Case 8 Flashcards
(145 cards)
1
Q
What is the function of Cooper’s Ligaments?
A
Fibrous connective tissue which supports the breast.
2
Q
What type of epithelium are acini cells?
A
Columnar
3
Q
What is the function of acini cells?
A
Produce milk
4
Q
What is the function of myoepithelial cells?
A
Contract to eject milk
5
Q
What effect does puberty have on the breast?
A
Elongation and bifurcation (branching) of lactiferous ducts, formation of spherical masses at the end of each duct, development of immature alveoli, increased fat deposition.
6
Q
Human Placental Lactogen
A
Reduces maternal insulin sensitivity.
Reduces maternal glucose utilisation.
Increased lipolysis with release of free fatty acids.
Increases availability of glucose for the foetus.
7
Q
Why do women suddenly produce milk following miscarriage/abortion?
A
Large amounts of progesterone and oestrogen inhibit prolactin during pregnancy.
These hormone levels fall suddenly following miscarriage/abortion.
8
Q
Where is milk stored during pregnancy?
A
Cannot be stored, it is absorbed into the blood.
9
Q
How is milk production prevented in women following miscarriage/abortion?
A
Dopamine agonist
10
Q
Which immunoglobulin is found in breast milk?
A
IgA
11
Q
What is the effect of dopamine on prolactin?
A
Inhibitory
12
Q
What is the effect of oxytocin on the lactating breast?
A
Contraction of myoepithelial cells
13
Q
What stimuli cause release of oxytocin?
A
Suckling
Mother hearing the sound of crying
14
Q
How does oxytocin cause contraction of myoepithelial cells?
A
Binding to its receptors causes an increase in intracellular calcium.
15
Q
How long must suckling cease for, for milk production to stop?
A
2-3 weeks
16
Q
Colostrum is high in…
A
Protein, minerals, vitamins A, D, E and K, immunoglobulins.
17
Q
Meconium
A
Earliest stool
18
Q
What important immunological effect does lactose have on the gut of the neonate?
A
Promotes growth of the intestinal flora.
19
Q
What is the function of Alpha Lactalbumin?
A
Regulatory subunit of lactose synthase. Transfer of galactose moieties to glucose.
Promotes growth of bifidobacterium (intestinal bacteria)
20
Q
Immunoglobulins found in breast milk:
A
IgA, IgG, IgM
21
Q
What is the role of lactoferrin found in breast milk?
A
Iron Chelation
Blocks adsorption/penetration of viruses (rotavirus)
Blocks adhesion of bacteria (e.g. Vibriocholerae, E. Coli)
Promotes intestinal growth and repair
Immune modulation(reduces production of IL-1,2,6 and TNF-alpha
22
Q
What is the function of lysozyme found in breast milk?
A
Inhibits endotoxin
Macrophage activation
Bacterial cell wall lysis
Increases IgA production
23
Q
What is the function of casein found in breast milk?
A
Inhibits adhesion of bacteria
Promotes growth of bifidobacterium (intestinal bacteria)
24
Q
What is the function of oligosaccharides in breast milk?
A
Prevent adhesion of common respiratory pathogens to respiratory epithelium (e.g. haemophilus influenzae, streptococcus pneumoniae)
25
What sort of fibres are involved in pain during Stage 1 of labour?
C fibres (slow, unmyelinated)
26
What vertebral levels are involved in pain during stage 1 of labour?
T10-L1
27
Which nerve plexi are involved in pain during stage 1 of labour?
Hypogastric
Paracervical
Lumbar sympathetic chain
28
What type of pain is felt during stage 1 of labour?
Cramping, poorly localised, Visceral pain
29
What type of pain is felt during stage 2 of labour?
Well localised, sharp, somatic pain
30
Which nerve plexi are involved in pain during stage 2 of labour?
Lumbosacral plexus and pudendal nerves
31
What vertebral levels are involved in pain during stage 2 of labour?
T10-L4
32
What sort of fibres are involved in pain during stage 2 of labour?
A delta fibres (fast, myelinated)
33
What are the effects of entonox?
Analgesia, euphoria, anxiolytic, sedatory
34
MOA of Pethidine
Mu-opioid receptor agonist
35
Why are NSAIDs contraindicated in pregnancy/labour?
