EFM exam
Hypoxemia - ANS-Decreased oxygen in blood
Hypoxia - ANS-Not enough oxygen to supply organs
Normal fetal PO2 - ANS-15-25 mmhm
What factors can change the maternal HR? - ANS-Intrinsic pacemakers (SA & AV node)
Cardiac conduction system
Autonomic regulation... Sympathetic, parasympathetic
Humoral factors (catecholamines)
Extrinsic factors (medications)
Local factors (Ca, K)
What are the 3 most common causes of decrease cardiac output in the OB patient? -
ANS-Reduced preload (HypoTN) from
-hypovolemia
-compression of inferior vena cava
-anesthesia
In what area of the placenta does exchange of gases, nutrients, waste, hormones,
antibodies & medications occur? - ANS-Maternal blood in the intervillous space
and fetal blood in the villous capillaries
These are separated by the blood-blood barrier
Oxygen, CO2, NaCl, lipids, vitamins and some drugs are exchanged by... - ANS-Simple
diffusion
Glucose & carbohydrates are exchanged by... - ANS-Facilitated diffusion
Amino acids, water-soluble vitamins & large ions are transported by... - ANS-Active
transport
What conditions decrease the volume of the blood in the intervillous space? -
ANS-Abruption
Infarction
Thrombosis
Infection
,...These can also decrease the surface area of the chorionic villous thus decreasing O2
absorption (less surface area = less absorption)
Diffusion across the blood-blood barrier is inversely proportional to _ - ANS-Distance.
Greater distance = less diffusion
Villous hemorrhage, thrombosis, infarction, deems, fibrosis...can increase distance
What could result from trauma that causes damages chorionic vessels? -
ANS-Maternal-fetal hemorrhage!
Ruptured vasa previa - ANS-Vasa previa is a placental vessels that crosses the
chorionic membrane and is close to the cervical os. It can be damaged from just a
cervical exam or cervical check!
What 3 shunts/mechanisms direct oxygenated blood to vital organs in the fetus? -
ANS-Ductus venous, foramen ovale, ductus arteriosus
When fetus is born, what changes are responsible for the fetus's transition to neonate
life? - ANS-Umbilical-placental circulation is eliminated
Clamping of umbilical cord eliminates umbilica.-placental circulation and raises the BP
in neonate's aorta
Flow across ductus arteriosus is reversed
Catecholamines release increases BP & HR
Expansion of neonate's lungs occurs
The fetal circulation is designed to send oxygenated blood primarily to what 3 organs in
the fetus? - ANS-brain, heart, adrenal gland
Which ventricle is dominant in the fetal heart? - ANS-Right ventricle
Because fetal circulation works in parallel rather than in series like adult circulation
Umbilical vein - type of blood it carries & where? - ANS-Carries oxygenated blood from
placenta to fetus
Compression of umbilical vein - ANS-Can cause acceleration, sometimes before a
variable or prolonged accelerations
Umbilical artery - ANS-Carries deoxygenated blood from fetus to placenta
Compression of umbilical artery - ANS-Variable
,Oxygen depletion cascade - ANS-aerobic metabolism
>hypoxemia
>tissue hypoxia
>anaerobic metabolism
>lactic acid build up
>metabolic acidosis
CO = HR x SV for a fetus - ANS-Cardiac output for a fetus is only related to their heart
rate, not their stroke volume. a fetus cannot regulate their stroke volume, only their
heart rate
Aerobic metabolism - ANS-O2 > ATP > by products are CO2 & H2O
Hypoxia can lead to what time of metabolism? - ANS-Anaerobic metabolism... by
product = lactic acid
Sustained hypoxia > sustained anaerobic metabolism with by product of lactic acid
leads to _ - ANS-Metabolic acidosis
Metabolic acidosis - ANS-Accumulation of lactic acid in the body (Low pH)
The body then tries to use buffer bases (bicarbonate) to help increase the pH to a more
basic/neutral level
Eventually the buffering capacity is exceeded and the pH is low and cannot be raised to
