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HYPERTENSIVE EMERGENCIES PROF. SIR J. W. ACHEAMPONG Hypertension Raised Blood Pressure above (140/80) Classification of Blood Pressure for Adults aged 15 years and older Category Systolic Pressure Diastolic Pressure Optimal <120 <80 Normal <130 <85 High normal 130 -139 85 – 89 Hypertension Stage I (mild) 140 – 159 90 – 99 Stage II(moderate) 160 – 179 100 – 119 Stage III(Severe) 180 – 209 110 – 119 Base on the average of ≥ 2 reading taken at each of 2 or more visits after an initial screening. Source: Joint National Committee on Prevention, Detection, Evaluation and Treatment of High Blood Pressure. Symptoms of signs Most patients – No specific symptom referable to their blood pressure elevation Symptoms when Present fall into 3 categories 1. Related to elevated Pressure itself. 2. Related to hypertensive vascular disease 3. Related to the underlying disease (2ndly) Related to elevated Pressure itself 1. Headache – localized to the occipital region when patient awakens in the morning but subsides spontaneously after several hours. 2. Dizziness 3. Palpitations 4. Early fatiguability 5. Impotence Vascular disease Epistaxis Haematuria Blurring of vision Weakness or dizziness due to transient cerebral ischaemia Angina pectosis Dyspnea Underlying disease Polyuria & polydipsia Muscle weakness 2ndly to hypokalaemia (Primary Aldosterism). Weight gain + emotional ability (Cushing’s Syndrome). Episodic headaches, palpitations, diaphoresis and postural dizziness (pheochromocytoma) Hypertensive Emergencies 1. Effects on the Heart Concentric LVH → function of chamber deteriorates →cavity dilates → symptoms & signs of Heart failure 2. Angina Pectoris – Accelerated coronary arterial disease – Increase myocardial oxygen requirement as a consequence of increased myocardial mass. Neurologic effects Retinal CNS CNS – Cerebral infarction – is secondary to the increased atherosclerosis – Cerebral haemorrhage – result of both elevated Arterial pressure and the development of Cerebral Vascular microaneurysms ( Charcot, Bouchard aneurysms). Hypertensive Encephalopathy Severe hypertension Disordered consciouness Increased intracranial pressure Retinopahty with papillaedema end seizures Transient Ischaemic Attack (TIA) Focal neurologic signs → 1 transient after 24 hrs. Effects on the Kidney Arteriosclerotic lesions of the afferent & efferent arteriole & glomerular capillary tufts are the most common renal vascular lesions decreased glomerular filtration and tubular dysfunction Renal failure Malignant Hypertension Marked raised BP Papilloedema Retinal haemorrhage and excidates Manifestations of hypertensive encephalopathy Severe headache Vomiting Visual disturbances (transient blindness) Transient paralyses Convulsions, strepor and coma All due to spasms of cerebral vessels and to cerebral oedema. Cardiac decompensation Rapidly declining renal function Hypertensive Emergencies Physical Examination Round face and truncal obesity (Cushing’s Syndrome) Is muscular development in the upper extremities out of proportion to that of lower ext. Coarctation of Aorta – Delayed femoral pulse Renal Artery Stenosis + Carotid stenosis – bruit Acromegaly Physical Examination cont’d Palpate enlarged kidney (polycystic) Weight and height (BMI) Extremities for oedema ± Evidence of previous CVA Examination of ocular fundi is mandatory (Keith – Wagener-Barker Classification) Examination of Heart & Lungs (LVF) Is there left ventricular lift Are 3rd & 4th heart sounds present Are there pulmonary rates Laboratory Tests for Evaluation of Hypertension Basic Tests for Initial Evaluation 1. Always included a) Urine for protein, blood, and glucose b) Microscopic urinalysis c) Hematocrit d) Serum potassium e) Serum creatinine and/or blood urea nitrogen f) Fasting glucose g) Total cholesterol h) electrocardiogram Laboratory Tests for Evaluation of Hypertension cont’d 2. Usually included, depending on cost and other factors a) Thyroid-stimulating hormone b) White blood cell count c) HDL and LDL cholesterol and triglycerides d) Serum calcium and phosphate e) Chest X-ray; limited echocardiogram Laboratory Tests for Evaluation of Hypertension cont’d Special Studies to Screen for Secondary Hypertension 1. Renovascular disease: angiotensin- converting enzyme inhibitor radionuclide renal scan, renal duplex Doppler flow studies, and MRI angiography 2. Pheochromocytoma: 24-h urine assay for creatinine, metanephrines, and catecholamines Laboratory Tests for Evaluation of Hypertension cont’d 3. Cushing’s syndrome: overnight dexamethasone suppression test or 24-h urine cortisol and creatinine 4. Primary aldosteronism: plasma aldosterone: renin activity ratio Note: HDL, high-density lipoprotein; LDL, low-density lipoprotein; MRI, magnetic resonance imaging Therapeutic Agents Used to Treat Malignant Hypertension Time Course of Action Oral Preparation Drug Route Starting Dose Onset Peak Duration Available IMMEDIATE ONSET Nitroprusside Continuous IV 0.25μg/kg/min <1min 1–2 min 2–5min No Nitroglycerin Continuous IV 5μg/min 1–5min 2–6 min 3–10min No Diazoxide IV bolus 50mg q 5–10 min up to 600mg 1–5min 2–4 min 4–12 h No Fenoldopan Continuous IV 0.1–0.3μg/kg per min <5 min 5–10 min 30min No Esinolol Continuous IV 250–500 μg/min x 1 min; then 1–2min 2–3 min 10–20 min No 50 - 100μg/kg per min x 4min DELAYED ONSET Enalaprilat IV 1.25mg q h 10–15min 3–4h 6–24h Yes Hydralazine IV, IM 5 – 10 mg q 20 min x 3 10-20 min 20-40 min 4-12 h Yes Labetalol IV 20-80 mg q 10 min up to 300 mg 5 min 20-30 min 3-6 h Yes Nicardipine IV 5-15 mg/h 5-10 min 20-40 min 1-4 h Yes Drug Therapy for Hypertension 1. Diuretics – Thiazides – most frequently used Frusemide heart failure 30% Spironolactone reduction in Mortality 2. Anti Adrenergic Agents a) β-Adrenergic Receptor Blockers (β- blockers) Propranolol Atenolol Metoprolol Drug Therapy for Hypertension cont’d b) α Adrenergic Receptor blockers Phentolamine Prozosin Doxazosin c) Central – Adrenergic Agents Clonidine methyldopa (Also blocking sympathetic Nerves) d) α/ β – Adrenergic Agents Carvedilol Labetalol Drug Therapy for Hypertension cont’d 3. Vasodilators Vascular smooth muscle – Hydralazine – Diazoxide – Nitropruscide 4. Angiotension – Converting Enzyme inhibitors – Captopril – Enalapril – Ranupril 5. Angiotension Receptor Antagonists – Losartan – Valsartan – Atacand (candesartan) 6. Calcium Channel Antagonists Vascular smooth muscle Dihydropyridines – Nifedipine – Amlodipine - Felodipine Benzothiazepines: Diatiazem Phenylalkylamine: Verapamil THANK YOU
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