Here is the design of a clinical trial:

Official Title: Infrared Illumination for Difficult Peripheral Venous Catheterization in Adult Critically-ill Patients

Included conditions:
- Peripheral Venous Catheterization

Study Armgroups:
- {'label': 'Infrared illumination group', 'type': 'EXPERIMENTAL', 'description': 'The nurse uses the Accuvein® device to identify the veins before puncture.', 'interventionNames': ['Device: ACCUVEIN']}
- {'label': 'Control group', 'type': 'NO_INTERVENTION', 'description': 'The nurse proceeds as usual (visual identification in the light of the room and palpation)'}

Interventions:
- {'type': 'DEVICE', 'name': 'ACCUVEIN', 'description': 'The nurse uses the Accuvein® device to identify the veins before puncture and then proceeds as usual, under illumination of the device.', 'armGroupLabels': ['Infrared illumination group']}

Primary Outcomes:
- {'measure': 'Percentage of primary success of peripheral venous catheterization in the upper limbs.', 'description': 'success defined as the need of a single puncture for the effective catheterization.\n\nThe effective catheterization is confirmed by obtaining venous reflux by declivity of the infusion bag.', 'timeFrame': 'Day 1'}

Please estimate the sample size based on the assumption: 
The study uses a two-sided alpha risk of 5% and aims for a power of 90%.
Sample size and its justification
        The sample size calculation is based on the results of a previous randomised trial in paediatrics with a similar device, which demonstrated an increase of more than 30% in the primary success rate in the subgroup at risk of difficult catheterisation.10 Given the limited sample size of the previous study (n=44 at risk of difficult catheterisation), the present project will use a more conservative difference to be detected of 15% between the two groups. This equates to an expected success rate of 47% (control)3 versus 62% (intervention). Based on these assumptions and a two-sided alpha risk of 5%, the inclusion of 230 patients per group (total 460) is required to detect a significant difference with a power of 90%.
        
          Recruitment
          Patients will be enrolled for 54 months starting in December 2019. The study timeline is as follows: (1) January 2021: winning grant award; (2) June 2019: approval by an independent ethics committee; (3) December 2019â2024: inclusion of patients; (5) 2024â2025: the investigators will review the data and check for protocol violations; (6) 2024â2025: the investigators will analyse the data, write the manuscript and submit it for publication.
        
        
          Allocation of intervention and data collection
          Centralised block randomisation using a 1:1 ratio will be prepared by the Clinical Research Unit before the start of the trial. Randomisation will be carried out using permuted blocks of varying size and stratified according to the centre and the experience of the operator in the ICU (â¥2âvs < 2 years) because of the likely impact of experience on the success of catheterisation. There is no need to stratify by patient characteristics, as patients are already selected based on a risk score for difficult catheterisation. Patients will be randomised electronically via a website. A computer-generated randomization list will be prepared prior to enrolment of the first patient into the trial. No patient can be enrolled twice. Investigators or research assistants at each centre will enter data into the e-CRF (CleanWeb) via a web browser. The centres can access the e-CRF forms via a web-based data collection system.