Pregnancy-Induced Hypertension (PIH)

• Toxemia/pregnancy-induced hypertension (PIH) is also known as pregnancy-associated hypertensive disorders.
• Pregnancy-induced hypertension is one of the most common complications during pregnancy.
• A major cause of maternal and fetal morbidity and mortality is pregnancy-induced hypertension.
• It is a vascular disease of unknown cause, occurring after the 20th to 24th week of gestation, disappearing by the 6th week postpartum.
• Pathophysiologic basis is vascular spasm leading to hypertension due to vascular effect, edema from interstitial effect and proteinuria due to kidney effect.

Triad of Symptoms

• Hypertension
• Edema
• Proteinuria (specifically albuminuria)

Predisposing Factors

• Age, primis under 20 and over 30
• Gravida of 5 or more pregnancies
• Low socioeconomic status (SES)
• Multiple pregnancies
• Underlying medical conditions such as heart disease, hypertension, and diabetes
• Family history of gestational hypertension
• History of gestational hypertension, or preeclampsia during past pregnancies
• Immune system disorder such as lupus
• Kidney disease
• Expecting multiple babies such as twins, triplets, or more

Hypertensive Disorders of Pregnancy

• Hypertensive disorders are also known as pregnancy-associated hypertensive disorders, or pregnancy-induced hypertension.
• Hypertensive disorders are the most common complications during pregnancy.
• A major cause of maternal and fetal morbidity and mortality is hypertensive disorders.
• Hypertensive disorders include gestational hypertension, preeclampsia, eclampsia, chronic hypertension, and chronic hypertension with superimposed preeclampsia.
• If preeclampsia is left untreated, it can lead to HELLP syndrome, which includes hemolysis, elevated liver enzymes, and low platelet count.
• 2-8% of pregnancies globally are complicated by preeclampsia alone.
• Hypertensive disorders are defined into five categories by the American College of Obstetricians and Gynecologists (ACOG).

Gestational Hypertensive Disorders

• Gestational hypertension is defined as systolic reading of 140 mm Hg or more and/or diastolic pressure of 90 mm Hg or more, on two readings at least 4 hours apart, after 20 weeks gestation.
• Gestational hypertension doesn't persist beyond 12 weeks postpartum, and usually resolves after a week postpartum.
• Preeclampsia is a pregnancy-specific condition, a new-onset of hypertension that happens most often after 20 weeks of gestation, with blood pressure elevated above 140 mm Hg systolic and 90 mm Hg diastolic.
• Hypertension usually comes with new-onset proteinuria.
• Other signs of preeclampsia include thrombocytopenia, impaired liver function, pulmonary edema, and visual disturbance, and they may present in some women without proteinuria.
• Eclampsia is the onset of seizure activity or coma in a woman with preeclampsia who doesn't have a history of preexisting pathology that can cause seizure activity.
• Maternal hypoxia, injury, and aspiration pneumonia can be caused by seizure.
• Eclampsia has an increased maternal mortality rate, especially in settings with low resources.

Chronic Hypertensive Disorders

• Chronic hypertension is hypertension diagnosed or present before pregnancy or before 20 weeks of gestation.
• More prevalent with increasing late childbearing and in persons with obesity, chronic hypertension is also classified as hypertension diagnosed, for the first time during pregnancy that does not resolve postpartum.
• Preeclampsia is considered superimposed when it complicates preexisting chronic hypertension.
• About half of women with chronic hypertension may develop superimposed preeclampsia; it is tied to increased maternal or fetal mortality.

Pathogenesis

• Diagnosis occurs via a roll-over test to assess the probability of developing toxemia which is performed between the 28th and 32nd week of pregnancy.
• Lying in the lateral recumbent position for 15 minutes until BP stabilizes occurs during the procedure.
• The patient then rolls over to supine position.
• BP is taken at 1 minute and 5 minutes after rollover.
• Interpretation: If diagnostic pressure increases 20 mm Hg or more, the patient is prone to toxemia.

Assessment Findings

• Generalized vasospasm and arteriolar vasoconstriction that cause increased peripheral resistance leads to decreased blood flow, which causes hypertension.
• Reduced blood flow to tissues leads to tissue ischemia and altered organ functioning, mostly affecting the kidneys, brain, and uterus.
• Renal vasospasm and decreased perfusion cause glomerular lesions including membrane damage that causes disturbed functions in the kidneys.
• Proteinuria, hypoproteinemia, altered a/g ratio, altered blood osmolarity, including fluid shift from intravascular compartments to interstitial spaces that cause edema are also effects.
• Angiotensin release also leads to further vasospasm and hypertension in the kidneys.
• Cerebral arteriospasm and edema can cause cerebral hypoxia and CNS irritability in the brain.
• Double vision, blurring, and dimness vision are visual disturbances that can happen.
• Hyperreflexia and hyperirritability can lead to convulsion and coma.
• Reduced placental perfusion in the uterus can cause small for gestational age babies (SGA).
• Generalized vasoconstriction and arteriospasm precipitate abruptio placenta.