Cause neonatal haemorrhage due to thrombocytopenia
| Interfere with prostaglandin synthesis (important for uterine contraction)
36
MOA of Entonox
Stimulates endogenous endomorphin and endomorphin secretion
37
Composition of Entonox
50% N2O and 50% O2
38
ADRs of Entonox
Nausea and vomiting
B12 inactivation with prolonged use
may be neurologically toxic
39
Contraindications of Entonox
Pneumothorax or other air cavity injury
40
What is the name of the active metabolite in pethidine?
Norpethidine
41
ADRs of Pethidine
```
Biliary Spasm
Bradycardia
Confusion
Constipation
Dependence
```
42
MOA of Pethidine
Mu-opioid receptor agonist
| + Postsynaptic Potassium efflux, hyperpolarisation prevents pain transmission
43
Route of administration of Pethidine as a labour analgesic
I/M injection
44
Contraindications for Pethidine
Acute respiratory depression
| Head injury
45
MOA of Bupivacaine
Sodium channel blocker in nociceptive axons - prevents transmission of action potential to CNS
46
Route of administration of Bupivacaine
IV injection
47
ADRs of Bupivacaine
Convulsions, cardiac arrhythmias, dizziness
48
Contraindications of Bupivacaine
Cardiac arrhythmia
49
What are the benefits of fentanyl over pethidine?
Same effect (mu-opioid R agonist) but with less potential for drug interaction
50
MOA of fentanyl
Mu-opioid receptor agonist - suppresses presynaptic GABA release
51
ADRs of fentanyl
```
Biliary Spasm
Bradycardia
Confusion
Constipation
Dependence
```
52
Contraindications of Fentanyl
Acute respiratory depression
| Head injury
53
What is the negative impact of opiates on labour?
Prolongs labour time
54
Which structures are penetrated when providing an epidural?
Skin, Subcutaneous tissue, supraspinous ligament, interspinous ligament, ligamentum flavum --> epidural space
55
When is an epidural given?
When cervical dilatation has reached 4-5cm
56
Which drugs can be given epidurally?
Bupivacaine and some opiates
57
What are the benefits of epidural administration of analgesia?
Prolonged effect and can be topped up
Minimal foetal transfer of drugs
Continued mobility - still able to push
58
What is the disadvantage of epidural compared to spinal analgesia?
Slower - effects reached 15-20 minutes after administration (cf. 5-10 minutes)
59
At what vertebral level is a spinal analgesic given?
Below L1-2
60
When is a spinal anaesthetic indicated?
Elective surgery
61
Which drug is used in a spinal anaesthetic?
Fentanyl
62
What are the benefits of intrathecal administration of analgesia?
Quick pain relief (5-10 minutes)
| Minimal foetal transfer of drugs
63
What are the disadvantages of intrathecal administration of analgesia?
Wears off after 1 hour and cannot be topped up
| Loss of mobilisation (unable to push - used in C-section)
64
Contraindications for neuraxial analgesia:
Patient refusal
Abnormal spinal anatomy - Spina bifida (low clonus), Lumbar fusion
Impaired coagulation (risk of spinal haematoma)
Infection (risk of meningitis or abscess)
Fixed cardiac output state (unable to compensate for vasodilation) e.g. Severe Aortic Stenosis, Massive haemorrhage
65
What type of headache is a complication of nauraxial analgesia?
Low pressure headache - dural puncture causing leakage of CSF
66
When is a neuraxial block indicated?
When an instrumental delivery will take place (+ episiotomy)
67
Target for Neuraxial block
Pudendal Nerve (S2,3,4)
68
Neuraxial block increases risk of:
Prolonged stage 2 labour
Instrumental Delivery
(reduces urge to push due to reduced sensation)
69
Why might adrenaline be used with an local anaesthetic?
Causes peripheral vasoconstriction. Prolongs duration of effect of LA at site of injection by preventing is from dissipating out as quickly.
Less LA needs to be used.
(Also reduces bleeding at the wound/incision site = easier to manage)
70
When is adrenaline contraindicated in use with a local anaesthetic during labour?
Episiotomy - tissue surrounding the site must have collateral blood supply to remain viable. Pudendal and perineal nerves might be damaged by becoming ischaemic.
71
When should caution be taken when coadministering adrenaline with LA?
