Risks And Countermeasures Of Contrast Medium Use in Patients With Chronic Kidney Disease

With the increasing popularity of cardiac interventional diagnosis and treatment, contrast-induced nephropathy (CIN) has become a hot spot in the prevention and treatment of perioperative complications in the interventional diagnosis and treatment of cardiovascular diseases. It is reported that due to the aging of the population, the proportion of inpatients with cardiovascular disease in Western countries combined with chronic kidney disease or diabetes has reached 50 percent to 60 percent in recent years, and the incidence of chronic kidney disease or diabetes in my country has gradually increased. Faced with the huge high-risk population of CIN, appropriate preventive measures should be given as soon as possible to improve the prognosis and improve quality of life.

Click to Buy Cistanche for kidney disease

Epidemiological data on the occurrence of CIN

The overall prevalence of chronic kidney disease in my country is 9.3%, that is, one in every 10 adults suffers from the disease. Studies have shown that in the population undergoing interventional therapy, the incidence of postoperative CIN in patients with normal basic renal function is less than 2%, while the serum creatinine (SCr) level is increased (SCr≥88.4 μmol/L in women, SCr≥114.9 μmol/L in men). ), the risk of CIN increases. When SCr>176.8μmol/L, the incidence of CIN>20%, when SCr>442.0μmol/L, permanent irreversible CIN may occur in 50 percent of cases. It can be seen that the occurrence of CIN is positively correlated with the basal level of SCr, especially in patients with acute myocardial infarction, renal transplantation, and potential renal damage, and in patients receiving interventional therapy, the incidence of CIN is significantly increased. Therefore, how to reduce the incidence of CIN in these high-risk patients has become the focus of research in this field.

Precautions for CIN

A large number of studies have been carried out at home and abroad to prevent the occurrence of CIN in high-risk groups. The recognized preventive measures are as follows.

Assess basic renal function to screen for at-risk groups

Renal function is usually graded according to the estimated glomerular filtration rate (eGFR). The calculation of eGFR is based on the modified MDRD formula recommended in the expert consensus on the prevention and treatment of CIN in my country: adult eGFR [ml/(min·1.73m2)]=175 ×【SCr(mg/dl)】-124×age-877×(0.79, female).

Hydration Treatment

Hydration therapy can increase renal blood flow, reduce renal vasoconstriction, shorten the residence time of contrast agents in the kidney, reduce cast formation, and reduce the incidence of CIN. Isotonic crystalloid fluid should be given 12 hours before the angiography and continued until 6-24 hours after the operation [speed 1-1.5ml/(kg·h)].

Contrast agent selection

The first-generation ionic monomeric hyperosmolar contrast medium (HOCM) has serious toxic and side effects, and the risk of CIN is high after application in patients with renal insufficiency. The second-generation non-ionic monomeric hypotonic contrast medium (LOCM) has an osmotic pressure that is still 2-3 times that of plasma, can be sterilized at high temperatures, and has improved tolerance and hydrophilicity. The third-generation non-ionic dimer isotonic contrast medium (IOCM) has extremely high water solubility, which reduces the osmotic pressure of the contrast medium, but the molecular structure increases, thereby increasing the viscosity. According to Poiseuille's law of rheology that blood flow in blood vessels follows, the flow resistance is inversely proportional to the radius of the blood vessel and proportional to the length of the blood vessel and blood viscosity, so the viscosity has a great influence on the blood flow resistance. The viscosity of the isotonic contrast agent at 14 degree is 2 times higher than that of the hypertonic or hypotonic contrast agent, but there is no significant difference between the three at 37 degree . Therefore, the isotonic contrast agent can be heated to 37 degree before application. to reduce its viscosity. The advantages and disadvantages of LOCM and IOCM have been verified by multiple trials in recent years, and most of the research results are indistinguishable. Therefore, the content of the recommended types of contrast agents has been canceled in the latest American guidelines. However, for patients with a high risk of CIN, there are many studies supporting the safety of limited application of IOCM.

