1 Electronic Fetal Monitoring FHR Reflects Fetal Oxygenation

Electronic Fetal Monitoring
PEC 2014
FHR Reflects Fetal Oxygenation
Extrinsic
— Maternal oxygenation
— Uterine blood flow
— Placental exchange
— Umbilical blood flow
Intrinsic
(Handout is subset of presentation slides)
Nancy O’Brien-Abel, MN, RNC
— Fetal circulation
— Oxygenation of tissues
— FHR regulation
Perinatal Clinical Specialist
[email protected]
Uterine Blood Flow During Pregnancy
↑ From 50 ml/min → approx. 700 ml/min
10–15% of maternal CO
70–90% passes through intervillous space
Intervillous space perfusion dependent
upon adequate uterine blood flow
Uteroplacental Perfusion
Factors that May Decrease
Excessive uterine activity (tachysystole,
hypertonus, abruptio placenta)
Maternal hypotension (supine, analgesia)
Maternal hypertension
Placental changes
(↓ surface area, edema, degenerative,
calcifications, infarcts, infection)
Vasoconstriction (exogenous – most
sympathomimetics, except ephedrine)
Nancy O’Brien-Abel, MN, RNC
2014_Perinatal Consulting, LLC
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Excessive Uterine Contractions
Maternal Supine
Hypotension
Tachysystole
↓ Uteroplacental Perfusion
↓ Fetal Oxygenation
Poseiro et al, 1969
Maternal Hypotension
Placental Changes
Epidural
BP 130/82 94/56
↑ IV fluids
Maternal Position Change
Adequate Umbilical Blood Flow
Fetal
Circulation
Moore & Persaud, 2003
with permission
Nancy O’Brien-Abel, MN, RNC
2014_Perinatal Consulting, LLC
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FHR
Regulation
Fetal Monitoring Techniques
Fetal Heart Rate (FHR)
— Intermittent Auscultation*
— Doppler
— Fetal Scalp Electrode (FSE)
CRC Cardioregulatory Ctr.
RCC Respiratory Control Ctr.
FMC Fetal Movement Ctr.
RAS Reticular Activating Ctr.
Uterine Contractions
— Palpation*
— Tocodynamometer (TOCO)
— Intrauterine Pressure Catheter (IUPC)
External
Fetal Monitoring
Techniques
FHR Auscultation
Internal Fetal Monitoring Techniques
Electronic Fetal Monitoring (EFM)
Fetal Heart Rate (FHR)
Uterine Activity
Nancy O’Brien-Abel, MN, RNC
2014_Perinatal Consulting, LLC
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2009
2008
Macones et al, Obstet Gynecol, 2008
New 5th edition
in 2014
Fetal Heart Rate Tracings
EFM Pattern Recognition
Appropriately Interpreting and Managing
Objectives
2010
Identify uterine activity, FHR variability, baseline rate,
tachycardia, bradycardia, accelerations and
decelerations
Discuss physiologic based interventions to maximize
uteroplacental blood flow, umbilical blood flow, and
fetal oxygenation, and to reduce uterine activity
Uterine Contractions
EFM Tracing Description
Clinical Assessment
Requires evaluation
1 min
Uterine Contractions
Baseline Rate
Baseline Variability
Presence of Accelerations
Periodic or Episodic Decelerations (early,
late, variable, prolonged)
frequency (min)
intensity
resting tone
duration (sec)
Changes or Trends in FHR Over Time
ACOG 2010, 2009; AWHONN 2009; NICHD 2008
Nancy O’Brien-Abel, MN, RNC
2014_Perinatal Consulting, LLC
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Uterine
Contractions
Frequency
Duration
Intensity
Resting Tone
Normal:
<5 contractions in 10 min., averaged over 30-min
Tachysystole:
>5 contractions in 10 min., averaged over 30-min
— Contraction lasting ≥ 2 min
— Contraction of normal duration
occurring within 1 min. of each other
ACOG 2009, 2005, 2003, 1999; AWHONN 2009, 2008; Simpson & Knox 2009;
Bakker et al. 2007; Simpson & James 2007
Frequency
Duration
Intensity
Resting Tone
Frequency
Duration
Intensity
Resting Tone
EFM Tracing Description
FHR Characteristics and Acidemia
Requires evaluation
Uterine Contractions
Baseline Rate
Baseline Variability
Presence of Accelerations
Periodic or Episodic Decelerations (early,
late, variable, prolonged)
Changes or Trends in FHR Over Time
NORMAL
INDETERMINATE
ABNORMAL
Fetal Acid-Base Status
Compensatory Response
Fetal Acid-Base Status
ALL required:
• Variability: moderate
• Baseline rate: 110-160 bpm
• Late or variable decels: absent
• Early decels: present or absent
• Accels: present or absent
Category I
EITHER required:
• Absent variability with
— Recurrent late decels, or
— Recurrent variable decels, or
— Bradycardia, OR
• Sinusoidal pattern
Category II
Category III
ACOG 2010, 2009; AWHONN 2009; NICHD 2008
Nancy O’Brien-Abel, MN, RNC
2014_Perinatal Consulting, LLC
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EFM and Critical Thinking
Fetal Acid-Base Status?
