Hypertensive Disorders In Pregnancy Flashcards
(114 cards)
1
Q
How is blood pressure calculated?
A
BP=COxTPR/SVR
2
Q
What happens to BP in preganncy?
A
Cardiac output increases by 40%
SVR decreases by 50%
Overall BP falls
3
Q
What happens to the BP in the second trimester?
A
Falls by 30/15mmHg
4
Q
What happens to the BP at term?
A
Rises to pre-pregnant level
5
Q
What happens to protein excretion in pregnancy?
A
It increases -> up to 0.3g/24 hours
Normal is 0.15g/24 hours
6
Q
What are the classes of HTN in pregnancy according to the RCPI 2016?
A
Mild, moderate and severe
7
Q
What is mild HTN in pregnancy?
A
> 140/90
8
Q
What is moderate HTN in pregnancy?
A
> 150/100
9
Q
What is severe HTN in pregnancy?
A
> 160/110
10
Q
How is HTN diagnosed in pregnancy?
A
Based on 2 measurements hours apart
If severe HTN then 15mins apart
11
Q
What are the 2 broad categories of HTN in pregnancy?
A
Chronic HTN
Pregnancy induced HTN
12
Q
What is chronic HTN in pregnancy?
A
HTN (+/- medication) before pregnancy
or
HTN before 20 weeks gestation
13
Q
Why is chronic HTN important in pregnancy?
A
6 fold increased risk of pre-eclampsia
Can have existing protein due to HTN
14
Q
Can someone with chronic HTN also have pre-eclampsia?
A
Yes superimposed pre-eclampsia possible
15
Q
What are the 3 types of HTN in pregnancy?
A
Gestational HTN
Pre-eclampsia
Eclampsia
16
Q
What is Gestational HTN?
A
New HTN >20 weeks no proteinuria
17
Q
Is gestational HTN a risk factor for pre-eclampsia?
A
15-25% will develop pre-eclampsia
50% if <32 weeks
18
Q
What is pre-eclampsia?
A
HTN + 1 or more new conditions >20 weeks
19
Q
What is eclampsia?
A
Tonic/clonic seizure in a/w/ features of pre-eclampsia
20
Q
What drug is the first line agent for HTN in pregnancy?
A
Labetalol (beta blocker)
21
Q
Who should not be given Labetalol to manage HTN in pregnancy?
A
Asthmatics - give nifedipine a calcium channel blocker
22
Q
What older anti-HTN is still sometimes used in pregnancy?
A
Methyldopa
23
Q
What are the issues with Methyldopa in pregnancy?
A
Takes a while to take effect
Causes sedation and low mood so recommend stopping 2 days before delivery
24
Q
What is the definition of pre-eclampsia?
A
Multisystem disorder of pregnancy usually manifest by HTN (>20 weeks) and proteinuria
25
What is the NICE guidelines 2019 definition of pre-eclampsia?
New onset hypertension after 20 weeks with 1 or more of:
* proteinuria (30mg/mmol)
* maternal organ dysfunction
* uteroplacental dysfunction
26
What is the RCPI 2016 definition of pre-eclampsia?
New hypertension after 20 weeks with signs of proteinuria or maternal organ dysfunction or growth restriction
27
What is the pathophysiology behind pre-eclampsia
1. Increased vascular permeability
2. Vasospasm/constriction
3. Clotting dysfunction
Which cause the manifestations and complications of pre-eclampsia
28
What is the pathophysiology of pre-eclampsia?
Placental disease (not foetal – can happen with moles, not uterine – can happen with intraabdominal pregnancy).
Incomplete trophoblastic invasion and microvascular disease (similar to atherosis of arterial disease elsewhere)
Spiral arteries are the uterine arteries that are dilated under the action of the invading trophoblast.
Endothelial cells are the layer of cells that line the interior surface of blood vessels
29
What are the stages of the pathophysiology of pre-eclampsia?
Stage 1: (< 20 weeks)
Incomplete trophoblastic invasion+spiral atheroma cause decreased uteroplacental flow.
