Background Including a pharmacist within the multidisciplinary Emergency Service (ES) team has been a basic objective in many hospitals in recent years.

Purpose To assess the efficiency of pharmaceutical care in the ES, based on an analysis of the pharmaceutical interventions (PIs) made and their impact upon the duration of hospital stay.

Materials and methods Analysis of the interventions was derived from a prospective observational study between October 2012 and March 2013, involving a pharmacist integrated in the healthcare team with a working schedule from 8:30 a.m. to 15:00 p.m.

All patient information, PIs, resolution and data to do with the treatment were collected and analysed using a sheet developed for this purpose, using an Excel database.

The level of risk associated with the pharmaceutical intervention was defined as a percentage risk of the patient’s hospital stay being prolonged had the intervention not been made (classification adapted from Overhage et al. and Bates et al.): fatal (60%), serious (40%), significant (10%) and nonsignificant (0%).

Results A total of 1176 PIs were accepted and implemented: complete/update medical order and medical report information 33.1%, change of proposed medicine 30.9%, change of proposed dose 12.2%, proposed drug suspension 7.3%, proposed start of treatment 4.9%, detection of incorrect practices or transcription/administration error 4.5%, monitoring recommendation 2.5%, change of frequency proposal 0.7%, and others 3.9%.

The therapeutic groups involved were mainly the following: group C(cardiovascular) 31.8%, group N(neurological) 17.5%, group A(gastrointestinal and metabolic) 9.8%, and group B(blood and hematopoietic organs, particularly heparins)12.9%.

The risk of prolonging hospital stay according to PI was: fatal 2.12%, serious 14.70%, significant 33.48%, and non-significant 49.69%.

Conclusions The most common PIs were:

• Complete/update information and change medicine.

• Group C was the main category involved in the PIs.

According to severity, over half of the PIs accepted implied a reduction in the duration of hospital stay (50.31%), resulting not only in increased patient safety but also in cost savings – thus demonstrating the efficiency of including a pharmacist in the ES.

No conflict of interest.