Preeclampsia Details

• Insufficient production of blood and platelets and Generalized vasoconstriction & microangiopathy (disease of the capillaries) are also underlying causes.
• Retention of sodium and water by body tissues is also an underlying cause.
• Cerebrovascular hemorrhage, acute pulmonary edema, and acute renal failure are medical complications.

Preeclampsia Types

• Sudden, excessive weight gain of 1 - 5 lbs per week (earliest sign of preeclampsia) due to edema which is persistent and found in the upper half of the body (e.g. inability to wear the wedding ring) is a sign and symptom of mild preeclampsia.
• Systolic BP of 140, or an increase of 30mm Hg or more and a diastolic of 90, or a rise of 15mm Hg. Or more taken twice 6 hours apart is a sign and symptom of mild preeclampsia.
• Proteinuria of 0.5 gms/liter or more is a sign and symptom of mild preeclampsia.
• BP of 160/110 is a sign and symptom of severe preeclampsia.
• Proteinuria of 3+ or 4+ on random is a sign and symptom of severe preeclampsia.
• Oliguria of 400 ml. or less in 24 hours (normal urine output/day = 1500ml.) is a sign and symptom of severe preeclampsia.
• Epigastric pains (considered as an "aura" to the development of convulsions) are visual and cerebral disturbances that are signs and symptoms of severe preeclampsia.
• Pulmonary edema, cyanosis, and peripheral edema are visual and cerebral disturbances that are signs and symptoms of severe preeclampsia
• Hepatic dysfunction is a sign and symptom of severe preeclampsia.

Eclampsia

• A major difference is the presence of convulsions in eclampsia.
• Increased BUN, increased uric acid, decreased CO2 combining power, convulsions, coma, and death from cerebral hemorrhage, circulatory collapse, or renal failure are also signs and symptoms.

Management of Eclampsia

• Getting complete bed rest which aids in sodium excretion is crucial, as sodium tends to be excreted more rapidly when the patient is at rest.
• Decreasing the metabolic rate to minimize oxygen demands as lowered oxygen tension in toxemia is the result of vasoconstriction and decreased blood flow that diminishes the amount of nutrients and oxygen in cells relies in energy conservation.
• Bed rest should be in a darkened, non-stimulating environment with minimal handling due to the possibility of convulsions.
• High-protein, high-carbohydrate, and moderate salt restriction should be part of the diet for someone who has mild eclampsia.
• For severe preeclampsia, high protein, high calorie and salt-poor (3 gms of salt per day) is recommended.
• The mother should lay in the left lateral recumbent position to avoid uterine pressure on the vena cava.
• Precautions include sudden rise in BP and prevent seizures.
• Other seizure precautions include an abrupt decrease of urinary output to

Medication Management

• The drug of choice is magnesium sulfate, a CNS depressant that lessens the possibility of convulsions, it also acts as a vasodilator, which decreases the BP.
• Magnesium sulfate also causes a shift of fluid from the extracellular spaces into the intestines from where the fluid can be excreted.
• The dosage of magnesium sulfate is 10 gms. initially, by slow IV push over 5-10mins, or deep IM, 5gms/buttock, then an IV drip of 1gm. Per hour (1gm/100 ml. D10W0 if:
• Deep tendon reflexes are present.
• Respiratory rate is at least 12 per minute
• Urine output is at least 100 ml. in 6 hrs.
• The therapeutic level of magnesium sulfate is 5-8 mg/100 ml.

Symptoms of Overdose from Medication

• Decreased urine output
• Depressed respiration
• LOC
• Earliest sign of magnesium sulfate toxicity
• Depressed or disappearance of deep tendon reflexes (knee jerk/patellar reflexes)

Additional Care Points

• Monitor maternal and fetal vital signs.
• Antidote is calcium gluconate, 10% IV, to maintain cardiac and vascular tone.
• The method of delivery is preferably vaginal, but if not possible, CS will have to be done.
• The danger of convulsions is present until 48 hours postpartum

Nursing Problem Priorities

• Blood pressure management and fetal monitoring are nursing problem priorities.
• Maternal health evaluation, proteinuria monitoring, medication management, and fluid balance are also priorities.
• Preventing complications, delivery planning, maternal education & support, & postpartum care are nursing problem priorities.