Lecture 1-Pediatric Anesthesia 2020

Question 1

Transition = the change from fetal to ___ life

Answer 1

Extrauterine

Question 2

Pre-term = prior to ___ weeks gestational age

Answer 2

37

Question 3

Neonate = ___-___ days of life

Answer 3

1-28

Question 4

Infant = ___ days to ___ year

Answer 4

29 days to 1 year

Question 5

Child > ___ year

Answer 5

> 1 year

Question 6

Most significant part of transition occurs within the first ___-___ hours after birth

Answer 6

24-72 hours

Question 7

Adaptive changes of the newborn—establish ___; convert ___; recover from birth ___; maintain core ___

Answer 7

Establish FRC; convert circulation; recover from birth asphyxia; maintain core temperature

Question 8

Fetal respiration—gas exchange occurs in the ___

Answer 8

Placenta

Question 9

Fetal Hgb shifts oxyhemoglobin dissociation curve to the ___ (right/left)—___ (increased/decreased) O2 loading in the lungs/placenta, ___ (increased/decreased) O2 unloading at tissues

Answer 9

Left—increased O2 loading in the lungs/placenta, decreased O2 unloading at tissues

Question 10

Hgb for full term neonate = ___-___ g/dL

Answer 10

18-20 g/dL

Question 11

Fetal lung development—___-___ weeks—capillary network surrounds saccules; unsupported survival is possible (will probably still need CPAP or positive pressure ventilation)

Answer 11

28-30 weeks

Question 12

Fetal lung development—___-___ weeks—true alveoli present, roughly 20 million at birth

Answer 12

36-40 weeks

Question 13

Fetal lung development—___-___ months—PaO2 rises as R to L mechanical shunts close

Answer 13

Birth-3 months

Question 14

Fetal lung development—up to __ years—rapid increase in alveoli—350 million at this age

Answer 14

6 years

Question 15

Fetus makes respiratory movements in utero, aka “___ breathing in utero”

Answer 15

Guppy

Question 16

Fetal respiratory movements serve as prenatal practice to ensure that respiratory system is developed and ready at birth—T/F?

Answer 16

True

Question 17

Adaptation of breathing—traditional view—___emia, ___carbia, ___osis of birth asphyxia stimulate ___ that produce ___ followed by rhythmic breathing

Answer 17

Hypoxemia, hypercarbia, acidosis of birth asphyxia stimulate chemoreceptors that produce gasping followed by rhythmic breathing

Question 18

With the onset of ventilation, pulmonary vascular resistance ___ (increases/decreases) dramatically, and the pulmonary blood flow ___ (increases/decreases) allowing gas exchange to occur

Answer 18

PVR decreases dramatically, and the pulmonary blood flow increases

Question 19

Changes in PO2, PCO2, and pH are responsible for the decrease in PVR—___ (increase/decrease) in PO2, ___ (increase/decrease) in CO2

Answer 19

Increase in PO2, decrease in CO2

Question 20

Adaptation of breathing—current view—rhythmic breathing occurs with ___ of the umbilical cord and ___ (increasing/decreasing) O2 tension from air breathing

Answer 20

Rhythmic breathing occurs with clamping of the umbilical cord and increasing O2 tension from air breathing

Question 21

The primary event of the respiratory system transition is initiation of ___

Answer 21

Ventilation

Question 22

Initiation of ventilation changes the alveoli from a ___-filled to an ___-filled state

Answer 22

Fluid-filled to an air-filled state

Question 23

Infants must generate high negative pressure, -___ cm H2O, to inflate the lungs—___ initiates this high negative pressure

Answer 23

-70 cm H2O—crying initiates this high negative pressure

Question 24

FRC of approximately ___-___ ml/kg is established to act as a buffer against cyclical alterations in PO2 and PCO2 between breaths

Answer 24

25-30 ml/kg

Question 25

Neonate and infant lungs are prone to collapse—weak elastic recoil, weak intercostal muscles, and intrathoracic airways collapse during exhalation—T/F?

Answer 25

True

Question 26

Small airway closure begins at volumes at or above FRC, leading to lung collapse and V/Q mismatch—T/F?

Answer 26

True

Question 27

Why don’t infants have lung collapse all of the time?—infants terminate the expiratory phase of breathing before reaching their true ___, which results in intrinsic ___ and a ___ (higher/lower) FRC

Answer 27

Before reaching their true FRC, which results in intrinsic PEEP and a higher FRC

Question 28

When infants are anesthetized, their protective mechanism of terminating the expiratory phase of breathing before reaching their true FRC is abolished, causing atelectasis to occur—T/F?

