OBJECTIVE: The review was performed to answer the following research question: "In VPNs, are high amounts of arginine in PN, compared with low amounts of arginine, associated with appropriate circulating concentrations of arginine?" Therefore, the aims were to 1) quantify the relationship between parenteral arginine intakes and plasma arginine concentrations in PN-dependent VPNs; 2) identify any features of study design that affect this relationship; and 3) estimate the target parenteral arginine dose to achieve desirable preterm plasma arginine concentrations.
DATA SOURCES: The PubMed, Scopus, Web of Science, and Cochrane databases were searched regardless of study design; review articles were not included.
DATA EXTRACTION: Only articles that discussed amino acid (AA) intake and measured plasma AA profile post PN in VPNs were included. Data were obtained using a data extraction checklist that was devised for the purpose of this review.
DATA ANALYSIS: Twelve articles met the inclusion criteria. The dose-concentration relationship of arginine content (%) and absolute arginine intake (mg/(kg × d)) with plasma arginine concentrations showed a significant positive correlation (P < 0.001).
CONCLUSION: Future studies using AA solutions with arginine content of 17%-20% and protein intakes of 3.5-4.0 g/kg per day may be needed to achieve higher plasma arginine concentrations.
METHODS: Study metrics were recorded. Learning points were captured during network development, categorized and included in a thematic analysis from which lessons learnt were identified.
RESULTS: 12 trials were supported by sites coordinated at national level and integrated at European level. A total of 9 CDA cycles were completed, resulting in 436 site CDAs signed in a median of 8.11 days. Lessons learnt included the importance of: relationship building by early engagement with partners; reducing misunderstanding by clear communication; flexibility, adaptability and experiential learning which are required for service improvement. Practical actions that infrastructure developers and users can take include operational planning with a view to fostering collaborations across stakeholders, sharing information about different approaches to clinical operations, and raising awareness of the need for explicit work on collaboration, communication, and planning. Traditionally, these activities are repeated for each trial. The use of a persistent network allows the benefits of collaboration to be recycled.
DISCUSSION: Building a successful framework for collaboration allows dedication and determination to carry over from one study to another. The initial investment of time to share assumptions and "state the obvious" by each user will support future trials.