Hypertensive disorders Flashcards
What is the definition of hypertension in pregnancy?
2 x readings pf 140/90 at least 4 hours apart
or
1 diastolic reading of 110
What are the 3 types of hypertension?
mild
moderate
severe
What is mild hypertension?
140-149/
90-99
What is moderate hypertension?
150-159/
100-109
What is severe hypertension? (emergency)
160+/110+
MAP of 125+
When does BP lower?
second trimester
What is MAP?
mean arterial pressure - average or mean value for arterial pressure represents pressure driving the blood through the arteries
How do you calculate map?
diastolic pressure+ 1/3 (systolic pressure - diastolic pressure)
What is chronic hypertension?
hypertension that predates a pregnancy or appears prior to 20/40 - may be superimposed or secondary to another medical condition
What is gestational hypertension?
New hypertension presenting after 20 weeks without significant proteinurea
What is pre-eclampsia?
Hypertension new to pregnancy manifesting after 20 weeks associated with new onset of proteinurea
What is severe pre-eclampsia?
pre-eclampsia with severe hypertension (160+/110+)
What is eclampsia?
convulsive condition associated with pre-eclampsia
When does gestational hypertension resolve?
usually 6 weeks postnatally
What is pre-eclampsia caused by?
Widespread endothelial cell damage secondary to ischaemic placenta
What risks are there for later life if you have pre-eclampsia?
Hypertension and cardiovascular disease
Lower/other risk factors for pre-eclampsia
- new partner
- booking bp /80+ or booking proteinurea 1+
- 1+ protein on more than one
- latin american or carribean
- donor eggs - other DNA
- postpartum - headache for 1-3 days
What can women be prescribed at booking if higher risk?
75mg aspiring from 12 weeks till birth
what does aspirin do?
changes how the placenta imbeds
What are the 5 high risk factors?
- prev hypertensive disorder in pregnancy
- chronic kidney disease
- autoimmune disease
- type 1 or 2 diabetes
- chronic hypertension
What are the moderate risk factors?
- primip
- age 40+
- pregnancy interval of 10+ years
- BMI or 35+
- family hx of pre-eclampsia
- multiple pregnancy
Antenatatal symptoms
- new hypertension
- new or significant proteinurea >1+
- mat symptoms of headache or visual disturbances
- epigastric pain or vomiting
- rfm or small for dates
- sudden and marked oedema- face/hands/ feet
Signs of severe pre-eclampsia
-hypertension >160/110 with proteinuria OR ->3+ proteinurea OR -thrombocytopenia - reduced platelets (<100) -creatinine >100 mmol/l
What are the 8 maternal complications of pre-eclampsia?
- intracranial haemorrhage
- placental abruption
- eclampsia
- HELLP syndrome
- Disemminated intravascular coagulation
- Renal failure
- Pulmonary oedema
- Acute respiratory distress syndrome
What is the leading cause of death from severe pre-eclampsia in the UK?
intracranial haemorrhage
What is HELLP syndrome?
H- haemolysis
EL- elevated liver enzymes
LP- low platelets
What is Disemminated intravascular coagulation?
A condition in which blood clots form throughout the body’s small blood vessels which reduce or block floor- damages organs. The increased clotting uses up platelets and clotting factors. With less of thees, serious bleeding can occur. It can cause internal and external bleeding.
What is renal failure?
Due to not passing urine, increased fluid in the body leaks into the tissues due to high blood pressure, leads to oedema
What is acute respiratory distress syndrome?
infections, injuries and other conditions cause fluid to build up in air sacs. Prevents lungs from filling with air and moving enough oxygen into the bloodstream.
What are fetal complications of pre-eclampsia?
- fetal growth restriction
- oligohydramnios
- hypoxia from placental insufficiency
- placental abruption
- premature delivery
Clinical signs of pre-eclampsia
- BP 160-180 or /110
- MAP >125
- protein 3+ in 24 hrs
- elevated serum creatinine
- elevated liver enzymes
- oliguria
- pulmonary oedema
- microangiopathic haemolysis
- thrombocytopenia
- cerebral or visual disturbances
- epigastric pain
- hyperreflexia - more twitchy on relfex tests more likely to fit
What happens to bloods in pre-eclampsia?
