
- one thin walled umbilical vein and two smaller, thick walled arteries can be seen and catheterized using sterile technique
- Complications:
- infection
- bleeding
- hemorrhage
- perforation of vessel
- thrombosis with distal embolization
- ischemia or infarction of lower extremities, bowel, orkidney
- arrhythmia if catheter is in the heart
- air embolus
- accidental placement in portal vein- get Xray
- Umbilical vein may remain patent for up to two weeks after birth and can be used in an emergency
- Contraindications:
- omphalocele
- gastroschesis
- peritonitis
16
Q
Arterial access in neonate:
umbilical artery catheter tip location
considerations
A
- The tip of the catheter should be at or just above the level of the aortic bifurcation and below the level of the renal arteries (L2)
- Peripheral a-line whould be inserted and umbilical removed once pt is stable
- flush gently to prevent cerebral or cardiac emboli
- all arterial catheters have the potential to cause distal thromboembolic disease
17
Q
How can arterial access help assess pulmonary hypertension and right to left shunting?
A
- Preductal and postductal oxygenation should be measured to assess right-left shunting
- shunting through DA is suggested if the preductal PaO2 is 15-20 mm Hg higher than the postductal PaO2
- Shunting at the FO will decrease the predicted value of the preductal PaO2 and will not produce a gradient compared with postductal PaO2
- Preductal SaO2 reflects cerebral oxygenation
- Right radial a-line: Preductal
- Umbilical a-line: Postductal
*
18
Q
Pharm reminders and pearls. Good luck
Versed and opioids
morphine
remi
propofol
A
- Versed and opioids combined in neonates can lead to severe hypotension- titrate carefully
- Morphine clearance is directly correlated with gestational age; reduce how much you give it
- Remi has similar PK to older children making it a reliable choice for an intra-op opioid
- Propofol elimination varies in neonates and preterm infants; may see longer half times
19
Q
Pharm reminders and pearls
SCH
NDNMB
Vec
cisatracurium
A
- Sch dose is increased at 3 mg/kg- pretreatment with atropine required
- NDNMB have significan variability and unpredictability, titrate carefully
- neonates ALWAYS need reversal
- Vec is considered “long acting” in infants d/t liver immaturity
- Cisatracurium produces reliable recovery d/t hoffman elimination; laudanosine can decrease sz threshold
20
Q
What are some urgent problems at time of birth?
A
- meconium aspiration
- choanal stenosis and atresia
- diaphragmatic hernia
- hypovolemia
- hypoglycemia
- tracheoesophageal fistula
- laryngeal anomalies
21
Q
Retinopathy of prematurity:
What can it lead to?
Cause?
Pathogenesis?
A
- ROP can lead to blindness if left uncorrected
- incidence inversely proportional to gestational age
- Causes (association)
- exact cause unknown
- prematurity
- low birth weight
- supplemental O2 therapy
- postnatal hypotension
- use of surfactant or inotrope
- need for mech ventilation
- Pathogenesis
- starts with O2- induced retinal vasoconstriction and endothelial cell death
- followed by unchecked neovascularization from angiogenic factors (VEGF)
- these factors do not respond to normal regulation d/t immaturity
22
Q
ROP:
treatment
What should you avoid?
A
- Treatment
- cryotherapy
- laser photocoagulation
- scleral buckling surgery
- vitrectomy
- Avoid:
- hyperoxia
- target SpO2 91-95%
23
Q
What is Subgaleal hemmorhage?
incidence
Sx
A
- Occurs in 1.5-30 per 10,000 births
- Venous bleeding btw the aponeurosis and the pariosteium and can increase considerably in size over firs hours to days of life
- Symptoms
- a large boggy, shifting collection of fluid over the cranial surface unrestricted by suture lines
- may extend to neck and behind ears, lifting ears forward
- This subaponeurotic space is large, can have hypovolemia d/t bleeding
- may see hyperbilirubinemia after RBC breakdown occurs
- may remain asymptomatic and be observed for 24-48 hours
24
Q
What is Meconium?
What causes aspiration?
When does it usually occur?
A
- Meconium is the breakdown product of the swallowed amniotic fluid, GI cells, and secretions
- Meconium is usually present after 34 weeks gestation
- intrauterine arterial hypoxemia can result in increased gut motility and defecation
- Fetal distress (arterial hypoxemia) causes gasping and the fetus can inhale the meconium into the lungs
- Birth within 24 hr of aspiration, the meconium is in major airways and is distributed through lungs with breathing
- obstruction in small airways causes Vent/perf mismatch
- RR can be > 100 bpm
- lung compliance decreases
25
Q
What can be seen in a severe case of meconium aspiration?
A
- PHTN and R-to-L shunting through patent FO and DA leading to hypoxemia
- Risk of pneumothorax
26
Q
Meconium aspiration:
Historic tx?
current tx?
A
- Historic tx:
- ETT immediately after delivery with sxn of meconium from airways
- Current tx:
- more conservative
- no routine oropharyngeal or nasopharyngeal sxn for infants born with eithe clear or meconium stained amniotic fluid
- ETT sxn is indicated for nonvigorous meconium-stained newborns
- If meconium is present:
- 1st orally suction, if vigorous nothing further req
- If still depressed, intubate and suction, if vigorous, extubate after sxn and re-intubate
- if not vivorous, keep tube and move to PPV
27
Q
Respiratory distress syndrome:
Primary cause and other causes?
Sx
Tx
long term problems
A
- Primary cause: lack of surfactant,
- decreased number of branching airways and alveoli
- atelectasis
- impaired gas exchange
- hypoxemia
- poor lung compliance and propensity for aveolar collapse
- Incidence inverely proportional to gestational age & birth weight
- Sx:
- tachypnea
- grunting
- retractions
- flaring
- Tx: Surfactant via ETT
- Long term problems: bronchopulmonary dysplasia
28
Q
Anesthesia consideration for a neonate with respiratory distress syndrome
A
Limit hypoxemia while avoiding hyperoxia
follow ABGs
29
Q
Bronchopulmonary dysplasia:
What is it?
Sx
Tx
A
- Chronic lung disease of infancy
- usually occurs in patients who were born premature and had extensive mechanical ventilation and high FiO2
- the lungs are hyperinflated
- Sx:
- intercostal retractions
- nasal flaring
- wheesing
- hypercapnia
- hypoxia
- Tx:
- adequate caloric intake
- resp support (mech ventilation, CPAP) PRN
- diuretics and bronchodilators PRN
30
Q
Laryngomalacia/bronchomalacia:
What is it?
A
- Excessive flaccidity of the laryngeal structures, prone to airway collapse
- Can be congenital or acquired
- laryngomalacia mor often congenital >85%
- bronchomalacia more likely sequelae of prolonged NICU admission
- Stridor present at birth
31
Q
What are vascular rings?
A
- anomalies of the aorta that may compress the trachea
- produce insp and exp obstruction
- may be difficult to advance a tracheal tube beyond obstruction
- Exit procedure may be done where they do partial delivery but keep baby hooked up to placenta so it can continue to get oxygen
