The peripherally inserted central catheter (PICC) was first described in the literature in 1929 (Quintão Vieira et al, 2020). It is an intravenous device made of polyurethane or silicone, both of which are biocompatible.
The PICC is a therapeutic resource for patients who require intravenous therapy to treat acute or long-term conditions. The device can be used in patients admitted to intensive care units (Oliveira et al, 2014; de Sá Neto et al, 2018); as it is a central catheter, it promotes safe and long-lasting venous access that allows the infusion of large volumes of drugs vasoactive drugs, parenteral nutrition and solutions with higher osmolarity.
The main adverse events associated with the device are bloodstream infections, thrombotic events, arterial puncture and nerve injury (Gorski et al, 2021). As a strategy, organisations such as the Centers for Disease Control and Prevention and the Infusion Nurses Society (INS) recommend practices such as infection prevention bundles, skin cleansing with topical antiseptic, minimising the number of catheter lumens, employing specialised vascular access teams, adopting strategies for timely catheter removal, following insertion protocols to avoid unnecessary catheterisation and professional education, among other approaches (Gorski et al, 2021).
Since 2001, Brazil's National Nursing Board has regulated catheter insertion by a qualified/trained nurse. According to Barbosa et al (2020), a total of 2500 PICC insertions were performed in 2015 in Brazil.
Despite protocols and training based on international and national guidelines on good practice and consideration of local realities (such as patient profile, equipment available and staffing resources), a standardised, validated instrument for analysing knowledge of PICCs is lacking.
A national US survey in 2013 reported that 86% of hospital doctors (328 out of 381) had cared for a patient with a PICC; 24% did not routinely examine the PICC for external problems, 5% did not know why the position of the tip of the PICC is checked after insertion at the bedside, and 57% did not think that hospital doctors should be trained to insert PICCs (Chopra et al, 2013).
Studies conducted with nurses revealed a lack of knowledge regarding catheter maintenance and care (Xu et al, 2020; Indarwati et al, 2022), which may create barriers to promoting and maintaining the PICC (Xu et al, 2020). This highlights the need for education to improve care.
In Brazil, few studies have investigated professionals' knowledge of PICCs, with the majority focused on intensive care, paediatric patients and oncology patients (Lourenço and Ohara, 2010; Stocco et al, 2011; Belo et al, 2012).
Building an instrument requires an assessment to verify its structure, logical sequence and appropriateness of language and that it is easy to understand, while paying attention to what will be evaluated (Rodrigues et al, 2021). Instruments that analyse nurses' knowledge about caring for patients with a PICC are still a nascent topic, and the lack of available instruments prompted the development of the present study. The use of validated instruments will allow the development of focused educational measures that will contribute to updating nurses with new skills. This, in turn, will result in high-quality nursing care and patient safety around PICC care.
Objective
The objective of this study was to develop an instrument for analysing nurses' knowledge about PICCs and evaluate its content validity.
Method
Study design
This was a psychometric study, including the construction of a knowledge instrument in two stages: instrument construction; and assessment of evidence of content validity by expert judges.
Instrument development
Before the development of the instrument, an integrative review was conducted. The authors — a nurse (KACB), a specialist nurse in medical and surgical clinics (MDSF), and a nurse certified in infusion therapy (AS) — worked at the same hospital while the research was carried out. The hospital has a team of nurses who work exclusively on vascular access, of which AS is a member; the team uses an evidence-based protocol (Agência Nacional de Vigilância Sanitária (ANVISA), 2017; Gorski et al, 2021) and provides training on good PICC practice for new staff followed by periodic education.
The vascular access team nurses are responsible for inserting vascular access devices, managing complications when requested by nursing practitioners, and sometimes providing practical training to other nurses. Nurses in the hospital are responsible for daily catheter care, assessment and maintenance, and can ask the team for support.
Nonetheless, the authors recognised that a standard instrument that assessed nurses' knowledge of general best practices was needed, not just institutional protocols. KACB and AS met to construct the items of the instrument based on recommendations of the international 2021 Infusion Therapy Standards of Practice (Gorski et al, 2021) and the Measures for the Prevention of Healthcare-Associated Infections document (ANVISA, 2017), as well to consider forms proposed by a similar study (Indarwati et al, 2022). During these meetings, the aim was to create an instrument with crucial items that was relevant to day-to-day nursing practice. After construction, MDSF evaluated the instrument to verify whether it was clear, whether all the items were obvious in meaning and whether there were any repeated words or double meanings. After this assessment, all nurses involved analysed the main components and whether the instrument was relevant to care practice.
The instrument for analysing nurses' knowledge about PICCs was composed of four domains with a total of 12 questions: catheter indication: four questions; PICC maintenance: three questions; complication management: three questions; and catheter removal: two questions. Each question had four alternative answers, only one of which was correct.
