BCRCP OBSTETRIC GUIDELINE 11 IN

June, 2006 Inside Summary______2 9. Management of Severe The TESS Ad Hoc Advisory Pre-Eclampsia______9-10 Working Group ______2 9.1 For Pharmacological Management of Severe 1. Introduction ______3 Hypertension see Section 10.2 9.2 General Measures 2. Relevance ______3-4 9.3 Basic Investigations 2.1 Adverse Maternal Outcome 9.4 Maternal assessment / Monitoring 2.2 Adverse Neonatal Outcome 9.5 Fetal Assessment 9.6 Thromboprophylaxis 3. Risk Factors______4 10. Pharmacological Treatment of 4. Classification ______4-5 Hypertensive Disorders in Pregnancy ______10-12 4.1 Measurement of Pressure 10.1 Initiation of Antihypertensive 4.2 Current Canadian Drug Treatment Hypertension Society (CHS) 10.2 Acute Management of Severe Definitions Hypertension 5. Pathophysiology______6-7 10.3 Recommended Treatment of Non-severe Hypertension 5.1 Placental Involvement in Pregnancy 5.2 HELLP Syndrome, Liver and Peripheral Vascular 11. Anticonvulsant Therapy: Magnesium Involvement Sulphate (MgSO4) ______12-13 5.3 Kidney Involvement 11.1 Prophylaxis 5.4 Central Involvement 11.2 Management of 5.5 Cardiovascular: Left 11.3 Management of Recurrent Ventricular Failure Seizures 5.6 Pulmonary Oedema 11.4 Magnesium Sulphate Protocol

6. Indications for Outpatient 12. Delivery Guidelines ______14-15 Assessment and Office 12.1 Steroids Management ______7 12.2 Mode of Delivery British Columbia 12.3 Anaesthsia and Fluids Reproductive Care 7. Indications to Consider 12.4 Indications for Central Venous Program Hospitalization ______7-8 Pressure (CVP) Monitoring F5 – 4500 Oak Street 7.1 Indications for Conservative Vancouver, BC Hospital Management 13. Postpartum______15 Canada V6H 3N1 7.2 Conservative Management 13.1 Fuid Management Tel: 604.875.3737 13.2 Analgesia Web: www.rcp.gov.bc.ca 8. Severe Pre-Eclampsia______8-9 8.1 Definitions 14. Special Problems (Antenatal and While every attempt has been 8.1.1 Adverse Conditions Postnatal) ______15-16 made to ensure that the in- 8.1.2 Severe Systolic 14.1 Oliguria formation contained herein is Hypertension 14.2 Dropping O2 Saturations clinically accurate and current, 8.1.3 Eclampsia 14.3 Blood Products the BCRCP acknowledges that 8.1.4 HELLP syndrome many issues remain controver- (partial/complete) 15. Stabilization Before Transfer __ 16 sial, and therefore may be sub- ject to practice interpretation. 8.1.5 Other signs of CNS disturbance 16. Outcome Indicators ______16 16.1 Maternal 16.2 Newborn

© References ______16 BCRCP, 2006 Appendix A ______18 Summary

This guideline reflects both the variable presentation The BC Women’s Maternal-Fetal Medicine & Obstetric and the systemic nature of Anaesthesia Teams are available to give advice as with and/or adverse conditions needed. Telephone: 604-875-2161 (referred to as pre-eclampsia in this guideline)1 and the other hypertensive disorders of pregnancy. The TESS Ad Hoc Advisory Working Group Recommendations for the comprehensive evaluation This document is an update of the previous BCRCP and management of organ dysfunction associated Hypertension in Pregnancy guideline (2000) and with pre-eclampsia are included. includes a local adaptation of the Yorkshire Obstetric The main points in the guideline are: Critical Care Group Regional Guidelines for the n Pre-eclampsia is a systemic disorder that may Management of Severe Pre-eclampsia. The prior work affect many organ systems of the Yorkshire group, and their willingness to share n For pre-eclampsia remote from term (<34 their document with us, is gratefully acknowledged. weeks), expectant management is associated This document is part of a research project titled with improved perinatal outcomes. Expectant “Translating Evidence-based Surveillance and management requires obsessive surveillance to Treatment Strategies” (TESS) which is designed to mitigate maternal risks and is a “package”. influence outcomes in all women with a hypertensive n Initial assessment and ongoing surveillance of disorder of pregnancy admitted to a BC healthcare women with a hypertensive disorder of pregnancy facility. TESS project information is available at should include assessment of all vulnerable www.obstgyn.ca/mfmresearch/guidelines. maternal organs as well as the . A set of standardized orders is included in Appendix A. The members of the ad hoc TESS Advisory Working n Initiate treatment: Group that produced this document were: • Immediately (in the absence of pre-pregnancy Peter von Dadelszen (Chair) renal disease or ) Consultant Obstetrician, o sBP >160 mmHg or dBP >110 mmHg BCWHHC & CFRI/UBC Centre for o sBP 140-159 mmHg and/or dBP 85-109 Healthcare Innovation and mmHg, based on practitioner preference, Improvement (CHIi) training, and experience Susan Barker Provincial Perinatal Analyst, • In the presence of pre-pregnancy renal disease or BCRCP Database Registry diabetes Sheryll Dale Manager, BCRCP Database • sBP >140 mmHg or dBP >90 mmHg Registry n Recommended treatment of non-severe hypertension in pregnancy Joanne Douglas Obstetrical Anaesthesiologist, • Treatment goal: dBP 80-105 mmHg (depending BCWHHC on practitioner preference) William Ehman Family Practitioner & Consultant, o First choice agent: (Aldomet) Nanaimo General Hospital o second choice agents: Sarah Gilgoff TESS Coordinator, BCWHHC (Trandate); Nifedipine (Adalat PA or XL) Sherry Hamilton Director, High Risk Antepartum o special indications (renal or cardiac Program, BCWHHC & CHIi diseases): diuretics Anthony Human Consultant Obstetrician, Royal • Drugs to avoid: angiotensin-converting enzyme Inland Hospital, Kamloops inhibitors; angiotensin II receptor antagonists; Shoo K. Lee Director, iCARE, University of atenolol Alberta, Edmonton n Acute management of severe hypertension Robert M. Liston Consultant Obstetrician, BCWHHC • Reduce dBP by 10 mmHg in the first instance and & CHIi maintain the at or below that Laura A Magee Consultant Obstetric Internist, level. BCWHHC & CHIi o First choice agent: Nifedipine Craig Mitton Faculty Scientist (Health o second choice agent: Labetalol Outcomes and Health Economics), n Anticonvulsant therapy CHIi • Prophylaxis: MgSO (4g IV stat, then 1g/hr) 4 Pauline Robertson Director, Decision Support, • Management of eclampsia: MgSO (4g IV stat, 4 BCWHHC then 1g/hr) Diane Sawchuck Perinatal Nurse Consultant, • Management of recurrent seizures: MgSO (2g IV 4 BCRCP & CHIi stat, then increase to 1.5g/hr) Karen Vida Director, Newborn Care Program n Fluids: total intake should not exceed 80 ml/hr; and Transport & Project Director, tolerate urine outputs as low as 10 ml/hr. Provincial Specialized Perinatal Services Program