? Due to altered immune responses
Stage 2: (> 20 weeks)
Ischaemic placenta by exaggerated maternal inflammatory response cause endothelial cell dysfunction leading to vasoconstriction, vascular permeability and clotting dysfunction.
30
What is the difference between early onset and late onset pre-eclampsia?
31
What will been seen on a uterine artery Doppler with pre-eclampsia?
Failure to develop this low resistance uterine circulation can be picked up
Reduced flow of uterine artery - ie spiral arterioles haven’t dilated (if they had dilated you would have lost the notch that’s seen in nonpregannt uterine artery Doppler)
32
When can uterine artery Doppler pick up abnormal waveforms? (And 3 things it can predict)
20-23 weeks which can predict adverse outcomes
Eg pre-eclampsia, IUGR, abruption
33
How else can pre-eclampsia be predicted?
Blood test for the ratio of **sFlt-1:PIGF** may be useful in later pregnancy to predict which women with hypertension will develop pre-eclampsia, but not routinely used to date.
Nice guidelines 2019 mentions this (placental growth factor testing to help rule out pre-eclampsia)
34
What is the epidemiology of pre-eclampsia?
2-3% of pregnancies (5-7% nullips)
35
What is the recurrence rate of pre-eclampsia?
15% recurrence (up to 50% if pre-eclampsia <28 weeks)
36
What are risk factors of pre-eclampsia? (7)
Nulliparity
Personal or family history of pre-eclampsia
Long gap between pregnancies (>10yrs)
Microvascular disease:
- HTN, renal disease, diabetes, sickle cell disease, autoimmune (incl. antiphospholipid)
Large placenta:
Twins, hydrops, molar pregnancies
Extremes of maternal age (esp >40)
Raised maternal BMI (>35)
37
What is hydrops?
Accumulation of fluid in 2 or more foetal spaces, a lot of hydrops comes out of anaemia
38
What are some of the high risk risk factors for pre-eclampsia? (5)
HTN, CKD, DM, autoimmune disease
Previous history
39
What are some of the moderate risk risk factors for pre-eclampsia? (5)
* Nulliparity
* pregnancy interval >10yrs
* family history of pre-eclampsia
* multiple pregnancies
* BMI>35
* age>40
40
What can be done to help prevent pre-eclampsia based on risk factors?
If 1 high risk or 2 moderate risk factors should take **75-150mg aspirin from 12 weeks** til delivery to prevent pre-eclampsia
41
What are the clinical features of pre-eclampsia usually?
Asymptomatic
42
What are the symptoms of pre-eclampsia? (3x4)
Headaches: ? Cerebral vasospasm, oedema, or hypertensio
Reversal cortical blindness due to cerebral oedema, due to retinal artery spasm or clots
Epigastric/RUQ pain: liver capsule oedema or liver ischaemia
Renal: decreased plasma volume or ischaemia ATN
43
What are the symptoms of pre-eclampsia?
Headaches: ? Cerebral vasospasm, oedema, or hypertensio
Reversal cortical blindness due to cerebral oedema, due to retinal artery spasm or clots
Epigastric/RUQ pain: liver capsule oedema or liver ischaemia
Renal: decreased plasma volume or ischaemia ATN
44
What clinical features of pre-eclampsia are seen on examination?
* HTN
* proteinuria
* massive/sudden/not postural oedema (ie not just in lower limbs also in hands and face)
45
What is usually the first sign of pre-eclampsia on examination?
HTN
46
What is a relatively late clinical examination sign of pre-eclampsia?
Proteinuria
47
What clinical features on examination are bad news when it comes to pre-eclampsia? 🚩 (4)
🚩 Epigastric tenderness
🚩 Papilloedema
🚩 Brisk reflexes
🚩 Clonus (sustained rythmic contraction of muscles after stretch. Due to hypertonia of UMN lesion)
48
What is thought to happen within 2 weeks of the onset of proteinuria in pre-eclampsia?