Another option would have been to use a five-point Likert scale, providing the respondent with a choice of the following: ‘strongly agree’, ‘agree’, ‘neutral’, ‘disagree or ‘strongly disagree’ (Xu et al, 2020; Indarwati et al, 2022). However, the intention was to record knowledge and, in the case of wrong answers, identify the factors related to this.
Evidence of content validity
The developed instrument was submitted to a panel of experts for content validation, which involved a process of verifying whether the studied phenomenon is reflected and represented reliably.
The experts should analyse each item, the significance of the measured objectives, their relevance in practical scenarios and their clarity, classifying them as essential items or non-essential items (Ayre and Scally, 2013), and suggesting additions or changes.
After the assessment by the panel, the content validity ratio (CVR) developed by Lawshe (1975) was applied using the formula below, where ne=number of panel members who considered that an item was essential and N=total is number of judges:
CVR = n e − ( N/2 ) N/2
The CVR is a linear representation of the level of agreement between the experts' assessments. The critical values of the CVR can be used to determine how many panel members need to agree on an essential item and, therefore, which items should be included or excluded (Ayre and Scally, 2013; Devellis, 2017). The numerical value of the CVR is determined using the Lawshe table (Belo et al, 2012; Ayre and Scally, 2013).
For a sample of judges of less than 10, it is recommended to carry out a CVR recalculation (Wilson et al, 2012).
Study site and sample
The study was carried out from August to September 2022 in the city of São Paulo, in the state of São Paulo, Brazil. Experts with the following inclusion criteria were invited: having worked for at least 5 years as specialists in vascular access and meeting at least two of the following criteria: experience in PICC insertion; having a master's or doctoral degree in the field; having completed a PICC certification course; publication related to vascular access; and knowledge of the INS 2021 guideline (Gorski et al, 2021).
Each selected expert who agreed to participate in the research signed an informed consent form. They were required to complete the assessment of the instrument using an Excel spreadsheet. Instructions were provided to them on the requirements and process of the study.
Ethical aspects
The hospital research ethics committee approved the project (resolution 466/2012, registration number 63133722.8.0000.5464).
Results
Eleven nurses were invited, nine of whom were accepted to be members of the panel of experts. Among them, 78% were women, 22% held a master's degree or doctorate, 67% worked in public hospitals and 88% were from the south-east region. All experts were experienced in the insertion of PICCs, understood the 2021 INS standards of practice 2021 and held PICC certification.
For a panel of nine expert judges, a critical CVR of ≥0.775 was considered, as Wilson et al (2012) recommended. The evaluated items and their CVR values are presented in Table 1.
Table 1. Instrument items to evaluate professionals' knowledge of peripherally inserted central catheters: assessment by experts
| Domain | Questions | CVR |
|---|---|---|
| Catheter indication | Some indications for a PICC are: | 1 |
| ( ) When there is a need to obtain and maintain central venous access to administer hypertonic; hyperosmolar (>900 mOsm/l) solutions and/or prolonged therapy (eg an antibiotic for ≥7 days) | 1 | |
| ( ) Facilitating the collection of laboratory tests | 0.778 | |
| ( ) All of the above | 0.778 | |
| ( ) I don't know | 0.778 | |
| Contraindications for PICC insertion are: | 1 | |
| ( ) Chronic kidney disease with a requirement for preservation of the vascular network and/or a history of venous thrombosis | 1 | |
| ( ) Use of anticoagulants regardless of dose | 1 | |
| ( ) All of the above | 0.778 | |
| ( ) I don't know | 0.778 | |
| Regarding PICC indications: | 1 | |
| ( ) Patients admitted to the intensive care unit, undergoing diagnostic investigation, stable and without established intravenous therapy are indicated for PICC | 1 | |
| ( ) Patients with PICCs for more than 30 days need prophylactic replacement to prevent bloodstream infection | 1 | |
| ( ) The PICC should not be chosen as a strategy for preventing bloodstream infection | 0.778 | |
| ( ) I don't know | 0.778 | |
| Among the possible complications during device insertion are: | 1 | |
| ( ) Temporary or permanent nerve injury, arrhythmia and embolism, among others | 1 | |
| ( ) The only complication in the installation is the lack of catheter progression and procedure failure | 1 | |
| ( ) I consider PICC insertion to be as safe as a peripheral catheter, with the function of a central line | 0.778 | |
| ( ) I don't know | 0.778 | |
| Maintenance of the PICC | Nursing care when handling a PICC includes: | 1 |