 British Columbia Reproductive Care Program 1. inTRODUCTION O10: Pre-existing hypertension complicating This guideline has been developed to reflect both pregnancy, and the puerperium the variable presentation and the systemic nature of O11: Pre-existing hypertensive disorder with pre-eclampsia1 and the other hypertensive disorders of superimposed proteinuria pregnancy.2-4 The recommendations are derived from the pattern of investigation used in other centres of O13: Gestational [pregnancy-induced] hyperten- excellence, in response to international guidelines,5-8 sion without significant proteinuria in response to current practice across Canada,9,10 and O14: Gestational [pregnancy-induced] hyperten- preliminary evidence that it may be possible to predict sion with significant proteinuria those women most at risk of doing poorly.11 It must be remembered that up to 40% of women who develop O15: Eclampsia eclampsia (seizures) will not have had both hyperten- The provincial rates for hypertensive disorders of sion and proteinuria in the week preceding their first pregnancy (HDP) by fiscal year were 5.5% in 2001/02, seizure.12 Therefore, to proffer the greatest safety to 5.7% in 2002/03, and 5.7% in 2003/04. As expected, women, we should consider (and continue to consider) due to increasing maternal age at first pregnancy, pre-eclampsia in all women presenting with either frequency of multiple births, and rates of obesity (all hypertension or proteinuria in pregnancy, as well as independent risk factors for the HDP), BC experienced those women who present with the symptoms of pre- an increased incidence in the HDP from fiscal years eclampsia in the absence of both hypertension and 2001/02 to 2003/04. proteinuria. Pre-eclampsia remains the most common cause of maternal mortality in North America, and it is appar- ent that the surveillance of women with suspected or confirmed pre-eclampsia is variable between practi- tioners.9,10 In an era of effective blood pressure con- 13,14 trol, it is end organ failure (especially hepatic and respiratory complications) that most commonly causes women to die from pre-eclampsia.4,15 This guideline includes recommendations for the comprehensive evaluation of organ dysfunction. The pattern of investigations presented in this guideline aims to standardize the approach to care within British Columbia, with consideration that the choice of Mondays to Thursdays provides the Of the 6,691 which were complicated best timing for delivery of infants (away from Friday by hypertension during this three-year period, evenings and weekends). Of course, some or all of 68% were gestational [pregnancy-induced] these investigations may be performed at other hypertension without significant proteinuria, 19% additional times, at the discretion of the attending were gestational [pregnancy-induced] hypertension physician. with significant proteinuria, 9% were pre-existing Since the introduction of the pre-printed physician hypertension complicating pregnancy, childbirth and orders (Appendix A) in September 2003, the incidence the puerperium, 2% were pre-existing hypertensive of an internationally-determined combined adverse disorder with superimposed proteinuria, and 2% were maternal outcome has fallen from 5.1% to 0.8% eclampsia. (p<0.05) in those women admitted to BC Women’s Hospital and Health Centre with pre-eclampsia for whom these orders were used.16

2. reLEVANCE The following data is from the British Columbia Perinatal Database Registry for fiscal years 2001/02, 2002/03, and 2003/04. During this three-year period, there were a total of 119,387 pregnancies (singleton and multiples) of which 6,691 (5.6%) were complicated by hypertension, and 112,696 were non-hypertensive pregnancies. For this dataset, hypertension is defined as any of the following conditions (classified by ICD 10 codes):

Obstetric Guideline 11 – Hypertension in Pregnancy  2.1 ADVERSE MATERNAL OUTCOME The rates of all adverse maternal and neonatal When evaluating pregnancy complications in BC, outcomes evaluated here are greater in the serious maternal morbidity is a more relevant outcome hypertensive cohort of pregnancies than in the to use than maternal mortality, as mortality is a rare non-hypertensive cohort. event. When adverse maternal outcomes are compared between hypertensive pregnancies (N=6,691) and non- By instituting the standardized protocol proposed hypertensive pregnancies (N=112,696) for fiscal years within this guideline for the assessment, 2001/02 to 2003/04, women with HDP have higher surveillance, and management of all women rates of: 5.1% versus 2.2%, abruption admitted to a BC healthcare facility with a HDP, 1.88% versus 1.15%, pulmonary oedema 0.28% versus the TESS project is anticipated to improve maternal 0.02%, and acute renal failure 0.09% versus 0.01%. and neonatal outcomes in BC.

3. riSK FACTORS

• Family history

• extremes of reproductive age

• Primigravida

• Multiple gestation

• Diabetes, renal disease, hypertension prior to pregnancy

2.2 ADVERSE NEONATAL OUTCOME • Collagen vascular disease For fiscal years 2001/02 to 2003/04, there were a • No mid-trimester fall in blood pressure total of 121,085 (singleton and multiple) infants born. Of these, 6,952 infants were born of women • excessive weight gain (>1kg/wk; >2lbs/wk) with pregnancy complicated by hypertension, and 114,133 were born of women with non-hypertensive • Finger and facial oedema pregnancies. Rates of adverse neonatal outcomes for those infants born of women with pregnancy complicated by hypertension are compared with 4. cLASSIFICATION infants born of women with non-hypertensive 4.1 MEASUREMENT OF BLOOD PRESSURE pregnancies. Blood pressure should be measured: Outcomes include: birth weight (BW) less than 10th • With the patient resting at 45˚ supported and percentile 12.1% versus 7.15%, BW less than 3rd with the upper arm at the level of the heart percentile 4.96% versus 2.36%, admission of term newborns (>37weeks gestational age) to level III NICU • Using a cuff size that is appropriate as too small 1% versus 0.5%, 5-minute APGAR score less than three a cuff will over estimate blood pressure and too 0.89% versus 0.66%, umbilical artery pH less than large a cuff will underestimate blood pressure seven 0.58% versus 0.19%, and intermittent positive pressure ventilation greater than five minutes 0.42% • Using manual sphygmomanometry – either a versus 0.24%. mercury device or a calibrated aneroid device is the standard. Automated devices, most of which are deflationary, may underestimate both systolic and diastolic values by 10-15 mmHg, especially in women with pre-eclampsia. Automated devices may be useful to follow trends in blood pressure, but in women considered to be at high risk these measurements should be validated against manual readings on a regular basis.

• Using Korotkoff V (disappearance of pulse sounds) for diastolic blood pressure as this value is more consistent and is the international standard.

 British Columbia Reproductive Care Program 4.2 CURRENT CANADIAN HYPERTENSION SOCIETY (CHS) DEFINITIONS

In these guidelines, ‘severe pre-eclampsia’ is generally synonymous with the Canadian Hypertension Society (CHS) definition of ‘gestational hypertension ± proteinuria with adverse conditions.’8 We have adapted the Yorkshire guidelines to be consistent with the current CHS definition of adverse conditions, with the addition of severe systolic hypertension and either eclampsia or HELLP syndrome arising in the absence of hypertension and/or proteinuria. Classification Definition

A. Pre-existing hypertension Diastolic hypertension that predates pregnancy or is diagnosed before 20 weeks gestation. In most cases hypertension persists > 42 days postpartum. It may be associated with proteinuria.

