Pregnancy Induced Hypertension (PIH)

Pregnancy induced hypertension (PIH) is caused sudden involuntary muscular convulsive movement (spasm) of the vessels during pregnancy manifested by hypertension, edema and albuminuria. It remains obscure and only occurs after 20weeks of gestation.

Pathological Changes

Cardiac output appears to decrease as preeclampsia worsens but generalized vasoconstriction occurs when it affects much of the physiological activities of the body. This causes capillary permeability to increase and the fluid which escapes contribute to the oedema within the tissues. The presence of excessive fluid retention produces generalized oedema.

The uterus is also affected, particularly the vessels supplying the placental bed. Vasoconstriction and D/C reduces the uterine blood flow and vascular lesions occur in the placental bed. Placental abruption can be the result.

The liver is affected in severe cases where intracapsular haemorrages and necrosis occur. Oedema of the liver cells produces epigastric pain and impaired liver function may result in jaundice.

The brain becomes oedematous and this, in conjunction with D/C, can produce thrombosis and necrosis of the blood vessel walls resulting in cerebrovascular accident.

The lungs become congested with fluid, in severe cases, oxygen is impaired and cyanosis occurs.

Diagnosis of Preeclampsia

Symptoms are rarely experienced by the mother until the disease has arrived at an advanced state. It is possible to identify the onset by the following which are known as the cardinal signs.

Blood Pressure – A rise of 15-20mmHg above the normal diastolic pressure or an increase above 90mmHg on two occasions.

Proteinuria in the absence of urinary tract infection is indicative of renal damage. The amount of protein in the urine is frequently taken as an index of the severity of preeclampsia OR it is considered to be the most serious manifestation.

Oedema may appear rather suddenly and be associated with a rapid rate of weight gain. Generalized oedema is significant and is classified as occult or clinical. Occult oedema may be suspected if there is a marked increase in weight whilst Clinical Oedema may be mild or severe in nature and the severity is related to the worsening of the preeclampsia.

The oedema pits on pressure and may be found in;

  • Feet, ankles and pretibial regions
  • The hands – it may be noticed by the fact that the mother’s rings are tight.
  • The lower abdomen
  • The vulvae
  • Sacral region

Facial oedema may be mild resulting in puffiness of the eye lids in the presence of two of the cardinal signs. A provisional diagnosis of preeclampsia may be made.

Classification

Mild – is diagnosed when, after resting, the mother’s diastolic blood pressure rises 15-20mmHg above the basal blood pressure recorded in early pregnancy or when the diastolic blood pressure rises above 90mmHg. Oedema of the feet, ankles and pretibial regions may be present.

Moderate – Preeclampsia is usually diagnosed when there is a marked rise in the systemic and diastolic pressure, when proteinuria is present in the absence of a urinary tract infection and when there is evidence of a more generalized oedema.

Severe – Preeclampsia is diagnosed when the blood pressure exceeds 170/110mmHg, when there is an increase in the protein, uria and where oedema is marked. The mother may complain of frontal headaches and visual disturbances.

Effects of Preeclampsia

Effects on the Mother

  • Placental abruption may occur with all the complications.
  • Haematological disturbances can occur and the kidney, lungs, heart and liver may be seriously damaged.
  • The capillaries within the fundus of the eye may be irreparably damaged and blindness can occur
  • The condition may worsen and eclampsia may occur

Effects of the fetus

  • Reduced placental function can result in low birth weight.
  • There is an increased incidence of hypoxia in both the antenatal and intranatal periods.
  • Placental abruption, if minor, will contribute to fetal hypoxia. If major, intra uterine death will occur.

Management

Depending on the severity of the disease, a mother may be admitted to the hospital. Treatment is symptomatic because the cause of preeclampsia is unknown.

Diet: Every pregnant woman needs an appropriate diet, rich in protein, fiber and vitamin. Intake of fluids should be encouraged.

Weight Should be estimated and recorded twice weekly if the mother is ambulant and oedema should be observed daily.

Urine: should be tested for protein and ketenes.

Fluid intake and output should be continuously measured.

Blood pressure is ascertained 4-hourly in moderate preeclampsia but will be taken 2 hourly or more frequently if the mother is severely affected.