| ( ) If the PICC is retracting and becomes external during manipulation, it must be reinserted immediately | 1 | |
| ( ) Perform a sterile dressing change every 7 days. It is not recommended before this period to avoid excessive manipulation even if the insertion site is dirty and the dressing is moist | 1 | |
| ( ) Flush the PICC before, between and after medication administrations, using a pulsatile flushing technique, with brief pauses after each ml | 0.778 | |
| ( ) I don't know | 0.778 | |
| When considering the prevention of complications related to PICCs, it is recommended: | 1 | |
| ( ) When taking care of a patient in contact isolation, do not change gloves when handling the catheter, as the health professional may be exposed to contamination and transfer it to the catheter | 1 | |
| ( ) To measure the circumference of the opposite arm where the PICC line is inserted and record the measurement | 1 | |
| ( ) To disinfect connectors using a pad swab containing 70% isopropyl alcohol or an alcohol-based antiseptic solution, with vigorous mechanical scrubbing for 5-15 seconds | 1 | |
| ( ) I don't know | 0.778 | |
| Regarding the assessment of the insertion site for signs and symptoms of catheter-related infection: | 1 | |
| ( ) In the presence of any erythema, I should suspect infection and request immediate catheter replacement | 1 | |
| ( ) The catheter can be maintained when there is no confirmatory evidence of infection | 0.778 | |
| ( ) If the patient has a fever, it is recommended that the catheter be removed immediately, as fever indicates a bloodstream infection | 0.778 | |
| ( ) I don't know | 0.778 | |
| Complication management | Measuring the brachial circumference is an important part of care because: | 1 |
| ( ) It identifies if there has been device traction | 1 | |
| ( ) An increase of 3 cm in circumference since the insertion day, associated or not with other signs such as pain, may indicate acute venous thrombosis | 1 | |
| ( ) If the upper arm circumference increases by ≥5 cm since the day of insertion, the device must no longer be used because it is unsafe | 1 | |
| ( ) I don't know | 0.778 | |
| The main complications related to PICCs are: | 1 | |
| ( ) Immobility and paraesthesia in the limb | 1 | |
| ( ) Catheter-related bloodstream infection and thrombosis | 1 | |
| ( ) Sepsis | 1 | |
| ( ) I don't know | 0.778 | |
| If a Doppler examination confirms the presence of a catheter-related thrombosis, the following is recommended: | 1 | |
| ( ) Immediate removal of the catheter | 1 | |
| ( ) Start anticoagulation treatment if possible, and assess the need for catheter removal based on symptoms, severity and the need for intravenous therapy | 1 | |
| ( ) Disable the catheter until the start of anticoagulation | 1 | |
| ( ) I don't know | 0.778 | |
| Catheter removal | These are indications for catheter removal: | 1 |
| ( ) Changes in the patient's infusion needs and/or transfer to another level of care | 1 | |
| ( ) It is safer to keep the PICC until hospital discharge | 1 | |
| ( ) Catheter has not been used for at least 96 hours | 1 | |
| ( ) I don't know | 0.778 | |
| During the removal of the catheter, this is recommended: | 1 | |
| ( ) Keeping the compressive dressing in place for at least 48 hours, avoiding bleeding | 1 | |
| ( ) Keeping the patient in the Trendelenburg/supine position is one of the recommendations to prevent air embolism | 1 | |
| ( ) Absolute rest for 1 hour after catheter removal | 1 | |
| ( ) I don't know | 0.778 |
CVR=content validity ratio, PICC=peripherally inserted central catheter
Nineteen changes were suggested for the instrument by at least five of the experts. The main changes concerned grammar, sentence restructuring, appropriate keywords, exclusion of information, proper order and the content. All suggestions were accepted and incorporated into the final instrument (Table 2). No scores below the critical CVR were recorded.
Table 2. Experts' proposed changes to the instrument
| Suggestions | Modifications made |
|---|---|
| Replacement of technical terms and rephrasing | Replacement of ‘deep venous access’ with ‘central venous access’ |
| Replacement of ‘venous thrombosis‘ with ‘acute venous thrombosis’ | |
| Replacement of ‘requires a PICC’ with ‘some indication for a PICC’ | |
| Replacement of ‘mechanical friction‘ with ‘vigorous mechanical scrubbing‘ | |
| Addition of ‘treatment’ after ‘start anticoagulation’ | |
| Exclusion/inclusion of information | Included contraindications for PICC insertion |
| Added ‘nursing care’ to the sentence ‘when handling a PICC’ | |
| Included symptom assessment for anticoagulation treatment |
Discussion
Pereira et al (2022) developed and validated an instrument for evaluating oncology patients' knowledge about totally implanted catheters using a Likert scale. They adopted an 80% agreement level among the judges, and most of the judges' considerations were about the value attributed to each question, redundancy and detail of the items (Pereira et al, 2022).
