Background Avoiding errors related to drug development, which can compromise the patient’s life, is essential in our profession.

Purpose To describe the quality of sterile intravenous mixtures (IVM) after implantation of a double check and to evaluate the effectiveness of the measures adopted since its implementation.

Material and methods Retrospective observational study in which double check record sheets were revised for 3 periods of 15 days, made over a year. The aspects evaluated were: name and concentration of the drug used, prepared dose and mL of drug used, number of new vials started, checking calculations of used and surplus mL, expiration of vials used, labelling, physicochemical characteristics of IVM, packaging, and sheets duly signed and filled out by the pharmacist and nurse. In addition it was confirmed that preparation labels contained lot and caducity of the vials used to ensure traceability of the IVM. The double check was by nursing staff on the ward; this nurse was different from the nurse who made the IVM and after the pharmacist checked correct completion of the form.

Results 712 IVM were developed during the 3 study periods (169, 219 and 324, respectively). They were revised 98.2%, 99% and 100% of the IVM and non-conformity with the double check was 20.7%, 20.5% and 12.6%. The most common errors produced were incomplete double checks in 62.8%, 33.3% and 82.1%, errors in calculations in 17.4% 22.2% and 7.1%, and no annotation of the lot and expiration in 14.2%, 28.8% and 3.6%, respectively. IVM with the record sheet but with a blank checklist were 1.8%, 3.2% and 1.2%. The measures introduced were: reinforcing the training of nurses to insist on the importance of the correct performance of the double check for the prevention of medication errors, to underline the importance of being able to perform the traceability of IVM, to check with automatic methods the calculations made and to visualise the correct volume of the mixture with higher optical precision.

Conclusion Double check provides greater security in the prevention and correction of problems related to drugs. Implementation of specific measures continuously has gradually reduced the number of errors.

References and/or Acknowledgements Best practice guidelines for preparation of drugs in the pharmacy services

No conflict of interest.