Pre-Eclampsia

Anaesthesia for the pathologic 

pregnancy 

Dr. M. Coppens 

AVU 13 september 2008 

Hypertensive disorders in pregnancy 

Pregnancy induced 

hypertension 

6-8 % of all 

gestations 

Chronic hypertension 

(Elevated BP prior to 20 weeks) 

PIH 

(no proteinuria) 

Preeclampsia 

(proteinuria +/- 

Edema) 

Severe 

preeclampsia 

Eclampsia 

HELLP 

Syndrome 

Dr. Marc Coppens 

1

Pre-Eclampsia 

• Classic triad : 

Hypertension (>140/90) 

Proteinuria (>1+ or >300 mg/24h) 

Generalized edema (least reliable) 

• Hypertension and proteinuria must be present 

on two occasions > 6 hr apart 

• Rapid weight gain is supportive evidence 


Pre-eclampsia: pathophysiology 

• Immunological conflict between genetic make-up of 

mother and baby, triggered by fœtal cells and DNA in 

the maternal circulation (first pregnancy or older multipara with new 

partner) 

• Focus: placenta: trophoblastic invasion 

• Endothelial cell dysfunction > placental ischemia 

• Prostacyclin/tromboxane imbalance 

– Vasoconstriction ↑ 

– Platelet aggregation ↑ 

– Uterine activity ↑ 

– Uteroplacental blood flow ↓ 

• Syncitine: genetic basis 


2

Thrombocytopenia 

Endothelium 

Thrombocytes 


Severe Pre-eclampsia: 

diagnostic criteria 

Headaches 

Visual disturbances 

Pulmonary edema 

Hepatic Dysfunction 

RUQ or epigastric pain 

Oliguria 

Elevated creatinine 

Proteinuria of 5 g or more in 24 h 

Systolic BP > 160 mmHg 

Diastolic BP > 110 mmHg 

Thrombocytopenia or hemolysis 


3

Clinical course of pre-eclampsia 

Eye 

Arteriolar spasm amaurosis 

Retinal hemorrhage blindness 

Papilledema 

Transient scotoma 

Respiratory System 

Pulmonary edema 

ARDS 

Liver 

Subcapsular hemorrhage 

Hepatic rupture 

Hematopoietic system 

HELLP 

DIC 

CNS 

Headache 

Seizures – grand mal type (tonic-clonic) 

Intracranial hemorrhage - CVA 

Encephalopathy – cerebral oedema 

Pancreas 

Kidneys 

Uteroplacental circulation 

IUGR Large placental infarct 

Abruption 

Fetal compromise 

Fetal demise: mortality x 2 


Cardiovascular changes 

• Hypovolemia 

• Hemoconcentration 

• Increased blood 

viscosity 

• Vasospasm 

• Interstitial oedema 

Hydrostat pressure ↑ 

Vasc permeability ↑ 

Colloid osm pressure ↓ 

Blood volume expansion in normal 

pregnancy !! 

Focus on systolic blood pressure 

28 patients with stroke 

23 systolic P > 160 

3 diastolic P > 110 

Obstet & Gynecol 2005;246-54 


4

Pre-eclampsia: therapy 

• Vasodilation 

• Plasma volume expansion 

• Anti-convulsant therapy 

• Correct clotting abnormalities 

• Delivery of the foetus 


Magnesium sulfate 

• Loading dose: 4 to 6 grams in 100 ml, given 

IV over 15 to 20 minutes 

• Continuous infusion: 2 to 3 grams per hour 

• Monitor: 

– Mg levels 

– Reflexes: stop Mg if patellar reflexes are absent 

– Mental status 

– Respiratory status: stop Mg if RR is < 16 /min 

– Urine output: stop Mg if < 100ml/4 hr 


5

Magnesium Levels 

mg/dl 

Normal 1.3 to 2.6 

Therapeutic 4 to 8 

Loss of patellar reflexes 8 to 10 

Somnolence 10 to 12 

Respiratory depression 12 to 17 

Paralysis 15 to 17 

Cardiac arrest 30 to 35 

Antidote is calcium gluconate one gram IV over 3 minutes 

97% excreted in urine 


Magnesium 

• Effects on neuromuscular junction ! 

