Pre eclampsia

CLASSIFICATION OF HYPERTENSION IN PREGNANCY

HTN is the most common medical disorder in pregnancy – occurs in up to 22% of all pregnancies

A. Gestational hypertension: Without proteinuria or pathological edema

B. Preeclampsia: Hypertension and protenuria with or without pathological edema

C. Eclampsia : Pre eclampsia complicated with convulsions or coma

D. Chronic hypertension

§  Essential Hypertension

§  Chronic Renal Disease

§  Coarctation of Aorta

§  Pheochromocytoma

§  Thyrotoxicosis

§  Connective tissue disease-systemic lupic erthematous

E. Pre eclampsia or eclampsia superimposed on chronic hypertension

 

PREECLAMPSIA

Definition

Preeclampsia is a multisysytem disorder of unknown etiology characterized by development of hypertension to the extent of 140/90mm Hg or more with protenuria after the 20^th week in a previously normotensive and non-protenuric patient.

Etiology

Cause unknown: theories suggest vasospasm and ischemia, or abnormal immune system response. Arteriolar vasospasm causes endothelial cell damage, increases capillary permeability, and leads to edema

Risk Factors

•Low socioeconomic class

•Multiple foetuses, or hydatid

•Maternal age <20 or >35yrs

•Primipara

•Gestational or pre-gestational DM

•Renal disease

•Family history- four times the risk

Pathophysiology

• The normal endovascular invasion of cytotrophoblast into the spiral arteries fails to occur beyond deciduas-myometrial junction
• The musculo elastic media in the myometrial segment remains responsive to vasoconstrictor stimuli resulting in decreased blood flow
• Areas of ischaemia in tertiary villi of placenta
• Microvilli from trophoblasts are shed into maternal vascular system
• Damaged endothelial cells release vasoconstrictive agents
• Vasoconstrictve agents like Thromboxane, Endothelin  are released, and vasospasm results – i.e. hypertension occurs

 

Signs and Symptoms

 

Mild preeclampsia

• SBP >140, DBP >90 taken 2 separate times 4-6 hrs apart
• Proteinuria: >1+ protein with urine dipstick or >300 mg protein in 24-hr urine sample
• Slight

Severe preeclampsia

• SBP >160 or DBP >110 on 2 different occasions at least 4-6 hrs apart on bedrest
• Proteinuria: >2+ on urine dipstick or >2g in 24 hr urine sample. Swollen glomerular capillaries result in stretched out capillary walls
• albumin/protein escapes into urine
• Oliguria: urine output <500 mL in 24 hrs
• Other symptoms: cerebral/visual disturbances, hyperreflexia, N&V, pulmonary edema, epigastric pain, thrombocytopenia

 

HELLP Syndrome

 

Complication of severe preeclampsia that involves hepatic dysfunction.

HELLP stands for:

H         : Hemolysis of RBCs

EL       : Elevated liver enzymes

LP       : Low platelets (<1,00,000/mm3)

 

Similar to pre-eclampsia with

–RUQ/ epigastric pain

–N/V

–Jaundice

–Deranged LFT

Diagnosis of pre-eclampsia

• Investigate all organ systems – CVS, CNS, Resp.
• Haematological – Platelets, haematocrit
• Renal – proteinuria, creatinnine, (uric acid)
• Hepatic – AST
• Placenta – Doppler U/S umbilical artery, fetal growth

 

MANAGEMENT

Rest: Admission in hospital and rest is helpful for  continued evaluation and treatment of the patient. While in bed patient should be in left lateral position as much as possible, to lessen the effects of venacaval compression. Rest – (1) increases the renal blood flow (2) increases the uterine blood flow improves the placental perfusion and (3) reduces the blood pressure.

 

Diet: The diet should contain adequate of protein (about 100 gm). Usual salt intake is not restricted. Fluids need not be restricted. Total calorie approximate 1600 cal / day.

 

Sedative: To cut down emotional factor, mild sedative may be given orally as phenobarbitone 60 mg or diazepam 5 mg at bed time.

 

Diuretics: The diuretics should not be used injudiciously as they cause harm to the baby by diminishing placental perfusion and by electrolyte imbalance. The compelling reasons for its use are – (1) cardiac failure (2) Pulmonary oedema (3) along with selective antihypertensive drug therapy (diazoxide group) where blood pressure reduction is associated with fluid retention. (4) Massive oedema, not relieved by rest and producing discomfort to the patient. The most potent diuretic commonly used is frusemide (Lasix) 40 mg – given orally after breakfast for 5 days in a week. In acute condition, IV route is preferred.

 

Antihypertensives:  Antihypertensive drugs have limited value in controlling blood pressure due to pre- eclampsia. The compelling indications of its use are: (1) Persistent rise of blood pressure specially where the diastolic pressure is over 110 mm Hg. The use is more urgent if associated with proteinuria. (2) In severe pre-eclampsia to bring down the blood pressure during continued pregnancy and during the period of induction of labour. The common oral drugs used are

 

Drug	Mode of action	Dose
·       Methyl dopa ·       Labetalol ·       Nifedipine ·       Hydralazine	Central and peripheral and adrenergic action Adrenoceptor antagonist (α and β blocker) Calcium channel blocker Vascular smooth muscle relaxant	250 – 500 mg tid or qid 250 mg tid or qid 10 – 20 mg bid 10 – 25 mg bid

 

In hypertensive crisis: Any of the drugs is helpful by intravenous infusion till the diastolic pressure comes down to <110 mm Hg.

