Wk 3: Hypertension/Pre-eclampsia/Clinical Deterioration Flashcards
What blood pressure is defined as pregnancy hypertension and thus the threshold for pre-eclampsia screening?
Systolic blood pressure (BP)= ≥ 140mmHg
and/or
Diastolic blood pressure= ≥90 mmHg
*some require proteinuria
These measurements should be confirmed by repeated readings over several hours.
- clinicians should commence therapy to target a blood pressure less than or equal to 140/90
What are the thresholds hypertension?
Mild Hypertension
Systolic BP 140 - 149
Diastolic BP 90 - 99
Moderate Hypertension
Systolic BP 150 -159 mmHg
Diastolic BP - 100-109 mmHg
Severe Hypertension
Systolic BP ≥160 mmHg (some say 170)
and/or
Diastolic BP ≥110 mmHg
Severe Hypertension requiring immediate treatment
Systolic BP ≥170 mmHg
and/or
Diastolic BP ≥ 110 mmHg
Define gestation/pregnancy-induced hypertension
- New onset of hypertension after 20 weeks gestation
- without any maternal or fetal features of pre-eclampsia
- BP returns to normal within 3 months postnatally
What is a key practice point for managing sever pre-eclampsia?
Lower blood pressure carefully, as inadequate placental perfusion may occur where placental circulation has adapted to a higher blood pressure.
If lowered to quickly, can cause;
- cerebral haemorrhage
- hypertensive encephalopathy
What is the management of severe hypertension?
- Admit to Hospital for Acute Treatment
- Do not allow BP to fall below 140/80
Antihypertensive therapy with (for all those with systolic >170 or diastolic >110); - Nifedipine, maximum 40 mg, oral
- Labetalol, 20–80 mg, IV bolus over 2 minutes
- Hydralazine, 5–10 mg, IV bolus over 5 minutes administered by a medical officer, or IM injection
Fluid restriction
- Nil by mouth
- 80 ml/hr IV crystalloid
Observations during acute Treatment of severe hypertension
- 15 minutely BP
- 30 minutely - complete set of vital signs, and assessment of response to treatment
- continuous oxygen saturation monitoring
- continuous fetal monitoring.
What assessment should be considered for hypertension?
Maternal assessment
- history: headache, visual disturbances, epigastric or right upper quadrant pain
- Vital signs: BP, pulse, respiratory rate, temperature
- General examination: abdominal palpation, reflexes, clonus.
- Spot urine PCR
- FBE
- platelets are < 100 x 109/L include:
- Liver function test - AST, ALT and LDH
- Clotting profile - coagulation profile (APTT, PT, fibrinogen)
- group and hold
- Urea, creatinine, electrolytes
- Abdominal palpation
- Reflexes and clonus
- Oedema
- MSU
- uric acid (in some organisations)
Fetal assessment
- Fetal movements
- CTG if >28wks
- US assessment of fetal growth,
AFI, UA dopplers
- Antenatal corticosteroids (Betamethasone) administration to a woman who is expected to birth pre-term should be considered
- Antenatal Magnesium Sulphate administration to the woman who is expected to birth pre-term (<30 weeks gestation) is recommended for the purpose of fetal neuroprotection
What further investigations should be considered for suspected pre-eclampsia?
Features of pre-eclampsia:
- urinalysis for protein
- urine microscopy
Thrombocytopenia or a falling
haemoglobin:
- investigate for disseminated
intravascular coagulation
and/or haemolysis
What is the management for moderate hypertension?
Ongoing treatment with antihypertensive medication
= Aim for BP <150/100
First line agents:
- Labetalol 100–400 mg TDS
- Methyldopa 250–750 mg TDS
Second line;
- nifedipine
Antenatal care – aim for BP <150/100
- Individualise schedule of antenatal visits
- BP monitoring as clinically indicated
- Routine CTG not indicated
- 28–30 weeks US for growth
- 30–32 weeks US for growth
What is the management of mild hypertension?
- optional antihypertensive therapy
What are some fetal and maternal indications for immediate delivery in the context of hypertension?