In general 1 or more foetal or maternal complications is likely to occur
49
What are maternal complications of pre-eclampsia an indication for?
Delivery
50
What are maternal complications of pre-eclampsia?
‘Don’t ever come home really pi**ed’
* death/DIC
* eclampsia: tonic clonic seizures
* CVA (haemorrhagic): due to HTN
* HELLP syndrome + hepatic failure (Haemolysis, ELevated Liver enzymes, Low Platelets)
* renal failure (monitor output and creatinine (increased creat))
* pulmonary oedema
(Hepatic = increase in transaminases, epigastric or RUQ pain)
(Haematological = low platelets (a/w/ HELLP), haemoglobin up or down)
51
Does delivery immediately stop the maternal complications of pre-eclampsia?
No can occur post-partum as it takes at least 24 hours to ‘cure’ the disease
52
What are some other maternal complications of pre-eclampsia?
* DVT/PE
* haemolysis - due to clot formation in small BV causing shearing effect on RBC (ELLP usually happens before H)
53
What are the parts of HELLP syndrome?
H - Haemolysis
EL = Elevated Liver enzymes
LP = Low Platelets
54
What is a/w/ the Haemolysis or HELLP syndrome? (3)
* Dark urine
* increased LDH
* anaemia
55
What is a/w/ the Elevated Liver enzymes of HELLP? (3)
* epigastric pain
* liver failure
* abnormal clotting profile
56
How do the Low Platelets of HELLP syndrome resolve?
Normally self-limiting
57
How common is HELLP syndrome?
5-20% of pre-eclampsia
58
What are 3 of the signs of HELLP syndrome on examination?
* subtle weight gain
* edema
* high blood pressure
59
What is the maternal mortality of HELLP?
1%
60
What is the perinatal mortality of HELLP?
10-60%
61
What happens before Haemolysis in HELLP syndrome?
Liver enzymes increase
Platelets decrease
Ie ELLP before H
62
What is the usually course of HELLP syndrome?
Usually self-limiting - but an cause permanent damage
63
What are the treatment options for HELLP syndrome?
* Plt transfusion if <50 (consider esp if coagulopathy or falling)
* if for c-section or vaginal delivery and plts <20 should have transfusion
* high dose steroids (dexamethasone 12 hrly) might improve parameters
64
What causes the dark urine in HELLP syndrome?
Haemoglobinuria
65
What are the foetal complications of pre-eclampsia? (4)
* perinatal mortality (5% of stillbirths)
* perinatal morbidity (10% of preterm deliveries)
* IUGR (if onset <34 weeks - early onset)
* placental abruption
66
What investigations are done for suspected pre-eclampsia?
* urine
* bloods
* foetal checks
67
How is the urine investigated for pre-eclampsia? (3)
* dipstick (screening test only: if 1+ or more further check needed)
* traditional 24 hour collection (>0.3g/24hr)
* PCR now more common (>30mg/mmol)
[Urine - protein in the urine if its trace its not significant, if its +1 it needs to be quantified, if its +2 then it is significant
- you can quanatiffy the protein by doing PCR (significant if >30mg/mmol) or 24hr collection (significant if >0.3G/24 hours)]
68
Why is PCR now recommended by NICE over the 24 hour collection?
* faster
* cheaper
69
Is proteinuria always present in pre-eclampsia?
Can be absent in early condition
70
What maternal blood test are ordered if suspecting preeclampsia? (4/5)
* FBC = Hb (high), Plt (low)
* LFTs = ALT/AST/LDH
* U&E
* Uric acid = hyperuricaemia (>290ummol/L in 28 weeks, >340umol/L in 34 weeks, >390umol/L in 36 weeks)(rough indication of uric acid upper limit of normal is the weeks gestation multiplied by 10)
* consider coag screen if severe pre-eclampsia
71
Why may some of the maternal bloods be abnormal in pre-eclampsia?
