III. Maternal & Fetal Monitoring Flashcards
How many stages of labor?
3
What stage is the longest stage?
Stage one
Begins with uterine contractions and continues until cervix fully dilated to 10cm.
Stage 1
Begins with cervical dilated to 10 cm until delivery of Fetus
Stage 2
stage: Until delivery of placenta
stage 3
The ideal labor epidural should cover sensory loss from ____ to ____.
T10 to S5
First Stage of labor:
Afferent/Efferent nerve impulses from the lower uterine segment and cervix cause visceral pain
Afferent
Afferent = sensory
Efferent = motor
First Stage of Labor:
Nerve cell bodies are located in the dorsal root ganglia of ____ to ____.
T10 to L1
What dermatome level is T10
umbilicus
what stage has pain that is poorly localized?
Stage 1
what stage of labor includes somatic pain that is well localized?
Stage 2
Afferent nerves innervating the vagina and perineum causes somatic pain which is better localized.
Stage 2 Labor:
somatic pain impulses (from the vagina and perineum) travel primarily via the ____ to dorsal root ganglia of S1-S5
pudendal nerve
How to assess a sensory nerve block:
- Explain the procedure and purpose to the patient
- Choose tool (ice cube, cold alcohol 4x4, broken tongue depressor)
- Establish Control (Ice): place the ice on an area well away from the possible dermatome cover such as the neck or face and ask if they feel cold.
- Apply the ice to an area likely blocked on the same side of the body and ask the patient, does this feel the same cold or different?
- Apply ice to areas above and below this point until it is clear at which level the top and bottom of the block is covered.
- Repeat the procedure on the opposite side of the body, as blocks may be uneven or unilateral.
Dermatome level:
C4
Clavicles (C is 4 clavicles)
Dermatome Level:
T4
Nipples (T is 4 tips of the nips)
Dermatome Level:
T6
Xiphoid
Dermatome Level:
T10
Umbilicus (0 looks like belly button)
Dermatome Level:
S1
Pinky Toe
Dermatome Level:
L1
Inguinal Line (top of bathing suit tan line - L1 is Lifeguard 1)
name of syndrome that affects pregnant women when laying supine = ↓ venous return and CO.
Aortocaval Compression Syndrome
When does aortocaval compression syndrome begin during pregnancy?
16-20 weeks gestation
Signs and symptoms of Aortocaval Compression Syndrome?
- HoTN
- Pallor
- Sweating
- Nausea & Vomiting (2/2 to HoTN)
Treatment for Aortocaval Compression Syndrome?
Left Uterine Displacement (LUD)
- wedge under right hip
- 15º tilt
LIst HTN disorders experienced during pregnancy:
- Gestational HTN/Pregnancy Induced HTN (PIH)
- Pre-Eclampsia
- Eclampsia
- Sever Pre-Eclampsia
- HELLP Syndrome
What is considered Gestational HTN/PIH?
139/89 after 20 weeks
Etiology of Gestational HTN/PIH
1. Abnormal sensitivity to catecholamines & hormones
2. Fetal maternal antigen antibody reaction’s
3. Production of vasoactive prostaglandins (Thromboxane A & Prostacycline)
What is a major symptom of preeclampsia that is missing in Gestational HTN/PIH?
proteinurea
Gestational HTN/PIH usually resolves by ____ postpartum and treatment is NOT needed.
12 weeks
Preeclampsia:
BP: ____
Proteinurea: ____
Sx: ____
> 140/90
300mg/24 hr
Edema, Headaches, Visual disturbances, Hyperreflexia
Severe Preeclampsia:
BP: ____
Proteinurea: ____
Sx: ____
160/110
>5g/24 hr
HELLP Syndrome (8Hemolysis, Thrombocytopenia, ↑Liver Enzymes, ↓PLT count)
The presence of what hallmark symptom graduates preeclampsia to eclampsia?
Seizures
Because these HTN pregnancy disorders can affect ____, we should monitor closely and give careful consideration to regional anesthetics.
blood coagulation
What coag studies are we interested in for pregnant HTN patients?
Full coag studies:
- PT
- PTT
- Fibrinogen
Most providers require what range of platelets IOT consider regional anesthesia?
70-100k
consider trend in PLT count
Is it safe to remove epidural catheter if PLT low?
Catheter should be left in
Get another set of labs and wait until PLT is safe range (100+ ideally), maybe for couple days
HELLP syndrome is a life threatening condition and is considered a sub-variant of ____.
Severe Pre-Eclampsia
HELLP stands for:
H: Hemolysis (RBC breakdown = Hgb breakdown = ↑Bilirubin)
EL: Elevated liver enzymes (ALT, AST)
LP: Low PLT count/thrombocytopenia (<100k)
What major vital may be normal with HELLP syndrome, delaying diagnosis?
BP
HELLP Tx:
- Transfusion
- Bedrest
- Continuous monitoring of mom & baby
- Mg
- manage HTN if present
At what point do we treat HTN in pregnant patients?