Maternal
- Inability to control hypertension
- uncontrollable pre-eclampsia
- uncontrolled hypertension
- Deteriorating biochemistry
aka deteriorating platelet count, deteriorating liver function and deteriorating renal function.
- Placental abruption
- Persistent neurological symptoms
- Persistent epigastric pain, nausea or vomiting with abnormal LFTs
- Acute pulmonary oedema
- Gestational age > 37 weeks
- HELLP Syndrome
Fetal
- Severe fetal growth restriction
- Abnormal CTG requiring immediate delivery
- gestational age >37wks
Explain the drug methyldopa. Including the;
- dose
- actions
- contraindications
- practice points
Dose: 250 mg-750 mg
every 8 hours/TDS
Actions: centrally acting adreergic agonist
Contraindications: depression
Practice points:
- Slow onset of action over
24 hours
- dry mouth
- sedation
- depression
- blurred vision
Withdrawal effect:
rebound hypertension
Prescribed;
- hypertension of any kind in pregnancy e.g. chronic hypertension
Explain the drug labetalol for ongoing treatment and acute treatment of hypertension. Including the;
- dose
- actions
- contraindications
- practice points
Dose:
Ongoing: 100mg-400mg every 8hrs/TDS
Acute: 20–80 mg; max 80mg/dose
Actions: Beta blocker with
mild alpha vasodilator effect
Contraindications: Asthma, chronic airways limitation
Side effects:
- Bradycardia
- bronchospasm
- headache
- nausea
- scalp tingling which usually
resolves within 24 hours
Explain the drug nifedipine in both the acute and ongoing context. Including the;
- dose
- actions
- contraindications
- practice points
Dose:
Acute: 10 mg tablet; max 40 mg
Onoging: 30mg or 60mg slow
release every 12 hours
Actions: calcium channel blocker/antagonist
Contraindications: aortic stenosis
Practice points:
- Severe headache in first
24 hours
- flushing
- tachycardia
- peripheral oedema
- constipation
Prescription:
- used in acute hypertensive situations
- may be used as a second line agent with labetalol or methyldopa
Define chronic hypertension
= Pre-existing hypertension that is a strong risk factor for the development of preeclampsia
and requires close clinical surveillance
Includes essential hypertension, secondary hypertension and white coat hypertension.
Define essential hypertension
= A systolic BP ≥ 140 mmHg and/or a diastolic BP ≥ 90 mmHg before pregnancy or before 20 weeks gestation without a known cause. It may include women presenting early in pregnancy on anti-hypertensive medications where no secondary cause for hypertension has been determined.
Considered chronic hypertension
Define secondary hypertension
= hypertension due to a condition such as;
- chronic kidney disease (e.g. glomerulonephritis, reflux nephropathy and adult
polycystic kidney disease)
- renal artery stenosis
- systemic disease with renal involvement (e.g. diabetes mellitus, systemic lupus erythematosus)
- endocrine disorders (e.g. phaeochromocytoma, Cushing’s syndrome and primary hyperaldosteronism)
- coarctation of the aorta
- medications.
Define white coat hypertension
= raised BP in the presence of a clinical attendant but normal BP in any other setting
What is the management of hypertension at A/N app?
- ?signs and symptoms of pre-eclampsia
- ?risk factors for pre-eclampsia and commence prophylaxis if present (150mg of aspirin daily, nocte + 1.5g calcium daily)
If sever hypertension
- follow hospital guidelines/previously discussed treatment of meds, FBC, NBM, crystalloid
If mild-mod
- ?first diagnosis or pre-existing
- ?medicated if pre-existing
Provide ongoing care of;
- Ophthalmic examination
- ECG (if not done recently)
- 24-hour urine catecholamines (if medicated)
- Urinalysis for proteinuria and spot urine PCR
- Serum electrolytes
Antenatal care – aim for BP <150/100
- Individualise schedule of antenatal visits
- 20 week US for morphology
- 28–30 weeks US for growth
- 30–32 weeks US for growth
- CTG if clinically indicated: e.g. abnormal fetal growth,
decreased fetal movement, unstable BP
What are some key practice point for antihypertensive therapy?
