Parenteral drug administration errors by nursing staff on an acute medical admissions ward during day duty

Parenteral therapy is a route of administration for drugs which are poorly absorbed via the oral route and it can provide a rapid response during an emergency. However, poorly prepared and/or administered parenteral therapy can cause potential harm to patients such as thrombus formation, severe hypersensitivity reactions and infection. Very few studies have investigated the incidence of medication errors associated with parenteral drug administration.

To determine the error rate during preparation and administration of parenteral medications by nursing staff and to propose strategies to reduce the error rate during parenteral administration.

A direct, disguised observation technique was used. The first author (JB) observed and recorded errors that occurred during the preparation and administration of parenteral medications on an admissions ward between 8.00 am and 4.30 pm from Monday to Friday for a 4-week period during December 1998. The staff were told that the observer was timing the administration; therefore they were not aware of the true nature of the study. This study was approved by the hospital audit committee.

Drug administration was witnessed for a 4-week period providing 107 opportunities for error. 27 errors were observed which equated to an error rate of 25.2% [95% confidence interval (CI) 17.0 to 33.5%] including wrong time errors. Excluding wrong time errors, the most frequently occurring type of error, reduced the error rate to 10.3% (95% CI 3.8 to 14.9%).

The error rate was lower than reported in the literature, this may be due to different methodologies, small sample size or effective nursing training and operating procedures. In the observed hospital, only nursing staff who have completed a training package are allowed to administer parenteral medications.

Based on our small study, and 2 previous small studies, we can conclude that parenteral medication administration errors are common in the UK; however, these studies are too small-scale to detect rare and serious errors.