Hyperuricaemia: uncertain of cause ? Deterioration in renal function
Low plts: plt aggregation on damaged endothelium ? Impending HELLP
LDH: haemoylsis
U+E: rising creat in renal failure
72
What investigations are done for the foetus in suspected pre-eclampsia? (3)
* ultrasound (foetal growth - IUGR)
* umbilical artery Doppler (AREDF)
* CTG
73
Does a pregnant lady with new HTN need to be admitted?
Yes all new HTN assessed on ward
74
Does a pregnant woman with mild-mod HTN need to be admitted?
No - OPD
* BP & urinalysis 2/weekly
* bloods weekly
* u/s every 2-4 weeks
75
When should a patient with HTN be admitted in preganncy? (4)
* proteinuria (2+, 0.3G/24hr, 3mg/mmol)
Or
* severe BP (160/110)
Or
* suspected foetal compromise
Or
* symptoms
76
What will be done if a pregnant woman has 1+ proteinuria and HTN?
If 1+ proteinuria – quantify and review in 2/7
77
What is the management of pre-eclampsia?
Progressive disease - delivery is the only cure
78
What its the management of pre-eclampsia based on?
Foetal and maternal considerations
79
Other than delivery what can be done as part of the management of pre-eclampsia? (4)
* corticosteroids
* control BP to minimise risk of ICH
* Mg SO4 to prevent eclampsia in severe disease
* anticipate adverse outcomes
80
When are **corticosteroids** given as part of the management of pre-eclampsia?
**24-34+6 weeks** gestation
(Can consider at earlier gestations)
81
Who are given corticosteroids as part of the management of pre-eclampsia?
Those at risk of pre-term birth
82
What **steroids (& their doses)** are given for the management of pre-eclampsia?
* Betamethasone 12mg IM x2 doses 24 hrs apart
* **D**examethasone 12mg IM 2 doses 12 hours apart (**D**ozen)
83
Why are steroids given as part of the management of pre-eclampsia?
Decreases:
RDS>IVH> necrotising enterocolitis
84
What anti hypertensives are given for moderate HTN in pregnancy? (3)
* Labetalol
* Nifedipine
* Methyldopa
85
What anti-hypertensives are given if severe HTN? (2)
IV hydralazine
IV labetalol
86
Why are antihypertensives given for HTN in pregnancy?
* aim = NICE guidelines 2019: offer pharmacological treatment if BP remains above 140/90 aiming for a 135/85 or less
* reduce hospitalisation and allow prolongation of pre-term pregnancy
87
What are the features of the oral anti-hypertensives given for pre-eclampsia
88
What should be done if the initial dose of antihypertensives fails to adequately control the BP?
If the initial dose of any antihypertensive drug fails to adequately control blood pressure, the
dose should be increased incrementally until the maximum dose is reached. If adequate
control of blood pressure has still not been achieved, a second antihypertensive agent may be
introduced. This drug should be prescribed in addition to and not instead of the first agent.
89
What are the steps of the treatment of severe HTN in pregnancy (SBP>=160)
1. Oral Labetalol 200mg, repeated after 30mins if needed
2. If not tolerated or not effective then IV labetalol bolus (up to 4), then infusion
(IV labetalol: 50mg bolus, repeated every 10mins up to a maximum of 200mg. When response achieved set up infusion of 20mg/hr (max 160mg/hr))
3. IV hydralazine bolus 2.5mg (can be repeated up to max dose 20mg)
4. PO (not s/l) nifedipine
90
91
What are the criteria for severe pre-eclampsia?
1. Eclampsia
2. Severe HTN eg SBP >160 with at least 1+ proteinuria
3. HTN eg SBP >140 +/- DBP >90 with significant proteinuria and **any of:**
- severe headache with visual disturbance
- epigastric pain
- liver tenderness
- platelet count <100x10^9/l
- ALT >50iu/l
- Creatinine >100mmol/l
92
What are the general measures to manage severe pre-eclampsia?