1. Essential Primary.

2. Secondary Secondary to such conditions as renal disease, phaeochromocytoma and Cushing syndrome.

B. Gestational hypertension Diastolic hypertension develops after 20 weeks gestation. In most cases it resolves < 42 days postpartum.

1. Without proteinuria Corresponds to previous terminology such as “pregnancy induced hypertension” and “non-proteinuric hypertension”. Protein excretion in 24-hour urine collection is < 0.3 g/d.

a. Without adverse conditions

b. With adverse conditions Convulsions (eclampsia), very high diastolic pressure (>110 mmHg), (platelet count <100 x 109 /L), oliguria (< 500 ml/d), pulmonary oedema, elevated liver enzyme levels, severe nausea and vomiting, frontal headache, visual disturbances, persistent abdominal pain in right upper quadrant, chest pain or shortness of breath, suspected abruptio placentae, HELLP syndrome, IUGR, oligohydramnios, or absent or reversed umbilical artery end diastolic flow as determined by Doppler velocimetry.

2. With proteinuria Corresponds to alternative terminology such as “pre-eclampsia”, “pre-eclamptic toxaemia” and “toxaemia”. Protein excretion in 24-hour urine collection is > 0.3 g/d.

a. Without adverse conditions

b. With adverse conditions Same conditions as in 1b; protein excretion >3 g/d 24-hour urine collection, especially with hypoalbuminaemia (albumin level <18 g/L).

C. Pre-existing hypertension + Pre-existing hypertension (as defined in A) associated with superimposed gestational further worsening of pressure and protein excretion > 0.3 g/d in 24- hypertension with proteinuria hour urine collection after 20 weeks gestation. Corresponds to alternative terminology “chronic hypertension with superimposed pre-eclampsia”.

D. Unclassifiable antenatally Hypertension with or without systemic manifestations if blood pressure was first recorded after 20 weeks gestation. Reassessment is necessary at or after 42 days postpartum. If the hypertension has resolved by then, the condition should be reclassified as gestational hypertension with or without proteinuria; if the hypertension has not resolved by then, the condition should be reclassified as pre-existing hypertension.

Obstetric Guideline 11 – Hypertension in Pregnancy 5 5. pATHOPHYSIOLOGY 5.1 PLACENTAL INVOLVEMENT Pre-eclampsia is a multisystem disease, with variable When inadequate fetal vascular development, progression leading to requiring recurrent ischemia-reperfusion injury, and vasospasm imminent treatment. Pre-eclampsia is associated with affect the uteroplacental bed, fetoplacental demands generalized vasospasm and progressive involvement outstrip the maternal circulatory supply. The fetus of essential organs such as the kidney, liver, brain, then becomes growth restricted and at increased risk and haematological systems. Maternal endothelial of and neonatal death. The incidence of IUGR cell damage associated with the release of substances in the context of pre-eclampsia ranges from 30-80%, from the poorly perfused placenta initiates a and the majority of IUGR is associated with early- dysfunctional cascade of coagulation, vasoconstriction onset disease. At term, there is an increased incidence and intravascular fluid redistribution that results in of pre-eclampsia in women with macrosomic . the clinical syndrome of pre-eclampsia/eclampsia. The following diagram models the pathogenesis of pre- 5.2 HELLP SYNDROME, LIVER AND PERIPHERAL eclampsia (Figure 1). VASCULAR INVOLVEMENT HELLP syndrome may develop in a setting of minimal changes in blood pressure and all the features below may not be present in individual patients: • Haemolysis

• Elevated liver enzymes

• Low platelets

Vasospasm and inflammatory infiltrates affecting the liver lead to elevated liver enzymes. In addition, peripheral vascular vasospasm and coagulation cascade activation in the microcirculation leads to sequestration and activation of platelets peripherally with destruction of red blood cells.

5.3 KIDNEY INVOLVEMENT Kidney involvement in pre-eclampsia leads to Figure 1. The pathogenesis of pre-eclampsia5. glomerular endotheliosis and excretion of protein. In this model of pre-eclampsia, the maternal syndrome This prognostic sign is associated with poorer develops from a number of alternative pathways outcomes: leading to uteroplacental mismatch, whereby • Two fold increase in perinatal mortality the fetoplacental demands outstrip the maternal circulatory supply. In response to the mismatch, and • The development of oliguria probably due in part to recurrent ischemia-reperfusion injury within the intervillous (maternal blood) space 5.4 CENTRAL NERVOUS SYSTEM INVOLVEMENT of the placenta and accelerated placental apoptosis, Cerebral vasospasm in combination with a soup of endothelium-damaging substrates is haemorrhage, ischaemia, and oedema of the cerebral released with resulting endothelial cell activation and hemispheres leads to: consequent development of the maternal syndrome • Seizures of pre-eclampsia. Some elements of the soup, namely activated peripheral blood leukocytes, can cause • Frontal headaches direct end-organ damage. There is cross-talk between elements of the soup (not illustrated). • Occipital headaches

ARDS: acute respiratory distress syndrome • Hemiplegia ATN: acute tubular necrosis • Visual disturbances DIC: disseminated intravascular coagulation PBLs: peripheral blood leukocytes PGs: eicosanoids ROS: reactive oxygen species+

 British Columbia Reproductive Care Program 5.5 CARDIOVASCULAR: LEFT VENTRICULAR • Any adverse features FAILURE • Ultrasound evidence of oligohydramnios or As a result of: inadequate fetal growth. • Vasospasm Once hospitalized, a decision should be made whether • Increased capillary permeability causing to pursue conservative management or to proceed to pulmonary oedema immediate delivery. • Cardiomyopathy of pre-eclampsia 7.1 INDICATIONS FOR CONSERVATIVE 5.6 PULMONARY OEDEMA HOSPITAL MANAGEMENT • stable, well-controlled blood pressure (sBP <160 mmHg / dBP <110 mmHg), and on less 6. indicATIONS FOR OUTPATIENT than maximal oral antihypertensive therapy for at ASSESSMENT AND OFFICE least two agents (i.e., 1200 mg labetalol/d + 2000 MANAGEMENT mg methyldopa/d + Adalat PA/XL 90 mg/d). • Blood pressure: sBP < 140 mmHg and • Proteinuria < 2+ on dipstick (<1g/day or <100 dBP < 90 mmHg mg/mmol by PCR); this marker of disease severity • Proteinuria: 1+ or less on dipstick on one may not exclude conservative management at occasion gestational ages remote from term, a plasma albumin <20 g/L places the patient at greatly • No adverse features increased risk of pulmonary oedema, and should be considered a contraindication for conservative • Normal platelet count management.

