A national survey of supplemental parenteral nutrition practices in adult intensive care units

Background Supplemental parenteral nutrition (SPN) is recommended in critically ill patients when energy and protein targets cannot be adequately achieved through oral or enteral nutrition (EN). However, its use in routine intensive care unit (ICU) practice remains variable, and the extent to which guideline-based recommendations are translated into bedside practice is poorly characterized. This study aimed to describe current SPN practices in adult ICUs and to explore potential gaps between self-perceived knowledge, availability of local protocols, and reported clinical implementation. Methods We conducted a national, cross-sectional electronic survey among healthcare professionals involved in medical nutrition therapy for critically ill adults in Spain. A 23-item questionnaire assessed respondent and ICU characteristics, availability of SPN-specific protocols, self-perceived knowledge, prescription patterns, criteria for initiation, estimation of energy requirements, monitoring, documentation, and willingness to participate in SPN-related training or research. Results A total of 179 professionals completed the survey. Although 88.8% reported being familiar with SPN and its indications, only 41.9% reported having a local protocol specifically addressing SPN, and 49.7% considered themselves up to date regarding SPN practices. SPN was mainly prescribed to meet energy–protein requirements and prevent malnutrition, with EN intolerance identified as the leading trigger for initiation (80.4%). Only 39.1% reported initiating SPN according to guideline-based timing criteria. The presence of an SPN-specific protocol was associated with better adherence to the recommended timing of initiation (58.7% vs. 25%; p = 0.005), greater use of indirect calorimetry to estimate energy requirements (34.7% vs. 10.6%; p < 0.001), and more frequent documentation of SPN in ICU discharge reports (25.3% vs. 9.7%; p = 0.01). Similarly, self-perceived updating was associated with greater familiarity with SPN (97.7% vs. 80%; p = 0.002), more frequent use when EN was insufficient (53.9% vs. 34.4%; p = 0.02), better adherence to initiation timing criteria (51.7% vs. 26.7%; p = 0.001), and better patient monitoring practices. Conclusion SPN is widely recognized by ICU healthcare professionals in Spain, but its implementation remains heterogeneous and is frequently not protocol-driven. These findings suggest a relevant implementation gap between guideline recommendations, self-perceived knowledge, and reported practice. Standardized multidisciplinary protocols, targeted education, structured monitoring, and improved documentation may help optimize the appropriate use of SPN in critically ill patients.