- a BP ≥ 160/100 mmHg treatment is essential
- mild-mod= Antihypertensive drug therapy is optional
- Antihypertensive drug therapy confers no clear benefit to women with mild pre-eclampsia.
- Lower blood pressure carefully, as inadequate placental perfusion may occur where placental circulation has adapted to a higher blood pressure.
Define pre-eclampsia
= A multi system disorder unique to pregnancy, characterised by hypertension and involvement of one or more organ systems and/or the fetus after 20 weeks’ gestation.
- resolves after delivery of the placenta, however, deranged blood values can take up to 3/12 to fully recover.
- Proteinuria is a common, recognised additional feature after hypertension but is not a sign necessary for clinical diagnosis.
Define superimposed pre-eclampsia
= chronic hypertension that develops one or more of the systemic features of pre-eclampsia after 20 weeks of gestation.
Define eclampsia
= New onset Grand Mal Seizure in a pregnant woman with pre-eclampsia
- Cause unknown, lots of theories as to the cause.
- some suggest that seziures are a result of cerebral vasospasm and endothelial damage leading to cerebral ischaemia, microinfarctions and oedema.
- can occur antenatally, intrapartum and postnatally
- most commonly occurs 24hrs postnatally
- is not the most commonest cause of seizures in pregnancy and the differential diagnosis includes
epilepsy and other medical problems that must be considered carefully, particularly when typical features of severe preeclampsia are lacking.
Define HELLP syndrome?
= HELLP =Haemolysis, elevated liver enzymes, low platelets
- Life-threatening pregnancy complication considered to be a variant of pre-eclampsia
H: hemolysis= break down of RBCs
EL: elevated liver enzyme
LP: low platelet count
- Mortality rate 1 - 2%
What are the symptoms of HELLP syndrome?
*may at first seem like pre-eclampsia
- Headache
- Nausea and vomiting/indigestion with pain after eating
- Abdominal or chest tenderness ad upper right quadrant pain from liver distension
- Shoulder pain or pain when breathing deeply
- Bleeding
- Changes in vision
- Swelling
Signs to consi
- Epigastric (abdominal) or substernal (chest) pain, including abdominal or chest tenderness and upper right side pain (from liver distention)
- upper r) quadrant pain indicative of hepatic involvement.
- pain relief responds poorly
- Nausea, vomiting, or indigestion with pain after eating
- Headache that won’t go away, even after taking medication such as acetaminophen
- Shoulder pain or pain when breathing deeply
- Bleeding
- Changes in vision including blurred vision, seeing double, or flashing lights or auras
- Swelling, especially of the face or hands
- Shortness of breath, difficult breathing, or gasping for air
What are some diagnostic markers of HELLP syndrome?
- High blood pressure
- Protein in the urine
- Abnormalities in laboratory blood work (increased liver enzymes, decreased platelets, and the presence of hemolysis)
What are some risk factors for developing HELLP syndrome?
- preeclampsia and eclampsia
- family history
- family history of certain autoimmune conditions
- family history of certain clotting disorders
What are the severity classes of HELLP syndrome?
= classified based on the blood test values which reflect the condition of the mothers blood vessels, liver and other organs.
Classes
*the lower class, the more dangerous the situation.
- Class I (severe thrombocytopenia): AST ≥ 70 IU/L, LDH ≥ 600 IU/L, platelets ≤ 50,000/uL
- Class II (moderate thrombocytopenia): AST ≥ 70 IU/L, LDH ≥ 600 IU/L, platelets > 50,000 ≤ 100,000/uL
- Class III (mild thrombocytopenia): AST ≥ 40 IU/L, LDH > 600 IU/L, platelets > 100,000 ≤ 150,000/uL
What is the significance of the platelets component of HELLP syndrome classing/diagnosis?
= (also known as thrombocytes) are colorless blood cells that help blood clot and stop bleeding by clumping and forming plugs in blood vessel injuries.