Answer 28

True

Question 29

___ can help maintain FRC/lung inflation in the neonate during anesthesia

Answer 29

PEEP of 5 cm H2O

Question 30

As kid is going to sleep and protective respiratory mechanisms are abolished, turn APL valve to about ___ to maintain PEEP

Answer 30

5

Question 31

Respiratory control is well developed in neonates—T/F?

Answer 31

False—even though their respiratory systems are normal by 3-4 weeks of age, the system likely remains immature for sometime, especially in pre-term babies

Question 32

Chemoreceptor control ___ (is/is not) present at birth

Answer 32

Is present at birth—can respond to hypercarbia

Question 33

Newborns respond to hypercarbia by ___ (increasing/decreasing) ventilation; the slope of the response curve is ___ (increased/decreased)

Answer 33

Increasing ventilation; the slope of the response curve is decreased

Question 34

___ia depresses the neonate’s response to CO2

Answer 34

Hypoxia

Question 35

Neonate’s response to hypoxia is biphasic—initial ___nea followed by ___ of respiration in about 2 min.

Answer 35

Initial hyperpnea followed by depression of respiration in about 2 min.

Question 36

The initial hyperpneic response to hypoxia in neonates is abolished by ___thermia and ___ (low/high) levels of anesthetic gases

Answer 36

Hypothermia and low levels of anesthetic gases

Question 37

___ is a common response and a real danger, especially in pre-term infants

Answer 37

Apnea

Question 38

By ___ weeks of age, hypoxia produces sustained hyperventilation

Answer 38

3

Question 39

Apnea of infancy = respiratory pauses exceeding ___ seconds or those accompanied by ___cardia or ___osis

Answer 39

Exceeding 20 seconds or those accompanied by bradycardia or cyanosis

Question 40

Hypoxia causes profound ___cardia in babies

Answer 40

Bradycardia

Question 41

HR 60 in a baby = ___, need to start ___

Answer 41

Hypoxia, need to start compressions

Question 42

Increased work of breathing in infants leads to ___

Answer 42

Fatigue

Question 43

Contributing factors for apnea of infancy—infants have very compliant upper airway structures and ribcage that tend to collapse during inspiration—T/F?

Answer 43

True

Question 44

Contributing factors for apnea of infancy—infants have inefficient ___ contraction; ___% of muscle fibers in the infant’s diaphragm are type I fatigue-resistant (in adults, 55% are this type)

Answer 44

Inefficient diaphragmatic contraction; 25% of muscle fibers in the infant’s diaphragm are type I fatigue-resistant

Question 45

Contributing factors for apnea of infancy—___ (increased/decreased) O2 consumption—___ml/kg; ___ (increased/decreased) FRC; ___ (increased/decreased) closing volume; once hypoxia ensues, these factors will result in abnormal breathing patterns and apnea much more quickly than in the older child or adult

Answer 45

Increased O2 consumption—6 ml/kg; decreased FRC; increased closing volume

Question 46

CV in the fetus—gas exchange occurs in the ___

Answer 46

Placenta

Question 47

CV in the fetus—lungs require only ___-___% of cardiac output

Answer 47

5-10%

Question 48

Fetal intracardiac and extracardiac shunts exist to minimize blood flow to the ___ while maximizing flow/O2 delivery to ___ systems

Answer 48

Minimize blood flow to the lungs while maximizing flow/O2 delivery to organ systems

Question 49

(3) fetal shunts:

Answer 49

• Ductus venosus
• Foramen ovale
• Ductus arteriosus

Question 50

Fetal circulation (parallel)—deoxygenated blood travels to the ___ aorta to the ___ arteries to the ___ (very ___ (high/low) resistance to flow)

Answer 50

Deoxygenated blood travels to the descending aorta to the umbilical arteries to the placenta (very low resistance to flow)

Question 51

Fetal circulation (parallel)—blood becomes oxygenated in the ___

Answer 51

Placenta

Question 52

Fetal circulation (parallel)—oxygenated blood returns to the fetus via the ___ vein (PO2 ___ mm Hg)

Answer 52

Oxygenated blood returns to the fetus via the umbilical vein (PO2 35 mm Hg)

Question 53

Fetal circulation (parallel)—ductus ___ diverts approximately ___% of oxygenated blood away from the fetal ___ (bypassing ___ circulation) into the ___ vena cava then to the ___ atrium

Answer 53

Ductus venosus diverts approximately 50% of oxygenated blood away from the fetal liver (bypassing hepatic circulation) into the inferior vena cava then to the right atrium

