Slide 2 Maternal Newborn Orientation Learning Module
Reproductive Care Program of Nova Scotia September, 2013
Hypertensive Disorders of Pregnancy (HDP) Slide 3 Objectives To
review classifications of HDP To understand the maternal, fetal and
neonatal implications To highlight skilled nursing care of women
with HDP To review treatments and prevention of complications Slide
4 www.sogc.org Canadian Hypertension Education Program
www.hypertension.ca/chep Slide 5 Hypertension in Pregnancy Affects
approximately 10% of all pregnancies Is a leading cause of maternal
and fetal/neonatal mortality and severe morbidity in Canada and the
world. responsible for approximately 13% of maternal deaths in
Canada Slide 6 Diagnosis of Hypertension* dBP 90 mmHg if dBP is
< 90 mmHg but sBP is 140 mmHg, close monitoring is advised
Severe hypertension sBP 160 mmHg and/or dBP 110 mmHg * Averaged
over 2 measurements and (preferably) confirmed on 2 occasions; in
15 minutes if severe Slide 7 Classification of HDP Pre-existing
hypertension pre-pregnancy, or prior to 20 weeks gestation
Gestational hypertension developing at or after 20 weeks gestation
Two subgroups exist for both pre-existing and gestational
hypertension: with co-morbid conditions (e.g. diabetes,
cardiovascular disease) preeclampsia Slide 8 Preeclampsia More
wide-ranging maternal and fetal implications than hypertension
alone Elevated BP (without preeclampsia) is of concern primarily as
a potential cause of maternal morbidity Described as a potentially
ominous disease peculiar to pregnancy; a pregnancy-specific
syndrome of reduced organ perfusion (Gifford, et al, 2000) Slide 9
Definition of Preeclampsia (SOGC) Hypertension (resistant, if
pre-existing) Proteinuria dipstick result of +2 or 24-hour
collection of 0.3 to 0.5g/d Adverse conditions resulting from
end-organ dysfunction including: complications such as
oligohydramnios symptoms of headache, visual disturbances or RUQ
pain abnormal lab tests - decreased platelet count or elevated
liver enzymes (*results in pregnancy may differ from standard
values) Slide 10 Physiologic Changes During normal pregnancy: Blood
volume increases by 30% to 50% Prostaglandin production is
increased resulting in vasodilation and decreased vascular
resistance BP normally falls during the second trimester Glomerular
filtration rate increases by 50%; renal plasma flow increases by as
much as 80% BUN and serum creatinine decrease Slide 11 Placental
Physiology In normal pregnancies: Placental implantation results in
remodeling of the uterine spiral arteries. The result is large
capacity vessels with low resistance, allowing increased placental
blood flow and oxygenation Spiral artereries Slide 12
Pathophysiology of Preeclampsia Placenta implantation is
ineffective/incomplete Endothelial dysfunction associated with
vascular reactivity and vasospasm Blood flow is decreased Placental
perfusion may be significantly decreased Maternal arteries become
damaged, potentially leading to activation of coagulation cascade
Slide 13 Progression of Preeclampsia The condition begins at
conception; the only cure is delivery Symptoms and adverse effects
worsen as pregnancy advances Slide 14 Severe Preeclampsia Criteria
for classification of severe preeclampsia: OnsetSlide 15 Risk
Factors for Preeclampsia Ethnicity: Nordic, African Canadian, South
Asian Excessive weight gain Family history New partner 1 st
pregnancy Previous history Age 40 Obesity (BMI 35) Pre-existing HTN
Multiple pregnancy Inter-pregnancy interval < 2 years or 10
years Slide 16 Maternal Complications Eclampsia Stroke Pulmonary
edema Abruption End organ dysfunction Slide 17 Signs/Symptoms of
End-Organ Dysfunction: Headache Visual disturbances RUQ pain
Nausea/vomiting Chest pain/dyspnea Slide 18 Fetal Complications
Oligohydramnios Intrauterine growth restriction (IUGR) Absent or
reversed end-diastolic flow in umbilical artery (Doppler)
Intrauterine fetal death (IUFD) Slide 19 HELLP Syndrome Commonly
considered a variant of preeclampsia Acronym for: Hemolysis Hgb,
LDH resulting from RBCs damaged by fibrin Elevated Liver enzymes
AST, ALT from liver edema and damage from fibrin Low Platelets
Thrombocytopenia < 150 x 10 9 /L from consumption of platelets
due to damaged vascular endothelium Slide 20 Caring for Women with
HDP Antepartum fetal health surveillance Encourage FM counting Goal
is 6 or more movements in 2 hours; at least daily and/or if
movement is perceived If there are < 6 movements in 2 hours,
further assessments are advised (SOGC) Ultrasound for fetal growth,
AFV or BPP and/or umbilical artery Doppler Slide 21 Caring for
Women with HDP No evidence to support introduction of a low salt
diet; strict bed rest is not advised Assess for signs and symptoms
of complications or end-organ dysfunction associated with
preeclampsia Follow an appropriate and consistent procedure for
assessing BP Slide 22 Guidelines for Assessment of BP Appropriate
size cuff 1 times arm circumference Standard (26-33 cm) Large
(33-41 cm) Extra large (> 41 cm) Woman should be sitting with
the cuff positioned at the level of the heart Reprinted with
permission of the Canadian Hypertension Education Program Slide 23
Steps for Taking an Accurate BP A woman should rest comfortably for
5 minutes prior to taking BP; she should be seated with her feet
resting on floor (or other), legs uncrossed with her arm well
supported; she should not be talking during the assessment. No
caffeine or nicotine within 30 minutes A regularly calibrated
aneroid device should be used; if used, an automated BP device
should be validated for use with women with preeclampsia. Slide 24
Taking an Accurate BP Increase cuff pressure rapidly to
approximately 30 mmHg above the disappearance of the radial pulse.
