What Does a Renal Dietitian Do?

Chronic kidney disease (CKD) definition: chronic kidney structural and dysfunction caused by various causes (history of kidney damage greater than 3 months), including normal and abnormal renal GFR pathological damage, abnormal blood or urine composition, and imaging CKD is abnormal when the examination is abnormal or the GFR decreases (<60ml / min · 1.73m ² ) for more than 3 months.

Basic Information

English name

chronic kidney disease, CKD

Visiting department

Nephrology

Common causes

Diabetes and hypertension are important factors for the worsening of kidney disease

Common symptoms

Loss of appetite, nausea, vomiting, odour in the mouth, etc.

Contagious

no

Chronic kidney disease staging

In recent years, the American Kidney Disease Foundation K / DOQI expert group has proposed new suggestions for the staging method of CKD. The first phase of CKD is to enhance the awareness and early prevention of early CKD.

Table the stages of chronic kidney disease

Staging	description	GFR [ml / (min · 1.73m 2	Description
1	Renal injury index (+), normal GFR	> 90	No abnormal GFR, focus on diagnosis and treatment of primary disease
2	Renal injury index (+) GFR decreases slightly	60 ~ 89	Slows CKD progression and reduces cardiovascular risk
3	Moderate GFR	30 ~ 59	Slow CKD progression and assess treatment complications
4	GFR severely decreased	15 ~ 29	Comprehensive treatment to treat complications
5	Renal failure	<15 or dialysis	Pre-dialysis preparation and dialysis treatment

Causes of chronic kidney disease

The causes of CKD mainly include primary glomerulonephritis, hypertension renal arteriosclerosis, diabetic nephropathy, secondary glomerulonephritis, tubulointerstitial disease (chronic pyelonephritis, chronic uric acid nephropathy, obstructive kidney disease, Drug-induced nephropathy, etc.), ischemic nephropathy, hereditary nephropathy (polycystic kidney disease, hereditary nephritis), etc. In developed countries, diabetic nephropathy and hypertension renal arteriolar sclerosis have become the main causes of chronic kidney disease. In China, these two diseases are still behind primary glomerulonephritis in various causes, but they have also become apparent in recent years. Increasing trend. According to relevant statistics, the prevalence of CKD in American adults (about 200 million in total) has reached 11.3%. According to some reports in China, the prevalence of CKD is about 10%. The main susceptible factors of CKD are age (such as old age), family history of CKD (including hereditary and non-hereditary nephropathy), diabetes, hypertension, obesity-metabolic syndrome, high protein diet, hyperlipidemia, and hyperuricemia Disease, autoimmune disease, urinary or systemic infection, hepatitis virus (such as hepatitis B or C virus) infection, urinary stones, urethral obstruction, urinary or systemic tumors, history of nephrotoxic drugs, cardiovascular disease , Anemia, smoking, low weight at birth, etc. Other risk factors include environmental pollution, low economic level, low medical insurance level, and low education level.

Clinical manifestations of chronic kidney disease

In different stages of CKD, its clinical manifestations are also different. Before CKD3, patients can be asymptomatic or have mild discomfort such as fatigue, backache, and nocturia, and a small number of patients may have anorexia, metabolic acidosis, and mild anemia. After CKD3, the above symptoms are more obvious, and they will be further exacerbated after entering the renal failure stage. Sometimes high blood pressure, heart failure, severe hyperkalemia, acid-base balance disorder, gastrointestinal symptoms, anemia, and abnormal mineral bone metabolism may occur , Hyperparathyroidism and central nervous system disorders, etc., can even be life threatening.

Gastrointestinal symptoms

The most common are gastrointestinal symptoms, which are mainly manifested by loss of appetite, nausea, vomiting, and oral odor.

2. Stomach and duodenum inflammation, ulcers, bleeding

Gastric and duodenal inflammation, ulcers, and bleeding are more common, and their incidence is higher than that of normal people. The blood system abnormalities of CKD patients are mainly manifested as renal anemia and bleeding tendency. Most patients generally have mild to moderate anemia. The cause is mainly due to erythropoietin deficiency, so it is called renal anemia. Respiratory symptoms such as shortness of breath and shortness of breath can occur when there is too much fluid or acidosis. Severe acidosis can cause deep breathing. Too much fluid and heart failure can cause pulmonary edema or pleural effusion. Some severe patients may be accompanied by uremia, pulmonary edema, uremia pleurisy, and uremia pulmonary calcification.