– Potentiation of the action of nondepolarizing 

muscle relaxants 

reduced dose requirement 

longer duration of action 

cave ‘priming dose’ 

– Succinylcholine and Mg ? 

fasciculations not seen !! 

Peripheral nerve stimulation 

Release AcChol ↓ 

Sensitivity ↓ 


6

Magnesium 

• Vasodilator activity 

– Direct and indirect effects 

– Sympathetic block 

• Direct smooth muscle relaxation 

in uterus 

– Inhibition of catecholamine release 

Control of hypertension at laryngoscopy and intubation 

Cave hypotension with regional anesthesia 

Cave postpartum hemorrhage 

Sense of warmth at the tongue with rapid bolus 


Management of imminent eclampsia or 

eclampsia 

• Airway, Breahting, Circulation 

• Left lateral position, maintain airway 

• Administer oxygen, check for aspiration or 

pulmonary oedema 

• MgSO 4 = therapy of choice 

• Vast majority of initial seizures are self-limiting 

• Diazepam, phenytoin not as first-line treatment 


7

Regional anesthesia for severe pre-eclampsia: 

possible disadvantages 

• Reduced plasma volume: risk for hypotension ↑ 

• Reduced uteroplacental perfusion > hypotension 

• IV fluid administration: risk for iatrogenic pulmonary 

oedema 

• More sensitive to pressor agents ( efedrine ) 

• Incrementally dosing the epidural catheter 

But, … 


Regional anesthesia for severe pre-eclampsia: 

CSE 

• Magnitude of maternal blood pressure declines 

similar after spinal and epidural anesthesia in severe 

preeclampsia Anesthesiology 1999;90:1276 

• Patients with severe preeclampsia experience less 

hypotension during spinal anesthesia for CS then 

healthy parturients Anest Analg 2003;97:867-72 

• Combined spinal epidural Reg Anesth Pain Med 2001;26:46 

– Low dose spinal ± epidural bolus 

– Rapid onset of spinal anesthesia 

– Especially beneficial in urgent C-section 


8

Anti-hypertensive medication 

Vasodilation 

• Protect cerebral 

circulation 

Fœtal distress 

Pre-renal oliguria 

• Compromised perfusion 

Contracted intravascular 

volume 

Preload ↓ 

Venous return ↓ 

CO ↓ 


Anti-hypertensive medications 

• Dihydralazine - Nepresol ® 

– Direct acting vasodilator > arteriolar 

– Loadingdose: 5 mg IV ( repeat/20 min, max 20 mg) 

– Maintenance dose: 1 mg/h Iv 

1 A or 25 mg in 50 ml NaCl 0.9 % - 2 ml/hr 

incompatible with gluc 5 % Side-effects: 

Tachycardia 

Hypotension 

Headache 

Long onset time !! 

Vomiting 

Epigastric pain 


9

Hydralazine vs labetalol 

• Hydralazine was associated with 

– More maternal hypotension ( OR 3,29 ) 

– More caesarean sections ( OR 1,3 ) 

– More placental abruption ( OR 4,17 ) 

– More maternal oliguria ( OR 4,0 ) 

– More adverse effects on FHR ( OR 2,0 ) 

– More maternal adverse effects 

– Less neonatal bradycardia 

BMJ 2003 


• Labetolol - Trandate ® 

– α en β blocking properties 

– Initial oral dose of 100 mg (30 min) 

– IV bolus: 25-50 mg IV – max 200 mg – 

– infusion 20 mg/hr (max 160 mg/hr) 

– Short-acting 

– Cave bronchoconstriction (asthma) 

– Growth restriction > in first trimester 


10

Anti-hypertensive medications 

• Nifedipine-Adalat ® 

– hypertensive crisis 

– oral administration: 10 mg 

– Long-acting ! 

– Drug interaction with Magnesium ( 100.000 

• Platelet count indicates severity of pre-eclampsia 

• Trends are important ! 

