Hypertension - Complications | Medical Science Optional Notes for UPSC PDF Download

Introduction

Elevated arterial pressure induces alterations in the vascular endothelium, especially in small vessels, consequently impacting various organ systems.

•  Hypertensive crisis 
• Preeclampsia/Eclampsia

Hypertensive Crisis

Definition of Hypertensive Crisis: A sudden elevation in blood pressure exceeding 180/120 mm Hg.

Hypertensive Urgency: A sudden rise in blood pressure without symptoms and without evidence of organ damage.

Hypertensive Emergency: A critically elevated blood pressure associated with signs of end-organ damage, particularly affecting the cardiovascular, central nervous, and renal systems.

• Cardiovascular Presentation (chest pain, dyspnea)
  • Pulmonary Edema
  • Myocardial Infarction
  • Congestive Heart Failure and Dilated Cardiomyopathy
  • Aortic Dissection
• Neurologic Presentation (headache, confusion, blurry vision)
  • Hypertensive Encephalopathy
  • Ischemic or Hemorrhagic Stroke
  • Malignant Hypertension: Severe hypertension accompanied by retinopathy (flame hemorrhages, papilledema)
• Renal Presentation: Azotemia and/or oliguria resulting from acute renal failure.

Hypertensive Crisis - Management

Hypertensive Urgency: Consider reinitiating or increasing the dosage of oral antihypertensive therapy.
Hypertensive Emergency: Promptly admit the patient to the ICU and initiate intravenous antihypertensive therapy without delay.

Intravenous Antihypertensives:

1. Calcium Channel Blockers: Nicardipine, Clevidipine
2. Nitric Oxide-Dependent Vasodilators: Sodium Nitroprusside, Nitroglycerin
3. Direct Arterial Vasodilators: Hydralazine
4. Anti-adrenergic Drugs
   • Selective Beta-1 Blocker: Esmolol
   • Non-selective Beta Blocker with Alpha-1 Antagonism: Labetalol
   • Non-selective Alpha Blocker: Phentolamine
5. D1 Agonist: Fenoldopam

The commonly employed drugs for treating hypertensive emergency include nitroprusside, labetalol, and nicardipine.

1. General Objective:

   • Lower blood pressure by a maximum of 25% within the initial hour to prevent coronary insufficiency and ensure adequate cerebral perfusion.
   • Attain a blood pressure target of 160/100-110 mm Hg over the subsequent 2-6 hours.
   • Normalize blood pressure over a period of 24-48 hours.

2. Special Cases:

   • In cases of severe pre-eclampsia/eclampsia or pheochromocytoma, aim for a systolic blood pressure below 140 mm Hg within the first hour.
   • For aortic dissection, strive for a systolic blood pressure below 120 mm Hg within the first 20 minutes.

Preeclampsia/Eclampsia

Gestational hypertension, defined as blood pressure exceeding 140/90 mmHg after 20 weeks in women who were normotensive previously.
Proteinuria 

• ≥ 300 mg/24h, or 
• Protein: creatinine ratio ≥ 0.3 or 
• Dipstick 1+ persistenta 

or 

• Thrombocytopenia 
• Platelets < 100,000/μL 
• Renal insufficiency 
• Creatinine > 1.1 mg/dL or doubling of baseline 
• Liver involvement 
• Cerebral symptoms 
• Serum transaminase levels twice normal 
• Headache, visual disturbances, convulsions 
• Pulmonary edema

Antihypertensive Medication in Pregnancy

Pharmacological Management during Pregnancy:
First-line treatments include methyldopa, labetalol, hydralazine (a vasodilator), and nifedipine (a calcium channel blocker). Second-line options comprise thiazides and clonidine (an alpha-2 agonist). Contraindicated medications encompass furosemide, ACE inhibitors, ARBs, and renin inhibitors (such as aliskiren).

The Working Group on High Blood Pressure in Pregnancy (2000) determined that limited data were available to make definitive recommendations for treating mild chronic hypertension during pregnancy. However, the group advised empirical therapy for women with blood pressure exceeding threshold levels of 150 to 160 mm Hg systolic or 100 to 110 mm Hg diastolic, or for those exhibiting target-organ damage like left ventricular hypertrophy or renal insufficiency. Additionally, they suggested that early hypertension treatment might likely reduce subsequent hospitalization rates during pregnancy.

Antihypertensives-General Medicine - Repeats

• A 20-year-old male presented to the emergency room with intense headaches, and his blood pressure measured 220/130 mm Hg. This marked the third instance of recording significantly high blood pressure. List the potential causes of secondary hypertension and provide a brief overview of the treatment approach for a patient with essential hypertension. (2010)
• What are the existing guidelines for classifying hypertension? Outline the factors contributing to secondary hypertension.