Obstetrics and Care of the Newborn

Detailed Lesson Plan

Chapter 37

Obstetrics and Care of the Newborn

235–280 minutes

Chapter 37 objectives can be found in an accompanying folder.
These objectives, which form the basis of each chapter, were developed from the new Education Standards and Instructional Guidelines. /
Minutes / Content Outline / Master Teaching Notes /
5 / I.  Introduction
A.  During this lesson, students will learn how to recognize and provide emergency medical care for obstetric and gynecological emergencies.
B.  Case Study
1.  Present The Dispatch and Upon Arrival information from the chapter.
2.  Discuss with students how they would proceed. / Case Study Discussion
·  How will you know if the patient is correct about her impression that delivery is imminent?
·  What equipment will you need immediately if delivery is imminent?
15 / II.  Anatomy and Physiology of the Obstetric Patient—Anatomy of Pregnancy
A.  Ovaries are the female gonads or sex glands, and they are responsible for secreting the hormones estrogen and progesterone and for development and release of the mature egg (ovum) necessary for reproduction.
B.  Fallopian tubes are thin, flexible tubelike structures that extend from the uterus to the ovaries; ovum is transported down the fallopian tube and into the uterus by peristalsis.
C.  Uterus is the pear-shaped organ (fundus, corpus or body, and cervix) that contains the developing fetus and produces contractions during labor and delivery; uterine wall is made up of the endometrium, myometrium, and perimetrium.
D.  Cervix connects with the vagina and contains a protective plug of mucus that is discharged at the beginning of labor (bloody show).
E.  Placenta is a disk-shaped inner lining of the uterus that begins to develop after the ovum is fertilized and attaches itself to the uterine wall; sole organ though which the fetus receives oxygen and nourishment and separates after delivery (afterbirth).
F.  Umbilical cord attaches the fetus to the placenta; contains one vein, two arteries, and a protective substance called Wharton’s jelly.
G.  Amniotic sac is filled with the amniotic fluid in which the infant floats; rupturing of the “bag of waters” is one of the first indications that labor is starting.
H.  The lower part of the birth canal is the vagina. / Discussion Question
From outermost to innermost, what are the layers of the uterus?
5 / III.  Anatomy and Physiology of the Obstetric Patient—Menstrual Cycle
A.  Controlled by the hormones estrogen and progesterone
B.  Cycle lasts 24 to 35 days with an average of 28 days.
C.  First day of the menstrual cycle begins with menstruation—sloughing of the endometrial tissues.
D.  After three to five days, estrogen levels increase and once again prepare the endometrium for implantation of a fertilized ovum.
E.  On the 14th day of the cycle, ovulation occurs and the mature ovum is released from the ovary.
F.  Ovum descends through the fallopian tube within the next five to seven days.
G.  If the ovum is not fertilized, it is discharged with the outer layer of endometrial tissue (approximately 14 days after ovulation). / Teaching Tip
Ask students to take turns, each listing one of the sequential events or benchmarks from ovulation to delivery.
Discussion Question
At what point in the menstrual cycle does ovulation occur?
Critical Thinking Discussion
·  How do multiple-gestation pregnancies occur?
·  How might hormonal contraceptives affect the reproductive tract to prevent pregnancy?
5 / IV.  Anatomy and Physiology of the Obstetric Patient—Prenatal Period
A.  Ovulation is the release of the mature ovum from the ovary.
B.  Fertilized egg implants in the wall of the uterus and pregnancy begins.
C.  Approximately three weeks after implantation of the fertilized egg, the placenta develops.
D.  The preembryonic stage is the first 14 days after conception.
E.  The embryonic stage is from day 15 to eight weeks.
F.  The fetal stage begins at eight weeks and ends with delivery of the baby (neonate).
G.  Gestational age refers to the age of the fetus in weeks from the time of fertilization of the ovum through delivery.
H.  Fully term pregnancy lasts approximately 280 days from the first day of the last normal menstrual cycle.
I.  Each three-month period is referred to as a trimester. (Most emergencies occur in the first or third trimester). / Discussion Questions
·  At what point does the placenta develop? In which portion of the uterus is it normally located?
·  How is gestational age measured?
15 / V.  Anatomy and Physiology of the Obstetric Patient—Physiologic Changes in Pregnancy
A.  Reproductive system
1.  Uterus grows to weight more than two pounds and holds 5,000 mL by the end of pregnancy.
2.  Uterus is extremely vascular and contains about one-sixth of the total blood volume of the mother.