– Admission platelet count 

– Repeat / 4 – 6 hrs 

• PC continue to fall postoperatively Check PC prior to 

– Nadir at 29 ± 15 hrs 

removal of epidural 

– Average time to PC > 100.000 = 60 hrs catheter 


11

Pre-eclampsia 


Corticosteroids for HELLP 

• Retrospective obs. studies: improvement in 

lab values: Plts ↑, ALT ↓, AST ↓ 

• Prospective randomised trials: improved 

outcome,lab values, BP, Urine output 

• More regional anesthesia: mean fall plts 

↓,mean platelets at delivery ↑, No with ↑ plts 


12

Systemic analgesia 

Pethidine: 

prolonged half-life in the mother: 2.5-3 h 

prolonged half-life in the neonate: 18-23 h 

accumulation of active metabolites: 60 h 

subtle neonatal depression for days ! 


Remifentanil in obstetrics 

• Low dose: no efficacy 

• High dose: adverse effects 

– Maternal desaturation/sedation 

– FHR abnormalities 

• PCIA remifentanil 

– Volikas: 0.5 µ/kg bolus remi, lock out 5 min 

– Vs pethidine/meperidine/dolantine 

– Pain scores significantly less for remi 

– More respiratory depression for pethidine IV 


13

Remifentanil vs pethidine 

bolus 

Lock-out 

infusion 

Blair 

40µ 

2 min 

Volikas 

0.5µ/kg 

2 min 

Roelant 

25µ 

5 min 

0.05 µ/kg 

Volmanen 

0.4µ/kg 

1 min 

Significant reduction in pain scores 

Desaturation possible ( Oxygen, monitoring, training, 

enough staff, sedation scores ) 

High maternal satisfaction 

Less neonatal adverse events 


Sectio preterm 


14

Sectio preterm 

Difference in local anaesthetic requirements: 

• à term ( 38-42 w ) vs preterm ( 28-35 w ) 

• CSE met hyperbare marcaine: 2.25 ml (11.25 

mgr) 

• Preterm: onvoldoende bij 21/25 parturienten 

• Onset bij preterme groep trager 

• À term: voldoende hoog block bij alle ptn T4 

• Minder hypotensie 

Compression of vena cava 

Increased sensitivity to local anesthetic 


Remifentanil 

• µ opioid receptor antagonist 

• High potency !!! 

• Low onset time 

• Rapidly hydrolyzed 

• Small volume of distibution 

• High clearance 

• Does not rely on pseudocholinesterase 


15

Remifentanil 

Case reports 

– Hemodynamic stability with CV disease 

– Facilitation of epid catheter placement 

– C section in preeclampsia and thrombocytopenia 

– PCA for labour 

– Acoustic neuroma & C section 

–TCI 

‘ the paediatricians commented on the lack of 

respiratory depression in view of the opioid given to 

the mother ‘ 


Placental transfer 

Anesthesiology, 1998 

• Elective C section with epidural anesthesia 

and concomitant IV infusion of remifentanil ( 

0,1 µg/kg/min ) - 16 patients 

• Increase, decrease or bolus according clinical 

judgment 

• Blood samples: ABG, remifentanil, 

remifentanil acid 

– maternal arterial 

– umbilical venous 

– umbilical arterial 


16


Maternal 

• blood pressure 

• heart rate 

• O 2 Sat 

• Pain score 

• Sedation score 

Neonatal 

• Apgar 

• Nacs 



• UV:MA ratio suggests a significant placental 

transfer 

• UA:UV ratio suggests rapid metabolism and 

rapid redistribution 


17


• Mean clearance: 

93.1 ml/min 

kg 

• Non obstetric patients: 41.2 ml/min 

kg 

• Physiologic changes of pregnancy 

– Larger blood volume 

– Increased cardiac output 

– Increased renal perfusion 

– Altered volume of distribution 

– Lower plasma protein concentration 

– Increase in nonspecific esterase activity 



• No adverse neonatal effects ! 