* One to one midwifery care
* HDU preferable
* Inform consultant obstetrician on duty
* Insert large bore IV cannula
* TED stockings
93
What basic blood investigations should be sent as part of the management of severe pre-eclampsia? (6)
* Serum electrolytes
* LFTs
* FBC
* Uric acid
* Coagulation
* Group and save serum
94
How should severe pre-eclampsia be managed by way of monitoring?
* BP 15 mins until stabilised, then 30 mins
* Urinary catheter – close input/output monitoring
* Continuous SaO2 monitoring
* Fluid balance
* Respiratory rate
* Temperature
* CVP, Arterial line & GCS if appropriate
* Fetal well-being: CTG initially, consider growth USS, liquor assessment and umbilical artery doppler flow velocity waveforms
* Blood tests should be repeated every 12 hours whilst on the protocol or more frequent if necessary
95
How is eclampsia prevented in cases of severe pre-eclampsia?
Mg SO4
(Magpie trial Lancet 2002
58% lower rate of progression to eclampsia than with placebo with?)
96
What is the MOA of magnesium sulphate in the prevention of eclampsia?
Primarily by reducing cerebral vasospasm (cerebral vasodilator)
97
How is MgSO4 dosed?
loading dose: **4g IV bolus** over 5 mins
Maintenance dose: **1g/hr** for 24 hrs or until 24hrs after delivery (whichever longest)
98
What is seen with Mg SO4 toxicity? (6)
* reduction in deep tendon reflexes
* loss of deep tendon reflexes
* respiratory paralysis
* hypotension
* CNS depression
* cardiac arrest
99
What should be done to reduce the risk of Mg SO4 toxicity starting?
Review at least every 4 hours
Consider stopping/reducing if:
- loss of deep tendon reflexes
- RR<12
- confusion
Can do levels:
Resp paralysis = 5-6.5mmol/L
Cardiac conduction issues >7.5mmol/L
100
What is the antidote to MgSO4 toxicity?
10mls of 10% calcium gluconate IV over 10 mins
101
Why is oliguria something to be aware of in MgSO4 toxicity?
97% excreted in urine
102
What are the indications for delivery in PET?
* **37 weeks onwards** (NICE 2019)
* clinical deterioration, maternal complications or foetal compromise
* usually gestational hypertension where BP <160/110 timing of birth should be agreed between the obstetrician and the patient after 37 weeks
103
What should be monitored during labour in cases of PET?
* monitor foetus = continuous CTG
* monitor mother = BP & fluid balance
104
What are 3 points to note about labour with PET?
* epidural may help to decrease BP
* 2nd sage - avoid long, no pushing if BP>160/110
* no ergometrine in 3rd stage (raised BP)
105
How is fluid managed post-partum with PET?
* fluid restrict: natural diuresis at 36-48 hrs
* the total amount (PO & IV) **<80ml/hour + losses**
106
Do mothers with PET need thromboprophylaxis post partum?
Yes - LMWH (until Mobil or 10 days post c-section)
107
What immediate post-natal care do mothers need following treatment for severe pre-eclampsia?
* in hospital at least 3 days, 4 hrly BP, discharge if BP <150/100 and bloods improving or normal
* communicate with GP
* check BP every 1-2 days for 2/52
* if on treatment arrange follow up at 2 weeks with GP/clinic (reduce if 130/80, stop if <120/70)
108
What is the timing of early onset pre-eclampsia?
<34 weeks
109
Does early onset preeclampsia impact foetal growth?
IUGR
110
What is the mechanism of onset of early onset preeclampsia?
* incomplete trophoblastic invasion
* altered secretion of angiogenic balance (eg endothelial cell injury)
111
What is the timing of late onset preeclampsia?
>34 weeks
112
Does late onset preeclampsia impact foetal growth?
No
113
What is the mechanism of onset of late onset preeclampsia?
* growth of placenta reaches its limit
* proteins that regulate sFLT-1, PIGF resulting in
114
What 3 signs of magnesium toxicity suggest stopping MgSO4?
- loss of deep tendon reflexes
- RR<12
- confusion