- Thrombocytopenia is a condition in which you have a low blood platelet count and is one of the defining characteristics of HELLP syndrome.
What is the treatment of HELLP syndrome?
- delivery of baby and placenta
- blood transfusions (sometimes with specifically RBC, platelets or plasma)
- corticosteroids for fetal lung development in very preterm pregnancy
How can HELLP syndrome be prevented?
- good physical health pre pregnancy
- regular antenatal care
- understanding of the warning and early signs
- aspirin if at risk. Prevents pre-eclampsia and thus chnaces of developing HELLP syndrome.
What is the impact of HELLP syndrome on the baby?
- if >1000g at birth appears to be no adverse long-term outcomes and same survival rates as non-HELLP babies.
- <1000g at birth long hospital stays., increased chance of needing ventilator support
- Placental abruption
- Placental failure with intrauterine hypoxia/asphyxia
- Extreme prematurity
Who are the three at-risk (based on a diagnosis) groups for hypertension?
- pre existing primary hypertension
- secondary chronic hypertension
- those who develop new onset hypertension in the second half of pregnancy
When is transfer to a tertiary hospital indicated in the context of hypertension and pregnancy?
- All pre-term pregnancies with severe pre-eclampsia, eclampsia or HELLP syndrome
- All term pregnancies complicated by eclampsia or HELLP syndrome
- Any pregnancy in which the health care provider believes his/her health care
facility would be unable to manage the complications of hypertension in
pregnancy.
What is the management of hypertension found in an antenatal setting?
- recheck in 15mins
- consult and refer to supporting hospital.
- if >160 systolic or >100 diastolic reccomende ambulance transfer.
Explain the normal progression of blood pressure in pregnancy
- falls in first trimester
- reaching a nadir by the second trimester
- rises again to pre-conception levels towards end of third trimester.
Define proteinuria
= urinary excretion of ≥0.3 g protein in a 24-hour specimen.
= ≥1+ reading on dipstick (must be with no evidence of UTI)
What are the 7 classifications of hypertension related conditions we must be aware of?
- Preeclampsia – eclampsia
- Gestational hypertension
- Chronic hypertension
- essential
- secondary
- white coat - Preeclampsia superimposed on chronic hypertension
How can pre-eclampsia be diagnosed?
- hypertension after 20wks
- accompanied with one or more of the following signs of organ involvement.
Renal involvement
- Significant proteinuria – a spot urine protein / creatinine ration > 30mg / mmol
- Serum or plasma creatinine greater than or equal to 90 micromol/L or
- Oliguria < 80mL / 4 hours
Haematological involvement
- Thrombocytopenia < 100,000 /µL
- Haemolysis: schistocytes or red cell fragments on blood film, raised bilirubin, raised lactate dehydrogenase > 600mIU/L, decreased haptoblobin
- DIC
Liver involvement
- Raised transaminases
- Severe epigastric or right upper quadrant pain
Neurological involvement
- Convulsions (Eclampsia)
- Persistent visual disturbances (photopsia, scotomata, cortical blindness,
posterior reversible encephalopathy syndrome, retinal vasospasm)
- Persistent, new headache
- Stroke
- Pulmonary oedema
- Fetal growth restriction (FGR)
Define superimposed preeclampsia
= when a woman with pre-existing hypertension develops systemic features of preeclampsia, after 20 weeks gestation.
- Worsening or accelerated hypertension should increase surveillance for preeclampsia but is not diagnostic.
What are some risk factors for pre-eclampsia?
Moderate risk
- Age 40 years or more
- First pregnancy/nulliparity
- Multiple pregnancy
- Interval since last pregnancy of more than 10 years
- Body mass index of >35 at presentation
- Family history of pre-eclampsia
High risk
- Autoimmune disease e.g. Systemic Lupus Erythematosus (SLE), antiphospholipid syndrome
- Chronic hypertension
- Chronic kidney disease
- Hypertensive disease during a previous pregnancy
- Diabetes
- African American ethnic background
- PAPP-A <0.45 MoM
- Antiphospholipid syndrome