a normal level
Sustained metabolic acidosis leads to _ - ANS-Metabolic acidemia
When the body cannot raise the pH to a normal level with buffering bases, sustained
low pH
What will sustained hypoxia & metabolic acidosis lead to? - ANS-Loss of peripheral
vascular smooth muscle contraction, which decreases peripheral vascular resistance
>>>>> Leads to Fetal Hypotension
>>>>>>>>>>Hypoxic injuries to fetal heart & brain
Distinguish between metabolic & respiratory academia - ANS-Metabolic acidemia is ^
lactic acid
Respiratory academia is ^ CO2
Causes of respiratory acidemia - ANS-increased CO2
, cord compression/true knot
-can develop rapidly and can correct rapidly
Intermittent Auscultation done with 4 devices - ANS-Stethoscope
Fetoscope
Doppler US
TVUS - Transvaginal US
Stethoscope for IA - ANS-Dome on maternal abdomen over fetal back
Fetoscope - ANS-Worn on listener's head
Bone conduction for HR
A reliable method for confirming presence of irregular HR
Doppler US - ANS-Transmits ultra high-frequency sound waves to the moving interface
of the fetal heart valves, this is deflected back to US
Transvaginal US - ANS-2 dimensional video using M-wave imaging
Procedure for Intermittent Auscultation - ANS-1. Leopold's
2. Gel, devices on fetal back
3. Count maternal radial pulse
4. Palpate ctxs so that you can count the FHR between contractions
5. Count FHR 30-60 seconds after ctxs
6. Auscultate before, during & after ctx
7. If HR discrepancies then auscultate for longer, consider need for EFM
Leopold's maneuver - ANS-Before Leopold's: empty bladder, knees flexed, towel under
right hip to prevent supine hypoTN
1. Fundus
2. Fetal back / Fetal parts
3. Over true pelvis inlet
head not engaged > Pallach's maneuver
Pallach's maneuver - ANS-If head is not engaged use this maneuver to determine if
head is flexed or extended
-Cephalic prominence on side with small parts = vertex
-Cephalic prominence on side with back = face is presenting
Intermittent Auscultation Category 1 - ANS-FHR BL 110-160
Hypoxemia - ANS-Decreased oxygen in blood
Hypoxia - ANS-Not enough oxygen to supply organs
Normal fetal PO2 - ANS-15-25 mmhm
What factors can change the maternal HR? - ANS-Intrinsic pacemakers (SA & AV node)
Cardiac conduction system
Autonomic regulation... Sympathetic, parasympathetic
Humoral factors (catecholamines)
Extrinsic factors (medications)
Local factors (Ca, K)
What are the 3 most common causes of decrease cardiac output in the OB patient? -
ANS-Reduced preload (HypoTN) from
-hypovolemia
-compression of inferior vena cava
-anesthesia
In what area of the placenta does exchange of gases, nutrients, waste, hormones,
antibodies & medications occur? - ANS-Maternal blood in the intervillous space
and fetal blood in the villous capillaries
These are separated by the blood-blood barrier
Oxygen, CO2, NaCl, lipids, vitamins and some drugs are exchanged by... - ANS-Simple
diffusion
Glucose & carbohydrates are exchanged by... - ANS-Facilitated diffusion
Amino acids, water-soluble vitamins & large ions are transported by... - ANS-Active
transport
What conditions decrease the volume of the blood in the intervillous space? -
ANS-Abruption
Infarction
Thrombosis
Infection
,...These can also decrease the surface area of the chorionic villous thus decreasing O2
absorption (less surface area = less absorption)
Diffusion across the blood-blood barrier is inversely proportional to _ - ANS-Distance.
Greater distance = less diffusion
Villous hemorrhage, thrombosis, infarction, deems, fibrosis...can increase distance
What could result from trauma that causes damages chorionic vessels? -
ANS-Maternal-fetal hemorrhage!
Ruptured vasa previa - ANS-Vasa previa is a placental vessels that crosses the
chorionic membrane and is close to the cervical os. It can be damaged from just a
cervical exam or cervical check!
