Neonatal Flashcards Preview

Advanced Principles II > Neonatal > Flashcards

Flashcards in Neonatal Deck (31)
Loading flashcards...
1

What are some neonatal concerns?

  • 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

What is the timeline for fetal development?

  • 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

How do the lungs develop?

  • 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

What is persistent fetal circulation?

Primary cause?

Initial tx?

other treatment

  • 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

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?

  • 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

What is the APGAR scoring and how is it done?

  • 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

Why do healthy neonates have cyanosis at 1 minute?

What is the most common cause of persistent cyanosis?

  • 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

What is the NRP algorithm?

9

How is a newborn/neonatal assessment done?

General

airway

  • 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

Newborn/neonatal assessment:

heart and lungs

neuro

back

musculoskeletal

  • 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

What labs are relevent during a newborn/neonatal assessment?

  • POC glucose
  • CBC or HCT
  • blood type
  • Coombs
  • bilirubin

12

What is important regarding fluid management in the neonate?

What is newborn fluid requirement?

  • 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

What is important regarding blood transfusion for neonates?

  • 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

Venous access:

common sites

site for venous cutdown

common site for central lines

  • Peripheral:
    • dorsum of hand
    • AC
    • dorsum of foot
    • scalp
  • Venous cutdowns: saphenous
  • Central lines:
    • IJ
    • subclavian
    • femoral
    • PICC lines in axillary vein

15

Vascular access via umbilical vein:

how is it done

complications

length of use

contraindications

  • 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

Arterial access in neonate:

umbilical artery catheter tip location

considerations

  • 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

How can arterial access help assess pulmonary hypertension and right to left shunting?

  • 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

Pharm reminders and pearls.  Good luck

Versed and opioids

morphine

remi

propofol

 

  • 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

Pharm reminders and pearls

SCH

NDNMB

Vec

cisatracurium

  • 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

What are some urgent problems at time of birth?

  • meconium aspiration
  • choanal stenosis and atresia
  • diaphragmatic hernia
  • hypovolemia
  • hypoglycemia
  • tracheoesophageal fistula
  • laryngeal anomalies

21

Retinopathy of prematurity:

What can it lead to?

Cause?

Pathogenesis?

 

  • 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

ROP:

treatment

What should you avoid?

  • Treatment
    • cryotherapy
    • laser photocoagulation
    • scleral buckling surgery
    • vitrectomy
  • Avoid:
    • hyperoxia
    • target SpO2 91-95%

23

What is Subgaleal hemmorhage?

incidence

Sx

 

  • 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

What is Meconium?

What causes aspiration?

When does it usually occur?

 

  • 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

What can be seen in a severe case of meconium aspiration?

  • PHTN and R-to-L shunting through patent FO and DA leading to hypoxemia
  • Risk of pneumothorax

26

Meconium aspiration:

Historic tx?

current tx?

  • 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

Respiratory distress syndrome:

Primary cause and other causes?

Sx

Tx

long term problems

  • 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

Anesthesia consideration for a neonate with respiratory distress syndrome

Limit hypoxemia while avoiding hyperoxia

follow ABGs

29

Bronchopulmonary dysplasia:

What is it?

Sx

Tx

  • 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

Laryngomalacia/bronchomalacia:

What is it?

 

  • 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