In the presence of any of the above signs, closer • Platelet count > 100 x 109/L; this marker of surveillance should include: disease severity may not exclude conservative management at gestational ages remote from • Frequent office visits (every 3 to 4 days) term, depending on the rate of platelet count • Close maternal and fetal assessment fall, and the presence or absence of concomitant liver enzyme abnormalities or coagulopathy. • Patient education regarding decreased activity and home/childcare assistance • Fetal assessment

Weekly assessment of: i. Deepest pocket >2 cm on ultrasound. • CBC, including platelets ii. Non-stress test without decelerations at • Uric acid (an elevated uric acid helps with the gestational ages remote from term. diagnosis of gestational hypertension) iii. end diastolic flow present on umbilical artery • Liver enzymes Doppler; at gestational ages <34 weeks, absent end diastolic flow does not necessarily Once hypertension and proteinuria have evolved, mandate delivery, but certainly does it is likely that a woman will be delivered for either mandate very close surveillance. Reversed maternal or fetal indications within two weeks. end diastolic flow on umbilical artery Doppler is an indication for delivery.

7. indicATIONS TO CONSIDER The most important factor in determining conservative HOSPITALIZATION management is gestational age. The presence • sBP > 140 mmHg and /or dBP > 90 mmHg of gestational hypertension with proteinuria at gestational age > 34 weeks may signify need for • Repeated proteinuria 1+ or greater on dipstick delivery, depending upon: or protein:creatinine ratio >30 mg protein per • Progression of the disease mmol creatinine • Assessment of the fetus • Hyperuricaemia (uric acid >350 mM) • status of the cervix • Platelet count <100 x 109/L

Obstetric Guideline 11 – Hypertension in Pregnancy  If the gestational age is <34 weeks, management must with one or more adverse conditions’) is defined as balance maternal risks against fetal benefits. Patient the occurrence of one/more of the following elements delivery may be delayed if: (outlined in sections 8.1.1 - 8.1.5). 8 • Blood pressure is controlled (i.e., sBP 8.1.1 Adverse conditions <160 mmHg and dBP <110 mmHg) Maternal symptoms: • severe nausea and vomiting • Fetal assessment remains within tolerable limits (see above) • frontal headache

• Platelet count remains >50 - 100 x 109/L, • visual disturbance depending on practitioner expertise, training and comfort • persistent epigastric or right upper quadrant pain The evidence supports conservative management of patients with adverse features between gestational • chest pain ages of 24 to 32 weeks in tertiary care centres in a modified intensive care unit with physicians very • shortness of breath 17 familiar with disease process. Maternal signs: Studies suggest that conservative management of • diastolic blood pressure of or over patients at gestational ages < 24 weeks is associated 110 mmHg (dBP >110 mmHg) with serious maternal complications and pregnancy termination should be considered. Under these • oliguria (<500 ml/d) circumstances, the patient may be eligible for • pulmonary oedema experimental therapy. • suspected abruptio placentae The BC Women’s Maternal-Fetal Medicine Team (604-875-2161) is available to give advice as needed. Maternal labs: • platelets <100 x 109/L 7.2 CONSERVATIVE MANAGEMENT • elevated liver enzymes (AST and/or ALT) • Bed rest • plasma albumin <18 g/L • Initial assessment and ongoing surveillance (as per Physician Orders, Appendix A) • heavy proteinuria (>3 g/d) • Fetal assessment including non-stress tests and / Fetal Assessment or ultrasound surveillance (full • intrauterine growth restriction or AFI/umbilical artery Doppler) • oligohydramnios • Daily assessment by the physician with close attention to: • absent or reversed end diastolic flow on umbilical artery Doppler • Weight gain 8.1.2 Severe systolic hypertension • Blood pressure variation over the previous 24 hours • sBP >160 mmHg (based on 3 blood pressure readings in a 15 minute period) • Proteinuria levels 8.1.3 Eclampsia • Fetal movement In clinical practice there are no reliable clinical markers to predict eclampsia (seizures). The • General symptoms following are thought to predict the onset of • Use steroids if < 34 weeks eclampsia. However, even when these symptoms are present, in most instances eclampsia does not develop: 8. SEVERE PRE-ECLAMPSIA • severe headaches (especially occipital 8.1 DEFINITIONS headaches) Severe pre-eclampsia (generally synonymous with • Brisk reflexes >3+ (3+ is hyperactive ‘gestational hypertension with/without proteinuria without clonus, 4+ is hyperactive with

 British Columbia Reproductive Care Program unsustained clonus, 5+ is hyperactive with • An intravenous cannula should always be sustained clonus) inserted. Intravenous fluid should be by controlled volumetric pump. Fluid administration • Visual disturbances should be judicious. 8.1.4 HELLP syndrome (partial/complete) 9.3 BASIC INVESTIGATIONS 8.1.5 Other signs of CNS disturbance (from Baseline investigations should follow those on Yorkshire guidelines) the Physician Orders for Gestational Hypertension • signs of clonus (>3 beats) (Appendix A). The orders listed are the minimum required, and may need to be repeated at more • Papilloedema frequent intervals in response to changing symptoms or signs. As such, orders may be repeated at the 9. MANAGEMENT OF SEVERE discretion of the clinician. Although this list is longer PRE-ECLAMPSIA than standard for most units, the incremental increase in cost is small. 9.1 FOR PHARMACOLOGICAL MANAGEMENT OF SEVERE HYPERTENSION, 9.4 MATERNAL ASSESSMENT/MONITORING SEE SECTION 10.2 • Blood pressure and pulse should be measured FOR PROPHYLAXIS AND TREATMENT OF every 15 minutes for a minimum of 4 hours until ECLAMPSIA, SEE SECTION 11 stabilized and then half hourly (footnote1) 9.2 GENERAL MEASURES (i.e., q15 min for >4h, then q30 min). The woman should be assessed and managed in a • At least initially, an indwelling catheter should quiet, well-lit room in a high dependency care type be inserted and urine output measured hourly situation. whenever intravenous fluids are given. All urine • Ideally there should be one-on-one nursing should be tested for proteinuria. Urine out- care; at least initially, when the stability of the puts as low as 10 ml/hour should be considered condition is being assessed. adequate in the absence of pre-existing renal disease. The UK Confidential Enquiries into • After initial assessment, transfer should be Maternal Deaths have found that excess considered for maternal or perinatal reasons maternal mortality is associated with ag- depending on the capacity of the local facility. gressive fluid use and not with transient renal compromise.18 • expectant management requires obsessive surveillance to mitigate maternal risks and is a • Fluid administration should be judicious and “package”. fluid balance should be monitored very carefully. Detailed input and output recordings should • Critical care flow charts should be commenced be charted (i.e., q1h). Careful fluid balance to record all physiological monitoring and is aimed at avoiding fluid overload. Total IV investigation results. All flow charts should input should be limited to 80 ml/hour be for a continuous 24 hour period of high (approximately 1 ml/kg/hr, using current dependency care. A new flow chart should weight). If oxytocin is used, it should be at high not be started until the previous one has a full concentration (20 U/500 ml N/S or Ringers) and 12 hour assessment. All treatments should be the volume of fluid included in the total input. recorded. Oliguria at this point should not precipitate any • Consider involving a consultant obstetrician specific intervention except to lower thresholds (even if only by telephone) and, if possible, for considering early delivery. As these women either a consultant anesthesiologist /GP are at high risk of Caesarean section, oral fluids anesthesiologist or consultant internist should also be limited. depending on local practice. Consultants should • Oxygen saturation should be measured be involved at an early stage in management. continuously and charted with blood pressure. • When oral antihypertensive treatment is If saturation falls below 95% then medical review possible, it should be regarded as the route of is essential. choice. 1. Initially check BP manually and compare with automated readings, as there can be a difference between the two. Then when using an automated machine take the difference into account – remember you are observing for trends.