Question 54

Fetal circulation (parallel)—oxygenated blood passes through the ___ into the ___ atrium, to the ___ ventricle, and is ejected out from the ___, feeding the coronary and cerebral circulations

Answer 54

Oxygenated blood passes through the foramen ovale into the left atrium, to the left ventricle, and is ejected out from the aorta, feeding the coronary and cerebral circulations

Question 55

Fetal circulation—deoxygenated blood from the fetus’ body is delivered into the ___, through the ___ atrium, to the ___ ventricle, to the main ___ artery

Answer 55

Deoxygenated blood from the fetus’ body is delivered into the SVC, through the right atrium, to the right ventricle, to the main pulmonary artery

Question 56

Fetal circulation (parallel)—pulmonary vascular resistance is ___ (low/high), so right ventricular output bypasses the ___ through the ___, which connects the ___ artery to the ___ aorta

Answer 56

PVR is high, so right ventricular output bypasses the lungs through the ductus arteriosus, which connects the pulmonary artery to the descending aorta

Question 57

Fetal circulation (parallel)—deoxygenated blood from the descending aorta feeds the ___ body of the fetus (PO2 ___ mm Hg)

Answer 57

Lower body of the fetus (PO2 22 mm Hg)

Question 58

Fetal circulation (parallel)—deoxygenated blood leaves the fetus through the ___ arteries to get back to the ___ to pick up oxygen

Answer 58

Leaves the fetus through the umbilical arteries to get back to the placenta to pick up oxygen

Question 59

Transitional circulation (series)—at birth, placental vessels are clamped—SVR ___ (increases/decreases) dramatically, causing ___ of shunts

Answer 59

SVR increases dramatically, causing reversal of shunts

Question 60

Transitional circulation (series)—initiation of ventilation ___ (increases/decreases) arterial and alveolar PO2, which ___ (constricts/dilates) pulmonary vasculature—PVR ___ (increases/decreases) dramatically, pulmonary blood flow ___ (increases/decreases) 450%, ___ of shunts

Answer 60

Initiation of ventilation increases arterial and alveolar PO2, which dilates pulmonary vasculature—PVR decreases dramatically, pulmonary blood flow increases 450%, reversal of shunts

Question 61

Transitional circulation (series)—LA pressure ___ (increases/decreases), RA pressure ___ (increases/decreases)

Answer 61

LA pressure increases, RA pressure decreases

Question 62

Transitional circulation (series)—foramen ovale closes ___

Answer 62

Immediately

Question 63

Transitional circulation (series)—ductus arteriosus constricts within several minutes due to ___ (increased/decreased) PO2 and ___ (increased/decreased) circulating prostaglandins (PGI2, PGE1); physiologic closure occurs in ___-___ hours, anatomic closure occurs in ___-___ weeks

Answer 63

Ductus arteriosus constricts within several minutes due to increased PO2 and decreased circulating prostaglandins; physiologic closure occurs in 10-15 hours, anatomic closure occurs in 2-3 weeks

Question 64

Transitional circulation (series)—ductus venosus becomes ___ over time; no specific time frame for closure

Answer 64

Fibrous

Question 65

The foramen ovale, ductus arteriosus, and ductus venosus are the shunts needed for effective fetal circulation that must close after birth to allow effective newborn circulation—T/F?

Answer 65

True

Question 66

___ (increased/decreased) SVR, ___ (increased/decreased) PVR allow for closure of fetal shunts; flow through FO and DA becomes ___ to ___, shunts close, and circulation becomes like that of an adult

Answer 66

Increased SVR, decreased PVR allow for closure of fetal shunts; flow through FO and DA becomes left to right, shunts close, and circulation becomes like that of an adult

Question 67

Circulation in utero—PVR ___ (high/low), SVR ___ (high/low)

Answer 67

PVR high, SVR low

Question 68

Extrauterine circulation—SVR ___ (high/low), PVR ___ (high/low); shunts physiologically close

Answer 68

SVR high, PVR low

Question 69

Pulmonary blood flow in fetus—___-___%

Answer 69

5-10% of CO (remember, goal in utero is to minimize blood flow to the lungs and maximize flow/O2 delivery to organ systems)

Question 70

Pulmonary blood flow in neonate—___%

Answer 70

100%

Question 71

PPHN =

Answer 71

Persistent pulmonary hypertension of newborn

Question 72

What does this describe?—persistence of fetal shunting beyond the normal transition period in the absence of a structural heart defect

Answer 72

PPHN

Question 73

Etiology of PPHN = ___ia and ___osis

Answer 73

Hypoxia and acidosis

Question 74

Consequences of PPHN—___ (increased/decreased) PVR; pulmonary ___tension; ___ (increased/decreased) pulmonary blood flow; ___ atrial pressure > ___ atrial pressure; ___ (increased/decreased) ductal flow; this can reopen the ___