Abdominal examination will be carried out, any discomfort, tenderness or pain experienced by the mother should be recorded and reported immediately. The fetal heart rate and fetal wellbeing is also recorded.

Sedation may be prescribed.

Management during labour

The nurse/midwife should remain with the mother throughout the course of labour. Preeclampsia can suddenly worsen at any time and it is essential to document the presence of oedema, the blood pressure, and urinary output.

Positioning the mother on the left side will prevent supine hypotension. Care of the bladder is essential and the mother should be encouraged to void urine regularly.

When the second stage commences the obstetrician and pediatrician should be notified. The latter will be present at the delivery in case the baby requires resuscitation. Occasionally, a short second stage is preferred. In this instance, the obstetrician will perform a forceps (vacuum) delivery.

Care after delivery

The blood pressure will be recorded after delivery and at least 4-hourly for 24 hours. If proteinuria has been present, the urine should be tested once or twice daily until it is clear. Urinary output should be recorded.

Signs of Impending Eclampsia

The nurse must be vigilant in monitoring the maternal condition and be alert to the following signs and symptoms which signal the onset of eclampsia:

  • A sharp rise in blood pressure.
  • Diminished urinary output (oliguria).
  • Increase in protein uria
  • Headache which is usually sever, persistent and frontal or occipital
  • Drowsiness or confusion
  • Visual disturbances such as blurring of vision or flashing lights due to retinal oedema
  • Nausea and vomiting
  • Epigastric pain

If any of these signs are observed in a patient with preeclampsia, make a full examination in order to ascertain if other signs are present and report for urgent action.

Eclampsia

Eclampsia is rarely seen. Usually pregnancy induced hypertension is diagnosed and treatment is instituted in order to prevent Eclampsia. It is characterized by convulsions and coma.

The stages of an eclamptic fit

Premonitory stage (lasts 10-20 seconds)

  • The mother is restless and rapid eye movements can be noted.
  • The head may be drawn to one side and twitching of the facial muscles may occur.
  • The mother has no perception of the impending fit and shows altered awareness.

Tonic Stage (lasts 10-20 seconds)

  • The muscles of the patient’s body go into spasm and becom rigid and her back may become arched.
  • Her teeth will become tightly clenched and her eyes staring.

The clonic stage (lasts 60-90 seconds)

  • Violent contraction and intermittent relaxation of the mother’s muscles produces conversions movements.
  • Salivation increases and foaming at the mouth occurs.
  • The mother’s face becomes congested and bloated and the features become distorted.
  • She is unconscious, her breaths abnormally and her pulse full; gradually the convulsion subsides.

Stage of Coma

  • Stertorous breathing continues and coma may persist for minutes or hours.
  • Further convulsions may occur before the mother regains consciousness.

Emergency Care of a mother with Eclampsia

  • Clear and maintain the mother’s airway (suction).
  • Administer oxygen and prevent severe hypoxia.
  • Prevent the mother from getting injured during the clonic stage
  • Monitor vital signs.

Treatment

General management of Eclampsia include Controlling convulsions, Controlling blood pressure, Delivering the baby.

Intravenous therapy will be commenced to maintain adequate hydration. The regimen will be prescribed according to the mother’s needs and ketoacidosis must be prevented. Dextrose 5% is used for intravenous drug administration.

  • Sedatives to control convulsion.
  • Where the hypertension is severe and requires rapid reduction, antihypertensive drugs are prescribed.
  • Uria, albumin and the volume of urine must be monitored.
  • Monitor and balance intake and output
  • Avoid disturbances (noise, light, etc)
  • Keep emergency drugs ready

Complications of Eclampsia

  • Cerebral: haemorrhage, thrombosis and mental confusion.
  • Renal: acute renal failure. 
  • Hepatic: liver necrosis.
  • Cardiac: myocardial failure.
  • Respiratory: asphyxia, pulmonary oedema, bronchopneumonia.
  • Visual: temporary blindness.
  • Injuries: bitten tongue, fractures.
  • Fetal hypoxia and still birth.

Read Also

Abortion
Ectopic Pregnancy
Antepartum Haemorrhage
Postpartum Haemorrhage

Post a Comment

0 Comments