• Slightly increased UV P CO2 values ~ maternal 

P CO2 


18



SURGERY & ANAESTHESIA 

in Pregnancy 

• 0.5% - 2% of gravidae undergo surgery 

• Pre-term labour and fetal loss are major risks 

• Pulmonary oedema is a major risk 

• Teratogenesis a minor risk 

• Regional is better than general 

• Consider delivery first if > 28-30 weeks 

• Safe Anaesthesia is based on sound 

understanding and application of pregnancy, 

physiology and pharmacology 

0.3 % amb non ob surgery 


19

Types of SURGERY in Pregnancy 

1. Surgery associated with Pregnancy: 

Cervical Cerclage 

Ovarian torsions, cysts, etc. 

Fetal surgery 

2. Surgery unrelated to Pregnancy: 

Severe Trauma 

Acute abdomen 

Neurosurgery (life-threatening) 

Cardiothoracic (decompensating) 


• Avoid maternal hypoxaemia, reduction in 

placental perfusion: intrauterine asphyxia 

• Maintenance of maternal pregnant 

physiology:avoid hypotension, hypohypercapnia 

• Consider direct and indirect toxic effects of 

anaesthetic drugs upon the feto-placental unit 


20

Respiratory: 

• ↑ VO 2 ; ↑ Minute Ventilation; ↓ pCO 2 ; ↓ FRC 

• Mucosal hyperaemia 

• ↑ risk of difficult intubation 

• ↑ risk of pulmonary aspiration 

Aspiration prophylaxis: 

Zantac 

Primperan 

Na-citrate 


Cardiovascular 

• ↑ CO; ↑ Blood Volume (100ml/kg); ↓ PCV 

• Aortocaval compression (> 20 weeks) 

• ↑ in baroreceptor responsiveness 

• ↓ vascular responsiveness 

• ↑ risk of thrombosis 


21

Avoiding hypotension 

• Prophylactic Phenylephrine Infusion for 

Preventing Hypotension During Spinal 

Anesthesia for Cesarean Delivery: 

100 µ/min 

no adverse effects on neonate 

• The full left lateral position reduces the 

incidence of early hypotension compared with 

the tilted supine position with tilt, and makes it 

easier to treat. 


Neurological: 

• ↓ MAC gaseous/volatile drugs: sensitivity 

• ↓ Dose requirements of LAs 

• ↑ Dose requirements others. e.g. SCh 

Gastrointestinal: 

• ↑ gastric volume 

Cave unconscious sedation ! 

• ↓ gastric pH 

• ↓ lower oesophageal sphincter tone 

Rapid sequence induction !! 


22

Anaesthesia techniques: 

MAINTAIN NORMOXIA, NORMOCARBIA 

Regional: ↓ fetal drug exposure (spinal, CSE) 

less 

blood loss, airway simplified, 

tocolysis more complicated, better 

analgesia, ↓ DVT risk 

General: 

Total control, simple tocolysis 

Sevoflurane produces dose-dependent depression of uterine muscle 

contractility. At concentrations of 3.5 MAC and above, uterine activity was 

virtually abolished. 


Anaesthesia & Gestation: 

Non-viable fetus: Follow general principles. 

Assess coagulopathy, uterine rupture 

1 st Trimester: Avoid surgery if possible. 

Assess fetal viability and status. 

Nausea, vomiting common. 

After 6-8 weeks, pregnancy physiology is 

well established. 


23


2 nd Trimester: ‘Best’ time for surgery. 

Uterine displacement beyond 18-20 weeks. 

Aspiration prophylaxis, intubate. 

Minimise uterine manipulation. 

Careful with ketamine, etc. 

Tocolysis usually required. 

Thromboprophylaxis advisable. 



3 rd Trimester: 

CONSIDER DELIVERY FIRST 

Uterine displacement. 

Aspiration prophylaxis, intubate. 

Minimise uterine manipulation. 

Care with ketamine. Avoid NSAIDs. 

Tocolytics often required. 

Thromboprophylaxis. 

Steroids (< 34 weeks). 