Answer 74

Increased PVR; pulmonary hypertension; decreased pulmonary blood flow; right atrial pressure > left atrial pressure; increased ductal flow; this can reopen the foramen ovale

Question 75

Signs and symptoms of PPHN—marked ___; ___pnea; ___osis; ___ to ___ shunt across foramen ovale and ductus arteriosus = marked ___

Answer 75

Marked cyanosis; tachypnea; acidosis; right to left shunt across foramen ovale and ductus arteriosus = marked cyanosis

Question 76

Before anatomic closure of the fetal shunts, transient right to left shunting may occur in normal neonates during coughing, bucking, or straining during anesthetic induction or emergence—T/F?

Answer 76

True

Question 77

Treatment of PPHN—___ventilation to maintain ___osis; pulmonary vaso___ (i.e.: prostaglandin); minimal handling; avoidance of ___

Answer 77

Hyperventilation to maintain alkalosis; pulmonary vasodilators (i.e.: prostaglandin); minimal handling; avoidance of stress

Question 78

Treatment of PPHN—adequate ___ and ___ is key!

Answer 78

Adequate ventilation and oxygenation is key!

Question 79

Renal system—major function in fetus is passive production of urine, which contributes to the formation of ___ fluid

Answer 79

Amniotic fluid

Question 80

Amniotic fluid is important for normal development of the fetal ___ and acts as a ___ absorber for the fetus

Answer 80

Important for normal development of the fetal lung and acts as a shock absorber for the fetus

Question 81

Characteristics of the fetal kidney—___ (high/low) renal blood flow; ___ (high/low) glomerular filtration rate

Answer 81

Low renal blood flow; low glomerular filtration rate

Question 82

Why does the fetus have low RBF and GFR?—kidneys are structurally immature with small size and number of glomeruli; ___ (high/low) systemic arterial pressure; ___ (high/low) renal vascular resistance; ___ (high/low) permeability of glomerular capillaries

Answer 82

Low systemic arterial pressure; high renal vascular resistance; low permeability of glomerular capillaries

Question 83

Transitional changes in the newborn (renal)—systemic arterial pressure ___ (increases/decreases); renal vascular resistance ___ (increases/decreases); ___ (increase/decrease) in size and function of kidney occurs through maturity

Answer 83

Systemic arterial pressure increases; renal vascular resistance decreases; increase in size and function of kidney occurs through maturity

Question 84

By ___ weeks, all nephrons are developed, so a premature baby has incomplete renal development

Answer 84

34 weeks

Question 85

In the first several days of life in the full term infant, there is diminished ability to ___ urine, resulting from the low GFR at birth; urine osmolarity is ___-___ mOsm/L; creatinine is ___-___ mg/dL

Answer 85

Concentrate; urine osmolarity is 700-800 mOsm/L; creatinine is 0.8-1.2 mg/dL

Question 86

Full term infants’ inability to concentrate urine in the first several days of life is d/t inadequate ___ conservation

Answer 86

Sodium

Question 87

Neonates have a normal RAAS that facilitates reabsorption of sodium in the distal tubule; however, immature neonatal tubules do not completely reabsorb sodium under the stimulus of aldosterone—T/F?

Answer 87

True

Question 88

Neonates will continue to excrete sodium, even in the presence of a severe sodium deficit d/t immaturity of their renal tubules—T/F?

Answer 88

True

Question 89

The neonate is considered an “obligate ___”

Answer 89

“Obligate sodium loser”

Question 90

Neonates can conserve filtered sodium—1st week = ___%; 2nd week = ___%; adults ___%

Answer 90

1st week = 70%; 2nd week = 84%; adult = 99.5%

Question 91

Adult urine sodium = ___-___ meq/L

Answer 91

5-10

Question 92

Neonate urine sodium = ___-___ meq/L

Answer 92

20-25 meq/L

Question 93

Since neonates cannot completely conserve sodium, a baby will continue to produce dilute urine to the point of ___ without adequate fluid replacement; IVF must contain ___ to prevent this

Answer 93

To the point of dehydration; IVF must contain sodium to prevent this

Question 94

___ (increased/decreased) renal blood flow and ___ (increased/decreased) renal vascular resistance result in rapid improvement in renal function within the first 3-4 days of life; this is reflected in the increased ability of the infant to ___ urine with time

Answer 94

Increased renal blood flow and decreased renal vascular resistance result in rapid improvement in renal function within the first 3-4 days of life; this is reflected in the increased ability of the infant to concentrate urine with time

Question 95

IV fluid replacement given to the neonate must contain ___; most facilities utilize ___ or ___

Answer 95

Must contain sodium; most facilities utilize NS or LR

Question 96

Maintenance fluid in the neonate—___ needs of the neonate must also be addressed

Answer 96

Glucose needs

Question 97

Maintenance fluid for neonates should contain ___

Answer 97

Glucose

Question 98

Balanced maintenance fluid in a baby = ___

Answer 98

D5.2NS

Question 99

In the face of ongoing surgical blood loss, neonates and infants will require red cell replacement sooner than later—T/F?