3.  Mucous plug forms in the opening to the cervix.
4.  Breasts enlarge and become more nodular in preparation for milk production.
B.  Respiratory system
1.  Oxygen demand of the mother increases.
2.  Respiratory tract resistance decreases.
3.  Tidal volume increases by 40 percent.
4.  Respiratory rate increases slightly.
5.  Oxygen consumption increases by 20 percent.
C.  Cardiovascular system
1.  Cardiac output increases.
2.  Maternal blood increases by 45 percent.
3.  Maternal heart rate increases by 10 to 15 bpm.
4.  Blood pressure decreases slightly during the first and second trimester.
D.  Gastrointestinal system
1.  Nausea and vomiting commonly occur during the first trimester.
2.  Bloating and constipation may occur.
E.  Urinary system
1.  Renal blood flow increases.
2.  Glomerular filtration increases by approximately 50 percent.
3.  Urinary bladder is displaced superiorly and anteriorly.
4.  Urinary frequency increases during first and third trimester.
F.  Musculoskeletal system
1.  Pelvic joints loosen as a result of hormone changes.
2.  Mother may experience back pain from compensating for the center of gravity. / Discussion Question
What are some of the physiological changes of pregnancy?
Knowledge Application
Students should be able to apply knowledge of the anatomy and physiology of the female reproductive system to the assessment and management of obstetric patients.
Weblink
Go to www.bradybooks.com and click on the mykit link for Prehospital Emergency Care, 9th edition to access a web resource on pregnancy, labor, and delivery.
20 / VI.  Antepartum (Predelivery) Emergencies—Antepartum Conditions Causing Hemorrhage
A.  Antepartum emergences are those that occur in the pregnant patient prior to the onset of labor.
B.  Hemorrhage is one of the leading causes of death in the pregnant patient.
C.  Patient may or may not have vaginal bleeding, depending on whether or not the margins of the placenta are intact or if the fetus is engaged low in the pelvis.
D.  Spontaneous abortion
1.  Pathophysiology
a.  Delivery of the fetus and placenta before the fetus is viable (usually after the 20th week)
b.  Cause may be genetic (50 percent of cases), uterine abnormality, infection, drugs, or maternal disease
c.  Patient history is extremely important; do not mistake spontaneous abortion for heaving period.
d.  Spontaneous abortion is different from elective abortion.
2.  Assessment
a.  Cramp-like lower abdominal pain similar to labor
b.  Moderate-to-severe vaginal bleeding, bright or dark red
c.  Passing of tissue or blood clots
3.  Emergency medical care
a.  Follow general guidelines for emergency medical care for antepartum emergencies (described later).
b.  Ask when patient’s last menstrual period began.
c.  Provide emotional support to the mother and members of her family throughout treatment and transport.
E.  Placenta previa
1.  Pathophysiology
a.  Associated with abnormal implantation of the placenta over or near the opening of the cervix
b.  Placenta is prematurely torn away from the lower portion of the uterine wall and results in bleeding.
c.  Total—Placenta completely covers the os and blocks the birth canal, preventing delivery of the baby.
d.  Partial—Placenta covers the os of the cervix partially and may obstruct delivery of the baby.
e.  Marginal—Placenta is implanted near the neck of the cervix and may tear when the cervix effaces and dilates.
f.  Predisposing factors
i.  Multiparity
ii. Rapid succession of pregnancies
iii.  Greater than 35 years of age
iv.  Previous placenta previa
v. History of early vaginal bleeding
vi.  Bleeding immediately after intercourse
2.  Assessment
a.  Third-trimester vaginal bleeding that is painless
b.  Look for signs of hypovolemic shock.
3.  Emergency medical care
a.  Follow general guidelines for emergency medical care for antepartum emergencies (described later).
b.  Administer oxygen via a nonrebreather mask at 15 lpm.
c.  Treat for shock, and transport immediately.
F.  Abruptio placentae
1.  Pathophysiology
a.  When small arteries located in the lining between the placenta and uterus are prone to rupture, accumulating blood begins to tear and separate the placenta from the uterine wall.
b.  Causes poor gas, nutrient, and waste exchange between the fetus and placenta and can cause severe maternal blood loss
c.  Complete—Placenta completely separates from the uterine wall (100 percent fetal mortality rate).
d.  Partial—Placenta is partially torn from the uterine wall (30 to 60 percent fetal mortality rate).
e.  Predisposing factors
i.  Hypertension
ii. Use of cocaine or other vasoactive drugs
iii.  Preeclampsia
iv.  Multiparity
v. Previous abruption
vi.  Smoking
vii.  Short umbilical cord
viii.  Premature rupture of the amniotic sac
ix.  Diabetes mellitus
2.  Assessment—Signs and symptoms
a.  Vaginal bleeding with constant abdominal pain
