Preeclampsia

 

Eclampsia (fitting) is serious consequence of severe preeclampsia

Table 1.10 Signs and symptoms of pre-eclampsia

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

  • Calculate REWS — AVPU, RR, O2 sats, pulse, BP, Temp
  • Weight, BGL 
  • 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

Table 1.11 Antihypertensive drugs for severe hypertension in pregnancy

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