Phlebitis and infiltration: vascular trauma associated with the peripheral venous catheter

ABSTRACT Objective: to determine the incidence rate and risk factors for the nursing-sensitive indicators phlebitis and infiltration in patients with peripheral venous catheters (PVCs). Method: cohort study with 110 patients. Scales were used to assess and document phlebitis and infiltration. Socio-demographic variables, clinical variables related to the PVC, medication and hospitalization variables were collected. Descriptive and inferential analysis and multivariate logistic models were used. Results: the incidence rate of phlebitis and infiltration was respectively 43.2 and 59.7 per 1000 catheter-days. Most PVCs with these vascular traumas were removed in the first 24 hours. Risk factors for phlebitis were: length of hospital stay (p=0.042) and number of catheters inserted (p<0.001); risk factors for infiltration were: piperacillin/tazobactan (p=0.024) and the number of catheters inserted (p<0.001). Conclusion: the investigation documented the incidence of nursing-sensitive indicators (phlebitis and infiltration) and revealed new risk factors related to infiltration. It also allowed a reflection on the nursing care necessary to prevent these vascular traumas and on the indications and contraindications of the PVC, supporting the implementation of the PICC as an alternative to PVC.


Introduction
Nursing care at the hospital is essential for health prevention and promotion, patient safety and restoration of health and well-being. This includes care related to the insertion of peripheral venous catheters (PVCs), and their maintenance and monitoring (1)(2) .
Evidence shows that 58.7% to 86.7% of patients have a venous catheter inserted during their hospitalization, so PVCs are a significant portion of the care delivered by nurses (3)(4)(5). PVCs have become an indispensable resource for hospital care, necessary for intravenous administration of medications, solutions, blood components, parenteral nutrition and also for diagnostic purposes (4,(6)(7) . However, these devices are not free of complications. Several studies have documented a high incidence of peripheral vascular trauma associated with the use of PVCs, including phlebitis and infiltration (7)(8)(9)(10)(11) .
Phlebitis is an inflammation in the intimal layer of the vein, developed in response to tissue damage caused by factors associated with the insertion and use of the PVC and the medications administered through it. It is identified by clinical manifestations such as pain, erythema, blushing, edema and palpable venous cord (12)(13) . Studies assessing the incidence of phlebitis found values between 1.2% and 54.5% (7,(14)(15)(16)(17) . The studies indicate factors related to the characteristics of the patient, of the PVC and of the medications administered as risk factors for the development of phlebitis (14)(15)17) .
Infiltration is another type of vascular trauma, resulting from a lesion in the layers of the vein and a subsequent perforation, leading to infiltration of non-vesicant solutions or medications in the tissues surrounding the catheter insertion site. When the solutions or medications have vesicant properties, the leakage is called extravasation (18)(19) . Edema is the most frequent clinical sign of infiltration, and it may be associated with others such as pale skin, pain, temperature decrease and/or sensitivity at the site.
This article warns us about the risk of peripheral vascular trauma associated with the use of PVC and points out the need to increase the evidence on nursingsensitive quality indicators, namely for the incidence of phlebitis and infiltration and the possible risk factors for these complications, with the objective of producing knowledge and implementing evidence-based practices in nursing care. Aiming at improving the quality of nursing care and patient well-being, this study was carried out to determine the incidence rate and risk factors for nursing-sensitive indicators -phlebitis and infiltration -in patients using PVCs.

Method
A descriptive cohort study was carried out in the medical clinic of a hospital in the central region of It should be mentioned that new patients were allowed to enter the cohort and there were no followup losses. On the last day of the study (September 10 th ) there were 28 patients on intravenous therapy.
In order to evaluate the entire period of treatment, the 28 patients were followed until the end of their intravenous treatment, totaling 82 days of follow-up.
When the patient had more than one PVC inserted, all of them were considered for statistical analysis.        Table 3 presents the variables that had a higher probability of being a risk factor for phlebitis and infiltration and the respective values of odds ratio (OR) and p-value.

Discussion
The assessment of the nursing-sensitive quality indicator incidence of phlebitis in 110 patients with a PVC showed a cumulative incidence of 11.5%. This result is in agreement with other studies, which found values between 10.1% and 43.0% (9)(10)(11)16,25) . The current rate (11.5%) represents a significant reduction when compared to the incidence of phlebitis found previously in this unit (43.8%) (14) . However, it still exceeds the 5% recommended by the Infusion Nurses Society (11) .
This difference in incidence may be associated with www.eerp.usp.br/rlae other practices) (14) . Another difference may be due to the different scales used to evaluate the signs and symptoms of phlebitis and its grades.
The infiltration was another outcome analyzed.
It presented clinical and epidemiological importance due to the cumulative incidence of 15.8% found in this investigation. This result is lower than other studies with rates of 23% and 31.5% (9)(10) and higher than the incidences of infiltration of 7% and 13% found in studies conducted in Portugal (14,16) . This difference may be due to the use of a scale (19) to evaluate the signs and symptoms of infiltration in the present study, reducing variability in documentation and information bias. A standardized evaluation of this indicator was not assured in other studies (14,16) .
It should be mentioned that the differences between the studies regarding the incidence of phlebitis and infiltration may also be due to the characteristics of the patients in the sample and the limitations particular to each study.

The risk factors for phlebitis revealed in this study
were the length of hospital stay and the number of catheters inserted in the patients, which are the same as those reported in a study carried out in Spain (25) .
The risk factors for the occurrence of infiltration were the antibiotic piperacillin/tazobactam and the number of catheters inserted in the patient. These risk factors were not identified in other studies, which have a low evidence level, since they are based on case reports and series of cases and have small samples (18,(20)(21)(22) . Only a retrospective study with children used logistic regression to assess the risk factors for infiltration, evidencing as risk factors insertion in the lower limbs, hospitalization in pediatrics and administration of medication (27) .
The clinical manifestations of phlebitis and infiltration were identified by the nurse mainly in the first 72 hours after insertion of the PVC (70.1% and 85.6%, respectively) and with a higher percentage in the first 24 hours. This result is in agreement with the period for manifestation of phlebitis and infiltration found in other studies (9,11,(16)(17) . In addition, this reinforces the consider the patient's preferences (6) . This analysis may indicate other venous catheters to the patient, such as peripherally inserted central catheters(PICC) (6) .