Two billion catheters are placed annually worldwide. Of all the people requiring vascular access, nearly a quarter have Difficult Intravenous access (DIVA), a source of multiple punctures. The increased risk of haematomas, haemorrhages, infection, pain and associated trauma is responsible for increased human costs and economic impact.

To limit the risks posed by the DIVA, practitioners have solutions such as the per-bone line, other types of lines, and placement of peripheral venous catheter with ultrasound or transluminescence. However, these solutions are not always applicable, depending on the care situation (non-substitutable venous access, fragile patient, etc.) or on the technical platform (available personnel and training, configuration of the premises, available equipment). Moreover, these actions are often taken after failures, in a non-anticipated and non-consensual manner.

In order to assess the risk of DIVA, F.Van Loon et al developed in 2016, and then modified in 2018, a DIVA Scale (the A-DIVA Scale) which allows a rapid scoring upstream of peripheral venous catheter placement to classify patients according to the risk of DIVA.

Composed of five items (non-palpable and non-visible vein, diameter < 3mm, history of DIVA, operator experience) worth one point each, the score allows three categories to be established: "low risk", "moderate risk", "high risk". The study showed that the proportion of first puncture failures increased with the risk of the patients (defined according to the categorized score).

The use of a tool such as the A-DIVA Scale is of interest if it allows the definition of actions to be taken in relation to the risk it identifies. In view of this, it appears essential to optimize the management of peripheral venous catheters, particularly for patients with DIVAs. The aim of this study is to develop a graduate and specific response to the issue of multiple punctures. Our project is to create and evaluate a specific algorithm, consisting of a risk assessment (the A-DIVA Scale) and a co-construct decision-making tree (the A-DIVA Tool). Built on the basis of objective clinical data collection and adapted to the possibilities and competencies, this new tool would bring real benefits to the patient in terms of safety (reduction of risks) and comfort (reduction of pain and duration of management), as well as a medico-economic benefit for the institutions. To date, such an algorithm does not exist and its beneficial effects have not been evaluated.

This is a mixed (quantitative and qualitative), multicentre, non-randomised, quasi-experimental, before-and-after, open, cross-sectional study, with control and experimental groups and comprising three phases. This division into three data collection phases allows detailed analysis of the targeted care procedure and avoids errors of assessment of the impact of the different tools introduced in the interventional phase (the A-DIVA Scale in phase 2, then the algorithm [composed of the A-DIVA Scale and the new decision-making tree (A-DIVA Tool] in phase 3).

Phase 1 (observational: 4 months): Description of the inclusion centers and collection of pre-intervention data.

This phase will provide information on the actual practices and organization in the inclusion centers. The main objective of this phase is to provide a detailed description of existing practices for peripheral venous catheter placement in the inclusion centers.

It consists of individual semi-directive explanatory interviews with healthcare professionals in the inclusion centers, and a collection of judgment criteria (excluding the feelings of patients and caregivers concerning the implementation of the DIVA score and the catheter placement algorithm). Collection of socio-demographic and clinical characteristics of patients and description of the care strategy implemented.

Phase 2 (interventional: 4 months - implementation of the A-DIVA Scale alone): Collection of data related to the isolated implementation of a systematic scoring of the A-DIVA score.

Phase 2 aims to evaluate the impact of the implementation of the A-DIVA Scale (classification score for DIVA) on practitioners' approaches to the peripheral venous catheter placement. It consists of a systematic collection of peripheral venous catheter placement practices for quantitative data and a questionnaire on the opinions of professionals on the use of the A-DIVA Scale for qualitative data. The main objective of this phase is to recognize the potential appearance of changes in practices through the implementation of a score for evaluating DIVA (compared with the initial practices clarified in phase 1).

Compared to phase 1: addition of systematic collection of the A-DIVA Scale with identification of the patient's risk group, systematic rating of pain and assessment of overall comfort.

Interphase: (8 months) Co-construction of the decision-making tree (the A-DIVA Tool).The interphase will allow to analyze the data collected in phase 1 and phase 2 and to develop the algorithm (composed by the A-DIVA Scale and the new A-DIVA Tool).

1. Organization of a working group (including the investigator and volunteer caregivers): The data acquired in phase 1 and 2 will be described and presented to the professionals of each center in order to provide a basis for co-constructing the decision-making tree during the work groups.
2. Validation of the algorithm according to the A-DIVA Scale based on literature data, research hypotheses and working group data. Presentation of the model to the care teams, validation of its acceptability and feasibility.

Phase 3 (interventional: 4 months - use of the algorithm composed of the A-DIVA Scale and the Co-constructed decision-making tree [The A-DIVA Tool]): Implementation and evaluation of the algorithm in the centers. The main objective of this phase is to evaluate the impact of the algorithm on the quality of peripheral venous catheter placement.

• Systematic collection of judgment criteria and socio-demographic and clinical characteristics of patients. Description of the care strategy implemented (algorithm). Systematic collection of the A-DIVA Scale with identification of the patient's risk group, systematic rating of pain and evaluation of overall comfort.
• In relation to phase 2: implementation of the algorithm and collection of data to evaluate the implementation of the algorithm (e.g., frequency of use, optimal implementation (yes/no))

Post processing - valorization (10 months): Data analysis and scientific production:

The post-processing will allow the analysis of all the data (phase 3 versus phase 1 in particular), the production of reports and scientific articles and the writing of the final report of the ALCOV study.

• Analysis of the satisfaction questionnaire (proposed to caregivers at the end of the study) to complete the evaluation of the implementation of the algorithm.
• Description of the data (global and phase-by-phase) and analysis of the data to answer the formulated objectives, coding of the data from the interviews and satisfaction questionnaires, production of reports and scientific articles.

Representativeness of the sample:

- Throughout the collection process (phase 1,2 and 3) the representativeness of the sample will be assessed. The data collected for this purpose will be, for each patient who has received a peripheral venous line and who meets the inclusion criteria: Included: yes/no, if no: reason.

Inclusion Criteria:

• Patient inclusion criteria: adult patients, initially requiring at least one peripheral venous catheter (PVC), having given their consent for the study.
• Inclusion criteria for healthcare professionals: Nurses, specialized nurses (IADE) and physicians attached to the department.

Exclusion Criteria:

Patient exclusion criteria :

• Minor patients
• Patients under curators or guardianship
• Patients who are non-communicative or unable to give consent
• Patients not requiring a peripheral venous catheter, polytrauma patients and patients in shock (septic, hemorrhagic, cardiogenic, spinal, specific to certain centers and equipped upstream)
• Patients who already have catheters on arrival.

Exclusion criteria for healthcare professionals: any professional not attached to the department and other professional categories.