Micronutrient use in critical care: Survey of clinical practice

Micronutrients, principally vitamins and minerals, play an important role both in health and in disease. Parenteral micronutrient products are commonly prescribed for critically ill patients both in line with the terms of the product's license, and for other indications where there is an underpinning physiological rationale, or precedent, for their use but little evidence. This survey sought to understand United Kingdom (UK) prescribing practice in this area.

A 12-question survey was circulated to healthcare professionals working in UK critical care units. The survey was designed to explore several aspects of micronutrient prescribing or recommendation practice by the critical care multidisciplinary team, including indications and underpinning clinical rationale for using these products, dosing, and considerations with respect to micronutrients delivered as part of nutrition. Results were analysed, exploring indications, considerations relating to diagnoses, therapies including renal replacement therapies, and method of nutrition.

217 responses were included in the analysis, with 58% from physicians and the remaining 42% from nurses, pharmacists, dietitians and other healthcare disciplines. Vitamins were most commonly prescribed or recommended for Wernicke's encephalopathy (prescribed or recommended by 76% of respondents), treatment of refeeding syndrome (64.5%), and for patients with unknown or uncertain alcohol intake history (63.6%). These clinically suspected or confirmed indications were cited more frequently as a reason to prescribe than laboratory identified deficiency states. 20% of respondents indicated that they would prescribe or recommend parenteral vitamins for patients requiring renal replacement therapy. The practice of vitamin C prescribing was heterogeneous, including dose and indication. Trace elements were prescribed or recommended less often than vitamins, with the most frequently reported indications being for patients requiring parenteral nutrition (42.9%), biochemically confirmed deficiency states (35.9%), and for treatment of refeeding syndrome (26.3%).

Micronutrient prescribing in ICUs in the UK is heterogeneous, with clinical scenarios where there is an evidence base or an established precedent for their use often guiding decisions to use micronutrient products. Further work to examine the potential benefits and harms on patient-oriented outcomes of micronutrient product administration should be undertaken, to facilitate their judicious and cost-effective use, with a focus on areas where they have a theoretical benefit.