24

Inhalation 

• Chloroform: hepatic failure 

• Ether & cyclopropane: explosion 

• Halothane: headache, exhaustion, … 

• 1967: adverse reproductive effects 

• Halothane in rats: aberrant skeletal 

development after 12 h exposure 

• Fink: rats exposed to high concentrations of 

nitrous oxide: more skeletal abno 

Prolonged exposure to trace concentrations 

Single or repeated high dose exposure 


Inhalational anaesthetics 

• No mutagenic effects ( N 2 O, E,I,D,S ) 

• No carcinogenic effects 

• N 2 O is the only inhaled anaesthetic that has 

been convincingly shown to be directly 

teratogenic in experimental animals 

• Interference with DNA synthesis (methionine 

synthethase) 

• Consensus: any teratogenic effects caused 

by changes in physiology ! 


25

Inhalational anaesthetics 

• No data to suggest that waste anaesthetic 

gases are a danger to those women working 

in a scavenged environment who are 

contemplating pregnancy or who are already 

pregnant 

• Scavenging of waste anaesthetic gases 

should be performed in whatever location an 

inhaled anaestetic is used 


• NSAID’s: avoid in 3th trimester: premature 

closure of ductus 

• Aspirine/NSAID’s: gastroschisis, mild cardiac 

defects, orofacial defects 

• BZD: oral cleft 

• Paracetamol is safe 

• NMB drugs: high molecular weight, do not 

reach fetal circulation 


26

Fetal monitoring 

Fetal heart rate variability decreased ! 

Ideally + external tocography !! 


EFFECTIVE TOCOLYTIC DRUGS 

• General (Volatile) Anaesthetics 

• Oxytocin antagonists (ATOSIBAN) 

• Calcium antagonists (esp Mg ++ ) 

• Nitric Oxide donors (GTN) 

• Beta-2 Sympathomimetics 

• Prostaglandin inhibitors (< 30/40) 

• Combination therapies 

• (Local Anaesthetics) 

• (Ethanol) 


27

ACUTE TOCOLYSIS - PRACTICALITIES 

General Anaesthesia: 

• Titrate volatile agent to effect while monitoring 

mother, fetus, uterine tone and contractility. 

• 1.5 – 2.0 MAC usually required. ( isoflurane, 

sevoflurane) 

• MAINTAIN TOCOLYSIS POST-OP. 


ACUTE TOCOLYSIS - PRACTICALITIES 

Regional Anaesthesia: 

• Magnesium Sulfate (4 – 6G + infusion) 

• Terbutaline 250mcg bolus 

• GTN boluses 3 – 4 mcg / kg 

(Atosiban) 

• MAINTAIN TOCOLYSIS POST-OP 


28


SUMMARY 

• Pre-term labour is greatest concern, and tocolytics 

needed 

• Expert planning and team work needed 

• Anaesthesia is safe, conditions that necessitate surgery 

and surgery itself, is more important 

• Reassure mother about drugs and anaesthesia 

• Follow basic principles of obstetric anaesthesia 

• Good post-op analgesia and fetal / uterine monitoring 

• Consider delivery if fetus is viable and > 28 weeks 


29

The obstetric patient with cardiac 

disease 


• Understanding the defect and the physiologic 

effects of pregnancy on hemodynamics 

– No inappropriate advice against pregnancy 

– Identifying those patients with unacceptable high 

risk (contraception) 

– Optimal perinatal care in co-operation with 

relevant specialities 

– Good communication with the on-call teams 


30


Anticoagulation 

• Heparin does not cross the placenta 

– No adverse effects on fetal development 

– But maternal thrombocytopenia and osteoporosis 

• Oral anticoagulants: 

– Readily crosses the placenta 

– Fetal warfarin syndrome: hydrocephalus, 

microcephaly, growth retardation, ophtalmic 

abnormalities 


31

• Vaginal delivery has been favoured 

– Induction of labour but, … 

Reversal of anticoagulation 

Side effects of drugs used to induce labour 

Labour and vaginal delivery associated with profound 

haemodynamic changes: 

1st stage: CO ↑ 10% 

uterine contraction: autotransfusion of 500 ml 

2nd stage: CO ↑ 50% 

immediately postpartum: autotransfusion 


Regional analgesia 

– Anticoagulation ?! 