(1) Labetalol (200 mg of normal saline) at the rate of 20 mg/hr t be doubled every 30 minutes. (2) Hydralazine 5 mg I.V. bolus to be followed by infusion 25 mg in 200 ml normal saline, the rate being 2.5 mg / hour to be doubled every 30 minutes.

(3) Nitroglycerin 5 μg/mins. I.V. or Sodium nitroprusside 0.25 – 5 μg/min I.V.      

Progress chart: The effect of treatment should be evaluated by maintaining a chart which records the following:

(1) Blood Pressure – at least four times a day.

(2)  State of oedema and daily weight.

(3) Fluid intake and urinary output.

(4) Urine examination on admission and to be repeated, if necessary.

(7) Fetal well being assessment

 

DURATION OF TREATMENT: The definitive treatment of pre-eclampsia is termination of pregnancy. The aim of the treatment is to continue the pregnancy, until the fetus becomes mature enough to survive in extra-uterine environment. Thus, the duration of treatment depends on – (1) severity of pre-eclampsia, (2) duration of pregnancy and (3) response to treatment.

 

Group – A : If the duration of pregnancy is remote from term, the patient may be discharged with advice to attend the antenatal clinic after one week. If the patient is near term, she should be kept foe a few days till completion of 37^th week. Thereafter, decision is to be taken either to terminate pregnancy or to wait for spontaneous onset of labour by the due date. It is not wise to allow the pregnancy to continue beyond the expected date.

Group – B: If the pregnancy is beyond 37 completed weeks, termination is to be considered without delay. If less than 37 weeks, expectant treatment may be extended judiciously at least up to 34 weeks. Careful maternal and fetal well being are to be monitored during the period with the available parameters.

Group – C: The couple is counseled. Termination of pregnancy is considered irrespective of duration of gestation. Seizure prophylaxis (magnesium sulphate) should be started. Steroid therapy is considered if the duration of pregnancy is <34 weeks. It prevents neonatal RDS, IVH and maternal thrombocytopenia.

 

METHODS OF TERMINATION:         

 

·       Induction of labour

Indications:

(1) Aggravation of the pre-eclamptic features in spite of medical treatment and / or appearance of newer symptoms such as epigastric pain.

(2) Hypertension persists in spite of medical treatment with pregnancy reaching 37 weeks or more.

(3) Acute fulminating pre-eclampsia irrespective of the period of gestation.

(4) Tendency of pregnancy to overrun the expected date.

           

Methods: If the cervix is ripe, surgical induction by low rupture of the membrane is the method of choice. Oxytocin infusion may be added to accelerate the process in selected cases. Raised blood pressure alone is not a contraindication to oxytoin infusion, if the cervix is unripe and the termination is not an urgent one, prostaglandin (PGE₂₎ gel 500 μg intercervical or 1-2 mg in the posterior fornix is inserted to make the cervix ripe when low rapture of the membranes can be performed.

·       Caesarean section

Indications:

(1)When an urgent termination is indicated but the cervix is unfavorable (unripe and closed) for surgical induction.

(2)Severe pre-eclampsia with a tendency to prolong the induction – delivery interval.

(3)Associated complicating factors such as elderly primigravide, contracted pelvis, malpresentation etc.

 

MANAGEMENT DURING LABOUR:

• Blood pressure tends to rise during labour and convulsions may occur (intra-partum eclampsia). The patient should be in bed.
• Liberal sedatives should be given in the form of pethidine 75-100 mg intramuscularly and to be repeated at intervals. Antihypertensive drugs may be given if the blood pressure becomes high.
• Blood pressure and urinary output are to be noted regularly so as to detect imminent eclampsia. Careful monitoring of the fetal well being is mandatory.
• Labour duration is curtailed by low rupture of the membranes in the first stage; and forceps or ventouse in second stage.
• Intravenous ergometrine following the delivery of the anterior shoulder is withheld as it may cause further rise of blood pressure.
• The patient should be sedated immediately following the delivery of the baby with intramuscular morphine 15 mg to prevent postpartum eclampsia and to keep the patient under close observation for several hours.

 

PUERPERIUM: The patient is to be watched closely for at least 48 hours, the period during which convulsions usually occur. Tab phenobarbitone 60mg in repeated doses can produce effective sedation. The patient is to be kept in the hospital, till the blood pressure is brought down to a safe level and proteinuria disappears.

 

Nursing Management

• Nursing management focuses on prompt diagnosis, prevention of complications, and delivery of an uncompromised fetus
• Monitor BP, proteinuria, and edema: edema in face, hands, abdominal area vs. dependent edema which is normal during pregnancy
• Observe for these symptoms: HA, visual disturbances, epigastric pain, RUQ pain, hyperreflexia, clonus
• Auscultate lungs for crackles or diminished lung sounds that might indicate pulmonary edema
• Signs of impending seizure (eclampsia): hyperreflexia, severe epigastric pain, , vomiting.
• Protecting the patient is key – side rails up and padded, suction accessible, O2 available
• Fetal surveillance
• Lab studies: CBC, clotting studies, liver enzymes
• type & screen or crossmatch