hypokalemiaandpotassiumdeficit-展示頁
2024-10-30 02:02本頁面
【正文】 rhea. His blood pressure was 90/60 mmHg, the pulse was 112/min, temperature is ℃ . The abdomen was distended with low skin elasticity. The laboratory results were: Arterial blood: pH=, PaCO2=26 mmHg PaO2= 108 mmHg. [Na+]=135 mmol/L [K+] = mmol/L [HCO3] = 16 mmol/L Urine: pH=, Specific gravity= ? The patient’s problems were: ? (1)isotonic dehydration ? (2)metabolic acidosis ? (3)hypokalemia. ? 病例分析 ? 1．患嬰， 3個月，入院前 1天開始發(fā)熱。 4) Blood dilution ? The concentration of potassium in plasma will reduce in dilute blood. ? Multiple factors in diabetes with ketosis and a. ? (3) Effect on the body ? 1) Effect on neuromuscular irritability ? 2) Effect on heart ? 3) Effect on the acidbase balance ? 4) Effect on the kidney 1) Effect on neuromuscular irritability Neuromuscular irritability (excitability) indicates the degree of difficulty or easy to start AP. High excitability means easy to start AP. Excitability is determined by the distance between the RMP and TMP. The less distance (difference) , the higher of excitability. (a) Decrease the neuromuscular irritability in acute hypokalemia. The negative value of RMP is increased (cell membrane is hyperpolarization, hyperpolarizative block). The difference between resting and threshold potential is increased. A greater stimulus is needed to produce an action potential (AP). (b) manifestations ① Effect on skeletal muscles The effects of hypokalemia depend on partly the decrease speed of serum [k+]. The rapidly decreased serum [k+] leads to skeletal muscle weakness, flabbiness (soft), and flaccid (soft) paralysis. The most severe problem of muscular paralysis is ?? ? In chronic potassium depletion, the k+ in ICF moves to ECF, both intracellular and extracellular [k+] are decreased, the ratio of [k+]i to [k+]e is not obviously changed, the resting potential is not changed. ? Chronic potassium depletion may lead to the muscle atrophy (thin and weakness of the muscle) , which is mainly caused by disturbance of protein metabolism. Chronic K deficiency decreases the ATP production and ATPase activity. In severe K deficiency (), during strenuous exercises the cells cannot release enough K to dilate the vessels, which can lead to ischemia and necrosis of muscle cells with energy metabolism disturbance (exertional rhabdomyolysis). ② Effect on SMC gastrointestinal tract, ? Decreased neuromuscular irritability causes: ? decreased intestinal motility, ? abdominal distension, ? anorexia, ? nausea ? constipation. ? bowel
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