– Minimizes cardiovascular changes during labour 

– Consider orthosympathic blockade 

– Use dilute local anaesthetic/opioid solutions 

– Consider CSE for C-section 


32

C-section 

bupi 

sal 

bupi 

sal 

c 

sal 

Test 

pinprick 

ether 

ethylchloride 

Low-dose CSE plus EVE 


Aorto-caval compression 

Anest Analg 2003;97:256-8 

To avoid any detrimental 

effect on maternal 

cardiac output the 

pregnant patient would 

ideally be kept in the full 

lateral position 

When it is necessary to lay 

the woman on the back 

tilting her to the left is 

preferable 

Even more important in 

compromised patients 


33

Phenylephrine 

• Excellent efficacy to maintain maternal blood 

pressure during spinal anesthesia for C- 

section 

• Less fetal acidosis compared to ephedrine 

• Good hemodynamics in the cardiovascular 

impaired patients 


Peripartum hemorrhage 


34

Postpartum hemorrhage 

Normal blood loss: 

vaginal: 500 ml / 24 hrs 

abdominal:1000 ml / 24 hrs 

4 T’s 

Tone 

Trauma 

Tissue 

Thrombi 

n 

Specific Cause 

Atonic uterus 

Cervical,vaginal, 

Perineal, uterine 

inversion, ruptured uterus 

Retained placenta 

Invasive placenta 

coagulopathies 

Relative 

frequenc 

70 % y 

20 % 

10 % 

1 % 


Postpartum hemorrhage: 

uterine atony 

• Most common cause of serious blood loss !! 

• 15 % of cardiac output to gravid uterus 

• Management 

– Fluid resuscitation 

–Oxygen 

– Uterine massage 

– Uterotonics 


35


uterine atony 

• High parity 

• Dysfunctional labor 

• Uterine distention 

– Multiple gestation 

– Polyhydramnios 

– Macrosomia 

• Retained placenta 

• Infection: chorioamnionitis 

• Medication 

– Prolonged oxytocin use 

– Tocolytic agents 

– Inhalational anesthetics 


Uterotonics 

• Oxytocin: bolus 5 U 

– Stimulation of upper uterine segment (rhytm) 

– Vasodilator 

– Cave hypotension, water intoxication 

– IM or dilute IV infusion 

– 10 units/500 ml ( max 80 mU/min) 


36

Synto: bolus vs infusion 


Adverse effects 


37

Uterotonics: methergine 

• Sustained increase in uterine tone 

Tetanic contraction of upper and lower uterine segment 

• IM 0.2 mg IM 

• Peripheral vasoconstriction and hypertension 

• Coronary vasospasm ( stess-test in cardiology ) 


Uterotonics 

• 15-methyl prostaglandin F2α or carboprost 

• Prostin ® /15M 

– Intramyometrially 

– Intramuscularly 

– 0.25 mgr up to 2 mgr 

• Systemic and pulmonary vasoconstriction 

– Cave accidental IV infusion 

– Rapid uptake by uterine venous sinuses 

– Severe systemic and pulmonary hypertension 

– Severe bronchospasm 


38

Misoprostol 



retained placenta 

• Occurs in 1% of deliveries 

• Anesthetic management 

– Uterine relaxation: 

• Nitroglycerin: 100 µgr 

• Onset time: 30-45 sec 

• Duration: 60-90 sec 

– Analgesia: 

• Epidural 

• Spinal 

• > 1 MAC Inhalatie 

Careful dosing !!! 