Control the amount of contrast agent

In patients with renal insufficiency, the dosage of contrast agent should be more strictly controlled during coronary interventional diagnosis and treatment, and the total amount of contrast agent should not exceed 2 times the basal GFR ml.

discontinuation of drugs that may cause kidney damage

Drugs such as metformin, non-steroidal anti-inflammatory drugs, loop diuretics, and nephrotoxic antibiotics were discontinued. A large number of clinical practices have proved that hydration and limiting the amount of contrast agents are the most effective preventive measures for CIN. However, even with standard hydration therapy and maximal restriction of contrast dose, some patients develop CIN. How to further reduce the risk of CIN? In recent years, studies have found that statin lipid-lowering drugs have a preventive effect on the occurrence of CIN in the perioperative period of coronary heart disease interventional therapy, and have been recommended by the European Society of Cardiology as class IA. Statins mainly prevent and treat CIN by protecting renal tubular endothelial function and resisting renal tubular inflammation and peroxidation. The center presided over the largest multi-center, prospective, randomized, controlled clinical study in China. A total of 3,000 patients with diabetes mellitus with mild to moderate renal insufficiency were selected and divided into a statin group and a blank control group. The results showed that in patients in the statin group The incidence of CIN was significantly lower than in the control group.

Typical clinical case

Based on the accumulation of a large amount of clinical experience and the application of careful prevention and treatment strategies, we have successfully treated patients with coronary heart disease who were at a very high risk of CIN [eGFR<30 ml/(min·1.73m2)]="" and="" who="" were="" in="" urgent="" need="" of="" interventional="" diagnosis="" and="" treatment.="" typical="" case:="" an="" 84-year-old="" male="" patient="" with="" a="" history="" of="" hypertension,="" diabetes,="" and="" typical="" exertional="" angina="" pectoris="" for="" 20="" years.="" in="" 2010,="" he="" underwent="" a="" right="" kidney,="" ureter,="" and="" partial="" cystectomy="" due="" to="" bladder="" transitional="" cell="" carcinoma.="" she="" was="" admitted="" to="" the="" hospital="" due="" to="" aggravation="" of="" angina="" pectoris="" symptoms.="" scr="" 238="" μmol/l="" [egfr="" 23="" ml/(min·1.73m²)]="" on="">

Intolerance to hydration therapy in another hospital due to heart failure. After admission, we controlled his blood pressure at 120-130/70-80 mmHg, stopped metformin, and switched to subcutaneous injection of long-acting insulin to make his fasting blood glucose <7.8 mmol/l="" and="" postprandial="" blood="" glucose=""><11.1 mmol/l;="" rosuvastatin="" 5="" mg/night="" and="" metoprolol="" 6.25mg,="" 2/day="" orally;="" the="" hydration="" treatment="" plan="" was="" changed="" to="" 0.2ml/(kg·h)="" (total=""><200ml )="" to="" increase="" the="" tolerance="" of="" the="" patient's="" cardiac="" function.="" the="" angina="" pectoris="" was="" not="" relieved="" significantly="" under="" drug="" treatment,="" and="" the="" surgery="" refused="" to="" perform="" bypass="" surgery.="" therefore,="" coronary="" angiography="" and="" interventional="" therapy="" were="" performed="" in="" the="" hospital="" for="" 21="" days.="" during="" the="" operation,="" 2="" coronary="" stents="" were="" successfully="" implanted.="" the="" isotonic="" contrast="" agent="" iodixanol="" only="" used="" 65ml="" (="" completion="" of="" this="" type="" of="" surgery="" usually="" requires="" 150="" to="" 200="" ml="" of="" contrast="">

Preoperative drug and hydration therapy were continued after the operation, and renal function was monitored daily. The fluctuation of eGFR was [2-25 ml/(min·1.73m²)], and he was cured and discharged. There was no adverse event during the two-year follow-up. The following experiences were concluded from the successful prevention and treatment of CIN in this very high-risk patient: (1) adequate hydration therapy should be performed before surgery, especially for very high-risk patients with eGFR<30 ml/(min·1.73m²),="" cardiac="" insufficiency="" is="" difficult="" to="" tolerate="" the="" hydration="" program="" can="" reduce="" the="" hydration="" speed="" and="" appropriately="" prolong="" the="" hydration="" treatment="" time;="" (2)="" fully="" control="" blood="" pressure="" and="" blood="" sugar;="" (3)="" stop="" drugs="" that="" may="" cause="" kidney="" damage="" such="" as="" biguanides="" at="" least="" 24="" hours="" before="" surgery;="" (4)="" experienced="" interventional="" physicians="" to="" minimize="" the="" dose="" of="" contrast="" media="">

for more information:ali.ma@wecistanche.com