Management of servere Hypertension

Management of servere Hypertension

Department of Obstetrics and Gynaecology

Se also
Hypertension
Treatment of Preexcisting Hypertension
Hypertension and sligth to moderate preeclamsia
Treatment of Serverhypertension
Treatment of Eclampsia
Drug

Definition:
BP more than 160/110 mmHg

Fluid Balance Management

Fluid intake should be restricted to 80 ml/hour. Over infusion increases the risk of pulmonary edema.
Urinary output should be measured hourly.
500 ml human albumin solution (HAS) should be considered:

prior to hydralazine therapy
prior to cesarean section
if oliguria is evident (defined as urinary output less than 100 ml in a consecutive four-hour period)
prior to the administration of regional anaesthesia

If the central venous pressure value is greater than 10 mmHg, 20 mg Furosemide should be considered.
If the central venous pressure value is less than 0.5
mmHg, HAS 500 ml should be considered.
A further dose of 20-40 mg Furosemide should beconsidered if there is persistent oliguria.
In case of severe preeclampsia (significant symptoms rapidly progressing and hypereflexia) or eclampsia give MgSO4.

Antihypertensive therapy should be used for pregnant women with severe hypertension for maternal benefit.
The exact level at which to institute antihypertensive treatment is controversial.

Most will treat = 160 systolic and = 100 diastolic (or = 110)

The target blood pressure is diastolic 95-105 mmHg, e.g. 150/100 mmHg.

Overzealous control runs the risk of jeopardizing the uteroplacental circulation and causing IUGR.

Use oral treatment if possible and avoid drastic reduction in blood pressure.

Drugs
Methyldopa is the drug of choice in pregnancy as it has been extensively studied. It has side effects including depression, sedation and postural hypotension.
Maximum plasma concentration after 3-6 hours and maximum effects after 24 to 48 hours
Dose: 250 mg X 3 to max 500 mg x 4.
Cave: Leverinsufficiens

Labetalol max plasma concentration after 1-2 hours, effect after ½ hours. Dose: 200 mg x 3 to max 300 mg x 4. Cave asthma, Acute therapy: begin with IV 20 mg followed at 10 minuts interval by dosis of 20 to 80 mg 40 mg then 80 mg up to a maximum cumulative dose of 300 mg. The fall in blood pressure begins within 5-10 minuts and last from 3 to 6 hours.

Nifedipine (Adalat) should be given orally not sublinqvaly as it can cause severe hypotension. The fall begins within 5 to 10 minuts and last from 3 to 6 hours.(max plasma concentration after 30-60 min). Dose: 10 mg x 2 max 30 mg x 3. Can cause headache.

Hydralacin: Dose 5 mg IV over one to two minuts repeated bolus 5-10 mg depending upon initial respons evey 20 minuts to a maximum cumulative dose of 20 mg. Cave: The fall in blood pressure begins within 10-30 minuts and last from two to four hours.

Magnesium Sulphate: (see contraindication below)
Loading dose 4 gms mixed with 50 mls of IV fluid (D5W, NS, LR, etc.) slowly over 10 min period followed by a maintenance infusion of 1 g/hr mantained for 24 hours after the last seizure.
Recurrent seizure should be treated with either a further bolus of 2 g magnesium sulphate or an increase in the infusion rate to 1,5 to 2,0 g/hour.
Magnesium toxically do not need to be monitored routinely and toxic can be clinical assed by clinical assement by loos of Patellar reflexes and respiratory depression.
Calcium gluconate 1 g over 10 minuts can be given if there is concern about respiratory depression.

Monitoring Serum Levels of Magnesium is seldom indicated. In case of fast treatment of hypertension - hydralacin iv or im or labetelalol oraly or IV nifedepine oraly not subligually

Contraindication:
Serious impaired renal function se-creatinine > 300mmol/l cardiac disease especially atrioventricular block. Myastemia gravis, respiratory paralysis.

Care:
Adalat and MgSO4 should not be given together (cardiotoxity) and can cause hypotension (risk for AMI)

Therapeutic range level 6-8 mg/l or 2-3.5 (4) mmol/l.
Magnesium Blood Levels:
1.8 mg (.75-1.25 mmol) - Normal
4.8 mg (1.65-3.3 mmol) - Therapeutic for seizure prophylaxis
10-12 mg (4.1-4.9 mmol) - Loss of knee jerk
12-15 mg (4.9-6.2 mmol) - Respiratory failure
> 15 mg (6.2 mmol) - Cardiac arrest