What 3 shunts/mechanisms direct oxygenated blood to vital organs in the fetus? -
ANS-Ductus venous, foramen ovale, ductus arteriosus
When fetus is born, what changes are responsible for the fetus's transition to neonate
life? - ANS-Umbilical-placental circulation is eliminated
Clamping of umbilical cord eliminates umbilica.-placental circulation and raises the BP
in neonate's aorta
Flow across ductus arteriosus is reversed
Catecholamines release increases BP & HR
Expansion of neonate's lungs occurs
The fetal circulation is designed to send oxygenated blood primarily to what 3 organs in
the fetus? - ANS-brain, heart, adrenal gland
Which ventricle is dominant in the fetal heart? - ANS-Right ventricle
Because fetal circulation works in parallel rather than in series like adult circulation
Umbilical vein - type of blood it carries & where? - ANS-Carries oxygenated blood from
placenta to fetus
Compression of umbilical vein - ANS-Can cause acceleration, sometimes before a
variable or prolonged accelerations
Umbilical artery - ANS-Carries deoxygenated blood from fetus to placenta
Compression of umbilical artery - ANS-Variable
,Oxygen depletion cascade - ANS-aerobic metabolism
>hypoxemia
>tissue hypoxia
>anaerobic metabolism
>lactic acid build up
>metabolic acidosis
CO = HR x SV for a fetus - ANS-Cardiac output for a fetus is only related to their heart
rate, not their stroke volume. a fetus cannot regulate their stroke volume, only their
heart rate
Aerobic metabolism - ANS-O2 > ATP > by products are CO2 & H2O
Hypoxia can lead to what time of metabolism? - ANS-Anaerobic metabolism... by
product = lactic acid
Sustained hypoxia > sustained anaerobic metabolism with by product of lactic acid
leads to _ - ANS-Metabolic acidosis
Metabolic acidosis - ANS-Accumulation of lactic acid in the body (Low pH)
The body then tries to use buffer bases (bicarbonate) to help increase the pH to a more
basic/neutral level
Eventually the buffering capacity is exceeded and the pH is low and cannot be raised to
a normal level
Sustained metabolic acidosis leads to _ - ANS-Metabolic acidemia
When the body cannot raise the pH to a normal level with buffering bases, sustained
low pH
What will sustained hypoxia & metabolic acidosis lead to? - ANS-Loss of peripheral
vascular smooth muscle contraction, which decreases peripheral vascular resistance
>>>>> Leads to Fetal Hypotension
>>>>>>>>>>Hypoxic injuries to fetal heart & brain
Distinguish between metabolic & respiratory academia - ANS-Metabolic acidemia is ^
lactic acid
Respiratory academia is ^ CO2
Causes of respiratory acidemia - ANS-increased CO2
, cord compression/true knot
-can develop rapidly and can correct rapidly
Intermittent Auscultation done with 4 devices - ANS-Stethoscope
Fetoscope
Doppler US
TVUS - Transvaginal US
Stethoscope for IA - ANS-Dome on maternal abdomen over fetal back
Fetoscope - ANS-Worn on listener's head
Bone conduction for HR
A reliable method for confirming presence of irregular HR
Doppler US - ANS-Transmits ultra high-frequency sound waves to the moving interface
of the fetal heart valves, this is deflected back to US
Transvaginal US - ANS-2 dimensional video using M-wave imaging
Procedure for Intermittent Auscultation - ANS-1. Leopold's
2. Gel, devices on fetal back
3. Count maternal radial pulse
4. Palpate ctxs so that you can count the FHR between contractions
5. Count FHR 30-60 seconds after ctxs
6. Auscultate before, during & after ctx
7. If HR discrepancies then auscultate for longer, consider need for EFM
Leopold's maneuver - ANS-Before Leopold's: empty bladder, knees flexed, towel under
right hip to prevent supine hypoTN
1. Fundus
2. Fetal back / Fetal parts
3. Over true pelvis inlet
head not engaged > Pallach's maneuver
Pallach's maneuver - ANS-If head is not engaged use this maneuver to determine if
head is flexed or extended
-Cephalic prominence on side with small parts = vertex
-Cephalic prominence on side with back = face is presenting
Intermittent Auscultation Category 1 - ANS-FHR BL 110-160