Underlying Cause?
In-Utero Resuscitation?
Labor Phase/Stage/Progress?
Consider Prompt Delivery?
*Given the wide variation of FHR tracings in Category II (Indeterminate), algorithm not meant to
represent assessment/management of all potential FHR tracings, rather provide an action template.
ACOG 2010
FHR Pattern Interpretation
Overview
Normal Baseline FHR
Moderate Variability (baseline)
Accelerations
Minimal/Absent /Marked Variability
Early/Late/Variable Decelerations
Prolonged Deceleration
Baseline Bradycardia/Tachycardia
Sinusoidal Pattern
Mean Baseline FHR
Baseline FHR
Approximate mean FHR rounded to increments of 5
bpm during a 10-min window, excluding:
— Accelerations and decelerations
— Periods of marked variability (>25 bpm)
Minimum of 2 min of identifiable BL segments (not
necessarily contiguous) in any 10-min window, or the BL
for that period is indeterminate
One may need to refer to the previous 10-min window
to determine BL
ACOG 2010, 2009; AWHONN 2009; NICHD 2008
Baseline FHR
Normal: 110 –160 bpm
Tachycardia: >160 bpm
Bradycardia: <110 bpm
ACOG 2010, 2009; AWHONN 2009; NICHD 2008
Nancy O’Brien-Abel, MN, RNC
2014_Perinatal Consulting, LLC
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Baseline Variability
Irregular fluctuations in baseline FHR (amplitude and
frequency)
Moderate Variability
6–25 bpm
Determined in 10-min window, excluding accelerations
and decelerations
Amplitude Range
Absent: Undetectable
Minimal: > 0 and < 5 bpm
Moderate: 6 to 25 bpm
Marked: > 25 bpm
ACOG 2010, 2009; AWHONN 2009; NICHD 2008
ACOG 2010, 2009; AWHONN 2009; NICHD 2008
Acceleration
Visually apparent, abrupt ↑ (onset to peak in <30 sec) in
FHR above baseline
Peak ≥15 bpm above baseline
Lasts ≥15 sec from onset to return to baseline
ACOG 2010, 2009; AWHONN 2009; NICHD 2008
Prolonged Acceleration
Lasts >2 min and <10 min duration
ACOG 2010, 2009; AWHONN 2009; NICHD 2008
Normal vs. Abnormal?
