Emergency Obstetrics Flashcards
1
Q
Labour - First Stage
A
Regular uterine contractions plus cervical change (dilation and effacement). The first stage of labour includes the latent and active phases.
2
Q
Labour - first stage
Latent phase
A
Latent phase
- The presence of uterine activity resulting in progressive effacement and dilation of the cervix proceeding to the active phase. It is complete when a nulliparous woman reaches 4 cm dilation and a parous woman reaches 4 - 5 cm. Cervical length should be less than 1 cm.
3
Q
Labour - first stage
Active phase
A
Active phase
- The presence of a pattern of contractions leading to cervical effacement and dilatation after 4 cm dilatation in a nulliparous woman or 4 - 5 cm dilatation in a parous woman.
4
Q
Labour - second stage
A
Full dilation to delivery of the baby
- Passive second stage - full dilation without active pushing
- Active second stage - full dilation with active pushing
5
Q
Labour - third stage
A
Immediately after delivery of the baby to delivery of the placenta
6
Q
Labour - fourth stage
A
Immediately after delivery of the placenta to one hour postpartum
7
Q
Dystocia
A
Delayed or arrested progress in labour, irrespective of cause
- In active first stage, greater than 4 hours of < 5 cm per hour dilatation, or No cervical dilatation over 2 hours
- In active second stage, greater than 1 hour of active pushing withou descent of the presenting part
8
Q
Gravidity
A
The total number of pregnancies regardless of duration and outcome.
- Gravidity refers to a uterus that contains a fetus, whatever the outcome (ie abortion, stillbirth, or live birth)
- We classify women according to the number of times her uterus has been occcupied (gravidity)
9
Q
Parity
A
The number of pregnancies completed to delivery during the viable period.
- Parity refers to delivery of a infant after the 28th week of gestation, irrespective of whether the infant was born alive or dead
- We classify woman according to the number of times she has carried a fetus more than 28 weeks (parity)
10
Q
Grand mutiparity
Definition
A
Refers to a woman who has had 5 or more births
11
Q
What are the four distinct classification of Parity?
A
T-P-A-L
- Term Infants
- Preterm infants
- Abortions
- Children Current Living
12
Q
Perinatal period
A
The interval between the birth of an infant born after 20 weeks gestation and the 28 completed days after birth.
13
Q
Birth
A
The complete expulsion or extraction from the mother of a fetus after 20 weeks gestation.
In the absence of accurate dating criteria, fetuses weighing < 500 g are usually not considered as births but rather are termed abortus
14
Q
Birthweight
A
The weight of a neonate determined immediately after delivery or soon thereafter as feasible. It should be expressed to the nearest gram.
15
Q
Live Birth
A
The term used to record a birth whenever the newborn after birth breathes sponstaneously or shows any other sign of life such as a heartbeat or definite spontaneous movement of voluntary muscles.
16
Q
Stillbirth or Fetal death
A
The absence of signs of life at or after birth
17
Q
Early Neonatal Death
A
Death of a liveborn neonate during the first 7 days after birth
18
Q
Late Neonatal Death
A
Death after 7 days but before 29 days
19
Q
Low birthweight
A
A newborn whose weight is < 2500g
20
Q
Very low birthweight
A
A newborn whose weight is < 1500g
21
Q
Extremely low birthweight
A
A newborn whose weight is < 1000g
22
Q
Term neonate
A
A neonate born any time after 37 completed weeks of gestation and up until 42 completed weeks of gestation ( 260 - 294 days)
American College of Obstetricians and Gynecologists
- Early term refers to neonates born at 37 completed weeks up to 38 weeks
- Full term denotes those born at 39 completed weeks up to 40 weeks
- Late term denotes those born at 41 completed weeks
23
Q
Preterm neonate
A
A neonate born anytime before 37 completed weeks (259th day)
24
Q
Postterm neonate
A
A neonate born anytime after completion of the 42nd week, beginning at day 295
25
Abortus
A fetus or embryo removed or expelled from the uterus during the first half of gestation - 20 weeks or less, or in the absence of accurate dating criteria, or weighing \< 500g
26
Induced termination of pregnancy
The purposeful interruption of an intrauterine pregnancy that has the intention other than to produce a liveborn neonate and that does not result in a live birth.