Obstetric Guideline 11 – Hypertension in Pregnancy  • Respiratory rate should be measured q1h (count catheter removal. If bleeding occurs during for a full minute). insertion of neuraxial anaesthesia initiation of LMWH therapy should be delayed 24 hours.19,20 • Temperature should be measured q4h.

• When present, CVP should be measured 10. PHARMACOLOGICAL TREATMENT continuously and charted with the blood OF HYPERTENSIVE DISORDERS IN pressure. PREGNANCY 21-23 9.5 FETAL ASSESSMENT It is clinically important to recognize that while acute • Non-stress test (cardiotocograph) (prior to hypertensive management to prevent maternal administration of MgSO , if possible). cerebral vascular accident is useful, rapid change 4 in maternal perfusion pressure can cause profound • Unless the situation mandates immediate alterations in uteroplacental perfusion and oxygen delivery, an initial ultrasound for growth, delivery that can precipitate non-reassuring FHR amniotic fluid assessment, and umbilical artery changes. All of these changes can be magnified in the

Doppler flow velocity waveform are advised. presence of MgSO4, which also has the potential to produce peripheral vasodilatation. 9.6 THROMBOPROPHYLAXIS Care must be taken to avoid rapid and profound • All women should have anti-embolic stockings changes in maternal blood pressure. Therefore, and/or heparin whilst they are immobile each of these antihypertensive medications must during the entire antenatal, intrapartum, be carefully titrated when considering acute and postpartum periods. Women with pre- management. eclampsia are at particularly increased risk for It must be noted that there is no evidence that thromboembolic disease as their condition antihypertensive agents alter fetal heart rate resolves.18 patterns.24 Therefore, should the fetal heart rate • Unfractionated heparin 5000 IU sc twice pattern deteriorate following the initiation of daily (bid) should be given until the woman antihypertensive medication, those changes should be is fully mobile. A prophylactic dose of low ascribed to deteriorating placental function, and not molecular weight heparin (LMWH) can be used to the medications themselves. postpartum.19,20 Control of blood pressure is essential to prevent maternal morbidity. Antihypertensive drug usage • Many clinicians do not see the use of should aim to decrease the dBP <110 mmHg. A unfractionated heparin as a contraindication significantly lower diastolic blood pressure may cause to the insertion of an epidural, providing there decreased placental perfusion, and fetal compromise. is no evidence of a coagulopathy. Ideally the After severe hypertension has been addressed, there epidural would be inserted 1 hour prior to the are insufficient data to determine the blood pressure next dose of unfractionated heparin, as there is associated with optimal maternal and perinatal a subset of patient who become therapeutically outcomes. ‘Less tight’ control (i.e., dBP 90-109 mmHg) anticoagulated during sc heparin therapy. As is associated with more transient hypertension. unfractionated heparin has its peak effect ‘Tight’ control or normalizing maternal blood pressure between 2 and 6 hrs following its administration (i.e., dBP <90 mmHg) may adversely effect fetal it probably is wise to avoid that time period growth.13,25 for insertion of an epidural unless the APTT is normal.19,20 Aim to reduce sBP <160 mmHg and dBP <110 mmHg, slowly and carefully. • Low molecular weight heparin is being used more widely in obstetric patients. Monitoring 10.1 INITIATION OF ANTIHYPERTENSIVE DRUG of the anti-Xa level is not recommended as TREATMENT 21-23 it is not predictive of the risk of bleeding. Regional anaesthesia should not be done A. Immediately (in the absence of within 12 hours of administration of LMWH for pre-pregnancy renal disease or thromboprophylaxis. Women receiving LMWH pregestational diabetes) for therapeutic anticoagulation should not • sBP > 160 mmHg or dBP > 110 mmHg receive regional anaesthesia for 24 hours after the last dose to ensure normal hemostasis. An • At sBP 140-159 mmHg and/or dBP 85-109 epidural catheter should be removed 10-12 hours mmHg, the initiation of antihypertensive after the last dose of LMWH. Subsequent LMWH medication will be based on practitioner dosing should occur a minimum of 2 hours after preference, training, and experience

10 British Columbia Reproductive Care Program B. In the presence of pre-pregnancy renal A.2 Labetalol disease or pregestational diabetes If the woman can tolerate oral therapy, dos- • sBP > 140 mmHg or dBP > 90 mmHg ing can be done immediately before venous access and so can achieve as quick a result 10.2 ACUTE MANAGEMENT OF SEVERE as an initial intravenous dose. Initially, 200 HYPERTENSION mg can be given orally. This should lead to As a guide, stabilization of blood pressure is a reduction in blood pressure in 30 - 60 min, to reduce diastolic blood pressure (dBP) by and peak at 2 - 3 hr. A second oral dose can 10 mmHg in the first instance and to maintain be given if needed. the blood pressure at or below that level. If there is no initial response to oral therapy A. First choice agents: by 30 minutes, or if it cannot be tolerated, A.1 Nifedipine (capsules or PA tablets) control should be by a repeated bolus of la- Nifedipine is the first choice agent as many betalol or by a labetalol infusion. Labetalol women who develop severe pregnancy is supplied in 100 mg/20 ml vial, or 5 mg/ml. hypertension are already on high/maximal doses of labetalol, so will be somewhat Give a bolus infusion of 20 mg (4 ml of insensitive to further ‘stat’ dosing with labetalol, 5 mg/ml) over at least 2 minutes. labetalol. Also, nifedipine may more This should have an onset of effect by 5 effectively control severely increased BP minutes and should be repeated if dBP has than does and labetalol.13,14 not been reduced within 30 minutes. This However, nifedipine capsules should can be repeated q 30 min to a maximum not be used in women with known dose of 200 mg (40 ml of labetalol, atherosclerotic cardiovascular disease 5 mg/ml). If labetalol is given at a rate or at increased risk for atherosclerotic < 10 mg/min, continuous ECG monitoring is cardiovascular disease (e.g., insulin- not required. dependent diabetes >15y duration, Following this, a labetalol infusion should maternal age >45y). be commenced: labetalol 5 mg/ml at a rate This can be given as either a 5 mg capsule of 20 mg/hr (4 ml/hr of labetalol, 5 mg/ml) to swallow (in the first instance) or as a via a volumetric pump. The infusion rate 10 mg oral tablet (‘PA’) (not a slow release should be doubled every half hour to a tablet, ‘XL’). maximum of 160 mg/hr (32 ml/hr) until dBP has been reduced by 10 mmHg and main- Blood pressure should be measured every tained at or below that level. 10 minutes in the first half hour after treat- ment, as there can be a very marked drop B. Alternative: in pressure when severe pre-eclampsia is Hydralazine treated. The dose should be repeated if a Given the relationship between satisfactory blood pressure response has uncontrolled severe maternal hypertension not occurred by 30 minutes (capsule) or 45 and , the randomized minutes (PA tablet). If two 5 mg capsules controlled trial evidence of antihypertensive are ineffective, 10 mg capsules may be ad- medications for use in severe pregnancy ministered. hypertension were reviewed.14 Of 21 trials (893 women), eight compared hydralazine If nifedipine (capsules or PA) controls with nifedipine and five compared blood pressure, then it may be changed hydralazine with labetalol. Hydralazine postnatally to a slow release preparation was associated with a trend towards (Adalat XL), which lasts 12-24 hours. less persistent severe hypertension than There has been some concern over inter- labetalol (relative risk (RR) 0.29 [95% action between magnesium sulphate and confidence interval (CI) 0.08, 1.04]; two nifedipine; however, the risk is <1%.26 trials), but more severe hypertension than nifedipine or isradipine (RR 1.41 [0.95, After two ‘stat’ doses of nifedipine, regular 2.09]; four trials); there was significant antihypertensive agents (e.g., labetalol, heterogeneity in outcome between trials nifedipine XL, alpha-methyldopa) should and differences in methodological quality. either be instituted or increased in dose.

