The main indications for nitric oxide gas inhalation therapy are acute and severe pulmonary hypertension, including arterial pulmonary hypertension (idiopathic/hereditary PAH, congenital heart disease, neonatal persistent pulmonary hypertension, etc.), pulmonary disease and/or pulmonary hypertension caused by hypoxia (COPD, sleep apnea, ARDS, interstitial lung disease, high altitude pulmonary edema, etc.), and pulmonary hypertension caused by pulmonary arterial obstructive disease. The number of patients with these diseases is large, and there are problems such as dangerous incidence and high mortality, and the clinical needs need to be met urgently.
Pulmonary hypertension is a hemodynamic and pathophysiological state in which pulmonary arterial pressure rises above a certain threshold, leading to right heart failure. It can be an independent disease or a complication. Primary pulmonary hypertension refers to pulmonary hypertension without obvious cardiopulmonary disease. There are many causes of secondary pulmonary hypertension, mainly including pulmonary small vasoconstriction, polycythemia-hyperviscosity syndrome, pulmonary arterial smooth muscle hypertrophy, etc. As a signaling molecule, nitric oxide can regulate pulmonary vascular smooth muscle tension and selectively dilate pulmonary blood vessels.
Pulmonary fibrosis is a chronic disease. When the lungs are damaged, collagen is secreted for repair, which will cause a large increase in fibroblasts, which will gradually form pulmonary fibrosis. Patients may experience breathing difficulties, cough, chest tightness and shortness of breath. For pulmonary fibrosis, it is necessary to actively treat and control the development of the disease. If it is not controlled in time, the disease will be aggravated. It is conservatively estimated that the current number of patients with idiopathic pulmonary fibrosis in China is about 500,000, and the number of cases is still increasing. The disorder is more common in older adults, occurs slightly more in men than in women, and has a highly variable and unpredictable natural history. The survival rate of patients with idiopathic pulmonary fibrosis is worrying, and the 5-year survival rate is worse than some tumors, only 30% to 50%.
The foot is a complex target organ in the multisystem disease of diabetes. Peripheral neuropathy and peripheral vascular disease lead to excessive mechanical pressure in diabetic patients, which can cause destruction and deformity of the soft tissue and bone and joint systems of the foot, and then lead to a series of foot problems, ranging from mild neurological symptoms to severe ulcers, infection, vascular disease, Charcot arthropathy, and neuropathic fractures. Even aggressive treatment cannot completely resolve the symptoms and complications of the lower extremity, and failure to treat can have disastrous consequences.
The incidence of diabetic foot ulcers is as high as 8.1% among diabetic patients over 50 years old in China. It is estimated that every 20 seconds in the world, a diabetic patient has a limb amputation; the annual mortality rate of diabetic foot ulcer patients is as high as 11%, and the mortality rate of amputation patients is as high as 22%; domestic and foreign studies have shown that diabetic foot ulcers cost a lot, accounting for about one-third of the total diabetes medical expenses. Diabetic foot ulcer is one of the main causes of disability and death in diabetic patients, and it is also a major public health problem that causes a heavy burden on society.
With the advancement of medical technology, various minimally invasive and interventional procedures have become routine treatments. However, the movement of exogenous materials back and forth in the blood vessel will increase mechanical friction, damage the vascular endothelium, and cause platelets to aggregate at the catheter tip and damaged site, which is prone to thrombosis. Studies have found that catheter-indwelling for more than 72-96 hours is prone to catheter-related infections such as phlebitis. In addition, exogenous implants can also be infected. For example, the infection rate of breast reconstruction and breast augmentation surgery is 1% to 35%. Long-term infection may cause breast implant-related graded large cell lymphoma. The combination of NO anti-infective function and sustained-release coating materials provides novel idea for solving such problems.