27
Primigravida
A woman who is pregnant for the first time
28
Primipara
A woman who has had only one delivery
29
Multigravida
A woman who has had two or more pregnancies irrespective of the outcome
30
Multipara
A woman who has had two or more deliveries
* A woman who has had more than five deliveries is referred to as a "grand mutipara"
31
Nullipara
A woman who has never delivered
32
Pregnancy is divided into three trimesters
What are they?
**First Trimester**
conception to 14 weeks
**Second Trimester**
14 - 28 weeks
**Third Trimester**
28 - 42 weeks
33
What is the normal duration of pregnancy?
40 weeks
34
List the key physiologic changes during pregnancy
35
How does blood volume change in pregnancy?
* Average woman has 4 - 5 litres of total blood volume
* Pregnancy causes blood volume to increase throughout gestation with a **40 - 50%** increase by term
* This increase in blood volume is neccessary to meet the metabolic needs of the fetus, to adequately perfuse maternal organs such as the uterus and kidneys and to help compensate for blood loss during delivery
36
How much blood volume does the uterus contain at term?
* 15 - 16 % of the mothers circulating blood volume
* During vaginal delivery a woman may have as much as 500 ml of blood loss
37
How does pregnancy change red blood cell volume?
* As blood volume increases so does the number of red blood cells (RBCs), which increase by as much as 33% over the normal count
* The increase in RBCs heightens the pregnant woman's need for iron, which is why most women have to take prenatal vitamins or iron supplements
* If the woman does not take iron the fetus can deplete maternal iron stores for its needs, resulting in iron deficiency
38
How does the White blood Cell Count change during pregnancy?
* WBC increases from an average of 4300 cells/ul before pregnancy to as high as 12000 cell/ul or more by the third trimester.
* Clotting factors are similarly increased while fibrinolytic factors are depressed
* These are important factors to consider if you are dealing with obstetric hemorrhage or thrombolic disease
39
How does the heart change during pregnancy?
* Increases in size by 10 - 15% with a collateral capacity increase of 70 - 80 ml
* Cardiac output increases by 40% by 22 weeks gestation
* As the uterus enlarges the myocadium is displaced upward to the left whch can cause a benign systolic flow murmur
40
How does heart rate and ECG change during pregnancy?
* Heart rate increases to 15 - 20 beats/min by term
* ECG changes may include ectopic beats and supraventricular tachycardia
* Slight left axis deviation and lead III changes such as low-voltage QRS, T wave inversion or flattening, or even occasional Q waves
41
How does preganancy affect a women's sensitivity to body positioning?
* Resting or lying supine can cause the uterus to impinge upon the inferior vena cava, thereby decreasing venous return to the heart
* Pressure by the fetus on the common iliac vein creates this problem as well
* Overtime if pressure is not relieved, cardiac ouput is decreased, blood pressure drops, and lower extremity edema will result
42
What are some of the risks related to Venous distention in pregnancy?
* The pressures exerted upon the circulatory sytem and the increased blood volume combine to produce venous distension of about 150%
* Blood return to the heart is decreased as the venous ends of the capillaries become dilated
* Gravid women who are bedridden or who spend a great deal of time lying down can develop **deep venous thrombosis**, which can lead to **pulmonary embolism**
43
How do you measure fundal height and what is the purpose?
