Background The clinical pharmacist's main functions in parenteral nutrition (PN) in the present clinical context are to ensure the quality and safety of the solutions prepared and to verify that the composition of the nutrition is the appropriate according to the type of patient and his/her clinical situation. Pharmaceutical interventions (PIs) are made to perform these checks.

Purpose The objective is to describe and to analyse the PIs made regarding the prescriptions for parenteral nutrition (PN) in a tertiary hospital.

Materials and methods A prospective study of the interventions in PN was conducted (January-June 2011). The PIs were classified into five categories: time of the intervention, type of patient (adult/paediatric, beginning/continuation), sufficiency of data on the application, accuracy in the reception/shipping of the request, problems of formulation and/or compatibility and departure from the clinical recommendations.

Results 1420 prescriptions for PN (780 adults and 640 children) were recorded for 250 patients (191 adults and 59 children). 99 interventions were recorded for 65 patients. 35.2% were made at the beginning of the prescription. 55.3% of the PIs were made about paediatric prescriptions corresponding to 33 patients. Regarding the kind of pharmaceutical intervention, 26.5% were made due to lack of information in the request for PN, 35% were about failures in the reception/shipping, 23.9% were to solve formulation problems and compatibility in the mixtures and in 15% departures from the clinical recommendations were detected, 11% corresponding to the detection of deviations in the composition of the formula with respect to the previous day without any justification and 4% to the detection of deviations in the maximum permitted levels of some nutrients.

Conclusions Pharmaceutical interventions detected a higher frequency of prescription errors in the use of paediatric PN (55.35%). A high percentage (23.9%) of the PIs were made to solve problems in the ordering and delivery of PN solutions to the wards.