Obstetric Guideline 11 – Hypertension in Pregnancy 11 Hydralazine was associated with more B.2 Labetalol (Trandate ®) maternal hypotension (RR 3.29 [1.50, 7.23]; Dosage: Recommended initial dose 13 trials); more Caesarean sections (RR 1.30 100 mg p.o. twice daily. The (1.08 to 1.59); 14 trials); more placental dose should be adjusted semi- abruption (RR 4.17 [1.19, 14.28]; five trials); weekly or weekly according to more maternal oliguria (RR 4.00 [1.22, 12.50]; the response. Maximal daily three trials); more adverse effects on fetal dose is 1200 mg (total). heart rate (RR 2.04 [1.32, 3.16]; 12 trials); and more low Apgar scores at one minute (RR C. Alternatives: 2.70 [1.27, 5.88]; three trials). For all but Apgar Nifedipine (Adalat PA®) scores, analysis by risk difference showed Dosage: Adalat PA: Initiate at 10 mg p.o. heterogeneity between trials. Hydralazine was twice daily. Usual maintenance associated with more maternal side effects dose is 10 - 20 mg p.o., b.i.d. (RR 1.50 [1.16, 1.94]; 12 trials) and with less neonatal bradycardia than labetalol (risk Adalat XL: Initiate at 30 mg daily. difference -0.24 [-0.42, -0.06]; three trials). Usual maintenance dose is 30-60 mg given once daily or in two The results of this meta-analysis are doses (e.g., 30 mg b.i.d.). not robust enough to guide clinical practice, but they do not support use of Maximal daily dose of nifedipine is hydralazine as first line for treatment 90 mg (total). of severe hypertension in pregnancy.14 Adequately powered clinical trials are needed, D. Special indications (renal or cardiac with a comparison of labetalol and nifedipine diseases) showing the most promise. • Diuretics

10.3 RECOMMENDED TREATMENT OF NON-SEVERE E. Drugs to Avoid HYPERTENSION IN PREGNANCY13,21-23,27 • Angiotensin-converting enzyme inhibitors Due to increased rates of hepatic metabolism and • Angiotensin II receptor antagonists renal clearance in pregnancy, and increased vascular reactivity associated with pre-eclampsia and other • Atenolol forms of gestational hypertension, maintenance doses may need to be split. For example, the CPS Motherisk is available to give safety information states that labetalol is a b.i.d. medication; in women with pre-eclampsia it may need to be given up to to patients, families and caregivers about four times per day to achieve a ‘smooth ride’ in antihypertensive use in pregnancy. blood pressure. www.motherisk.org; (416) 813-6780 A. Treatment Goal dBP 80 - 110 mmHg (depending on practitioner preference) 11. ANTICONVULSANT THERAPY: MAGNESIUM SULPHATE (MgSO4) B. First choice agents: 11.1 PROPHYLAXIS B.1 Methyldopa (Aldomet ®) Following the MAGPIE study, women considered Dosage: 250 mg p.o. 2 or 3 times a day in to have severe pre-eclampsia (see Section 8) should

the first 48 hours (some experts be started on magnesium sulphate (MgSO4). The administer a loading dose of corollary to that is that if a woman is deemed to need 750-1000 mg p.o.). The daily magnesium sulphate, then she needs care according dosage may then be increased or to these guidelines.29 decreased, preferably at intervals of not less than 2 days, until the 11.2 MANAGEMENT OF ECLAMPSIA desired response is achieved. • Call appropriate personnel, including the Maximum daily dose is 2000 mg anesthesiologist (if available) (total). Support for methyldopa results from the 7 year follow-up • Commence MgSO4 according to the protocol (see neurodevelopmental data from a page 13): MgSO is the drug of choice for both 28 4 single randomized controlled trial. seizure termination and for the prevention of seizure recurrence.30

12 British Columbia Reproductive Care Program ml ⅔/⅓ (1,000 ml total). Infuse at 1 g/hr (50 • Briefly, give a stat bolus dose MgSO4 4g IV over ml/hr) using a volumetric infusion pump. The 20 - 30 minutes, followed by MgSO4 1g/hr IV. maximum storage time for prepared MgSO4 • Consider creating an ‘eclampsia box’ for all is 24 hours. obstetric areas. Each box should contain: C. Clinical assessment • A protocol outlining the administration of The medical staff are responsible for the magnesium sulphate. assessment of the patient and the decision • A detailed description of the treatment to continue the infusion. The decision for regimen. continuing the infusion should be made q4h.

• Sufficient magnesium sulphate for the The following observations should be loading dose, for 24 hours’ maintenance performed: therapy, and for treatment of one recurrent i) continuous pulse oximetry seizure. ii) hourly urine output • 1g calcium gluconate in case of magnesium toxicity. iii) hourly respiratory rate

• Requirements to initiate intravenous iv) deep tendon reflexes q4h therapy (needles, syringes, 500 mL normal saline, tubing, and an intravenous cannula v) level of consciousness q4h 12- or 14-G). (Glasgow Coma Score)