* The measurement of the fundus of the uterus (the top, portion, opposite the cervix) can indicate possible development problems
* The fundas is measured in centimetres by running a measuring tape vertically from the top of the pubic bone to the top of the fundus
* At 22 weeks gestation the fundus of the uterus is approximately at the level of the umbilicus (20 cm in length from the pubic bone to the fundus) It increases by 1 cm for every additional week of gestation
44
What is the lithotomy postion
The standard position for delivery is when the woman is supine (on her back) with her knees spread apart, or her feet in stirrups.
* In the supine position, maternal cardiac output can increase as much as 25% from uterine contractions, with pulse pressure increasing by about 25% as well
* Impingement on the inferior vena cava may cause the heart rate to decrease by about 15% in turn causing stroke volume to increase as much as 30%
45
What are the effects on the respiratory system during pregnancy?
* Uterus pushes the the diaphragm up toward the abdominal cavity which decrease functional residual capacity
* Progesterone causes bronchodilation and decreased airway resistance
* Oxygen consumption increases by 20%
* Tidal volume increases gradually to about 40% and the overall minute ventilation incrases by 50% or about 10 l/min
* The PaCO2 decreases by about 5 mmHg
46
How does pregnancy affect lung volumes and capacities?
* Decrease in expiratory reserve volume
* Decrease in functional residual capacity
* Decrease in residual volume
Tidal volume and inspiratory reserve volume increase causing the inspiratory capacity to increase
47
Why should you avoid nasal intubations in pregnant patients?
* Structural changes within the respiratory mucous membrane result in increased vascularity and edema.
* Estrogen affects the nasal tract, leading the respiratory membrane friable, and making epistaxis a potential emergency
* Nasal intubation should be avoided and if neccessary select the next smaller size ETT to avoid trauma
48
What causes weight gain in pregnancy?
* Increased blood volume
* Increase in intracellular and extracellular fluid (2.7 to 3 kg)
* Uterine growth (1.4 kg)
* Placental growth (1 kg)
* Fetal growth ( 3 kg)
* Increased breast tissue ( 1 - 1.4 kg)
* Increased protein and fat deposits
* Average weight gain in pregnancy 12.3 kg
49
How does pregnancy change the demand for carbohydrates?
* Increases the demand for carbohydrates based on fetal demand for glucose
* Insulin molecule is to large to pass through the placental barrier so several fetoplacental and maternal hormones are utilized to compensate for theincreased carbohydrate requirement
* Woman may become diabetic during pregnancy but will return to normal postpartum
50
Gestational Diabetes Mellitus (GDM)
GDM is the inability to process cadrbohydrates during pregnancy. Increased maternal insulin production results in increased placental prduction of human placental lactogen which leads to an imbalance between the supply of the mother's insulin and glucose production.
Treatment consists of diet control or insulin therapy if required
51
Obstructed Labour
No cervical dilation over 2 hours despite evidence of strong contractions
52
List some medical condition that can adversely affect the health of both the woman and the developing fetus.
* Heart Disease
* Hypertension
* Diabetes
* Respiratory Disorders
* Renal Disorders
* Hemoglobinopathies
* Isoimmunization (Rh Disease)
* Group B Steptococci Perinatal Infections
* Perinatal Viral and Parasitic Infections
* Epilepsy
* Seizures
* Thyroid disorders
* Cholestasis
53
How does heart disease affect the pregnant patient?
* Heart defects and dysrythmias may be benign under normal conditions but the added stress of pregnancy could create major problems.
* Has the patient experienced any episodes of dizziness, light headedness or syncopal episodes. This could be indicative of a dysrythmia that can become critical during the stresses of labour
54
Women with preeclampsia occuring prior to 37 weeks are at signicant risk for:
* Stillbirth
* Abruption
* Spontaneous preterm rupture of membranes
* Small for gestational age babies in subsequent pregnancy
There is evidence that hypertensive disorders of pregnancy, particulary in pre-existing (chronic) hypertension, and independent of antihypertensive use, are associated with increased risk of:
* congential malformations in the newborn
* Esophageal atresia
* Ventricular septal defect
55
What is the concern with Eclampsia?