Open the control valve so that the rate of deflation of the cuff is
approximately 2 mmHg per heart beat Note the first appearance of
sound (phase I Korotkoff) sBP and absence of sound (Phase V
Korotkoff) dBP Slide 25 Taking an Accurate BP Record the BP to the
closest 2 mmHg on the manometer; record the womans pulse. For the
initial assessment, BP should be taken on both arms; the arm with
the higher BP should be then used consistently. Slide 26
Antihypertensive Therapy Decisions about antihypertensive therapy
are influenced by the presence of co-morbid conditions Women
without co-morbid conditions should have therapy to lower dBP to 80
to 105 mmHg For women with co-morbid conditions, the goal is for
sBP to be 130 to 139 mmHg, and the dBP to be 80 to 90 mmHg Slide 27
Non-Severe Hypertension Labetolol 100 to 400 mg bid to tid (maximum
2g/day) Nifedipine PA tablets (intermediate release) 10 to 20 mg po
bid to tid (maximum 1200 mg/day) XL tablets (slow-release) 20 to 60
mg po od (maximum 120 mg/d) Methyldopa 250 to 500 mg po bid to qid
(maximum 2 g/day) Slide 28 Therapy for Severe Hypertension
Labetolol 20 mg IV; repeat 20 to 80 mg q 30 minutes, or 1 to 2
mg/min, to a maximum of 300 mg Hydralazine 5 mg IV; repeat 5 to 10
mg q 30 minutes, or 0.5 to 10 mg/hr, to a maximum of 20 mg
Nifedipine (oral) 5 to 10 mg capsule (either bitten and swallowed
or just swallowed), q 30 minutes, or 10 mg PA tablet q 45 minutes,
to a maximum of 80 mg/d Slide 29 Points re Antihypertensives Note
that there are 3 preparations of Nifedipine - capsules,
intermediate-release tablets (PA), and slow- release tablets (SL)
Care must be taken to avoid a drop in dBP to < 80 mmHg as
uteroplacental perfusion may be adversely affected. Women with
preeclampsia are more likely to experience hypotension with
antihypertensive treatment. Atenolol is not advised because of
negative effects on fetal growth; ACE inhibitors and ARBs are
fetotoxic, especially to the fetal kidneys Slide 30 Labour and
Birth Timing of birth depends on gestation, the presence and
severity of complications and/or signs and symptoms of end-organ
dysfunction If gestation is < 34 weeks, administration of
steroids will be considered Induction (with cervical ripening, if
necessary) is preferred unless there are other obstetrics
indications for cesarean section Slide 31 Other Considerations for
Labour and Birth Early anesthesia consultation is advised
Epidural/spinal anesthesia/analgesia is preferred, if indicated,
provided platelets are >75 x 10 9 /L Platelets may be
administered prior to vaginal or cesarean birth if < 20 to 50 x
10 9 /L Routine IV bolus prior to administration of epidural
medication or to improve abnormal EFM tracing is avoided
Antihypertensives are continued during labour Slide 32 Magnesium
Sulphate (MgSO 4 ) Given to prevent or treat eclampsia IV loading
dose (usually 4 gm), followed by 1 to 2 gm/hr If a seizure occurs,
another bolus will be given Slide 33 Care of Women Receiving MgSO 4
Close assessment is indicated, including FHR Avoid fluid overload;
administer MgSO 4 bolus in 100 ml of IV fluid Calculate intake and
output hourly; caution if urine output is low because the risk of
magnesium toxicity increases Assess for signs of magnesium
toxicity: weakness hyporeflexia respiratory rate Slide 34 Antidote
10 ml of 10% solution of calcium gluconate given IV over 3 minutes
Stop MgSO 4 infusion Provide respiratory support Slide 35 If a
Seizure Occurs Call for help Promote lateral position Prepare MgSO
4 bolus (and infusion if not already started) Post seizure: ensure
adequacy of airway check vital signs, O 2 saturation, and FHR
assess for signs of abruption Slide 36 Postpartum Care Hypertension
may worsen (or symptoms may first appear) following birth BP peaks
at day 3 to 6 MgSO 4 will be continued usually 24 hours (duration
varies) NSAIDs should not be used if BP is difficult to control,
platelets are < 50 x 10 9 /L, there is oliguria, or elevated
creatinine Slide 37 True/False Quiz 1.Stroke in pregnancy is
unlikely unless sBP is >180 to 200 mmHg. TF 2.The BP goal for
pregnant women with co- morbid conditions is 130 to 139/80 to 90
mmHg.TF 3.Pulmonary edema from fluid administration is a leading
cause of death in women with preeclampsia. TF 4.MgSo 4 is given to
lower BP.TF Slide 38 True/False Answers 1.Stroke in pregnancy is
unlikely unless sBP is >180 to 200 mmHg. TF 2.The BP goal for
pregnant women with co- morbid conditions is 130 to 139/80 to 90
mmHg.TF 3.Pulmonary edema from fluid administration is a leading
cause of death in women with preeclampsia. TF 4.MgSo 4 is given to
lower BP.TF Slide 39 Summary Hypertensive Disorders of Pregnancy
are associated with a number of potentially serious maternal, fetal
and pregnancy complications. Careful assessment for development of
a HDP is essential throughout pregnancy, during labour and in the
postpartum period. Slide 40 Thank you! We welcome your feedback.
Please take a few moments to complete a short evaluation:
http://rcp.nshealth.ca/education/learning-modules/evaluation If you
have any questions, please contact the RCP office at
[email protected] or [email protected]