Answer 99

True

Question 100

Higher Hgb/Hct is required in neonates/infants because of ___ (high/low) oxygen demand with limited ability to increase cardiac ___; Hct ___% is the lowest acceptable

Answer 100

High oxygen demand with limited ability to increase cardiac output; Hct 35% is the lowest acceptable

Question 101

Neonates/infants have ___ (increased/decreased) blood volume per unit weight

Answer 101

Increased

Question 102

Neonates/infants have ___ (increased/decreased) cardiac output per unit weight

Answer 102

Increased

Question 103

___ ml/kg blood volume in term baby

Answer 103

90 ml/kg

Question 104

___ ml/kg blood volume in pre-term baby

Answer 104

100 ml/kg

Question 105

Ability of infants to thermoregulate is significantly limited and easily overwhelmed—T/F?

Answer 105

True

Question 106

The neonate’s limited thermal range is a function of their ___ size; ___ (increased/decreased) surface area to volume ratio; ___ (increased/decreased) thermal conductance

Answer 106

Small size; increased surface area to volume ratio; increased thermal conductance

Question 107

Heat loss occurs in two stages in neonates/infants—transfer of heat from body ___ to skin ___ (internal temperature gradient); dissipation of heat from the skin surface to the ___ (external heat gradient)

Answer 107

Transfer of heat from body core to skin surface (internal temperature gradient); dissipation of heat from the skin surface to the environment (external heat gradient)

Question 108

Heat loss is governed by what (4) methods:

Answer 108

• Radiation
• Convection
• Conduction
• Evaporation

Question 109

What heat loss method is this describing?—electromagnetic energy from the body to colder objects in the room (requires no direct contact, heat emitted from an object or body); highest percentage of heat loss

Answer 109

Radiation

Question 110

What heat loss method is this describing?—heat loss from surface to air currents

Answer 110

Convection

Question 111

What heat loss method is this describing?—surface to surface heat loss

Answer 111

Conduction

Question 112

What heat loss method is this describing?—heat loss via vaporization

Answer 112

Evaporation

Question 113

Heat production is achieved by ___ and ___ muscle activity; ___ thermogenesis—major component in the neonate

Answer 113

Voluntary and involuntary muscle activity; non-shivering thermogenesis—major component in the neonate

Question 114

Non-shivering thermogenesis = metabolism of ___

Answer 114

Brown fat

Question 115

Non-shivering thermogenesis develops in the fetus between ___-___ weeks gestation; comprises ___-___% of the neonate’s total body weight; located in the ___stinum, between the ___, around the ___, in the ___

Answer 115

26-30 weeks gestation; comprises 2-6% of the neonate’s total body weight; located in the mediastinum, between the scapulae, around the adrenals, in the axilla

Question 116

Brown fat in the neonate has an abundant ___ supply and rich innervation from the ___ nervous system

Answer 116

Has an abundant vascular supply and rich innervation from the sympathetic nervous system

Question 117

Non-shivering thermogenesis occurs with ___ stress; is mediated by the ___ nervous system; ___ is produced as a product of fatty acid metabolism

Answer 117

Occurs with cold stress; is mediated by the sympathetic nervous system; heat is produced as a product of fatty acid metabolism

Question 118

Consequences of non-shivering thermogenesis = ___ (increased/decreased) O2 consumption&raquo_space; ___ia&raquo_space; ___osis;

___ (increased/decreased) glucose utilization&raquo_space; release of ___ acid&raquo_space; ___glycemia

___ (increased/decreased) surfactant production&raquo_space; ___ of alveoli&raquo_space; ___ of fetal circulation (foramen ovale and ductus arteriosus)

Answer 118

Increased O2 consumption&raquo_space; hypoxia&raquo_space; acidosis

Increased glucose utilization&raquo_space; release of lactic acid&raquo_space; hypoglycemia

Decreased surfactant production&raquo_space; collapse of alveoli&raquo_space; reopening of fetal circulation (foramen ovale and ductus arteriosus)