"Etiology of Hypertension" is a brilliant example of a paper on the cardiovascular system. Primary or Essential Hypertension: In > 95% of cases where no cause is found are said to have essential hypertension. The primary abnormality may lie in Kidney, blood vessels, and over the active sympathetic system. The cause can be genetic, environmental factors that predispose to hypertension- high salt intake, heavy consumption of alcohol, obesity, lack of exercise, impaired intrauterine growth. Secondary Hypertension: Causes- Alcohol, pregnancy (pre-eclampsia), renal vascular disease, polycystic kidney disease, endocrine diseases (Pheochromocytoma, Cushing's syndrome, primary hyperaldosteronism, hyperthyroidism), Drugs (Oral contraceptives, anabolic steroids, corticosteroids, anti-inflammatory drugs), Coarctation of the aorta. In the majority of the diabetics, hypertension co-exists.
This is because of atherosclerosis of blood vessels which increases peripheral vascular resistance. Blood pressure = cardiac output X peripheral vascular resistance Both these conditions- hypertension (HT) and DM affect vital organs like heart, kidneys because of enhanced afterload and preload, there is stress over the heart to propel the blood into blood vessels, as a result, there is stretching of cardiac muscle fibers so as to improve muscle contraction (cardiac output). Initially, cardiac output is maintained by this compensatory mechanism but over time this compensatory mechanism fails causing heart failure resulting in cardiac hypertrophy. Blood supply to kidneys decreases, resulting in stimulation of RAS (Renin-Angiotensin System) which causes salt and water retention causing volume overload. Diabetic Ketoacidosis (DKA): Cardinal biochemical features: Hyperglycemia, Hyperketonaemia, metabolic acidosis. Hyperglycemia causes osmotic diuresis leading to loss of sodium and potassium.
The metabolic acidosis forces H-ion into cells, displacing K-ions which may be lost in urine or vomiting. There is a marked contraction of extracellular space with haemoconcentration, decreased blood volume, hypotension with renal ischemia, and oliguria. Drugs- For control of hypertension with Diabetes, the best choice of drugs encompass= ACE inhibitor- Captopril or Angiotensin receptor blocker- Losartan. For such an obese patient of more than 200 kgs, it has been found that operations like gastric bypass are superior to behavioral, medical therapy. Postoperative care encompasses a high protein diet, low-fat diet, fortified with multivitamins, iron, calcium on a daily basis.
Ursodiol may be given to reduce the risk of gallstone development. Nursing care encompasses regular monitoring of BP, blood sugar level, diet control.
ReferencesWudel LJ, Jr, Wright JK, Debelak JP, et al. 2002. Prevention of gallstone formation in morbidly obese patients undergoing rapid weight loss: results of a randomized controlled pilot study. J Surg Res; 102(1), 50- 56.