Chronic renal failure (CRF) is a clinical syndrome with various causes of chronic progressive renal parenchymal damage, resulting in significant renal atrophy and inability to maintain basic functions, with clinical manifestations of metabolite retention, imbalance of water, electrolyte and acid-base balance, and systemic involvement of all systems.
Pharmacological treatment of chronic renal failure
1. Correction of acidosis and water and electrolyte disorders
(1) Correction of metabolic toxicity: The treatment of metabolic acidosis is mainly oral sodium bicarbonate (NaHCO3). If necessary, intravenous input can be given to moderate and severe patients to basically correct acidosis after 72 hours or more. For patients with obvious heart failure, the total amount of NaHCO3 input should be prevented from being too much, and the input rate should be slow to avoid aggravating the heart load or even heart failure.
(2) prevention and treatment of sodium disorders: appropriate restriction of sodium intake, the general intake of NaCl should not exceed 6-8 g/d. For patients with obvious edema and hypertension, the sodium intake is generally 2-3 g/d (NaCl intake 5-7 g/d), individual severe cases can be limited to 1-2 g/d (NaCl 2.5-5 g). Tab diuretics (furosemide, bumetanide, etc.) can also be applied as needed. Thiazide diuretics and potassium storage diuretics are very ineffective in CRF disease (Scr>220μmol/L) and should not be applied. In acute heart failure with severe pulmonary edema, simple ultrafiltration and continuous hemofiltration (e.g. continuous veno-venous hemofiltration) should be given promptly.
(3) Prevention and treatment of hyperkalemia: Patients with renal failure are prone to hyperkalemia, especially when the serum potassium level is >5.5 mmol/L. Potassium intake should be more strictly restricted. While limiting potassium intake, attention should be paid to timely correction of acidosis and appropriate application of diuretics (furosemide, bumetanide, etc.) to increase urinary potassium excretion in order to effectively prevent hyperkalemia.
2.Treatment of hypertension
Timely and reasonable treatment of hypertension is not only to control certain symptoms of hypertension, but also to proactively protect target organs (heart, kidney, brain, etc.). Angiotensin-converting enzyme inhibitors (ACEI), angiotensin II receptor antagonists (ARB), calcium channel antagonists, collaterals diuretics, β-blockers, and vasodilators can be applied, with ACEI, ARB, and calcium antagonists being more widely used. The blood pressure of CRF patients should be <130/80mmHg before dialysis, and the blood pressure of maintenance dialysis patients should not exceed 140/90mmHg.
3. Treatment of anemia and application of erythropoiesis stimulating agent (ESA)
When hemoglobin (Hb) <110g/L or erythropoietic cell pressure (Hct) <33%, the cause of anemia should be examined. If there is iron deficiency, it should be treated with iron supplementation, and if necessary, ESA treatment, including human recombinant erythropoietin (rHuEPO), daipoetin, etc., can be applied until Hb rises to 110-120g/L.
4. Treatment of hypocalcemia, hyperphosphatemia and renal bone disease
When GFR<50ml/min, then phosphorus intake should be appropriately restricted (<800~1000mg/d). When GFR<30ml/min, while limiting phosphorus intake, phosphorus binding agents need to be applied orally, with calcium carbonate and calcium raffinate being preferable. For those with significant hyperphosphatemia (serum phosphorus >7mg/dl) or serum Ca, P product >65 (mg2/dl2), the application of calcium should be suspended to prevent the aggravation of metastatic calcification. In this case, short-term administration of aluminum hydroxide preparation or sevelamer can be considered, and calcium can be taken again when the Ca and P product is <65 (mg2/dl2).
For patients with significant hypocalcemia, 1,25(OH)2D3 (calcitriol) can be given orally; after 2-4 weeks, if calcium levels and symptoms do not improve, the dosage can be increased. The blood Ca, P and PTH concentrations should be monitored during treatment, so that the blood IPTH of CRF patients before dialysis is kept at 35-110 pg/ml; the blood calcium and phosphorus product of dialysis patients is <55 mg2/dl2 (4.52 mmol2/L2), and the blood PTH is kept at 150-300 pg/ml.
5. Prevention and control of infection
Usually, attention should be paid to preventing colds and preventing infections from various pathogens. The principles of antibiotic selection and application are the same as those for general infections, except that the dose should be adjusted. In the case of similar efficacy, the drug with the least nephrotoxicity should be selected.
6. Treatment of hyperlipidemia
Patients with CRF before dialysis are treated with the same principles as general hyperlipidemia and should be treated actively. However, for maintenance dialysis patients, the criteria for hyperlipidemia should be relaxed, such as maintaining blood cholesterol level at 250-300mg/dl and blood triglyceride level at 150-200mg/dl is good.
7.Oral adsorption therapy and catheterization therapy
Oral adsorption therapy (oral oxidized starch or activated charcoal preparation), catheterization therapy (oral rhubarb preparation), and colon dialysis can increase the excretion of uremic toxins by using the gastrointestinal route. The above therapies are mainly applied to patients with CRF before dialysis, and play a supplementary role in reducing azotemia in patients.
8.Other
(1) diabetic renal failure patients with declining GFR, insulin dosage must be adjusted accordingly, and should generally be gradually reduced.
(2) Hyperuricemia usually does not require treatment, but if gout is present, allopurinol should be given.
(3) Topical emulsifying oil for skin pruritus, oral antihistamines, control of hyperphosphatemia and intensive dialysis or high throughput dialysis are effective in some patients.