• Three sets of tubes for all bloodwork The infusion should only continue if, after each 4 required during the peri-ictal period hour period: (baseline, 4h post-seizure, and 8h post-seizure) as well as three arterial blood i) the biceps reflex is present gas syringes. ii) the respiratory rate is > 12/min. • Once stabilized, the woman should be delivered iii) the urine output is greater than 100 ml in • Oximetry should be instituted if not already in the previous 4 hours. place THERE IS NO NEED TO MEASURE MAGNESIUM LEVELS WITH THE ABOVE PROTOCOL. 11.3 MANAGEMENT OF RECURRENT SEIZURES Give a stat bolus dose of MgSO 2g IV over 20 - 30 4 D. The antidote is 1g (10 ml) of 10% calcium minutes, and increase the MgSO infusion rate from 4 gluconate given slowly IV (approximately 1 g/hr to 1.5 g/hr IV. Continue observations and 1.5 ml/min or 1g/7 min) consider the need for ventilation. 97% of magnesium is excreted in the urine; therefore the presence of oliguria can lead 11.4 MAGNESIUM SULPHATE PROTOCOL: to toxic levels. If the above criteria (biceps USING MgSO 50% 0.5 G/ML OR 5 G/10 ML 4 reflexes, respiratory rate, and urinary output) AMPOULES are not met, then administration of MgSO4 MgSO4 is given as a loading dose followed by a should be discontinued. If magnesium is continuous infusion for 24 hours or until 24 hours not being excreted then the serum levels after delivery – whichever is the later. should not fall and no other anticonvulsant is needed. Magnesium should be re-introduced A. Loading dose: - MgSO4 4g IV over 20 - 30 minutes if urine output improves. Use a 50 ml syringe and draw up 4 g (8 ml) E. Side effects MgSO and then add 22 ml ⅔/⅓ to make a 4 Motor paralysis, absent tendon reflexes, total volume of 30 ml. Administer over 30 respiratory depression and cardiac minutes at an infusion rate of 60 ml/hour, arrhythmia (increased conduction time) can using a volumetric infusion pump. all occur, but will be minimized if MgSO4 B. Maintenance dose: MgSO 1g/hr IV is administered slowly and the patient is 4 observed as above. Draw up 20 g (40 ml) MgSO4 and add to 960

Obstetric Guideline 11 – Hypertension in Pregnancy 13 12. DELIVERY GUIDELINES to elective operative vaginal delivery. An epidural will normally be used. The third stage should be “Planned delivery on the best day in the best managed with either OXYTOCIN 5 units I.V., or way” 10 units I.M. Ergometrine should not be given • The delivery should be well planned, done on in any form. the best day, performed in the best place, by the best route, and with the best support team. 12.3 ANAESTHESIA AND FLUIDS Timing affects the outcome for both mother and • Consider involving the anesthesiologist early baby. If the mother is unstable, then delivery is in the care of the pre-eclamptic patient. The inappropriate and increases risk. Once stabilized anesthesiologist may be required to provide with antihypertensive drugs and MgSO4, a analgesia/anaesthesia for labour and delivery, decision regarding delivery should be made. Caesarean section anaesthesia, insertion of lines for invasive monitoring (arterial line, CVP) and • In the absence of convulsions, prolonging management of care. the pregnancy may be possible to improve the outcome of a premature fetus but only • Fluid management should be judicious with two if the mother remains stable. This ‘expectant purposes: avoidance of pulmonary oedema and management’ is associated with markedly avoidance of hypotension. There is an excess of improved outcomes for the fetus, but does incur maternal mortality associated with aggressive 13,31 some, as yet unquantified, maternal risk. hydration in women with pre-eclampsia.18 A fluid bolus is not necessary routinely prior to • Continued close monitoring of mother and fetus regional anaesthesia for labour unless there is is needed. It seems ideal to achieve delivery, a compromised fetus or the woman is obviously particularly of premature infants, during normal dehydrated. One may consider a small bolus working hours (i.e., 8 am to 4 pm). of colloid (pentastarch) to avoid hypotension • even a few hours may be helpful if it allows during regional anesthesia for Caesarean 32 the neonatal unit to be more organized or to delivery. Women with pre-eclampsia are transfer a mother to a place where an ICU bed is not at increased risk for post-regional 33 available, assuming the mother is stable before hypotension. There is no evidence that a transfer (see stabilization section, p15). bolus of crystalloid as a preload prevents hypotension.34 12.1 STEROIDS • epidural, combined spinal epidural and spinal • If the pregnancy can be prolonged in excess of 4 anaesthesia are not specifically contraindicated in hours, steroids help mature the fetal lungs and women with severe pre-eclampsia and, generally, reduce neonatal mortality. Since the benefits are recommended unless there is evidence of to the fetus peak between 48 hours and 6 days, coagulopathy, local or systemic sepsis, patient then, after 48 hours, further consideration refusal or other contraindications.35,36 Studies should be given to delivery, as further delay may have shown that the incidence of profound not be advantageous to the baby or mother. In hypotension in women with severe pre- all situations a planned elective delivery suiting eclampsia is similar when either spinal or epidural all professionals is appropriate. anaesthesia is used.37-39 12.2 MODE OF DELIVERY • Hypotension during regional anaesthesia can be • The mode of delivery should be discussed with treated with both ephedrine and phenylephrine, the Consultant Obstetrician. Delivery is not titrated in small bolus doses or as an infusion.34,38 necessarily by Caesarean section, but if gestation is less than 32 weeks it may be preferable, as • General anaesthesia may be required in the the practice of expectant management will setting of acute fetal compromise or when there dictate that delivery is occurring in response is a contraindication to regional anaesthesia. to deteriorating maternal and/or fetal status. Considerations include a possible difficult airway After 34 weeks, vaginal delivery should be that may require awake intubation as well as considered in a cephalic presentation. Vaginal the need to ablate the hypertensive response prostaglandins will increase the chance of to intubation.40 Labetalol 10 mg IV q5 – 10min success. Antihypertensive treatment should be is effective; alternatives (to be used instead of continued throughout assessment, surveillance, or with labetalol) include: opioids (fentanyl 3-5 labour, delivery, and the immediate puerperium. mcg/kg, remifentanil 0.5-1 mcg/kg), lidocaine 1.5 mg/kg, and nitroglycerin 100-300 mcg. A • If vaginal delivery is planned, then the second full induction dose of thiopental (5-7 mg/kg) or stage should be short with consideration given propofol (2 mg/kg) and full intubating dose of a