Eclampsia is significantly associated with:
* Maternal death
* Need for assisted ventilation
* Adult respiratory distress syndrome
* Acute renal failure
* Embolism
* Neonatal death
56
Chronic Hypertension in Pregnancy
* A blood pressure that is equal to or greater than 140/90 mm Hg, which exists prior to pregnancy, occurs before the 20th week of pregnancy, or continues to persist postpartum.
* Diastolic pressures higher than 110 mm Hg place the patient at risk for stroke and other cardiovascular dangers
* Blood pressure is taken in the same arm \> 15 minutes apart after an initial rest period of 10 minutes
57
Gestation Hypertension
* Develops after the 20th week of pregnancy with no organ dysfunction
* More common in obese women and those that are glucose intolerant.
58
Severe Hypertension
* Systolic pressure \> 160 mmHg
* Diastolic pressure \> 110 mmHg
* Blood pressure is taken in the same arm 15 minutes apart after an inital rest period of 10 minutes
59
Preeclampsia
* Gestational or Chronic Hypertension along with one or more of the following new onset conditions:
* Proteinuria
* Other maternal organ dysfunction (renal, liver, neurologic, hematologic)
* Uteroplacental dysfunction (fetal growth restriction)
60
What are the first and second most common causes of Maternal Death?
* Post Partum hemorrhage is the most common cause of mortality
* Hypertensive disorders along with embolism are the second most common causes of mortality
61
Following confirmation of hypertension, how do you assess for symptoms and signs suggesting involvement of other organ systems?
**Central Nervous System**
* Presence of severe headache
* Visual disturbance
* Tremulousness, irritability
* Hyperreflexia
**Cardiorespiratory**
* Chest pain
* Dyspnea
* Distended neck veins
**Hematologic**
* Bleeding
* Petechiae
**Hepatic**
* RUQ/epigastic pain
* Severe nausea and vomiting
**Renal**
* Reduced urine output \< 15 ml/hr
* Edema and weight gain
* Proteinuria
62
What is the role of Antihypertensive Therapy in Pregnancy?
* Antyhypertensive medication reduces the risk of developing severe hypertension and its potential sequalae (cerebrovascular accident)
* Should aim to reduce the systolic blood pressure to \< 160 mmHg and the diastolic to \< 110 mmHg over a few hours as too rapid of a drop in maternal BP may cause a reduction in utero-placental perfusion.
* A reasonable goal is to keep SBP 130 - 155 mmHg and DBP 80 - 105 mmHg
63
Name 3 medications that are used to treat Severe Hypertension in pregnancy.
1. Labetalol
2. Nifedipine
3. Hydralazine
64
What is the dose and onset of Labetalol for the management of Severe Hypertension in pregnancy?
**Dose**
* 20 mg; repeat 20 - 80 mg every 30 minutes; maximum 300 mg
**Onset**
* 5 minutes
**Caution**
* Women with asthma or heart failure
* May cause neonatal bradycardia
65
What are the signs of a second stage of labour and imminent birth?
* Strong Contractions lasting 60 - 90 seconds
* primips: q 2 - 3 minutes
* Multips: q 5 minutes
* Cramping likely severe enough to impede ambulation
* Contractions associated with urge to push or move bowels
* Patient reports feeling pressure in her buttocks
* Patient says baby is coming
* Bloody show visible at perineum
* Presenting part or bulging membranes visible at perineum
66
Early Labour
* Begining of labour. Uterine contractions are mild and irregular. Early labour is unpredictable in length and can occur on and off over a few days.
* Initial cervical change occurs, including effacement and dilation up to 3 to 4 cm, which may be accompanied by scant bloody (pink, red, or brown) discharge.