b.  Mild, sharp, or acute abdominal pain due to muscle spasm of the uterus
c.  Lower back pain
d.  Uterine contractions
e.  Tender abdomen (upon palpation)
f.  Dark or bright red bleeding
g.  Hypovoemic shock (Remember that more than 2,500 mL of blood can be concealed in the uterus.
3.  Emergency care
a.  Treatment is same as for placenta previa.
b.  Administer oxygen, treat for shock, and provide immediate transport.
G.  Ruptured uterus
1.  Pathophysiology
a.  Spontaneous or traumatic rupture of the uterine wall, releasing the fetus into the abdominal cavity
b.  Mortality to the mother is 5–20 percent; infant mortality is over 50 percent.
c.  Ruptured uterus requires immediate surgery.
2.  Assessment
a.  History of previous uterine rupture
b.  History or findings of abdominal trauma
c.  History of a large fetus
d.  Having borne more than two children
e.  History of prolonged and difficult labor
f.  History of prior Caesarean section or uterine surgery
g.  Tearing or shearing sensation in the abdomen
h.  Constant and severe abdominal pain
i.  Nausea
j.  Signs and symptoms of shock
k.  Vaginal bleeding (typically minor)
l.  Cessation of noticeable uterine contractions
m.  Ability to palpate the infant in the abdominal cavity
3.  Emergency medical care
a.  Follow general guidelines for emergency medical care for antepartum emergencies (described later).
b.  Administer oxygen at 15 lpm by nonrebreather mask.
c.  Provide immediate transport.
H.  Ectopic pregnancy
1.  Pathophysiology
a.  Egg is implanted outside the uterus in either the fallopian tub, on the abdominal peritoneal covering, on the outside wall of the uterus, on the ovary, or on the cervix.
b.  Tissue ultimately ruptures (third leading cause of maternal death).
c.  Predisposing factors
i.  Previous ectopic pregnancies
ii. Pelvis inflammatory disease (PID)
iii.  Adhesions from surgery
iv.  Tubal surgery
2.  Assessment
a.  Dull aching-type pain that is poorly localized and then becomes sudden
b.  Shoulder pain
c.  Vaginal bleeding (heaving, light, or absent)
d.  Lower abdominal pain
e.  Tender, bloated abdomen
f.  Palpable mass in the abdomen (rare)
g.  Weakness or dizziness when sitting or standing
h.  Decreased blood pressure
i.  Increased pulse rate
j.  Signs of shock (hypoperfusion)
k.  Discoloration around the navel
l.  Urge to defecate
3.  Emergency medical care
a.  Follow general guidelines for emergency medical care for antepartum emergencies (described later).
b.  Treat the patient for shock.
c.  Administer oxygen at 15 lpm by nonrebreather mask.
d.  Constantly reassess vital signs.
e.  Provide immediate transport. / Teaching Tip
Arrange for an OB nurse to guest speak on these emergencies.
Weblink
Go to www.bradybooks.com and click on the mykit link for Prehospital Emergency Care, 9th edition to access a web resource on vaginal bleeding during pregnancy.
Discussion Question
How are placenta previa and abruptio placenta different?
Critical Thinking Discussion
·  Why is maternal cocaine use a risk factor for abruptio placenta?
·  What are some other potential risks of maternal substance abuse?
Discussion Question
What are some risk factors for uterine rupture?
Discussion Question
What is an ectopic pregnancy?
15 / VII.  Antepartum (Predelivery) Emergencies—Antepartum Seizures and Blood Pressure Disturbances
A.  Seizures during pregnancy
1.  Can be life-threatening to mother and fetus
2.  Provide emergency medical care the same as for any seizure patient.
3.  Protect the pregnant patient from injuring herself.
4.  Transport the patient in a calm and quiet manner, and place her on her side.
5.  Seizures may be associated with eclampsia.
B.  Preeclampsia (toxemia)/eclampsia
1.  Pathophysiology
a.  Most frequently occurs in the last trimester and affects women in their 20s who are pregnant for the first time
b.  Eclampsia is a more severe form of preeclampsia and can include coma or seizures (causing the placenta to separate from the uterine wall).
2.  Assessment
a.  History of hypertension, diabetes, kidney disease, liver disease, or heart disease
b.  No previous pregnancies
c.  History of poor nutrition
d.  Sudden weight gain (two pounds a week or more)
e.  Altered mental status
f.  Abdominal pain
g.  Blurred vision or spots before the eyes
h.  Excessive swelling of the face, fingers, legs, or feet
i.  Decreased urine output
j.  Severe, persistent headache
k.  Elevated blood pressure—Pregnancy induced hypertension (PIH) is defined as a blood pressure in a pregnant woman that is great than 140/90 mmHg on two or more occasions at six hours apart; or a systolic blood pressure of greater than 30 mmHg and a diastolic blood pressure greater than 15 mmHg from blood pressure prior to pregnancy.
3.  Emergency medical care
a.  Follow general guidelines for emergency medical care for antepartum emergencies (described later).