3. Cardiovascular disease

Cardiovascular disease is one of the major complications and the most common cause of death in patients with CKD. With the continuous deterioration of renal function, the prevalence of heart failure has increased significantly, reaching 65% to 70% in the uremia period. Heart failure is the most common cause of death in patients with uremia. Hemodialysis patients have more atherosclerosis and vascular calcification than patients before dialysis, and atherosclerosis often develops more rapidly. Uremic cardiomyopathy is mainly related to factors such as retention of metabolic waste and anemia, and pericardial effusion is also quite common in patients with CKD.

4. Neuromuscular system symptoms

Neuromuscular symptoms may include insomnia, inattention, and memory loss in the early stages of CKD. As the disease progresses, there are often indifferent reactions, convulsions, hallucinations, lethargy, coma, and mental disorders. Peripheral neuropathy is also common. Hypocalcemia, hyperphosphatemia, and deficiency of active vitamin D can induce secondary hyperparathyroidism (referred to as hyperparathyroidism); the above factors also cause renal osteodystrophy (that is, renal bone disease), including Fibrocystic osteitis (high turnover bone disease), osteomalacia (low turnover bone disease), poor osteogenesis, osteoporosis and mixed bone disease.

5. Endocrine disorders

CKD patients often have endocrine dysfunction, kidney endocrine dysfunction, including: 1,25 (OH) ₂ vitamin D ₃ , erythropoietin deficiency, and elevated renin-angiotensin II levels; can also cause hypothalamus -Pituitary endocrine disorders: such as prolactin, melanin-stimulating hormone (MSH), luteinizing hormone (FSH), follicle-stimulating hormone (LH), and adrenocorticotropic hormone (ACTH); elevated levels in most patients Hyperparathyroidism, insulin receptor disorders, elevated glucagon, etc. About a quarter of patients have a mild decrease in thyroxine levels.

Some patients may be accompanied by skin symptoms such as pigmentation, calcium, itching, difficulty in sweating, and ulcers. Some patients may have hypogonadism, manifested as gonad maturity or atrophy, low libido, amenorrhea, infertility, etc., which may be related to abnormal serum sex hormone levels, uremic toxin effects, and lack of certain nutrients such as zinc.

Chronic kidney disease treatment

In order to clarify the prevention and control goals of different stages of CKD, it is necessary to put forward the concept of tertiary prevention. The so-called primary prevention, also known as primary prevention, refers to the timely and effective treatment of existing kidney diseases or diseases that may cause kidney damage (such as diabetes, hypertension, etc.) to prevent the occurrence of chronic renal failure (CRF). Secondary prevention refers to the timely treatment of patients with mild to moderate CRF, delaying, stopping or reversing the progress of chronic renal failure and preventing the occurrence of uremia. The third level of prevention refers to the early treatment of uremia patients to prevent the occurrence of some serious complications of uremia and improve the survival rate and quality of life of patients.

The end result of the progression of chronic renal insufficiency is end-stage renal failure (ESRF), and patients will have to rely on renal replacement therapy to survive. Despite considerable progress in dialysis treatment, ESRF patients still have a higher mortality rate and a lower quality of life. Therefore, the treatment of patients with CKD includes treatment of delayed progression of chronic renal insufficiency and treatment of various comorbidities.

1. Delayed onset and progression of chronic renal insufficiency

(1) Primary disease treatment The primary disease causing CKD is treated.

(2) Progress of chronic renal insufficiency Progress of chronic renal insufficiency includes the following measures:

1) Control of blood pressure Active control of blood pressure can reduce proteinuria, can reduce glomerular hyperfiltration, and slow the progression of chronic renal failure. The selection principle of antihypertensive drugs varies according to the stage of CKD. When CCr> 30ml / min, angiotensin-converting enzyme inhibitor (ACEI) or angiotensin II receptor 1 antagonist (ARB) may be preferred, if necessary Combination of other antihypertensive drugs. When the Ccr of the patient drops below 30ml / min, the application of ACEI and ARB may cause low perfusion pressure in the glomerulus and make the glomerular filtration rate too low. Therefore, it should be used with caution in non-dialysis CKD patients.

