Pediatric Anesthesia - Quiz 1 Flashcards Preview

Summer 2020 - Advanced Anesthesia - Pediatrics > Pediatric Anesthesia - Quiz 1 > Flashcards

Flashcards in Pediatric Anesthesia - Quiz 1 Deck (67)
Loading flashcards...
1
Q

What is the age of a Neonate?

A

1 - 28 days of life

2
Q

What is the age of an Infant vs Child?

A

Infant: 28 days - 1 yr

Child: > 1 yr

3
Q

When does the most significant part of transition occur for a newborn?

A

24 -72 hrs after birth

4
Q

What are the adaptive changes for a Newborn?

A

Establish FRC

Convert Circulation

Recover from Asphyxia

Maintain Core Temp

5
Q

Where does Gas Exchange occur in regards to Fetal Respiration?

A

Placenta

6
Q

How is the majority of O2 Transport accomplished by the Fetus?

A

Left Fetal Hgb Shift

7
Q

What happens to O2 Unloading after birth?

A

Becomes Insufficient

8
Q

What is the normal Hgb for a full term Neonate?

A

18 - 20 g/dL

9
Q

How developed is the Fetal Lung at 4 weeks?

A

Lung Buds develop from Foregut

10
Q

At what week of gestation does the Fetal Lung have Complete branching of the Bronchial Tree to 28 Divisions?

A

16 Weeks - no more cartilaginous airway formation

11
Q

When does the Fetal Lung have Alveoli & Type II Cells w/ Surfacant?

A

24 Weeks

12
Q

What happens w/ Fetal Lung Development at 28-30 weeks?

A

Capillary Network surrounds Saccules & baby can survive w/o support

13
Q

When does the Fetal Lung have true Alveoli present?

A

36 - 40 weeks - about 20 million @ birth

14
Q

What happens in Fetal Lung Development at Birth to 3 months?

A

PaO2 rises as R-to-L mechanical shunts close

15
Q

What happens to the number of Alveoli present once the the child reaches 6 years of age?

A

Rapid increase to 350 million Alveoli

16
Q

When does the Fetus start to “Guppy Breathe” in Utero?

A

30 weeks at a rate of 60 breaths/min

Prenatal Respiratory Practice

17
Q

What happens in utero that could cause Lung Hypoplasia?

A

Denervation or damage to the Diaphragm

18
Q

How does the Carotid, Aortic, and Peripheral Chemoreceptors play a role in Fetal Breathing?

A

Does NOT alter fetal breathing or Initation of Ventilation at birth

19
Q

What initiates in utero Rhythmic Breathing?

A

Clamping of Umbilical Cord & Increasing O2 Tension from Air Breathing

20
Q

What augments and maintains continuous rhythmic breathing?

A

Hyperoxia w/ Air Breathing & Low Fetal PaO2

Continuous breathing does NOT depend on PaCO2

21
Q

What depresses or abolishes continuous breathing?

A

Hypoxia

22
Q

What happens to the Fetal Lungs w/ onset of Ventilation?

A

↓Pulm. Vascular Resistance d/t ↑PO2 & ↓PCO2

&

↑Pulm. Blood Flow

23
Q

The primary event of Respiratory transition is the Initiation of Ventilation. How do Alveoli change at this point?

A

Fluid-filled Alveoli to Air-Filled

24
Q

What helps overcome the Large Surface Tension forces in the Newborn’s Lungs?

A

Small Radius of the Diaphragm’s Curve

&

High Negative Pressure of -70 cm H2O generated by the baby

25
Q

What is the FRC for a Newborn?

A

25 - 30 mL/kg - buffer for PO2 & PCO2 changes b/t breaths

26
Q

Neonates have weak elastic recoil and intercostal muscles, making them prone to what?

A

Lung and Intra-Thoracic Airway Collapse during Exhalation

27
Q

What happens when Closing Volumes are equal or above the FRC?

A

Small airway closure

Lung Collapse

V/Q Mismatch

28
Q

What is unique about how the infant’s lungs work that prevents their lungs from collapsing all the time?

A

Infants end their expiratory phase early

This creates PEEP & a higher FRC

Anesthesia inhibits this function

29
Q

Do neonates have respiratory control in response to hypercarbia?

A

Yes, but the control is still immature. They will hyperventilate, but the slope of response is decreased

30
Q

What depresses the Neonate’s response to CO2?

A

Hypoxia

31
Q

What are the 2 phases of the Neonate’s response to Hypoxia?

A

First Phase: Hyperpnea

Second Phase: Depressed Respirations after 2 min.

32
Q

What abolishes the Neonate’s Hyperpnea response to Hypoxia?

A

Hypothermia & Anesthetic Gas

33
Q

How does Hypoxia affect the baby’s heart rate?

A

Profound Bradycardia

34
Q

What is Apnea of Infancy?

A

Respiratory pause > 20 sec or w/ Bradycardia or Cyanosis

35
Q

What factors contribute to Apnea of Infancy?