## Footnote
*PESP page 12*
67
Assessing Contractions
68
Mechanism of Labour and Birth
* Descent - descent of fetal head into pelvis, continuing until birth
* Flexion - chin to chest flexion, fetus leads with a smaller presentin diameter through pelvis
* Internal Rotation - back of fetal head turns to front of pelvis
* Extension - birth of head, face, chin extends out of the patients body
* Restitution - the fetus turns its head to line up with shoulders internally
* Birth - the shoulders and body emerge
69
APGAR Score
Assigned at 1 and 5 minutes of life
70
Denied Pregnancy
Refers to a patient who unconsciously denies the existence of the pregnancy
Physcopathology which includes:
* depersonalization
* dissociative hallucinations
* dissociative psychosis
71
Hidden Pregnancy
A conceal pregnancy in patients who know they are pregnant but actively hide their pregnancies from family, partner, friends and general public.
May be associated with previous trauma such as early sexual or physical abuse
72
What are the risks associated with Denied or Hidden Pregnancies?
* Elevated risk of poor outcomes due to limited or no access to prenatal care
73
How can due date or gestation be calculated if unknown?
* Nine months plus one week from first day of last menstural period
* Uterus at umbilicus = approximately 20 weeks gestation; uterus at costal edge = approximately 36 weeks
* Measure the symphysis-fundal height; each cm equals one week of gestation
74
Ecoptic pregnancy
Signs and Symptoms ?
Abdominal pelvic pain
Lateral sudden sharp and severe
Unexplained hypotension
Usually presents around 6 - 8 weeks gestation
75
What are the risk factors of Ectopic Pregnancy?
Previous Ectopic Pregnancy
Pregnancies that occur via IVF
Twin pregnancies
Advanced Age \> 35 years
76
What is Spontaneous Abortion?
* \< 20 weeks or \< 500 g occurs before 8 weeks
* Red flags
* heavy PV bleeding (\>1pad/hr x 6h)
* fever or discharge (septic abortion)
77
What is a Molar Pregnancy?
* A rare complication characterized by the abnormal growth of trophoblasts, the cells that normally develop into the placenta.
* The placental tissue is abnormal ans swollen and appears to form fluid-filled cysts.
* There may be formation of a fetus but the fetus is not able to survive.
78
Misoprostol
79
What are the Co-Morbid Disorders in Pregnancy?
* Diabetes
* Hyperthyroidism
* Cardiac arrthymias
* Aortic dissection
* ACS
* peripartum cardiomyopathy
* Venous Thromoboembolism
* PE
* headaches
80
Diabetes
* Insulin requirements increase with advancing pregnancy
* Increase risk of pre-eclampsia, preterm labour, spotaneous abortion and DKA
* Pregnant women have 3-5x higher risk of hypoglycemia
81
What is the more common cardiac arrhythmia in pregnancy?
* PSVT is the most common
* Caused by changes in hormones
82
Thromboembolic Disease
* 5x risk in pregnancy and worse 3 months post delivery
* Leading cause of maternal morbidity and mortality in industrialised nations
* Patho:hypercoagulability in pregnancy with increased venous stasis
* LEft tool (Leg symptoms, Edema, first trimester)
83
Thromboembolic Disease - PE
* 24% of DVT complicated by PE
* S&S:sweating, pleuritic chest pain, tachycardia, leg swelling/pain, dyspnea, cough, tachypnea, haemoptysis.
* Massive PE: sustained hypotension \< 90 mmHg for \> 15 min with S&S shock
* Large clot can lead to RV dysfunction
84
Thromboembolic Disease - PE
Therapy?
* Treatment of life threatening PE includes systemic catheter guided thrombolysis or embolectomy.
85
Headache in Pregnancy
Causes?
* Subarachnoid bleed
* Intracerebral bleed
* Stroke (ischaemic/thrombotic)
* Central Venous thrombosis
* Migraine
86
Headache in Pregnancy
Red flags?