BP >159/109
What are common drugs used to treat PIH?
- Oral Hydralazine (most common)
- Labetalol
- Clonidine
- Nifedipine
- NTG/SNP
What are specific treatments for Preeclampsia?
- Manage HTN (same as PIH)
- Seizure Prophylaxis: Mg Sulfate (2 g/15min ≤ 4-6 g loading dose followed by 1-2 g/hr)
- Definitive treatment is delivery of baby [BQ] (Board Question)
Specific treatments for Eclampsia
- Prevent aspiration
- Manage airway
- Control seizures
- Midazolam 1-2 mg
- Ativan 2-4 mg
- Diazepam 5-10 mg (Textbook answer)
- THEN Mg Sulfate 1-2 g/hr
Mg Sulfate helps with both seizure prophylaxis and ____.
BP management
If mother starts seizing while pregnant, what procedure will take place immediately.
STAT c-section
uses for Mg Sulfate:
- Prevention of Eclampsia & Seizures
- Tocolytic (inhibits uterine contraction, slow/stops premature labor)
- Cerebral Protectant for premature babies
Therapeutic level of Mg Sulfate
4-8 mEq/L (4.8-9.6 mg/dL)
Patients receiving Mg Sulfate should be closely monitored for ____.
Mg Toxicity
T/F: Mg Toxicity symptoms are easily discernable in pregnant patients.
False
are the first symptoms of magnesium toxicity are fatigue, nausea and vomiting, blurred vision, EKG changes. These symptoms are not uncommon in otherwise healthy pregnant patients
What EKG changes are a result of magnesium toxicity?
- Prolonged PRI
- Widened QRS
Mg Sulfate dose dependent side effects table picture
Treatment for Mg toxicity?
1 g Calcium Gluconate IV over 10 min
What consideration should anesthetist make if a patient is on magnesium at therapeutic levels?
- Mg potentiates NMB : Reduce doses of Rocuronium
- Tocolytic ∵ can cause post-partum hemorrhage: Hemabate, Methergine, Pitocin
3 types of fetal monitoring
- Auscultation
- Electronic Fetal Monitoring
- Internal fetal monitoring
2 Auscultation methods:
- Fetoscope (low-tech)
- Portable Doppler
Benefits of Auscultation methods:
- Quick & portable
- Detects Baseline
- FHR rhythm and dysrhythmias
- Helps detect changes in heart rate
- Differentiates maternal from fetal HR
Limitations of Auscultation methods:
- No printout: cannot assess changes over time
- Not continuous: acute changes can be missed
- Cannot assess variability
- Maternal position limiting (supine difficult)
- Difficult to use on obese patients
Electronic Fetal Monitoring (EFM) uses what two external belts?
- Doppler (FHR monitor)
- Tocodynamometer (contraction monitor)
The tocodynamometer uses a ____ that records uterine contraction duration & intervals.
pressure transducer
Electronic fetal monitoring picture
Electronic fetal monitoring picture 2
EFM Benefits:
- Noninvasive
- Continuous documentation
- Not labor intensive
- Shows variability (over time)
- Works well independent of pt position
EFM Limitations:
- Restricts patient movement
- Not ECG but measures cardiac motion
- Double counting or picks up maternal heart tones (especially if mom HR is tachycardic)
newer technology is wireless and does NOT restrict movement
Internal Fetal Monitoring uses a ____ ____ electrode.
fetal spiral
what must occur before the fetal spiral electrode is used for fetal monitoring?
The amniotic sac must be broken in order to allow obstetrician to place electrode vaginally through uterus onto baby’s forehead.
What method is most accurate assessment of fetal HR?
Internal Fetal Monitoring via Fetal Spinal Electrode (FSE)
Benefits of FSE:
- Detects FHR variability
- Detects dysrhythmias (R-R interval monitoring on EKG)
- Mother may have mobility
new tech has wireless models to allow for ambulation
Limitations of FSE:
- Can be used only after the membranes of the amniotic have ruptured (after “water breaks”): ↑risk of infection (invasive)
- Discomfort during placement
- Contraindicated in patient’s with herpes outbreak
↑risk of transferring virus to baby - Contraindicated in HIV+ women due to infection risk.
likely not an option during early labor
2 methods of monitoring uterine activity:
- Tocodynamometer: external
- Intrauterine pressure catheter (IUPC): Internal
Main limitation of external tocodynamometer
hard to use in obese patients and dependent on position
Main benefit of external tocodynamometer:
noninvasive
Main benefits of IUPC:
- More accurate uterine pressure (mmHg) monitoring
- Accurate timing of heart rate changes with contraction
Main limitation of IUPC:
Invasive
Where is tocodynamometer placed?
over the fundus of uterus
superior of the two belts on the abdomen
Internal Fetal Monitoring Fetal Spinal Electrode Picture
How do we determine the baseline of the FHR?
the average FHR over 10 min, rounded to the nearest 5 bpm
Normal fetal heart rate (FHR)
110-160
what does fetal heart rate best indicate clinically (i.e., what other vital is it closely correlated with)?
how well oxygenated the baby is (oxygenation status)
Two classifications of clinical changes in fetal heart rate:
- Accelerations
- Decelerations (Early, Late, Variable)
FHR: The Graph Display
the intervals between the vertical red lines represent ____ minute/s.