14 British Columbia Reproductive Care Program muscle relaxant should also be used.40 Esmolol blocks fail to achieve 40 ml, then further action is is best avoided due to fetal concerns.40 Prior to appropriate, as follows: extubation, consider using labetalol (or a listed alternative, with the exception of an opioid). A. If total input is more than 750 ml in excess of Neonatology should be informed that the output in the last 24 hours (or since starting neonate may be depressed at birth. the regime) then 20 mg of i.v. furosemide should be given. Pentaspan should then be The BC Women’s Obstetric Anaesthesia Team given as above if a diuresis occurs. is available to give advice as needed. Telephone: 604-875-2161 OR B. If total input is less than 750 ml in excess of 12.4 INDICATIONS FOR CENTRAL VENOUS output in the last 24 hours (or since starting PRESSURE (CVP) MONITORING the regime) then an infusion of 250 ml of pentaspan over 20 minutes should be given. A CVP may be indicated: The urine output should then be watched • at Caesarean section, particularly if blood loss is until the end of the next 4-hour block. If excessive. the urine output is still low then 20 mg of IV furosemide should be given. If a diuresis • regardless of delivery mode, if blood loss is in excess of 200 ml occurs in the next hour excessive or delivery is complicated by other the fluid should be replaced with 250 ml of factors such as abruptio placentae. pentaspan in addition to baseline fluids. Remember that a CVP may not reflect the true central If the urine output fails to respond to furosemide in haemodynamics (i.e. pulmonary capillary wedge either situation, then a discussion with a member of pressure, PCWP) in women with pre-eclampsia. the BC Women’s Maternal-Fetal Medicine Team (604-875-2161) would be appropriate. 13. POSTPARTUM 13.2 ANALGESIA High risk women should not be placed onto Women with pre-eclampsia have vulnerable renal low risk discharge pathways. Women should function. Therefore, non-steroidal anti-inflammatory only be discharged when there is a clear trend agents should be avoided in women whose urine towards improvement in clinical and laboratory output is <40 ml/hr. assessments, when there is an ability to provide adequate outpatient surveillance, and when follow-up can be arranged within a week for 14. SPECIAL PROBLEMS (ANTENATAL AND clinical and blood pressure assessment. It is POSTNATAL) reasonable to discharge women with BP 14.1 OLIGURIA < 160/100 mmHg for at least 24 hours. If oliguria perists (requiring fluid challenge or The community health nurse should visit on the furosemide), then the electrolytes and creatinine need st nd 1 or 2 day after discharge, and the woman to be carefully assessed and checked q6h. If there is should visit her physician within 1 week of concern over rising creatinine and/or potassium, the discharge. case should be discussed with a member of the BC Women’s Maternal-Fetal Medicine Team 13.1 FLUID MANAGEMENT (604-875-2161). • Following delivery the woman should be fluid restricted in order to wait for the natural diuresis 14.2 DROPPING O2 SATURATIONS which usually occurs around 36-48 hours post If the woman has dropping oxygen saturation, it is delivery. most likely due to fluid overload. • Total intravenous fluid should be given at • Input and output should be assessed together 80 ml/hr. This total includes normal saline, or with either clinical or invasive assessment of equivalent, plus other infusions of drugs. After the fluid balance. Clinical assessment should delivery, oral fluids can be given in a relatively include maternal symptoms, cardiovascular and unrestricted way. respiratory status, and a chest X-ray. However, the most appropriate treatment is likely to be • Urine output should be recorded hourly and furosemide (10 mg) and oxygen. each 4-hour block should be totalled and recorded on the chart. Each 4-hour block should • If there is no diuresis and the oxygen saturation total in excess of 40 ml. If two consecutive does not rise, then referral to a nephrologist should be considered.

Obstetric Guideline 11 – Hypertension in Pregnancy 15 14.3 BLOOD PRODUCTS • Gestational hypertension with significant Cases requiring large volumes of colloid such as fresh proteinuria (includes HELLP Syndrome) frozen plasma, blood, or platelets can lead to fluid • Pulmonary oedema overload. Significant haemorrhage or HELLP needs to be managed by an experienced specialist practitioner. • Acute renal failure The BC Women’s Maternal-Fetal Medicine Team (604-875-2161) is available to give advice as needed. • Breastfeeding at discharge • Maternal mortality 15. STABILIZATION BEFORE TRANSFER When the woman is ill and requires delivery, transfer 16.2 NEWBORN for fetal reasons is often considered. However, if the • Birthweight <10th and 3rd percentiles woman requires transfer for delivery, it is even more important that her condition is stabilized. Therefore, • Apgar < 3 at 5 minutes we recommend the following as a minimum requirement before transfer: • Umbilical artery pH < 7 • Blood pressure should be stabilized at an • IPPV > 5 minutes acceptable level according to the above protocol. Also, when the woman is ventilated it • NICU admission > 37 weeks is important to ensure ventilatory requirements are stable and oxygen saturations are being • Perinatal mortality rate maintained. • Neonatal mortality rate • All basic investigations should have been performed (see suggested Physician Orders) and the results clearly recorded in the accompanying REFERENCES notes or telephoned through as soon as available. 1. Magee LA, von Dadelszen P. Hypertension and pregnancy. Part I. Can J Diagn 1999; 16(June):75-80. • Fetal well being has been assessed (see 2. von Dadelszen P. The PIERS (Pre-eclampsia Integrated suggested Physician Orders) to be certain that Estimate of RiSk) model: predicting adverse maternal outcomes in pre-eclampsia [CIHR application; grant no: transfer is in the fetal interest before delivery. MOP 67069]. 2003. Steroids should be given if the woman is preterm 3. von Dadelszen P. Activation of maternal peripheral blood (<34+0 weeks). leukocytes in pre-eclampsia [ Oriel College, University of Oxford; 2000. • Appropriate personnel are available to transfer 4. von Dadelszen P, Magee LA, Lee SK, Stewart SD, Simone the woman. This will normally mean at least a C, Koren G et al. Activated protein C in normal human senior nurse, often with an anesthesiologist. pregnancy and pregnancies complicated by severe preeclampsia: a therapeutic opportunity? Crit Care Med 2002; 30(8):1883-1892. • Transfer has been discussed with appropriate 5. Report of the National High Blood Pressure Education consultant medical staff and nursing leadership Program Working Group on High Blood Pressure in and all the relevant people at the receiving unit Pregnancy. Am J Obstet Gynecol 2000; 183(1):S1-S22. (e.g., the neonatal unit and neonatal medical 6. Brown MA, Hague WM, Higgins J, Lowe S, McCowan L, staff, the obstetrician, the nurse in charge of Oats J et al. The detection, investigation and management delivery suite, intensive care, and the intensive of hypertension in pregnancy: full consensus statement. Aust NZ J Obstet Gynaecol 2000; 40:139-155. care anesthesiologist (where appropriate). 7. Brown MA, Lindheimer MD, de Swiet M, Van Assche A, Moutquin JM. The classification and diagnosis of the The BC Women’s Maternal-Fetal Medicine Team hypertensive disorders of pregnancy: statement from the (604-875-2161) is available to give advice as International Society for the Study of Hypertension in needed. Pregnancy (ISSHP). Hypertens Pregn 2001; 20:ix-xiv. 8. Helewa ME, Burrows RF, Smith J, Williams K, Brain P, Rabkin SW. Report of the Canadian Hypertension Society 16. OUTCOME INDICATORS Consensus Conference: 1. Definitions, evaluation and classification of hypertensive disorders in pregnancy. CMAJ 16.1 MATERNAL 1997; 157(6):715-725. • Gestational hypertension without significant 9. Caetano M, Ornstein MP, von Dadelszen P, Hannah ME, proteinuria (includes gestational hypertension, Logan A, Gruslin A et al. A survey of Canadian practitioners mild pre-eclampsia, transient hypertension of regarding the management of hypertension in pregnancy. Hypertens Pregn 2004; 23(in press). pregnancy)

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Obstetric Guideline 11 – Hypertension in Pregnancy 17 Appendix A

18 British Columbia Reproductive Care Program Obstetric Guideline 11 – Hypertension in Pregnancy 19 20 British Columbia Reproductive Care Program