2) Diet A low protein diet can reduce high perfusion, hypertension and high filtration in the glomeruli, reduce proteinuria, and thus slow the progression of glomerulosclerosis and interstitial fibrosis in CRF patients. When the GFR is lower than 25ml / (min.l.73rm²), the amount of protein should be limited to 0.6g / (kg.d). It should be ensured that sufficient calorie intake is greater than 35 kcal / (kg.d) to maximize the use of protein in the diet. In addition, essential amino acids or keto acid amino acid mixtures can be supplemented. In addition, salt intake should be restricted for patients with hypertension and edema. Patients with dyslipidemia should make dietary adjustments and should be treated with lipid-lowering drugs if necessary.

3) Correction for the acute exacerbation of chronic renal failure CRF is a slowly progressing disease, but because patients are more susceptible to a variety of risk factors, renal function may deteriorate during the course of the disease. Common risk factors are: insufficient blood volume, including hypotension, dehydration, shock, etc .; severe infection and sepsis; tissue trauma or major bleeding; kidney damage from endogenous or exogenous toxins; urinary tract obstruction; Uncontrolled severe hypertension and malignant hypertension. Carefully identifying the cause of the accelerated progress of renal function and taking targeted treatments can help improve renal function.

2. Prevention and treatment of CRF comorbidities

(1) Maintaining water and electrolyte balance and correcting metabolic acidosis. The amount of intake and withdrawal should be adjusted according to urine volume, blood pressure, and edema. Whether to limit sodium intake should be determined by the presence of hypertension and edema. In the event of hyperkalemia, the inducing factors should be corrected. At the same time, intravenous drip of 5% sodium bicarbonate, intravenous glucose plus insulin, intravenous bolus of 10% calcium gluconate, oral potassium-lowering resin can be given. The above measures are ineffective or severely high. Hemodialysis is required for potassiumemia (> 6.5mmol / L). Metabolic acidosis is common in patients with CRF. It is involved in malnutrition and renal bone disease through its effects on protein metabolism and 1,25 (OH) ₂ D ₃ production. Patients with mild acidosis only need to take sodium bicarbonate orally, and those with heavier carbon dioxide binding power <15rnmol / L need intravenous intravenous sodium bicarbonate.

(2) Prevention and treatment of cardiovascular diseases Strict control of blood pressure, blood lipids, blood sugar, avoiding excessive capacity, correcting metabolic acidosis, and correcting bad living habits (such as smoking, too little activity, etc.) can help reduce cardiovascular complications happened.

(3) Correction of renal anemia Application of recombinant human erythropoietin can correct renal anemia, and its target values are hemoglobin of 100 ~ 120g / L, and hematocrit of 31% ~ 32%. Correcting anemia can improve the blood supply and function of important organs, especially the heart, and improve the quality of life of patients with CRF. Special attention should be paid to iron supplementation when using erythropoietin, because iron deficiency is a common cause of its effect.

(4) Prevention and treatment of renal osteopathy By limiting the intake of phosphorus in the diet, the application of phosphorus binders can correct hyperphosphatemia. Hypocalcemia should be supplemented with calcium. Patients with hyperparathyroidism can consider 1, 25 (OH) ₂ D ₃ treatment on the basis of controlling blood phosphorus, and blood calcium, phosphorus and whole parathyroid hormone (iPTH) levels should be closely monitored during medication. The target value of iPTH is 150 ~ 200pg / ml (normal reference value is 10 ~ 65pg / ml, but patients with uremia need higher iPTH levels than normal people to maintain normal bone transformation), while avoiding high blood calcium and metastatic calcification happened.

When the disease progresses to ESRD in CKD patients, renal replacement therapy should be actively performed, including hemodialysis, peritoneal dialysis and kidney transplantation. The method of renal replacement therapy depends on the specific situation of the patient.