- haemoglobin due to haemoconcentration
- haematocrit due to -plasma volume - leaking out
- platelets due to aggregation following damage to lining of blood vessels
- uric acid - serial measurements more useful
- urates
What is haematocrit?
how much space in the blood is occupied by red blood cells - if they take up more space they are usually bigger and vice versa
When do we act for high blood pressure?
- check BP and urinalysis at every visit
- systolic >150 - hypertensives
- systolic >180 - emergency
- if >140 or /90 2x or immediately after birth - consultant unit
What is the timing of eclampsia?
38% antenatally
18% intrapartum
44% postnatally
What is the death rate for those who have eclamptic fits?
2%
Management of eclampsia - basic
- key people told
- basic life support - abc
- prevent seizures - mag sulf
- lower bp - labetalol oral/IV OR nifedipine oral OR hydralazine IV
What are the drugs used to lower BP in emergencies?
1st line - labetalol
2nd line - nifidipine
3rd line- hydralazine
How do we give labetalol?
- initial oral dose 200mg
- second oral dose given if needed
- maintenance dose 200mg
- If oral not working or non tolerable - IV
- Bolus 50mg IV given over 5 minutes
- repeat if BP >160/105 in doses of 50mg up to 200mg at 10 minute intervals
- After give infusion of labetalol 5mg/hour at a rate of 4ml/hr
- double rate every 1/2 hour up to 32 ml/hour
- bradycardia countered with IV atropine sulphate 0.6-2.4mg in divided doses of 600mcg
When should we not give labetalol?
asthmatic
afrocarribean
What does labetalol do?
beta blocker- blocks beta receptors with control heart rate and smooth muscle contractility
- compete with adrenaline
- reduces peripheral resistance
- protects heart from reflex sympathetic drive
What is methyldopa for?
mild-moderate hypertension in pregnancy, also known as aldomet. acts on brain stem. counteracts effects of epinephrine, norepinephrine and dopamine. inhibits sympathetic nervous system causing vasodilation and bradycardia
How do we give nifedipine?
- 10mg orally
- repeat every 30 mins until max 30mg given
- can be given with labetalol
- may give if map >120
- calcium channel blocker
- maintenance dose 10mg qds
What does nifidipine do?
inhibits passage of calcium ions into smooth muscle reducing contractility
allows arterioles to dilate and decreases bp
hr increases which can cause myocardial ischaemia
How do we give hydralazine
Bolus given 5mg over 15mins
Can give further 5mg after 20 mins if BP >160
-Maintenance IVI starting at 5ml/hr to titrate BP to 140-150
-usual rate 2-3ml/hr
-reduce rate if mat hr >120
What can rapid reduction in BP cause?
cardiovascular collapse
myocardial ischaemia
compromise fetal oxygen supply
3 main ways to manage eclampsia
monitor symptoms
maintain fluid balance
expedite delivery
How do we monitor symptoms for eclampsia?
- hourly basic obs
- resps
- neurological obs
- sats
- ECG
- CVP
- urgent bloods
- CTG
How do we maintain fluid balance for eclampsia?
- restrict hourly input - 1ml/kg/hr
- hourly urine output via urometer
What can overloading fluid cause?
pulmonary oedema
What should be controlled before a CS under GA?
BP
Why should BP be controlled for GA?
pressor effects of intubation- intubation increases BP, reflex response and is momentary but can be enough to raise intracranial pressure
What are the 3 outcomes of extremely high BP?
Give anti- hypertensive
Placental abruption
Intracranial haeomorrhage
What does a sudden drop in bp and no antihypertensive given mean?
bleeding
What should you consider for pre-eclamptic women for an epidural?
- Low platelets- risk of bleeding
- Fluid before due to hypotension- could cause fluid overload in PET women
What are the signs of magnesium toxicity?
- loss of reflexes
- somnolence
- respiratory depression
- paralysis
- cardiac arrest
What is the antidote to magnesium toxicity?
calcium gluconate
What is magnesium toxicity?
hypermagnesemia
