The elderly patients with coronary heart disease is often complicated with chronic kidney disease, and these high risk patients has a risk of developing contrast induced acute kidney injury after undergoing percutaneous coronary intervention. Hydration is an important prevention to reduce the risk of contrast induced acute kidney injury , but hydration may cause acute left heart failure in elderly patients with renal insufficiency. We designed to give the elderly patients necessary hydration volume to reduce the risk of contrast induced acute kidney injury, and meanwhile avoid acute pulmonary edema caused by excessive preload. This study aimed to explore tailored hydration guided by lung water monitoring to prevent contrast induced acute kidney in elderly patients with renal insufficiency undergoing percutaneous coronary intervention. This study randomly divided elderly patients who are planning to undergo coronary intervention into two groups: tailored hydration group guided by remote dielectric sensing (ReDS system) and control group. The intervention group uses ReDS system to dynamically monitor the lung water index of enrolled patient, and fluid infusion rate is dynamically adjusted by lung water index to prevent the occurrence of acute pulmonary edema. We plan to evaluate the occurrence of postoperative acute kidney injury and acute pulmonary edema in two groups during the perioperative period. We follow up both major cardiovascular events and hemodialysis events in two groups.