FHR Accelerations
Fetal AcidAcid-Base Status
<32 Weeks Gestation
— Peak >10 bpm, and
— Duration >10 sec
ACOG 2010, 2009; AWHONN 2009; NICHD 2008
Nancy O’Brien-Abel, MN, RNC
2014_Perinatal Consulting, LLC
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Minimal Variability
Marked Variability (Saltatory)
> Undetectable and <5 bpm
>25 bpm
ACOG 2010, 2009; AWHONN 2009; NICHD 2008
Absent Variability
Undetectable Variation From Baseline
ACOG 2010, 2009; AWHONN 2009; NICHD 2008
FHR Decelerations
ACOG 2010, 2009; AWHONN 2009; NICHD 2008
FHR Decelerations
1st Distinguished on basis of waveform, “abrupt” or
“gradual” onset
2nd Timing in relation to contraction
Early, Late, Variable, Prolonged
Early Deceleration
Late, Variable, Early
“Recurrent”
— Occur with >50% of contractions
in any 20-min window
“Intermittent”
— Occur with <50% of contractions
in any 20-min window
ACOG 2010, 2009; AWHONN 2009; NICHD 2008
Visually apparent, usually symmetrical, gradual ↓ (onset to
nadir in ≥30 sec) and return to baseline FHR associated with
uterine ctx
Nadir occurs at same time as peak of ctx
In most cases, onset, nadir, & recovery are coincident with
beginning, peak, & ending of ctx
ACOG 2010, 2009; AWHONN 2009; NICHD 2008
Nancy O’Brien-Abel, MN, RNC
2014_Perinatal Consulting, LLC
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Early Decelerations
Late Deceleration
Fetal head compression
Altered cerebral blood flow
Vagal reflex and cardiac slowing
Visually apparent, usually symmetrical, gradual ↓
(onset of deceleration to nadir ≥30 sec) and return to
baseline FHR associated with uterine ctx
Delay in timing—nadir after peak of ctx
Onset, nadir & recovery occur after beginning, peak
& ending of ctx
ACOG 2010, 2009; AWHONN 2009; NICHD 2008
Late Deceleration
Physiology
Uteroplacental insufficiency results in ↓
maternal/fetal O2 transfer
Position change
6 cms
Pitocin off
Variable Deceleration
Visually apparent, abrupt ↓ in FHR (onset of decel
to beginning of nadir <30 sec) below baseline
↓ in FHR ≥15 bpm below baseline, lasting ≥15 sec,
and <2 min in duration
Onset, depth and duration commonly vary
ACOG 2010, 2010; AWHONN 2009; NICHD 2008
Nancy O’Brien-Abel, MN, RNC
2014_Perinatal Consulting, LLC
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Variable Deceleration
Physiology
Umbilical cord
compression resulting
in baroreceptor
stimulation
Prolonged Deceleration
7 cm per MD
1950
Visually apparent ↓ in FHR >15 bpm below BL
Lasting >2 min, but <10 min
ACOG 2010, 2009; AWHONN 2009; NICHD 2008
Prolonged Deceleration
Uterine tachysystole or hypertonus
Abruptio placenta
Acute maternal hypotension
Uterine rupture
Maternal hypoxia (seizure or respiratory depression)
Umbilical cord accidents
Terminal fetal conditions
Ruptured vasa previa
Rapid fetal descent
Vagal stimulation or maternal Valsalva
Nancy O’Brien-Abel, MN, RNC
2014_Perinatal Consulting, LLC
9 cm/C/0 st
To right side
Instructed to push
Remains supine
Prolonged decel
with return to BL
10
FHR Bradycardia
Bradycardia x20 min. to birth
–
Nursing Interventions?
Baseline FHR < 110 bpm for > 10 min
Oxygen Depletion Cascade
Aerobic Metabolism
Hypoxemia
Tissue Hypoxia
Anaerobic Metabolism
Lactic Acid Build Up
METABOLIC
ACIDOSIS
FHR Tachycardia
Baseline FHR > 160 bpm for > 10 min
Maternal or Fetal Infection (e.g., chorioamnionitis;
pyelonephritis)
Progressive Disruption of Fetal Oxygenation (hypoxia,
metabolic acidosis) (e.g., fetal bleeding)
Fetal Anemia
Nursing Interventions?
Maternal Hyperthyroidism
Fetal Tachyarrhythmias (sinus tachycardia, SVT)
Medications/Drugs
— Sympathomimetics (terbutaline, ritodrine, albuterol)
— Parasympatholytic (atropine, phenothiazines)
— Other (caffeine, theophylline, cocaine, methamphetamine)
Nancy O’Brien-Abel, MN, RNC
2014_Perinatal Consulting, LLC
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G2 P0, 39 4/7 wks
SROM x 24 hrs
ROM x 30 hrs
Pt shaking
Temp 37.9°C
VE 6 cm/90%/0 St
Sinusoidal Heart Rate
Sinusoidal FHR Pattern
Associations
True SHR Pattern
— Severe fetal anemia (e.g., massive FMH, TTTS,
ruptured vasa previa, Rh isoimmunization)
— Severe hypoxia/acidosis/asphyxia
Physiologic States/Drug-Induced
— Rhythmic movements of fetal mouth or sucking
— Fetal non-REM sleep
— Effect of certain drugs, particularly narcotics
Visually apparent, smooth, sine wave-like undulating pattern
Cycle frequency 3-5/min., persists for > 20 min.