In areas of poor collateralisation,
High value structures (nerves),
End extremity arteries (fingers and toes)
72
Storage of excess iron in the liver
Ferritin
73
Storage of excess iron in the bone marrow
Haemosiderin
74
Daily Iron requirement for a pregnant female:
4-7mg
75
Cause of low Hb and low MCV
Iron deficiency
| Haemoglobinopathy (defect in Hb production)
76
Cause of low Hb and high MCV
B12/Folate deficiency
| Haematological problem
77
What factors suggest iron deficiency during pregnancy?
Hb < 105g/L (still consider if <115g/L)
Increased MCV
Serum Ferritin <15mcg/L
78
Treatment of iron deficiency anaemia in pregnancy:
120-149mg of elemental iron/day given either orally or parenterally
79
Iron has a number of dose-related ADRs:
```
Nausea
Abdominal Pain
Constipation
Diarrhoea
Black stools
```
80
What is the function of B12 and Folate?
DNA synthesis - involved in remethylation
81
Daily Folate requirement during pregnancy:
300-400𝛍g/day (cf. 100 normally)
82
Thrombocytopenia
Low platelets
83
Fanconi Anaemia
Inherited condition - reduction in all blood cells produced by bone marrow
84
Myelodysplasia
Group of cancers in which immature blood cells in bone marrow do not become mature and healthy
85
HELLP
A variant of preeclampsia - Haemolysis, Elevated Liver Enzymes, Low Platelet Count
86
Platelet count (increases/decreases) throughout pregnancy
Decreases
87
For a vaginal delivery, platelet count must be:
>30x10 9/L
88
For a C-section, platelet count must be:
>50x10 9/L
89
Epidural cannot be given if platelet count is..
Less than 100x10 9/L
90
Spinal cannot be given if platelet count is...
Less than 50x10 9/L
91
Amniotic Fluid Embolism
Amniotic fluid enters bloodstream, activates coagulation cascade causing cardiac arrest.
92
Why does hypersplenism cause thrombocytopenia?
Larger spleen can store more platelets.
93
Pregnancy increases risk of venous thromboembolism by...
5-10x
94
Clinical Presentation of DVT
Initially cramping,
| Followed by leg swelling, pain and tenderness.
95
Clinical Presentation of Pulmonary Embolism
```
Dyspnoea
Pleuritic Chest Pain
Cough
Haemoptysis
Syncope
```
96
Treatment for DVT/PE in pregnancy
Enoxaparin (1mg/kg/bd)
| i.e. Low Molecular Weight Heparin
97
A type blood can receive
A or O
98
B type blood can receive
B or O
99
AB type blood can receive
Any other blood type
100
O type blood can receive
O only
101
What type of immunoglobulin are anti-D (anti Rhesus D)?
IgG - therefore able to cross the placenta
102
What percentage of the caucasian population are RhD Negative?
15%
103
When are RhD Negative, pregnant women given anti-D?
After each potential 'sensitising' event e.g. car accident
Prophylactically at 28 and 35 weeks
Within 72 hours of childbirth (If baby is RhD positive)
104
What action does anti-D have when given to the mother?
Destroys any foetal RhD antigens in the maternal bloodstream before she makes them herself.
105
Kleihauer Testing
Used to estimate volume of haemorrhage and allow correct dose of anti-D to be calculated.
Foetal Hb stains darkly whereas maternal Hb are light.
Size of bleed is estimated using proportion of foetal and maternal cells in blood.
106
Criteria for blood to be transfused:
CMV negative
Irradiated (prevents any residual lymphocytes from attacking patient as foreign)
Hep E negative
107
Indication for Red Blood Cell Transfusion
Anaemia
| Perioperative blood loss
108
Indication for platelet transfusion
Thrombocytopenia:
Patients undergoing chemotherapy
Patients with aplastic anaemia
Patients with disseminated intravascular coagulation
109
What is the B antigen?
D-Galactose
110
What is the A antigen?
N-Acetyl-D-galactosamine
111
What type of immunoglobulins are ABO antibodies?
IgM
112
Clinical Presentation of Acute Transfusion-related Lung Injury
Acute dyspnoea with hypoxia
Bilateral pulmonary infiltrates
Within 6 hours of transfusion with no obvious cause
113
What is the cause of Transfusion-related Acute Lung Injury?
