Preeclampsia

Eclampsia (fitting) is serious consequence of severe preeclampsia

• If woman fitting at presentation — see Fits in the second half of pregnancy

Do first

• Call for help
• Lie woman on her left side
• Give oxygen to
• Target O₂ sats 94–98%
• OR if moderate/severe COPD — 88–92%
• Put in IV cannula, largest possible
• Put second IV cannula in other arm when you have time
• Put in indwelling urinary catheter as soon as possible

Medical consult — doctor must talk with obstetrician about treatment

• Treatment includes
• Sending to hospital
• Giving medicines to lower BP (eg nifedipine, hydralazine)
• Giving magnesium sulfate to prevent fits
• If less than 35 weeks pregnant giving medicines to help mature baby’s lungs —Betamethasone ​ IM — 11.4mg — 2 doses 24 hours apart
• OR dexamethasone IM — 6mg — 4 doses 12 hours apart

Do not

• Do not let woman eat or drink anything — may need operation 

Check

• U/A for protein, send urine for MC&S

Do — if directed by doctor

Treatment to lower BP

• Keep very careful fluid balance charts throughout
• Give normal saline IV 250mL at start of treatment to prevent hypotension (low blood pressure)
• If asked to give nifedipine
  
• Give nifedipine (IR) oral — 20mg
• Do not use slow-release (SR, CR, OROS) tablets — if immediate release (IR) tablets are not available consult obstetrician or pharmacist for access and guidance 
• Medical consult 45 minutes after giving
• If BP still high — usually give second dose nifedipine (IR) oral — 20mg
• If BP still high 45 minutes after second dose — medical consult
• If asked to give hydralazine
• Give hydralazine IV bolus — 5–10mg — see Giving hydralazine
• Medical consult 20 minutes after giving
• If BP still high — usually give second bolus dose hydralazine IV
• Doctor may ask for maintenance hydralazine infusion
• If diastolic BP falls below 90mmHg — medical consult

Treatment to prevent fits

• Give loading dose of magnesium sulfate THEN give maintenance treatment — see giving medicines for preeclampsia 
• High dose nifedipine and high dose magnesium sulfate given together can interact and cause serious low BP and/or breathing problems — use with care
• If using nifedipine — give magnesium sulfate as an infusion without loading dose. Can give bolus dose later if woman has fit

While waiting for evacuation

• Check pulse, RR, BP, O₂ sats according to schedule for medicine given
• If magnesium sulfate infusion running — also check patella reflexes 
• Check every hour — temp, urine output — aim for 0.5mL/kg/hr, coma scale score
• When fitting and BP controlled — do first check in labour even if no contractions

Giving medicines for preeclampsia

• Take care not to overload with IV fluids
• Monitor fluid balance very carefully
• If giving hydralazine and magnesium sulfate infusions — already getting 45–125mL of fluid/hour
• Do not give extra fluid unless directed by doctor

Giving magnesium sulfate

• Loading dose must be given IV
• Maintenance treatment can be IV or IM
• If overdose — treat with calcium gluconate 10% — have 10mL dose ready before starting magnesium sulfate treatment

Check

• Pulse, RR, BP, O₂ sats, urine output, patella reflexes — loss of patella reflex can be first sign of magnesium overdose
• Before starting magnesium sulfate woman must have
• Patella reflex
• RR more than 16 breaths/min
• Urine output more than 0.5mL/kg/hr
• ​During treatment
• RR, BP, patella reflex every 15 minutes for at least 2 hours
• If stable after 2 hours — repeat every hour
• O₂ sats, urine output every hour
• Tell woman she may feel a bit sick, hot, sweaty or have blurred vision

Do

• Give magnesium sulfate IV through its own dedicated line — do not use same line as hydralazine
• Flush line with 10mL normal saline first to make sure it is working

Loading dose

• Give magnesium sulfate IV — loading dose 4g over 10 minutes
• Draw up 4g (8mL) of magnesium sulfate 50% — in 20mL syringe
• Add 12mL sterile water or saline to the same syringe to make a 20% solution (4gm in 20mL)
• Give this 4g magnesium sulfate 20% solution IV over 10 minutes using a burette attached to infusion pump
• If no infusion pump — give as IV push over 10 minutes 

IV maintenance

• Give magnesium sulfate IV infusion — 4g (8mL) at 1g/hr 
  
• Add 4g (8mL) to 100mL normal saline
• Run solution at 25mL/hr through infusion pump
• Label 'magnesium sulfate 4g in normal saline 100mL'

IM maintenance

• Use only if IV maintenance can't be given safely (eg no infusion pump) — medical consult
• Straight after IV loading dose — give magnesium sulfate deep IM — 10g (20mL) in 2 doses — 1 dose (5g/10mL) in each buttock. Use 21G needle
• THEN give magnesium sulfate IM — 5g (10mL) every 4 hours — until woman evacuated

Stop maintenance treatment and do medical consult if

• Patella reflex absent
• RR less than 16 breaths/min
• Urine output less than 0.5mL/kg/hr

If RR less than 12 breaths/min or woman stops breathing

• Stop infusion
• Start resuscitation — see Life support — DRS ABC
• Give calcium gluconate 10% IV — 10mL (1 ampoule) over 2–5 minutes

If woman has fit during maintenance treatment 

• Give magnesium sulfate IV — 4g (8mL) directly from syringe over 5 minutes
• Urgent medical consult

Giving hydralazine

Check

• Check pulse, RR, BP, O₂ sats
• During treatment — check pulse, RR, BP, O₂ sats
  
• Every 5 minutes for 15 minutes
• THEN every 15 minutes for 1 hour
• THEN every 30 minutes until BP remains stable
• Tell woman she may feel a bit sick or hot from this medicine

Do

Give IV hydralazine through its own dedicated line — it is incompatible with many drugs including magnesium sulfate and glucose

IV bolus

• Medical consult for dose
• To reconstitute — mix 20mg ampoule hydralazine with 2mL normal saline to dissolve THEN add 18mL normal saline to give 20mL hydralazine at 1mg/mL
• Inject hydralazine dose slowly over 3–5 minutes 

IV maintenance infusion

• Give hydralazine IV infusion — 50mg at 6mg/hr
• Add 50mg (2½ ampoules) to 500mL normal saline
• Medical consult if
• Diastolic BP less than 90mmHg or stays at more than 100mmHg
• Systolic BP less than 145mmHg
• Pulse more than 120 beats/min
• Change rate of infusion as advised by doctor
• BP usually controlled with hydralazine maintenance dose of 3–9mg/hr (30–90mL/hr solution)

Supporting resources

• How to access nifedipine IR
• MgSO4 Dosing and Monitoring Checklist