* New onset in pregnancy or post partum
* New characteristics than previous
* visual disturbances
* Worst ever
* Meningismus
* Fever
* Altered LOC, signs of increased ICP
* Retinal Haemorrhage, HTN
87
What is the role of Progestereone and oestrogen?
* maintain pregnancy and adapt the mothers body for delivery and breastfeeding
88
What is the role of Human chorionic gonadotrophin?
* maintains corpus luteum to allow secretion of progesterone and oestrogen, suppresses maternal lymphocytes to prevent placental rejection.
* **hCG** levels used as indicators for pregnancy
89
What is the role of placental lactogen?
* promotes foetal growth, produces a degree of maternal insulin resistance to change availability of glucose for foetus.
90
What is the role of Relaxin?
* Inhibits uterine activity during pregnancy, relaxes pelvic ligaments and softens cervix
91
What is the size and volume of the Uterus at Term?
* Grows up to 1000g in size with a volume of 5000 ml.
* Top of uterus reaches the umbilicus at 20 weeks
* Top reaches the xiphisternum at 36 - 40 weeks
92
What is the rate of blood supply to the Uterus at term?
* 500 - 700 ml/min at term (increased risk of haemorrhage)
*
93
How does the uterus affect the bowel and inferiro vena cava?
* Displaces the bowel
* Can compress the inferior vena cava when the mother is supine (compromises maternal blood flow, not foetal)
94
How does the placement of the placenta affect the potential for antepartum haemorrhage?
* The placenta typically anchors in the top segment where there are three layers of muscle fibres.
* If it anchors lower, there are only two layers and an increased risk of antepartum haemorrhage with premature separation.
95
Why is the placenta vulnerable to shearing forces?
* The placenta lacks elastic tissue and is particularly vulnerable to shearing forces' particularly those caused by blunt injury that could result in a placental abruption.
96
Explain why the foetus has less protection as pregnancy develops.
* As pregnancy develops the wall of the uterus becomes progressively thinner, and simultaneously the amniotic fluid surrounding the foetus gets less, thus offering less protection for the foetus.
97
How does pregnancy affect the Cervix and Vagina?
* Increased vascularity and secretory effects with a mucus plug and more acidic environment to protect from infections.
98
How does pregnancy affect the Respiratory System?
* As the baby grows, its metabolic needs increase, necessitating increased oxygen supply and removal of CO2.
* The womans residual volume decreases with enlarging uterus, airway resistance decreases, tidal volume increases.
* Arterial PaO2 increases to **105 mmHg**, and maternal sensitivity to CO2 is decreased to **32 mmHg** (resulting in increased O2 consumption)
99
In pregnancy why does the plasma volume increase by 45% at 32 weeks?
* Allows for autotransfusion from uterus to mother post delivery to compensate for PPH.
100
How does pregnancy affect circulating volume?
* Increased requirement for circulating volume with fluid and electrolyte retention to meet metabolic needs.
* ADH and aldosterone have a role in maintaining plasma volume.
* Generalised vasodilation with overall drop in blood pressure to allow for addtional blood volume.
101
What are the changes in Cardiac Ouput during pregnancy?
* Increased CO by 30-40% via heart rate and stroke volume and decreased systemic vascular resistance
102
What changes might be seen on the 12 Lead ECG during Pregnancy?
* Heart muscle increases in size and displaces to the left (Left Axis Deviation on 12 Lead)
103
Differential Diagnosis of Ectopic Pregnancy
List Pregnant Conditions
* Normal Intrauterine pregnancy
* Threatened abortion
* Inevitable abortion
* Molar pregnancy
* Implantation bleeding
104
The classic sign of amenorrhea from 4-12 weeks after the last normal period is reported in?
70% of ectopic pregnancy cases
105
How effective is McRoberts Maneuver?
60 - 80% effective
106
How long should Suprapubic Pressure be applied?
30 seconds
Considered 30 second drills
*Continous firm pressure*
107
How do you estimate blood loss in PPH?
*