Antibodies in donor plasma reacting with 'primed' white blood cells in the lungs
114
What is the effect of falling progesterone in the initiation of labour?
Synthesis of PGE2 - uterine contractions
115
Where is oxytocin released from?
Posterior pituitary
116
During initiation of labour, oxytocin is released in response to:
Stretching of uterine tissues
117
How does increased oestrogen bring about initial contractions?
Increases expression of oxytocin receptors on myometrium.
Causes production of PGE2 and PGF2 by chorion and decidua
--> Increased calcium influx --> CONTRACTION
118
Labour: Stage 1, Latent
Up to 3cm dilatation
3-8 hours
Contractions every 10 minutes lasting 20 seconds
119
Labour: Stage 1, Active
3-10cm dilatation
2-6 hours
3 Contractions every 10 minutes, lasting 40 seconds
120
Labour: Stage 2
Passive Vs Active?
From full dilatation to onset of involuntary expulsive contractions
Passive - No maternal urge to push, foetal head is high in pelvis
Active - Maternal urge to push, foetal head is low in pelvis (longer in primiparous than multiparous)
121
Labour: Stage 3
Delivery of placenta and membranes
| Should be less than 30 minutes
122
Changes occurring in neonate on delivery:
Closure of foramen ovale
Closure of umbilical arteries
Closure of umbilical vein and ductus venosus
Closure of ductus arteriosus
123
Foramen ovale becomes...
Fossa ovale
124
How does the foramen ovale close?
Inflation of lungs during first cry
| Increase in pressure in the left atrium
125
How are the umbilical arteries closed during childbirth?
Wall contraction - due to thermal/mechanical stimuli and change in O2 tension
126
Ductus venosus becomes....
Ligamentum venosum
127
Umbilical vein becomes...
Ligamentum teres hepatis
128
Ductus arteriosus connects...
Pulmonary vein and aorta
129
How is the ductus arteriosus closed during childbirth?
Muscle wall contraction AND bradykinin release by lung inflation
130
Ductus arteriosus becomes...
Ligamentum arteriosum
131
How is blood volume increased during pregnancy?
Progesterone and Oestrogen cause a decrease in resistance and pressure.
Kidneys retain more water as a result.
132
Why does pregnancy cause dyspnoea on exertion?
Reduced total lung capacity
133
Explain why voice quality may change during pregnancy.
Progesterone causes an increase in red blood cells.
Oedema of respiratory tract (fluid moves into lungs from blood)
Nasal stiffness and obstruction of Eustachian tube
134
Cutaneous changes during pregnancy:
Linea nigra (pigmentation from umbilicus to pubic symphysis)
Chloasma Gravidarum (butterfly-like pigmentation of face)
Falling of hairs and increased brittleness of nails.
135
What is the effect of increased thyroid function during pregnancy?
Increased thyroxine
- Increased basal metabolic rate
- Increased heart rate
- Increased GI activity
136
What causes morning sickness?
Progesterone reduces contractility of GI smooth muscle. Nausea and vomiting for first 12 weeks.
137
Why might a pregnant woman become constipated?
Compression of rectum
138
Why are pregnant women at an increased risk of UTIs?
Pressure on ureters increases risk of backflow of urine
139
Why do pregnant women have increased micturition?
```
Increased cardiac output
Increased GFR
Decreased concentration of urea and creatinine (removed quicker)
Decreased plasma osmolality
More urine produced.
```
i.e. Increased renal function
140
Cervical Cerclage
Stitching together of cervix if it begins dilating prematurely during 2nd trimester
141
Where is the mucus plug located in a pregnant woman?
Between vagina and uterine contents
142
Relaxin
Hormone produced by placenta causing relaxation of pelvic ligaments and pubic symphysis
Therefore, woman will have a waddling gate
143
Decidua
Uterine lining during pregnancy. Forms the maternal part of the placenta
144
Initiation of labour
Ageing placenta - less progesterone to inhibit uterine contractions.
Uterine stretching causes oxytocin release from p.pituitary - causes uterine contractions
Increased oestrogen - increased expression of oxytocin receptors on myometrium
145
How does oxytocin cause uterine contraction?
Oxytocin binds to its receptors.
Chorion and decidua synthesise PGE2 and PGF2
PGs cause calcium influx
**Uterine contraction**
