205: HTN notes

HTN Notes for 205

references: wikipedia, Lemone/Burk

Blood pressure: pressure of blood on arterial walls

A Certain amount of pressure is needed to keep vessels open. Sufficient blood volume and pressure difference are needed to keep blood going forward.

High pressure does these bad things:

• Harder for the heart to pump [its pumping against high pressures]
• Alters vessel structure
• Negative effects on sensitive peripheral tissues [eyes, kidneys, CNS.]

BP is made up of:

• Amount of pressure from the squish of the heart [CO] during systole
• The tension or resistance of the arterial walls [varies by elasticity]—that’s called systemic vascular resisitance/SVR.
• So BP is CO and SVR

Diastole is the refilling of the heart and maintains blood flow thru the vessels

The difference between systole and diastole is usually 40 points [mmHg.]

MAP: mean arterial BP = systolic+ 2(diastolic)/3

Arterioles alter BP in response to:

To increase BP:

• SNS: increase HR, constricts arterioles in response to baroreceptors. Adrenalines do the same
• Renin/Angiotensin/Aldosterone system does the same in response to Blood Flow thru the kidneys. Aldosterone is a water and sodium saver.
• ADH or vasopressin: vasoconstricts and saves water

To Decrease BP:

• ANP and BNP are released in response to stretching by excess Blood Volume. They diurese and also vasodilate
• Adrenomedullin: vasodilator from smooth muscle in vessels

Risk Factors:

HTN increases risk of Stroke x4

HTN increases risk of Heart Failure 2-3x

Family history: 30% genetic link

Age: definitely up in older years

Race: African Americans

Obesity: esp abdominal focus. Genetic factors might be behind the trine of diabetes/obesity/HTN

Diabetes: excess circulating insulin effect SNS, vascular muscles, and water/mineral output

ETOH: regular cosnsumption of 3+ drinks per day

Stress: think SNS

Complications:

harder work for Left Ventricle; hypertrophy, dysrhythmia

Atherosclerosis increases, therefore heart failure more likely, stroke also more likely

Most deaths from AMI or heart failure

Nephrosclerosis: renal insufficiency; happens more in black population; causes 10% of HTN deaths

NANDA

Ineffective health maintenance

Risk for noncompliance

Imbalanced nutrition; more than body requirements

Excess fluid volume

NIC:

Health education

Self-modification assistance

Self-responsibility facilitation

NOC:

Adherence Behavior

Health-Promotion Behavior

Treatment Behavior: illness or injury

HTN Crisis: Emergency= 180/120+

Often with non-compliance and quitting Rx suddenly

Pregnant Women w/ Preeclampsia

Looks like: headache, confusion, swelling of optic nerve/blurred vision, etc

Must bring down BP slowly to prevent ischemia of cardiac, renal, brain tissue.

Drug interventions: nitroprusside, NTG, Ca Channel Blocker, ACE inhibitor, SNS blockers

Pre-eclampsia: WIKI

is a medical condition where hypertension arises in pregnancy (pregnancy-induced hypertension) in association with significant protein in the urine. Its cause remains unclear, although the principal cause appears to be a substance or substances from the placenta causing endothelial dysfunction in the maternal blood vessels.^[1] While blood pressure elevation is the most visible sign of the disease, it involves generalized damage to the maternal endothelium and kidneys and liver, with the release of vasopressive factors only secondary to the original damage.

Pre-eclampsia may develop at varying times within pregnancy and its progress differs among patients; most cases are diagnosed pre-term. It has no known cure apart from ending the pregnancy (induction of labor or abortion). It may also occur up to six weeks post-partum. Of dangerous pregnancy complications, it is the most common; it may affect both the mother and the fetus.

In some cases women with preeclampsia or eclampsia can be stabilized temporarily with magnesium sulfate intravenously to forestall seizures while steroid injections are administered to promote fetal lung maturation. Magnesium sulfate as a possible treatment was considered at least as far back as 1955,^[10] but only in recent years did its use in the UK replace the use of diazepam or phenytoin.^[11] Evidence for the use of magnesium sulphate came from the international MAGPIE study.

Eclampsia is a serious complication of pregnancy and is characterised by convulsions. Usually eclampsia occurs after the onset of pre-eclampsia though sometimes no pre-eclamptic symptoms are recognisable. The convulsions may appear before, during or after labour, though cases of eclampsia after just 20 weeks of pregnancy have been recorded.

The majority of cases are heralded by pregnancy-induced hypertension and proteinuria but the only true sign of eclampsia is an eclamptic convulsion, of which there are four stages. Patients with edema and oliguria may develop renal failure or pulmonary edema.ki