A

↑Work of Breathing

↑O2 Consumption & Closing Volume

Compliant Upper Airway & Ribs = Easy Collapse

Inefficient Diaphragmatic Contraction

Only 25% Type 1 Diaphragm Muscles
(vs. 55% in Adults)

↓FRC

36
Q

Why do Fetal Intracardiac & Extracardiac Shunts Exist?

A

To Minimize blood flow to Lungs & Maximize flow to Organs

37
Q

What are the Fetal Shunts that develop in birth?

A

Ductus Venosus

Foramen Ovale

Ductus Arteriosus

38
Q

How does Fetal Blood circulate?

A

Deoxygenated blood –> Descending Aorta –> Umbilical Arteries –> Placenta –> Oxygenated Blood –> Umbilical Vein –> 50% to Liver / 50% to Ductus Venosus –> IVC –> RA –> RV –> Ductus Arteriosus –> PA & Aorta

39
Q

The Umbical Arteries to the Placenta have very _____ resistance to blood flow

A

The Umbical Arteries to the Placenta have very Low resistance to blood flow

40
Q

What is the PO2 of the Oxygenated blood that returns via the Umbilical Vein?

A

35 mmHg

41
Q

With Fetal Circulation, the Pulmonary Vascular Resistance is very _____ & the SVR is very ______

A

With Fetal Circulation, the Pulmonary Vascular Resistance is very High & the SVR is very Low

42
Q

What is the PO2 of the Blood entering the Descending Aorta that then goes to the Placenta?

A

22 mmHg

43
Q

In Fetal Circulation, which pathway does O2 rich blood go directly from the Right Atrium to the Left Atrium?

A

Foramen Ovale

44
Q

What happens during the Transitional Fetal Circulation when the Umbilcal Cord is cut?

A

↑SVR

Reversal of Shunts

Breathing Starts

↓Pulm. Vascular Resistance

↑LA Pressure

↓RA Pressure

Foramen Ovale Closes

45
Q

What happens to Pulmonary Blood Flow when Fetal Ventilation first starts?

A

450% Increase in Pulm Blood Flow

46
Q

During Transitional Circulation, how does increased PO2 affect the Ductus Arteriosus?

A

Constricts w/in Minutes and Circulating Prostaglandins decrease

47
Q

How long does it take for the Ductus Arteriosus to close?

A

Physiologic: 10 -15 hrs

Anatomic: 2-3 wks

48
Q

What causes Persistent Pulmonary Hypertension of the Newborn (PPHN)?

A

Persistent Fetal Shunting after Transition Period

Hypoxia

Acidosis

49
Q

What can cause the Reopening of The Foramen Ovale?

A

Persistent Pulmonary Hypertension in the Neonate

&

Cold Stress

50
Q

What are the symptoms of PPHN?

A

Cyanosis

Tachypnea

Acidosis

R-to-L Shunt across FO & DA

51
Q

What causes the normal condition of Transient R-to-L shunting before anatomical ductus closure?

A

When baby coughs, bucks, or strains during induction or emergence

52
Q

How is PPHN treated?

A

Hyperventilation

Pulmonary Vasodilators - Prostaglandin

Minimal Handling

Avoid Stress

53
Q

What is the major function of the Fetal Renal System?

A

Passive Urine formation contributing to Amniotic fluid

54
Q

Fetal kidneys have ____ Renal Blood Flow & GFR

A

Fetal kidneys have Low Renal Blood Flow & GFR

55
Q

What happens to the Renal System during the Transitional Stage?

A

↑SVR

↓Renal Vascular Resistance

↑Kidney Size & Fxn

56
Q

At what gestational period are all fetal nephrons developed?

A

34 weeks

57
Q

What is the Urine Osmolarity of a Neonate at birth?

A

700 - 800 mOsm/L

58
Q

What is the Creatnine of a Neonate at birth?

A

0.8 - 1.2 mg/dL

59
Q

Why does the Neonate have trouble Concentrating Urine?

A

Inadequate Sodium Conservation

Neonates have normal Renin-Angiotensin System, but immature Tubules

The baby is an “Obligate Sodium Loser”

60
Q

What is the Normal Urine Sodium in an Adult vs Baby?

A

Adult: 5-10 mEq/L

Neonate: 20-25 mEq/L

61
Q

What is an important point in regards to fluid management in the Neonate?

A

Fluids must contain Sodium

Ideal Fluid: D5 0.2% NS

62
Q

Why is a Hematocrit of 35% the lowest acceptable for the Neonate?

A

High O2 Demand

Limited ability to Increase CO

Increased Blood Volume & CO per weight

63
Q

What is the Blood volume for a Term Baby vs. a Pre-Term Baby?

A

Term: 90mL/kg

Pre-Term: 100mL/kg

64
Q

Why are Neonates more susceptible to heat loss?

A

Small Size

Increased Surface Area

Increased Thermal Conductance

65
Q

How does the Neonate produce heat?

A

Voluntary/Involuntary Muscle Activity

&

Non-Shivering Thermogenesis

66
Q

How does Non-Shivering Thermogenesis work?

A

Metabolism of Brown Fat located in the Mediastinum b/t the Scapulae & around the Adrenals in the Axilla

67
Q

What mediates Non-Shivering Thermogenesis?

A

Sympathetic Nervous System