With the transformation of the medical model, the patient's demand for the quality of medical care services is constantly improving, and at the same time, the demand for the alleviation of the pain of intravenous infusion is also getting higher and higher. At present, intravenous infusion of potassium chloride solution to correct patients' water and electrolyte imbalance is very common in clinical practice. However, intravenous potassium supplementation is prone to cause pain or radiating pain in the localized area of infusion, which brings a lot of pain to the patients and directly affects the effect of fluid input. How to solve this problem has been a difficult problem plaguing the nursing community. It is the nurse's duty and the patient's right to alleviate the pain of patients during infusion. Now, the mechanism of occurrence of pain caused by intravenous potassium supplementation, related factors and nursing interventions taken, which have been understood, are summarized as follows.
1 Causes of pain caused by intravenous potassium supplementation and related factors
1.1 Causes of pain caused by potassium chloride solution Potassium chloride preparations are hypertonic drugs, with a pH value between 5.0 and 7.0, while potassium ions themselves are also an analgesic factor, which enter the tissues and then act on the nerve endings receptors, depolarizing them and causing pain. Potassium ions can also directly stimulate the upper wall of blood vessels, and through the sympathetic nerves of the upper wall of blood vessels to cause subcutaneous and epidermal tissue myoelectric burst wave, single wave release ability to intensify the touch of free nerve endings and cause stimulation of pain and radiating pain [1]. In addition, potassium ions can also cause the body's neuromediators such as adrenaline, 5-hydroxytryptamine and other substances in different degrees of elevation [2], inducing pain reflex.
1.2 Factors related to the analgesia caused by potassium chloride solution
1.2.1 Anatomical and physiological factors Phytophysiology of the nervous system that the skin vasculature is innervated by the sympathetic nerves, and that the stimulation of sympathetic nerves in the skin can cause the secretion of the vertical hairs, sweat glands, and vasoconstriction. Receptors are widely distributed in the body, and the receptors for nociception are mainly free nerve endings, which can be divided into surface receptors and deep receptors according to different distribution sites. Surface receptors are mainly distributed in all layers of the skin, when the nerve is close to the endings, the myelin sheath of the axon disappears, and becomes bare branches scattered between the tissue cells and capillaries, which have a greater density of distribution, and are more sensitive to the stimulus sensation, while the distribution of the joint ligaments, tendons, myocardium, periosteum and arterial and venous blood vessels in the lower wall of the free nerve endings are sparse compared to the skin, and the sensitivity to the stimulus is low [3]. At the same time, reflecting the degree of pain of the nerves are mostly accompanied by the venous route, which is mainly distributed in the superficial surface of the veins of the superficial subcutaneous, and the closer the surface of the endings of the body, the greater the ratio of sensory nerve bundles, the higher the pain sensitivity [4].
1.2.2 Individual differences in pain tolerance There are great differences in human pain perception and tolerance, the same nature, the same intensity of the stimulus can cause different degrees of pain response in different individuals. Factors affecting pain perception and tolerance include the patient's age, gender, the characteristics of the disease and other physiological factors, but also by personal life experience, cultural upbringing, emotion, personality and attention and other psychosocial factors.Jane [5] found that the genetic coding of the human pain response system and neuromodulatory mechanisms due to gender differences in the existence of great differences, so gender is also a factor affecting pain perception. factor that affects pain perception. The human body's pain perception and tolerance in infancy and childhood is low, with the growth of age, the human body's sensitivity to pain gradually increased, and the adult stage of the strongest sensitivity to pain. After entering the old age stage, the functions of all parts of the human body gradually decline, and the sensitivity to pain is also gradually reduced. At the same time, some patients have fear and nervousness about intravenous infusion, and are in a state of excessive anxiety for a long time, so that their sensitivity to pain is enhanced throughout the infusion process, and they are more likely to have a feeling of pain.
1.2.3 Infusion factors (1) improper choice of infusion set, particles is another important factor leading to infusion pain. Some studies have proposed that infusion phlebitis is related to the number of particles in the drug solution through clinical verification [6]. Usually there are a large number of particles in the drug, the vast majority of which are below 10 μm, accounting for about 98.4% of the total number of particles, and the ordinary infusion set now used in the clinic has almost no filtration effect on the particles in this range. A large number of particles into the blood vessels, stimulating the blood vessel wall, causing pain. Inappropriate choice of needle type, the clinical use of 7-gauge needles for venous puncture, needle caliber is large, the skin stimulation is large, the needle into the subcutaneous tissue and nerve endings of the strong stimulation, pain is obvious. (2) Operational factors. (1) improper selection of blood vessels: the selection of blood vessels blindly pursue the success rate of puncture, emphasizing the "one shot", without fully considering the physical and chemical properties of the drugs used to stimulate the blood vessels, but also ignored the programmed infusion of blood vessel selection requirements; ② intravenous drip too fast: the patient entered a large amount of liquid every day, intravenous infusion time is long! The patient produces impatience and adjusts the infusion speed without authorization, causing pain; ③ The length of needle insertion after puncture is too long: the length of needle insertion is too long, which increases the damage area to the vessel wall and local mechanical stimulation; ④ The angle of needle insertion during puncture is too small: routinely inserting the needle at an angle of 20 °, with a large area of skin damage, the skin is not easy to enter the needle with the tip of the needle when inserting the needle, and the stimulation of the needle on the skin is prolonged, and the pain is obvious; ⑤ Fixing of needle shanks Methods: In the routine fixation, the tip of the needle is beveled upward, and the drug directly stimulates the upper wall of the blood vessel near the skin side of the blood vessel, and the distribution of nociceptive nerve endings on this side is richer, which is easy to cause pain; (3) The infusion time is too long. Routine in order to reduce the input of potassium ions caused by the pain reaction, often used to dilute the potassium concentration and slow down the drip rate and other methods, but often affects the drug plan, while prolonging the infusion time to the patient's rest and activities to bring inconvenience, increasing the chance of leakage. The inconvenience of patients' rest and activities and the prolonged infusion time puts patients in a state of excessive anxiety and reduces their tolerance to pain, and a small pain stimulus can cause a strong pain response.