Hypovolemia 

Manual removal 


39

Placenta previa 

• Abnormal implantation of placenta 

• Prenatal ultrasonographic diagnosis: anterior or posterior 

• More common with prior C section 

• Painless vaginal bleeding thirth trimester 

• Blood loss – placental surface area ↓ 


Placenta accreta 

• Abnormal attachment of placenta to uterine 

wall 

• Risk factors 

– Placenta praevia 

• No previous CS: 0.5% 

• 1 previous CS: 24% 

• 2 previous CS: 50% 

• ≥ 4 previous CS: 67% 


40

Placenta accreta 

• Risk factors: 

– Multiparity 

– Previous CS 

– Advanced maternal age 

– Previous dilatation and curettage 



41

Abruptio placentae 

• Bleeding into the decidua 

basalis leads to separation of 

the placenta. 

• Hematoma formation further 

separates the placenta from 

the uterine wall, causing 

compression of these 

structures and compromise of 

blood supply to the fetus. 

• Revealed hemorrhage = solutio 


Preterm labor 

• Preterm delivery = birth before 37 weeks gestation 

• Preterm labor = uterine contractions prior to 37 w 

cervical effacement and dilation 

• PROM = premature rupture of membranes 

Rupture one hour or more prior to onset of labor 

• PPROM = preterm premature rupture of membranes 

premature rupture of membranes at less than 37 w 


42

PPROM : complications 

• Fetal complications 

– Infection 

– Prematurity 

• Maternal complications 

– Chorioamnionitis 

– Endomyometritis 

– Operative intervention 


Corticosteroids in PTL 

• Effectively reduce RDS, IVH,and infant 

mortality at 24-34 weeks gestation 

• Criteria: 24-34 weeks gestation + 

– No contraindication to 24-48 h delay in delivery 

– No contraindication to steroids 

• Betamethasone 12 mg IM, 2 doses, 24 h 

apart 

• Dexamethasone 6 mg IM, 4 doses, 12 hours 

apart 


43

Tocolytic agents 

• « buying time » for 

– Steroid induced maturity of fetal lungs 

– Maternal transfer to MIC (maternal intensive care) 

• Terbutaline 

• Ritodrine = Prepar ® 


Prepar 

• Beta 1 -agonist side effects 

Shortness of breath 

Hypotension 

Cardiac arrhytmias 

• Hypokalemia is one of the most common side effects 

– Increase in plasma insulin 

– Stimulation of cellular intake of potassium 

After cessation: decrease in insulin might produce a rebound 

release of intracellular potassium 

Hyperkalemia 

Max 90-150 minutes after cessation 


44

Venous thromboembolism 

• Virchow’s triade: 

– Increased pro-coagulant factors and reduced fibrinolysis 

– Venous flow is altered 

– Trauma to venous system ( vaginal delivery, cesarean) 

• Reduction in blood flow velocity 

– 2nd trimester, nadir at 34 weeks, 6 weeks postpartum 

– Common femoral vein 

Diameter increases ( 9.1 to 12.7 mm) 

Flow velocity falls ( 14.8 to 4.5 cm/second) 

> Cesarean section !!! 

> DVT:in 85 % of cases left leg 


Risk factors of VTE 

• Age > 35 

• Weight > 80 kg 

• Multiparity 

• Family history of VTE 

• Deficiencies: 

– Antithrombin 

– Protein C 

– Protein S 

• Gene variants: 

– Factor V Leiden 

– Prothrombin 

• Lupus anticoagulant 


45

Basic Literature 

• The role of the anaesthetist in the 

management of the pre-eclamptic patient. 

Dyer, Current Opinion in Anaesthesiology 

2007,20: 168-174 

• First trimester anesthesia exposure and fetal 

outcome. A review. Allaert, Acta 

Anaesthesiologica Belgica 2007, vol 58, 2, pg 

119 


Suggested reading 

• Severe cardiac disease in pregnancy, part I: 

impact of congenital and acquired cardiac 

diseases during pregnancy. Van Mook: 

Current Opinion in Critical Care 2005, 

11:430-434 

• Severe cardiac disease in pregnancy, part II: 

impact of congenital and acquired cardiac 

diseases during pregnancy. Van Mook: 

Current Opinion in Critical Care 2005, 

11:435-448 


46

Suggested reading 

• Options for systemic labour analgesia. Evron 

Current Opinion in Anaesthesiology, 2007, 

20:181-185; 


47

Pre-Eclampsia

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