FHR

Question 1

Rate of fetal blood flow in placenta and 4 things it’s dependent on

Answer 1

500ml/min

Cardiac activity, BP, R to L shunts, systemic and pulmonary vascular resistance

Question 2

Factors that reduce UBF

Answer 2

Umbilical cord compression
Maternal hypotension & hypertension
Aortocaval syndrome
Vasoconstriction in uterine vessels (predominantly alpha)
Hypertonic uterine contractions

Question 3

What is the main determinant of fetal pO2

Answer 3

Maternal uterine venous pO2

Question 4

Fetal metabolic acidosis ABG

Answer 4

Ph <7.2, HCO3 < 20 BE -6

Question 5

Reliability is poor while sensitivity is high

Answer 5

FHR monitoring

Question 6

FHR at 20 weeks and at term

Answer 6

155bpm then slows down to 140 bpm as PNS matures

Question 7

What determines baseline fetal HR

Answer 7

Tonic effects on the SA node

Question 8

What are some causes of fetal bradycardia (<110 BPM for >10 minutes)

Answer 8

Maternal hypoxia, drugs decreasing UPP, hypotension, vagal stimuli
Fetal acidosis, asphyxia, cord compression

Question 9

What are some causes of fetal tachycardia (>160bpm for >10 min)

Answer 9

Maternal fever, chorioamnioitis, Drugs (terbutaline, ephedrine, atropine)
Fetal hypoxia, arrythmias

Question 10

Most reliable sign of fetal compromise d/t fewer false alarms

Answer 10

Baseline variability

Question 11

How is variability reduced

Answer 11

CNS depressants (opioids, sedatives, anesthetic agents, barbs, magnesium)
Hypoxemia
Fetal sleep
Acidosis
Anencephaly
Cardiac anomalies

Question 12

Absent variability is indicative of

Answer 12

Metabolic acidosis and depression of fetal brain stem and heart

Question 13

Periodic accelerations related to fetal movements and uterine pressure

Answer 13

Long term variability

Normal is 15-40 an hour

Question 14

R to R variability

Answer 14

Short term
3-6 bpm
Measured by fetal scalp electrode

Question 15

Treatment of Early decelerations

Answer 15

LUD & oxygen

Question 16

D/t fetal head compression
Benign with contraction & well tolerated by healthy fetus
No risk for fetal hypoxemia

Answer 16

Early decelerations

Question 17

Treatment of late decelerations

Answer 17

LUD, O2, IVF, vasopressors, poss C/S

Question 18

Ominous type of deceleration, indicator of UP insufficiency
Risk for fetal hypoxemia
Gradual decrease of FHR below baseline
Caused by: maternal hypotension, hypovolemia, acidosis, pre-eclampsia

Answer 18

Late deceleration

Question 19

This type of deceleration indicates cord compression
Risk for fetal hypoxemia
Abrupt decrease in FHR below baseline
No consistent pattern between FHR and contraction

Answer 19

Variable deceleration

Question 20

Treatment of variable deceleration

Answer 20

LUD, O2, IVF, amnioinfusion - urgent assessment of fetal status

Question 21

Treatment for prolonged decelerations

Answer 21

LUD, O2, IVF, vasopressors, stat c section

Question 22

This type of deceleration is a visually apparent sustained decrease in FHR
Caused by asphyxia, hyperstimulation, examination, supine hypotension
Can be a terminal fetal rhythm

Answer 22

Prolonged deceleration

Question 23

Level 1 emergent CS is usually for what type of NRFHR

Answer 23

Late decelerations without variability or bradycardia sustained below 70

Question 24

Treatment for NRFHR

Answer 24

LUD
O2
Treat hypotension - fluids and pressors
D/c pitocin
Treat uterine hypertony - terbutaline 0.25mg sc
Pelvic exam for cord prolapse
Internal monitoring
Amnioinfusion

Question 25

FHR tracings in category III

Answer 25

``` Absent variability plus Bradycardia or Variable decels or Late decels or Sinusoidal pattern ```

Question 26

FHR tracings in Category II

Answer 26

Recurrent variable decels Tachycardia Bradycardia without absence of FHR variability

Question 27

What is normal fetal scalp blood gas

Answer 27

Ph <7.25, pco2 <50 po2 >20

Question 28

Fetus maintains normal aerobic metabolism until

Answer 28

O2 falls to 50% of normal

Question 29

What happens with acute hypoxemia

Answer 29

PRIMARY Maintain BF and O2 in major organs with increased CO and HR Then FHR slows decreasing o2 consumption SECONDARY O2 uptake by fetal hgb becomes less efficient as pH decreases- go to anaerobic metabolism Will lead to fetal asphyxia

Question 30

Chronic hypoxia is d/t

Answer 30

Chronic decreased UPP - pre eclampsia Maternal hypertension Maternal DM

Question 31

What happens to the fetus with chonic hypoxia

Answer 31

IUGR and delay in neural development

Question 32

What leads to hypoxic ischemic encephalopathy

Answer 32

Surviving severe asphyxia - adaptive mechanisms fail - arterial O2 falls - myocardial depression - loss of autoregulation with CBF

Question 33

FHR tracing methods

Answer 33

Continuous electronic | Intermittent ausculation

Question 34

Which FHR tracing method is required for neuraxial

Answer 34

Continuous electronic

Question 35

Indicators of overall well being

Answer 35

Short and long term variability | Accelerations

Question 36

Short term variability represents a

Answer 36

Normal functioning autonomic system and reassuring for fetal o2

Question 37

Decrease of long term variability is d/t

Answer 37

Fetal sleep, drug effects (opioids, mag, atropine), fetal hypoxia

Question 38

Onset to nadir is >30 | Onset to nadir is < 30 seconds

Answer 38

Late decelerations | Prolonged and variable

Question 39

Stat C/S indicated with

Answer 39

Prolonged & late variability without variability | Sustained brady <70bpm

Question 40

Neonatal resuscitation med doses Epi Naloxone Crystalloid

Answer 40

Crystalloid 10ml/kg over 5-10 min Epi 0.01. To 0.03 mg Nalaxone 0.1 mg/kg

Question 41

Part A of neonatal resuscitation

Answer 41

Term gestation? Amniotic fluid clear? Breathing crying? Good muscle tone? Provide warmth Position clear airway Dry stimulate resposition

Question 42

Apneic or HR <100 for neonatal?

Answer 42

PPV

Question 43

HR < 60

Answer 43

Provide PPV, chest compressions | And if still HR < 60 give epi and IVF