Peripheral intravenous (PIV) therapy is the process of injecting fluid directly into the patient's vein. In cases where fluid and electrolyte balance cannot be achieved in patients who cannot be fed orally, in the administration of chemotherapy, antibiotics, and other intravenously administered drugs, intravenous therapy is frequently used in patients followed at the intensive care level, and fluids are given directly into the bloodstream. Although peripheral IV therapy has many benefits on the patient, complications such as phlebitis, infiltration, extravasation, thrombosis, cellulitis, and bloodstream infection may occur. The occurrence of these complications is related to inadequate catheter care, length and diameter of the catheter, length of stay in the vein, the substance it is produced, the patient's vascular structure and position, the type and flow rate of the given fluid, the length of stay in the hospital, and the individual characteristics of the patient.

Peripheral intravenous catheter complications may develop during catheterization or during infusion or may occur 24-96 hours after catheter removal. When these complications are encountered, the duration of the hospital stay of the patient is prolonged, and as a result, mortality and morbidity rates increase. The incidence of PIV catheter complications in our country is close to 50%. Among the complications, the most common and the most important complication is phlebitis. While the incidence of phlebitis is between 24.3% and 31.8% according to national studies, this rate is between 2.63% and 44% in international studies. Studies have reported that the incidence of phlebitis is higher in individuals receiving chemotherapy. Because chemotherapy treatments are usually administered by the PIV route. The irritant, vesicant, non-vesicant properties of chemotherapy drugs, high pH and osmolarity levels, and repeated cure treatments damage peripheral veins. In addition, antibiotics, hypertonic solutions, blood, and nutritional products, and analgesics are risk factors for the development of phlebitis.

Phlebitis is defined as the inflammation of the tunica intima layer of the vein. Phlebitis occurs in three ways: mechanical, chemical, and bacterial. Mechanical phlebitis; It is seen for reasons such as the individual characteristics of the patient, the catheter insertion site, the catheter type, and number, the material used in the catheter fixation, the length of time the catheter stays in the vein, the treatment time, the skill of the person inserting the catheter, the determination of the appropriate vein, the fluid flow rate, the use of infusion pumps, and the number of drugs given. Chemical phlebitis; It is seen when irritating drugs are given intravenously in a liquid with a density of 600 mOsm/lt or the pH of the fluids is less than 5 and greater than 9. Bacterial phlebitis is caused by factors such as cleaning the area with antiseptic, the frequency of changing the infusion set from the material on which the catheter is fixed, and the care of the catheter site. Symptoms of phlebitis are redness, erythema, pain, edema, palpable stiffness along the vein (venous cord), prominence of the venous line, tenderness, discharge, and warmth. The catheter site should be followed up with the "Visual Infusion Phlebitis Diagnostic Scale" in terms of these symptoms. However, in a study conducted by Arpa and Cengiz, it was found that nurses did not know the scale and had a lack of knowledge. Therefore, not following the catheter site and not recognizing the symptoms increase the incidence of phlebitis. When one of the symptoms of phlebitis is observed, the degree of phlebitis should be defined according to the scale and appropriate nursing interventions should be planned.

In the care of the patient with phlebitis, the infusion should be terminated, the catheter should be removed, the extremity should be elevated, and a new catheter should be inserted to continue treatment from another site. The area where phlebitis develops should not be used for a new catheterization for at least 48 hours. Symptoms such as redness, pain, swelling, and length of venous cord-shaped hardening in the area where phlebitis develops should be followed according to the visual phlebitis scale. In addition, it is stated in the literature that local warm application can be applied to the area with phlebitis symptoms. However, there is no clear information in the literature regarding when to start local warm application, its duration, and frequency.

Local warm application is frequently used by nurses to provide dilatation of blood vessels, to reduce inflammation by increasing oxygen circulation in hypoxic conditions, and for the non-pharmacological treatment of pain and tenderness. Hot/cold applications can be applied in two ways, wet or dry. The web application provides a moist environment in the area, increases blood flow to the area, carries nutrients, leukocytes, and antibodies, and increases the rate of wound healing. Wet application is more effective than dry application as the heat spreads rapidly to the deep tissues. However, changing the compresses frequently is important for the effectiveness of the application, as it causes evaporation with vasodilation and cooling of the skin.

Thermophore, aquathermic pad, hot or cold gel, hot water bath, ice accumulators, electric heating pad, and compresses are used for hot or cold applications. In the research to be conducted, a warm wet compress will be used. Compresses are used to apply local heat. Compress temperature is brought to the range of 26-34°C (79-93°F) for warm application. Compresses can be prepared in a wide variety of sizes and allowed to apply a certain temperature to the body area.

In the literature, it is stated in the literature that in the case of phlebitis, applying warm wet compresses to the affected area can be used to accelerate the blood flow and to reduce sensitivity and pain with the effect of tissue healing in the area. However, studies on this subject are limited. In a study conducted by Annisa et al. (2017) in 36 individuals aged 1 month to 17 years who developed phlebitis, one group was treated with warm water (n=16) and the other group (n=16) with 0.9% NaCl 3 to 4 times a day. Compress was applied for 20 minutes. When the phlebitis area was followed 24 and 48 hours later, it was stated that the degree of phlebitis decreased statistically significantly. In a study conducted by Hidayah et al. (2017) on 40 individuals aged 17-44 years, it was reported that there was a statistically significant difference in vessel diameter before and after warm wet application and reduced phlebitis. In the study of Gauttan and Vati (2016) with 60 individuals, it was found that wet heat and cold application for 20 minutes every two hours is equally effective and can be used for the treatment of phlebitis.

The Infusion Nurses Association (IHD) stated that it is very important to reduce the incidence of phlebitis to 5% and below, to prevent its occurrence, to be recognized early and to take necessary precautions, or to care about it occurs. Nurses working in clinics such as oncology, hematology, and palliative where phlebitis is common should have sufficient knowledge of phlebitis prevention, care, treatment, and practice. Nursing care provided by following current developments and using evidence-based nursing practices will decrease the incidence of phlebitis and increase the quality of care. In the literature, it is stated that warm application can be used in the care of phlebitis. However, it is not specified what the application will be done with, the temperature and how many times a day it will be done. Therefore, the aim of this study is to determine the effect of warm wet application in the care of peripheral venous catheter-related phlebitis.