- Hemodynamic Pathophysiology: Blood pressure (BP) is determined by cardiac output (CO) multiplied by systemic vascular resistance (SVR). Hypertension occurs when regulatory mechanisms (sympathetic nervous, vascular endothelium, renal, and endocrine) fail. The hallmark is persistently increased SVR, leading to vessel remodeling, atherosclerosis, and ischemia.
- Diagnostic Classification: Based on two or more accurate readings on separate occasions, BP is categorized as:
- Normal: <120 SBP and <80 DBP mmHg
- Elevated: 120–129 SBP and <80 DBP mmHg
- Stage 1: 130–139 SBP or 80–89 DBP mmHg
- Stage 2: >=140 SBP or >=90 DBP mmHg
- Target Organ Damage: Often asymptomatic ("silent killer") until severe. Complications include cardiovascular (LVH, CAD, heart failure), cerebrovascular (stroke, encephalopathy), renal (nephrosclerosis, CKD), retinal (vision loss), and peripheral vascular disease.
- Hypertensive Crisis: Occurs at SBP >180 and/or DBP >120 mmHg.
- Hypertensive Emergency: Active target organ damage exists. Requires immediate hospitalization and IV drug titration (e.g., sodium nitroprusside). The goal is to reduce Mean Arterial Pressure (MAP) by 20% to 25% to prevent ischemia.
- Hypertensive Urgency: No active target organ damage; managed with oral drugs (e.g., captopril, labetalol, clonidine).
High-Yield Clinical Management & Interventions
- First-Line Pharmacotherapy: Preferred agents for Stage 1 include thiazide diuretics, calcium channel blockers (CCBs), and ACE inhibitors or ARBs. Loop or potassium-sparing diuretics may also be utilized. Orthostatic hypotension and sexual dysfunction are common side effects that hinder adherence.
- Actionable Lifestyle Modifications: Mandated for all elevated or hypertensive patients:
- Diet & Sodium: Adopt the DASH diet; restrict sodium to <=2300 mg/day (ideally <=1500 mg/day).
- Exercise & Weight: Minimum 150 minutes of moderate exercise per week. Weight loss reduces BP by 1 mmHg per kg lost.
- Substances: Avoid nicotine; limit alcohol (males: <=2 drinks/day; females: <=1 drink/day).
- Nursing Best Practices: Use correct cuff size (falsely high if too small). Assess for orthostatic changes (SBP drop >=20, DBP >=10, or HR increase >=20 bpm upon standing). Teach proper home BP monitoring (legs uncrossed, arm at heart level, rest 5 mins).