Indarwati et al (2022) used three experts to assess the feasibility, clarity, logical sequence and relevance of an instrument to analyse paediatric nurses' knowledge related to peripheral intravenous catheters (PIVCs). The instrument was reviewed until it achieved strong reliability; the primary considerations concerned the grade of questions (elementary, easy or very hard) (Indarwati et al, 2022).
The present study used the CVR with a cut-off point of 0.775; this is similar to the approach of Jesus et al (2022), who validated a nurses' care instrument for critically ill patients with a central venous catheter using a content validity index (CVI) with a minimum score per item of 0.788.
During content validation, some judges, following ANVISA (2017) recommendations, suggested a minimum time period of 5-15 second to carry out the item ‘Perform disinfection of connections and connectors with an antiseptic solution based on alcohol, with vigorous mechanical scrubbing’.
Indications for a central vascular access device, according to the recommendations of ANVISA (2017) and the INS (Gorski et al, 2021), include patients without suitable conditions for peripheral venous puncture, multiple infusions, chemotherapy treatment, invasive monitoring, infusion therapy inappropriate for peripheral access, peripheral intravenous access failure or difficulty and long-term intermittent therapy. However, the Italian Group for Long-Term Central Venous Access Studies also recommends PICC use when there is a need for frequent collection of laboratory samples and rapid fluid infusions (Pittiruti and Scoppettuol, 2017). The differences between the European and American guidelines may explain the distribution of judges' scores regarding device insertion questions.
Regarding the duration of intravenous therapy, a midline catheter is recommended for intravenous therapy lasting 5-15 days and a central vascular access for therapy for >15 days (Gorski et al, 2021). However, the midline catheter is not popular in Brazil, which contributes to the choice of PICC as the second option after PIVC. In all cases, it is essential when choosing a device to assess whether the benefits of a central catheter outweigh the risks (Gorski et al, 2021).
The differences between guidelines and in recommendations, as well as the influence of organisational culture — which is defined as ordinary conduct that guides behaviour and attitudes (Santos et al, 2019) — can influence experts' judgements, especially given their heterogeneity. The experts in this study worked in public and private institutions, which had noticeable differences regarding material and human resources, in addition to which they worked in various regions of Brazil with different state nursing councils. Despite the variations, the judges' consensus reflected best practices based on international and national evidence, as there was no disagreement below the critical CVR; this shows that the instrument has superior applicability to local protocols.
It was suggested that the option ‘I do not know’ was excluded. However, the authors discussed providing the professional answering the questionnaire with an option to indicate an absence of knowledge of an issue. Excluding this would have made respondents guess the answer, making it impossible to analyse their real learning needs (ie to determine whether they do not have the knowledge or misunderstand the issue). It was therefore decided to retain the ‘I don't know’ option.
Through this, it is expected that focused educational measures will be implemented (Pereira et al, 2022) to improve care in practice (Jesus et al, 2022). Frequent, systematic assessment allows competency, attitude and skills profile to be monitored. Health institutions implement and adapt protocols according to local needs but more research needs to be done into validating these instruments in daily practice (Jesus et al, 2022). Drawing on the results, focused learning can be implemented for professionals, especially nurses with team care and administration responsibilities (Soares et al, 2019),
The present study can contribute to a better understanding of the practice and knowledge of nurses who directly care for patients with PICCs. With this instrument, it is possible to identify the main knowledge gaps through a diagnostic assessment and use the results to inform the planning of institutional training.
Limitation
The number of experts involved in content validity may be a limitation of this study. A larger sample would allow more suggestions and improvements.
Conclusion
This study involved the assessment of the content validity of an instrument constructed for knowledge analysis; this is relevant to practice as no standardised knowledge analysis instruments exist.
It is proposed to use the knowledge assessment instrument for diagnostic analysis and subsequent implementation of specific interventions based on professionals' knowledge gaps, and then to evaluate indicators of care quality concomitantly with knowledge to verify the impact of knowledge in practice.
KEY POINTS
- Knowledge analysis enables gaps in understanding to be identified
- Content validation ensures that the phenomenon studied is reflected and represented reliably
- The instrument to analyse nurses' knowledge must have an appropriate structure and language; the content must be validated
- Using a knowledge analysis instrument can improve understanding of the practice and knowledge of nurses who handle peripherally inserted central catheters (PICCs) daily; focused training can then be delivered to improve care
- Improving knowledge of PICC use can minimise their unnecessary use, reduce complications related to handling, encourage timely removal and prevent adverse events
CPD reflective questions
- Have you received any training related to inserting, maintaining and removing peripherally inserted central catheters (PICCs)?
- In your workplace, is there any instrument that guides health professionals on the timely indication for and/or removal of PICCs?
- Has your knowledge regarding PICCs been analysed? Please consider aspects such as competence, behaviour and procedural skills