week 12 htn crisis

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Questions and Answers

What is the main difference between primary and secondary hypertension?

Primary hypertension has no definitive cause, while secondary hypertension has an identified cause.

What triggers the RAAS system in renal hypertension?

Renal ischemia

What is the main mechanism of hormonal hypertension?

Increased catecholamines, leading to increased heart rate and contractility, and increased systemic vascular resistance.

What are some risk factors for hypertension similar to cardiovascular disease risk factors?

Diabetes, smoking, obesity, alcohol, caffeine, and stress. Signup and view all the answers

What is the definition of hypertensive urgency?

Elevated blood pressure without signs of target organ damage. Signup and view all the answers

What are the typical blood pressure values associated with hypertensive emergency?

Diastolic BP >120-130 mmHg and systolic >180 mmHg. Signup and view all the answers

What is the role of baroreceptors and chemoreceptors in autoregulatory failure?

They contribute to the failure of the autoregulatory mechanism, leading to hypertension. Signup and view all the answers

What is the effect of increased sympathetic activity on the cardiovascular system?

Increased heart rate and contractility, and increased systemic vascular resistance. Signup and view all the answers

What is the relationship between heredity and hypertension?

Heredity can contribute to the development of hypertension. Signup and view all the answers

What are some examples of secondary hypertension causes?

Pheochromocytoma, Cushing's syndrome, renal dysfunction/disease, pregnancy, and preeclampsia/eclampsia. Signup and view all the answers

What is the recommended rate of reduction in blood pressure in the first hour?

No more than 25% in the first hour Signup and view all the answers

What is the target blood pressure range to be achieved within 2-6 hours?

160/100 mmHg Signup and view all the answers

What is the purpose of using vasodilators in hypertension management?

To dilate blood vessels and reduce blood pressure Signup and view all the answers

What is the underlying cause of pre-eclampsia?

Unknown, but can be worsened by HELLP syndrome Signup and view all the answers

What is the principle underlying the use of Poiseuille's Law in understanding blood flow?

The relationship between vasoconstriction, vasodilation, and flow rate Signup and view all the answers

What is the common treatment approach for hypertension during pregnancy?

Parenteral hydralazine, labetalol, and oral nifedipine Signup and view all the answers

What is the definition of hypertensive emergency?

Elevated BP with signs of target organ damage Signup and view all the answers

What are the possible causes of hypertensive crisis?

Renal disease/dysfunction, rebound hypertension, illicit drug use, certain medications Signup and view all the answers

What is the pathophysiology of primary hypertension?

Not well understood, but likely involves dysregulation of RAAS, inflammation, and genetic factors Signup and view all the answers

What are the clinical presentations of hypertensive crisis?

Headache, visual disturbances, dizziness, vomiting, papilledema, epistaxis, dyspnea, arrhythmias Signup and view all the answers

What are the target organ damages associated with hypertensive crisis?

Cardiovascular, renal, and neurological damages Signup and view all the answers

What is hypertensive encephalopathy?

A significant blood pressure rise disrupting cerebral autoregulation, leading to cerebral edema and neurological symptoms Signup and view all the answers

Hypertensive encephalopathy

Hypertensive encephalopathy involves a significant blood pressure rise disrupting cerebral autoregulation, leading to cerebral edema and neurological symptoms Signup and view all the answers

target Organ Damage

Cardiovascular: Aortic dissection, ACS, heart failure, pulmonary edema, myocardial ischemia Renal: Acute and chronic renal disease, hematuria, proteinuria, acute tubular necrosis Neurological: Cerebrovascular accident, intracerebral hemorrhage, hypertensive encephalopathy Signup and view all the answers

What medication treatment is used in managing hypertensive emergencies?

Vasodilators (e.g., GTN, sodium nitroprusside, hydralazine) Medication Management Central-acting adrenergic agents (e.g., clonidine) Calcium channel blockers (e.g., verapamil, nicardipine, nifedipine) ACE inhibitors (e.g., captopril) Beta-adrenergic antagonists (e.g., atenolol) Signup and view all the answers

Study Notes

Hypertension

Autoregulatory failure, including baroreceptors and chemoreceptors, can lead to primary (essential) hypertension.
Renal ischemia can trigger the RAAS system, increasing total peripheral resistance (TPR) and Na+ water retention.
Hormonal hypertension can occur due to increased catecholamines, leading to increased heart rate, contractility, and sympathetic activity.

Primary vs. Secondary Hypertension

Primary (essential) hypertension has no definitive cause, while secondary hypertension has an identified cause.
Possible mechanisms of primary hypertension include renal hypertension, hormonal hypertension, and heredity.
Secondary hypertension can be caused by pheochromocytoma, Cushing's syndrome, renal dysfunction/disease, pregnancy, and preeclampsia/eclampsia.

Risk Factors

Risk factors for hypertension include diabetes, smoking, obesity, alcohol, caffeine, stress, and multiple antihypertensives.

Hypertensive Urgency vs. Hypertensive Emergency

Hypertensive urgency is elevated blood pressure without signs of target organ damage.
Hypertensive emergency is elevated blood pressure with signs of target organ damage, such as headache, blurred vision, shortness of breath, and chest pain.

Pathophysiology

The pathophysiology of primary hypertension is not well understood, but likely involves dysregulation of the RAAS, inflammation, and genetic factors.

Hypertensive Crisis

Hypertensive crisis is a medical emergency that can lead to acute organ damage if not reduced.
Patients without a history of hypertension are at higher risk of worse outcomes.
Causes of hypertensive crisis include renal disease/dysfunction, rebound hypertension, illicit drug use, and certain medications.

Clinical Presentation

Symptoms of hypertensive crisis include headache, visual disturbances, dizziness, vomiting, papilledema, epistaxis, and dyspnea.
Clinical presentation may also include proteinuria, hematuria, anemia, and elevated creatinine.

Nursing Assessment

A thorough history, bilateral arm BP, presence of JVP, lung sounds, ECG, and lab results are necessary for nursing assessment.
Neurological changes should also be monitored.

Target Organ Damage

Cardiovascular damage can include aortic dissection, ACS, heart failure, pulmonary edema, and myocardial ischemia.
Renal damage can include acute and chronic renal disease, hematuria, proteinuria, and acute tubular necrosis.
Neurological damage can include cerebrovascular accident, intracerebral hemorrhage, and hypertensive encephalopathy.

Nursing Care

Manage headache by reducing blood pressure gradually.
Monitor glucose levels and check urine/urine saves.
Darken room/photophobia to reduce symptoms.

General Principles

Reduce BP gradually, not too quickly (no more than 25% in the first hour).
Aim for 160/100 mmHg within 2-6 hours, then normal BP over 24-48 hours.
Avoid excessive falls in BP to prevent organ ischemia.

Treatment

Medications include vasodilators (e.g., GTN, sodium nitroprusside, hydralazine), central-acting adrenergic agents (e.g., clonidine), calcium channel blockers (e.g., verapamil, nicardipine, nifedipine), ACE inhibitors (e.g., captopril), and beta-adrenergic antagonists (e.g., atenolol).

Pre-eclampsia

Hypertension during pregnancy with no identified cause can lead to pre-eclampsia.
Relieved at the time of birth, but can worsen with HELLP (hemolysis, elevated liver enzymes, low platelets) syndrome.
Parenteral hydralazine, labetalol, and oral nifedipine are common treatments for pre-eclampsia.

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