1 minute
FHR: The Graph Display
Fetal heart tracing is displayed in the lower/upper pane?
upper
FHR: The Graph Display
what is displayed in the lower pane of the FHR graph?
uterine activity
FHR Display Graph Picture
what is the normal beat-to-beat variability in a healthy fetus?
5-25 bpm
measured from peak HR to lowest HR
beat to beat variability:
Minimal: _____
Moderate: _____
Marked: _____
Minimal: >5
Moderate: 5-25
Marked: >25
The following situations can decrease B-B variability:
- Hypoxia/Acidosis
- Congenital anomalies
ø Anencephalic fetus: born w/o part of brain/skull - Medication Administration (↓CNS + Cross Placenta)
ø Narcotics
ø Sedatives/Anesthetics
ø High dose anticholinergics
If signs of fetal distress are present what should be done first?
alert obstetrician immediately
Determine variability:
Normal “Moderate” Variability
Determine variability:
Minimal
BUT this is sign of distress: there should be some degree of variability coinciding with contractions
Fetal Tachycardia range:
> 160 bpm
causes of fetal tachycardia
- Recovery following asphyxia
- Maternal or fetal infection
- Catecholamine administration
- Tachydysrhythmias
- Thyrotoxicosis
Fetal Bradycardia range:
<110 for >2 MINUTES
Causes of fetal bradycardia
- Acute hypoxia
ø Idiopathic and benign if short lived - Drugs:
ø Beta Blocker
ø LA administration
Most dangerous fetal rhythm
FHR < 60 bpm
will result in cardiac decompensation
what are some things nurses may do as first line if baby is experiencing bradycardia?
- supplemental O2
- change mom position (all fours)
If baby’s heart rate does not return to normal (after bradycardia) after a couple minutes, what will the next course of action?
STAT C-section
Temporary increase in FHR
Acceleration
requirements to considered “acceleration”
<32 weeks: 10 bpm >15 sec, but <2 min
>32 weeks: 15 bpm >15 sec, but <2 min
Causes of fetal accelerations
Fetal movement
Fetal stimulation
Maternal contractions
Accelerations are said to correlate with ____.
fetal well-being
reassuring sign; if they occur often mother may get supplemental O2
Gradual decrease and return to baseline
Deceleration
the lowest point of decel (slowest FHR):
Nadir
Early or late decels are termed in relation to ____.
uterine contraction
EARLY decels are said to occur when the FHR decreases coincide with ____.
onset of uterine contractions
Early Decels:
Time from onset to the lowest point of deceleration is ____.
≥30s
Early decels:
____ occurs with the peak of contraction.
Nadir
Common etiology of early decels:
Fetal head compression (2/2 uterine squeeze)
Mild hypoxia (well-tolerated)
Early decels are caused by ____ produced when the head is compressed by uterine contraction.
vagal response
Onset and depth of early decelerations mirror ____.
the shape of the contractions
Early decelerations tend to be proportional to ____.
the strength of the contraction.
Early decels graph picture
T/F: Early decels are typically benign, common, and not an emergent situation.
True
Graphically speaking, what is the difference in early and late decels?
- Late decels do NOT initiate with the onset of contraction; rather, the onset is at or after peak contraction.
- The Nadir occurs AFTER peak contraction (shifted right).
Late decelerations are characterized by decreasing FHR waveform and a return to baseline. The onset to Nadir is ____ seconds.
> 30 sec
Common etiology of late decelerations:
Uteroplacental insufficiency (prolonged asphyxia & fetal hypoxia)
Hypoxia causes bradycardia, not contraction like in early decels
What type of decel?
Late decels
An abrupt, visually apparent decrease in the FHR below the baseline & recovery
variable deceleration
Variable decelerations have what onset to nadir?
<30 seconds
Common etiology of variable decelerations:
- Cord Compression
ø Due to oligohydramnios (↓ Amniotic Fluid) - Sustained head compression (vagal response)
Variable decelerations have a ____ relationship to contraction.
variable (duh)
if decel has a Nadir that occurs after peak contraction, it is either a “LATE” decel or “VARIABLE” decel; how can we decide?
LATE: onset to Nair > 30sec
VARIABLE: onset to Nadir < 30 sec (“abrupt”
What type of decel?
Variable decel
What type of decel?
Variable Decel
The more severe & sustained the bradycardia = the more severe the hypoxia = the higher the ____ of the baby
stress
Besides sustained bradycardia, what are the two worst rhythms?
- late decels
- variable decels
VEAL CHOP mnemonic picture