Modanlou and Murata, 2004
ACOG 2010, 2009; AWHONN 2009; NICHD 2008
FHR Evolution Over Time
FHR Evolution Over Time
Situational Blindness
Situational Blindness
10:22
7 hours later…
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Nancy O’Brien-Abel, MN, RNC
2014_Perinatal Consulting, LLC
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Now It’s Your Turn
EFM Pattern Interpretation
EFM Pattern Recognition
Objectives
Identify uterine activity, FHR variability, baseline rate,
tachycardia, bradycardia, accelerations and
decelerations
Discuss physiologic based interventions to maximize
uteroplacental blood flow, umbilical blood flow, and
fetal oxygenation, and to reduce uterine activity
FHR Reflects Fetal Oxygenation/Acidemia
Physiologic Basis
— Maternal conditions
— ↓ Uterine blood flow
— ↓ Placental exchange
— ↓ Umbilical blood flow
— Fetal conditions
Assess FHR Characteristics
— “Normal”
— “Indeterminate”
— “Abnormal”
Intrauterine Resuscitation
“In“In-Utero Resuscitation”
Indeterminate and Abnormal Tracings
Change maternal position
↓ Uterine activity
IV fluid bolus
Correct maternal hypotension
Oxygen administration
Amnioinfusion
Alteration in 2nd stage maternal pushing efforts
If prolapsed umbilical cord, elevate fetal presenting
part while moving toward operative birth
ACOG 2010; AWHONN 2009; Garite & Simpson, 2011
Nancy O’Brien-Abel, MN, RNC
2014_Perinatal Consulting, LLC
*Given the wide variation of FHR tracings in Category II (Indeterminate),
algorithm not meant to represent assessment/management of all potential FHR tracings,
rather provide an action template.
Adapted from ACOG 2010
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Promote Fetal O2 and Improve
Uteroplacental Blood Flow
Correct Maternal Hypotension
Epidural
BP 130/82 94/56
Initiate lateral position (R or L)
Administer maternal O2
Administer IV fluid bolus
DC oxytocin or cervical ripening
Consider tocolytic (terbutaline)
In 2nd stage, consider stop pushing
temporarily, or push every other,
or every 3rd contx.
↑ IV fluids
Maternal position change
If not improved, anesth. provider
Modified Maternal Pushing
T 97.6
Pushing x 2 hrs
Position changes
No oxytocin
O2 applied
T 98.0
1720
1800
Pushing every other ctx
Vacuum birth
Apgars 7/9
Alleviate Umbilical Cord Compression
Initiate maternal repositioning
Consider amnioinfusion (during 1st stage)
If prolapsed umb. cord, elevate presenting part
while preparations underway for operative delivery
Nancy O’Brien-Abel, MN, RNC
2014_Perinatal Consulting, LLC
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Reduce Uterine Activity
SROM clear fluid
Interventions??
↓ or DC oxytocin or cervical ripening agents
Administer IV fluid bolus
Initiate lateral position (R or L)
If no response, consider tocolytic (terbutaline)
Oxytocin
Induction Agent
Most commonly
used induction agent
in US and worldwide
Too Much Oxytocin
Excessive Contractions
↓ Uteroplacental Perfusion
Smith & Merrill, 2006
High-alert medication
Institute for Safe Medication Practice, August 2007
Uterine
Contractions
↓ Fetal Oxygenation
Uterine Tachysystole
Normal:
<5 contractions in 10 min., averaged over 30-min
Tachysystole:
>5 contractions in 10 min., averaged over 30-min
— Contraction lasting ≥ 2 min
— Contraction of normal duration
occurring within 1 min. of each other
Nursing Interventions?
ACOG 2009, 2005, 2003, 1999; AWHONN 2009, 2008; Simpson & Knox 2009;
Bakker et al. 2007; Simpson & James 2007
Nancy O’Brien-Abel, MN, RNC
2014_Perinatal Consulting, LLC
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Uterine Tachysystole
Tachysystole Management
ACOG Practice Bulletin 116, 2010
Too Much Oxytocin
Coupling” Uterine Contractions
Now It’s Your Turn
Interpretation and
Nursing Interventions
Oxytocin receptor site desensitization
Often rest period and IV fluids will allow oxytocin
receptors to re-sensitize
Daywood, 1995; Phaneuf et al, 2000; Zeeman et al, 1997
Thank you!
[email protected]
Nancy O’Brien-Abel, MN, RNC
2014_Perinatal Consulting, LLC
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