Hypertensive disorder pregnancy Flashcards
Discuss hypertensive categories in preganancy
Gestational hypertension – occurs during pregnancy, resovles with delivery recognized by a new blood pressure of 140/90 mmhg or higher
Pre-eclampsia – gestational hypertension with one or more of the followin
- renal impairment – proteinuria >300mg in 24hours , high Cr
- liver disease – epigastric pain, liver tenderness, -elevated transaminases
- neurological problems – seizures, visual disturbance, -papilloedema, clonus
- haematological disturbance – thrombocytopaenia, -haemolysis, DIC
- fetal growth restriction – non reassuring CTG, reverse flow on Doppler, IUGR
Eclampsia is the occurence of siezures in the patients with signs of pre-eclampsia – progression is unpredictable and may develop rapidly
Preganancy aggrevated hypertension – chronic HTN with syperimposed pre-eclampsia or eclampsia
Discuss risk factors for the development of pregnancy related hypertensive disorders
Epi-
-Women under 20 or over 35
Pregnnacy
- Primigravidas
- Twin pregnancy
- Molar pregnancies
Co-morbidities
- those with hyperlipidaemia
- pregestational diabetes
- obesity - BMI >30
- family history
-Prothrombotic connective tissue disorders -SLE protein C and S deficiencies antiphospholipid syndrome factor V leiden mutation hyperhomocysteinemia
Discuss pathophysiology of pre-eclampsia
vaso-spastic disease unique to pregnancy – unknown cause
Vasospasm, ischaemia and thrombosis associated with pre-eclamptic change cause injury to maternal organs, placental infarction and abruption and foetal death from hypoxia or prematurity
Vascular responsiveness is usually depressed in pregnancy with a high output low resistance state – in pre-ecmplasia there is an even higher output state with an unusually high vascular resistance
Cause is unclear but may be due to imbalance between prostocyclin and thromboxane from ednothelial dysfucntion – this is supported by the fact that antiplatelet agents reduce risk of development of PET
Discuss clinical features of PET
HTN
Proteinia although not always present
Odema – difficult to asses in pregnant women as usually some degree of dependent odema
Neuro
- Headache - persistent or severe
- Visual (scotomata, photophobia, blurred vision, temporary blindness)
- Eclampsia
- Hyperreflexia
CVS
- Increased SVR
- Raised CO
GIT
- Severe epigastric pain
- RUQ pain
- HELLP
Renal
- Proteinuria - >30mg/mol
- Oliguria <500ml/day
Haem
- Haemolysis
- THrombocytopenia
Foetus
- Foetal demise
- foetal growth restriction
Discuss complications of PET
HELLP syndrome develops in 5-10% of women with pre-eclampsia. Characterized by haemolysis, elevated liver enzymses, low platelt count.
Eclampsia – occurence of seizures or coma\
warning sings include headache, nausea and vomiting, visual disturbances. elevated total leukocyte count and creatinine
Particularly in early eclampsia <32 weeks gestation seizure may develop early and HTN may not be assoicated with oedema or proteinuria
Pulmonary oedema
Placental abruption
Foetal risk
- > 24 weeks delaying pregnancy is outweighed by the high maternal risk
- 24-33 weeks foeus risks are RDS, longer ICU admission and high risk of c section
What percentage of post partum women who develop eclampsia were undiagnosed with pre-eclampsia at delivery
55%
How long can patient present with pre-eclamptic or eclamptic symptoms after delivery
For up to 4 weeks
Discuss diagnositic testing in eclampsia
Foetal and maternal monitoring
FBC, U&E, LFTS, coags platelet count
Baseline magnesium level is important
Glucose level especially in those with true seizures
If nil history of pre-eclampsia was obtained prior to seizure or refractory to magnesium sulfate a CT head should be performed to exclude central venous thromobosis or intracranial haemorrhage both of which can occur without HTN
CT changes can be seen in 50% of patients with eclampsia
Discuss management of pre-eclampsia -non pharm
Need to determine the gestation of the child to inform further treatment
Bed rest and minimal exertion is the only demonstrated means of reducing blood pressure and allowing the pregnancy to be sustained longer
Definitive treatment is for delivery of the child – although expectant management is standard for women less than 34 weeks of gestation
left lateral postion to avoid aorto-caval compression
Discuss management of eclampsia - seizure
Eclamptic seizures are controlled in almost all cases with adequate doses of magnesium – start with a 4 gram loading dose and then 2gram/hour (LIFTL 5 gram loading 1gram.hr – MAGPIE trial) – monitor for overdose,
- respiratory depression
- drowsiness
- loss of reflexes
If seizures persist can trial other anti seizure medications – diazapam, phenytoin
As in all seizure alternative causes should be considered – hypoglycaemia, epilepsy, intracranial catastrophy
Discuss management of eclampsia and pre-eclampsia - htn
Rapid lowering of blood pressure can result in uterine hypoperfusion so specific antihypertensives should not be used unless diastolic >105
Aim BP <140/110
- methyldopa PO 0.5-3g/day
- labetalol IV 5-10mg injected slowly
- nifedipine PO 10-20mg or IV 100-200mg over 2 min
- beta-blockers (metoprolol, pindolol, propanolol, esmolol)
- hydrallazine IV 10-20mg slowly
- GTN IV 0.1-0.8mcg/kg/min
- SNP IV 1-4mcg/kg/min
Discuss intra-operative management of eclampsia
single shot spinal, CSE and epidural have all been employed
hypotension less common
GA; abate hypertensive response to intubation (1mg alfentanil), monitor for APO @ emergence
use arterial line
avoid syntometrine and ergometrine -> acute hypertension
Postoperative/delivery Management
continue antihypertensives continue MgSO4 NSAIDS if not contraindicated thromboprophylaxis manage APO in standard manner (LMNOP)
Discuss fluid balance in eclampsia
Although TBW is excessive in eclamptic patient the intravascular volume is contracted and the eclamptic patient is sensitive to fluid shift.
Diuretics and hyperosmotic agents should be avoided
Catious fluid replacement as excessive fluid increases extravascular fluid stores that are difficult to mobilise post partum and lead to increase risk of APO.
List risk factors for the development of pre-eclampsia
Past histroy Pregestational daibetes Chornic hypertension Preprgancny overweight or obesity SLE, antiphospholipid syndrome CKD Multifeotal pregnancy Nulliparity Family histroy Extremes of age particuarlly advanced >35 Use of assisted reproductive technology
