Acute hemolysis caused by tubing bends during hemodialysis is one of the complications that threaten the patient's life. Although the incidence of hemolysis caused by tubing bends during hemodialysis is very low, its harm is extremely serious. If it is not discovered in time and effective measures are not taken, it may cause complications such as hyperkalemia, acute pancreatitis, and even death.
Mechanical hemolysis is usually caused by varying degrees of blockage in the blood circuit, including: the opening of the needle is close to the blood vessel wall, or is compressed by subcutaneous hematoma, which seriously obstructs blood flow; single-needle dialysis; excessive pressure on the blood pump drum, tubing bends, and blood is subjected to shear force. Tubing bends often occur in the section from the back of the pump to the inlet of the dialyzer, especially near the fixed or supporting tubing clamps and the section of the tubing close to the inlet of the dialyzer.
Harm of hemolysis
Hemolysis not only causes discomfort to patients, but also causes anemia, aggravates hemodynamic instability, causes hemolytic vasoconstriction and hypertension, obstructs blood supply to coronary arteries and brain tissue, or causes hypotension and decreased blood oxygen saturation during dialysis. If the cause of hemolysis is not promptly identified and properly treated, hemodialysis will be forced to stop due to lack of symptom relief, which will inevitably reduce the dialysis effect. Severe hemolysis can cause acute pancreatitis, hyperkalemia, arrhythmia, and even death. The severity of the consequences of hemolysis on patients is related to the patient's own factors. The survival period of red blood cells in patients with uremia is significantly shortened, oxidative stress is aggravated, and antioxidant capacity is reduced, all of which cause patients to have varying degrees of hemolysis.
Diagnosis of hemodialysis hemolysis
Nausea, shortness of breath, abdominal/back pain, chills, and acute hypertension occur during dialysis. Severe hemolysis patients may even have their skin color turn brown. The blood color at the back of the blood line pump, especially at the venous pot, is wine-colored; after centrifuging the blood sample, the supernatant shows pink; blood tests show that serum haptoglobin is significantly reduced to disappearance, lactate dehydrogenase (LDH) is significantly increased, and hematocrit is reduced. Since the pressure alarm device cannot effectively alarm for less severe hemolysis, medical staff and technicians are mainly required to check the installation status of the pipeline, including whether the pipeline is bent, whether there is abnormal and obvious pulsation, whether the blood in the pipeline is discolored, etc., and monitor the pressure changes and trends of the pipeline. If the arterial and venous pressures are significantly reduced at the same time (>25 mmHg), the pipeline may be bent.